Wind Power to Clean Water, the Kenya case

Transcription

Wind Power to Clean Water, the
Kenya case
Design of a wind driven reverse osmosis desalination system
to be installed in Kilifi and a study of its implementation
Delft University of Technology
Maksymilian Szabunia
Photograph by Nicko Margolies
Design of a wind driven reverse osmosis desalination system to be
installed in Kilifi and a study of its implementation
Master of Science Thesis
For obtaining the degree of Master of Science in Sustainable Energy Technology at
30/03/2015
Wind Energy Research Group, Faculty of Aerospace Engineering, Delft University of Technology
Faculty of Applied Sciences, Delft University of Technology
Supervisors: Prof.dr. Gerard van Bussel and Dr. Linda Kamp
Department of Wind Energy
The undersigned hereby certify that they have read and recommend to the Faculty of Aerospace
Engineering for acceptance a thesis entitled
by
in partial fulfilment of the requirements for the degree of
Master of Science Sustainable Energy Technologies
Dated: 30/03/2015
Supervisor(s):
Prof.dr. G.J.W. van Bussel
Dr. L.M. Kamp
Reader(s):
Dr.ir. S.G.J. Heijman
"The human future depends on our ability to combine
the knowledge of science with the wisdom of wildness"
Charles A. Lindbergh, Dec. 22, 1967
Acknowledgments
vii
Acknowledgments
Developing this Master Thesis gave me the opportunity of crossing paths with many people I would like to
thank for their support throughout the duration of this project; however, I would like to start by thanking
my family, who has been supporting me from the distance since the beginning of the Masters. My grandma,
my brothers, my dad and especially my mom, who has been constantly advising me and encouraging me to
do what makes me happy. I would also like to make a special mention to my grandfather, who passed away
in Venezuela last summer in the middle of my TU Delft experience. It was really tough for me not being able
to be with him in his last moments, but I know he was really proud of me and very happy that I was here,
growing. I owe to him a lot of who I am as a person.
I would like to thank my direct supervisor Prof.dr. Gerard van Bussel and my second supervisor Dr. Linda
Kamp. They helped me shaping the project and then guided me throughout its entire realization.
Furthermore I would also like to thank Ir. Michiel Zaayer for helping me during the last phase of the design
and for answering to my inquiries, as well as Ir. Nando Timmer, Ir. Ruud van Rooij and Ir. Gael de Oliveira
Andrade for their support with the code used. I would also like to thank Dr.ir. Bas Heijman, who advised
me on the reverse osmosis array and pump components of the system every time I had a question.
I am especially thankful to Sjoerd Dijkstra from Winddrinker B.V, the social enterprise behind the idea of
the project. Everything started with a phone call and a following meeting we had several months ago, and
since then he has always been there, willing to help and giving me words of encouragement especially in
the most difficult moments. None of this would have been possible without him. Special words of gratitude
go also to William Dijkstra, whose practical approach and experience influenced the design of the system.
I would also like to thank all the experts and stakeholders in the Netherlands and Kenya I had the
opportunity to talk to. The information obtained from all those interviews, meetings, phone calls and emails exchanged have been fundamental to the realization of this project.
One of the most important parts of this Thesis was the trip I did to Kilifi, where I had the chance of meeting
wonderful people. To one person I am especially thankful, and this is George Gasston. His friendship,
hospitality and support on different aspects such as the network, the transport and the Swahili language
allowed me to do a better work and to have an incredible month on a part of the World I never even
dreamed I was going to be able to visit. I also must thank DUWIND, Universiteitfonds Delft and
StuDevelopment, as this trip to Kenya would not have been possible without their financial support.
With the submission of this thesis my time in Delft has come to an end. When people asks me for my
experience in the last couple of years I always describe it as the best time of my life, and the friends I made
here are a huge reasons for that. Is impossible for me to mention all of them, but I would like to especially
thank Mats, Esteban, Aksel, Thanos, Sam, Laura, Kat, Simon, Jorge and Zaid. Thanks for being there.
Preface
viii
Preface
I always knew I would continue studying after earning my undergraduate degree in Mechanical
Engineering; however, I decided it was important for me to gain some work experience first, so I joined an
engineering firm specialized in design, installation and industrial maintenance for the construction and the
aluminium industries in Venezuela. After a couple of years I decided to continue my studies in the
Renewable Energies field, so I moved to the Netherlands to pursuit a Master Degree in Sustainable Energy
Technology (SET) at the Delft University of Technology (TU Delft). I really wanted to be involved in a
program in which I could learn how to use engineering and technology to reduce the negative impact of the
world’s energy consumption on the environment.
I was born in Venezuela, the country with the biggest proven oil reserves in the World and where the energy
transition is not seen as a priority, therefore no alternative ways of doing things are being considered;
however, I think the shift from conventional to renewables sources of energy must be done globally sooner
than later, not only for economic or political reasons, but for ecological and humanitarian reasons as well.
I want to support this change and I want to be part of it.
SET is a very broad program, and although I followed the Wind Energy track, as I planned to do even before
coming to Delft, I also got very interested in different sources of energy and how they can impact our
societies, on how they can be used to improve the living conditions of the people. This is when I first started
to study the topic of Sustainable Development. When I started looking for a graduation project I spent time
making sure I found a thesis in which I could apply different skills I learned during the program and that
also had a practical component. Through the Delft Centre of Entrepreneurship, whom I knew from the time
I spent working for the Energy Club of the Delft Energy Initiative, I got in contact with Sjoerd Dijkstra of
Winddrinker BV, who was looking for a student to help them designing a wind driven reverse osmosis
desalination system for Kilifi, in Kenya. I was immediately interested. Nevertheless, because it has been
proven that dumping the technology on a developing country brings more harm than good, I also wanted
to study the impact such system would have in the area. The idea was approved by all the parts involved.
The project had the combination of technical research and application in a developing country I was looking
for.
A period of hard work, which many times was very exhausting with frustrating days, started; however, and
as part of the project, later I had the opportunity of spending a month in Kilifi talking and interviewing
different stakeholders and collecting some missing data. The experience of being there and getting in
contact with the people that will eventually benefit from the water produced by a system I was designing
and to use the knowledge obtained there to finish my project was a very fulfilling experience that pushed
me to continue working.
Now, with the completion of my Master Thesis and its defence a very challenging time, full of experiences
that have changed my perception of life, is coming to an end. If you are reading this document you probably
have similar interests to me, and I can just encourage you to go abroad, spend some time exploring, talking
to the people and trying different things. This will help you find the correct answers. Thank you for reading
these lines and I hope this report is valuable for you.
Abstract
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Abstract
Kenya is, along with many other countries mainly from Sub-Saharan Africa, suffering from severe problems
on access to improved drinking water sources. The country is below the water scarcity threshold and not
on track to meet the Millennium Development Goal target related to this aspect, and especially its rural
communities are suffering this. Climate change is increasing the problems by raising global temperatures
and causing droughts, which in agriculture-dependent countries like Kenya where the weather is already
warm and the incomes are low they have a bigger impact. In addition, the country high population growth
rate since 2010 is putting even more pressure on water and energy sources.
Therefore, the main objective of the current thesis was to find the optimal windpump configuration for a
wind driven reverse osmosis brackish water desalination system to be implemented in the town of Kilifi in
the coast of Kenya. The research was divided in a social part and a technical part, closely related to each
other. The social part consisted in a stakeholders analysis through which it was possible to identify several
organizations related to the project, some of which have a bigger role and capacity of influence the system's
successful implementation in Kilifi than others. This is the case of Winddrinker Holdings, the project
initiator, manager and most important actor, Hatenboer Water, CAT Pumps, Bertus Dijkstra, TU Delft,
KIMAWASCO, the CWSB, Organic Essentials Limited and the Jua Kali. For a better visualization the
stakeholders were divided in 8 different blocks (technology development, knowledge development,
funding, government, owners, users, intermediaries and consumers) and presented in a map. The social
research also involved a market research to evaluate the possible end users of the fresh water produced by
the system in Kilifi, from which three market segments were identified, namely the community, the hotels
and the farms. Currently most Kilifi inhabitants get water from the municipality tap provided by
KIMAWASCO at a very low price, but mainly the most isolated communities of the county are suffering the
unreliability of the system and are obliged to fetch water from wells. Therefore alternative projects are
being proposed in the area, especially for these isolated communities, involving different technologies.
Desalination of water that is sold at affordable prices is already performed by DWL, who has the low end
of the middle class of the coast as the main market. Hotels have been suffering water service cuts that
severely affects their business and they are therefore looking for solutions. However tourism, which is the
most important economic activity in the area, has been very low for the last few years and this could impact
their capacity of investing in water. The farms are using their own borehole water, but this is very salty and
inappropriate for some of their activities; nevertheless, they have been using it for many years and
considering the big amounts of water they consume they are not very interested in new propositions.
The technical part of the research consisted in the design of the wind driven reverse osmosis desalination
plant to help the Kilifi inhabitants to solve their water problems. The simplicity of this system makes it a
better fit for rural areas in developing countries than other desalination methods. The context in which the
system will be installed and operated, studied during the field research, determined the characteristics of
the system, which besides simple was meant to be robust, easy to operate and maintain, made out of offthe-shelf components and with no electrical components that add complexity to the system an increase its
costs. The system will operate off-grid, using the wind to produce all the required energy and not depend
on the Kenyan unreliable power grid. Kilifi has a temperate climate and an average wind speed of 3.8 m/s.
The wind turbine rotor will have a radius of 4.5 meters with 24 blades and a design tip speed ratio of 1.2.
The blades are curved plates with a tube at quarter chord with design aerodynamic conditions of 8 degrees
for the angle of attack and 1.2 for the lift coefficient. The twist angles go from 50.1 degrees at the hub to 23
degrees at the tip, while the chord distribution has a value very close to 0.10 throughout most of the entire
blade. The final solidity of the designed wind turbine rotor is 0.76. It will be mechanically coupled to a
positive displacement CAT 2531 pump with a transmission ratio of 32 (1:2, 1:4 and 1:4 gears), delivering
brackish water stored underground with a TDS of 5,026 ppm to a custom-made Hatenboer Water reverse
osmosis array with two modules in parallel made out of six ESPA2-4040 membranes connected in series
for a maximum capacity of 5 cubic meters per hour with a recovery of 50%. The cut-in wind speed of the
system is 4 meters per second, while its rated wind speed is 6 meters per second. The rated power of the
wind turbine is 2.32 kilowatts. The system will produce fresh water until a cut-out wind speed to be
determined from a future structural analysis is reached. This cut-out speed is usually around 3 times the
average wind speed, and velocities between 4 and 12 meters per second have a probability of occur almost
43% of the time in Kilifi. This means that the system is expected to produce for around 3,750 hours every
year and surpass the initial system daily production goal of 20,000 to 30.000 litres of fresh water.
x
Table of Contents
xi
Table of Contents
1
Introduction .................................................................................................................................................................................. 19
1.2
Problem statement ......................................................................................................................................................... 20
1.2.1 Water .................................................................................................................................................................................... 20
1.2.2 Energy .................................................................................................................................................................................. 22
1.3
Objectives ........................................................................................................................................................................... 24
1.4
Methodology ..................................................................................................................................................................... 24
1.4.1 Theoretical background ............................................................................................................................................... 24
1.4.2 Field study .......................................................................................................................................................................... 25
1.4.3 Design ................................................................................................................................................................................... 27
1.4.4 Matching .............................................................................................................................................................................. 29
1.5 Report structure ....................................................................................................................................................................... 29
2
Stakeholders analysis ............................................................................................................................................................... 30
2.1
Stakeholders map ........................................................................................................................................................... 30
2.2
Stakeholders description ............................................................................................................................................ 32
2.2.1 Current stakeholders ..................................................................................................................................................... 33
2.2.2 Possible future stakeholders ...................................................................................................................................... 40
2.3
3
Summary of the stakeholders analysis ................................................................................................................. 42
Market research .......................................................................................................................................................................... 45
3.1
Market segments ............................................................................................................................................................. 45
3.1.1 Community ......................................................................................................................................................................... 46
3.1.2 Hotel/Resorts ................................................................................................................................................................... 48
3.1.3 Farmers................................................................................................................................................................................ 51
3.2
Kilifi-Mariakani Water and Sewerage Company ............................................................................................... 53
3.3
Alternative water projects .......................................................................................................................................... 55
3.3.1 Chipande Water Project ............................................................................................................................................... 55
3.3.2 Musichovweka Water Project .................................................................................................................................... 55
3.3.3 Cash-Food for Assets ..................................................................................................................................................... 55
3.3.4 Sombeza Water and Sanitation Improvement Project (SWASIP) ............................................................. 55
4
3.4
Opportunity ....................................................................................................................................................................... 56
3.5
Summary of the market research ............................................................................................................................ 58
System design .............................................................................................................................................................................. 62
4.1
Design premises .............................................................................................................................................................. 62
4.1.1 Wind driven reverse osmosis desalination for small scale stand-alone applications ...................... 62
4.1.2 Somalialand project ....................................................................................................................................................... 63
4.1.3 Project innovation........................................................................................................................................................... 63
4.1.4 Design constraints factors ........................................................................................................................................... 64
4.2
System operation overview ....................................................................................................................................... 65
4.3
Reverse osmosis .............................................................................................................................................................. 65
4.3.2 Project reverse osmosis array ................................................................................................................................... 68
Table of Contents
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4.3.3 Kilifi water .......................................................................................................................................................................... 68
4.3.4 Pressures............................................................................................................................................................................. 69
4.4
Pump .................................................................................................................................................................................... 72
4.4.2 Type ....................................................................................................................................................................................... 73
4.4.3 Sizing ..................................................................................................................................................................................... 73
4.4.4 Options ................................................................................................................................................................................. 74
4.4.5 Calculations ........................................................................................................................................................................ 76
4.4.6 Results .................................................................................................................................................................................. 77
4.4.7 Pump selection ................................................................................................................................................................. 82
4.5
Wind Turbine Rotor Design ....................................................................................................................................... 84
4.5.1 Design premises ............................................................................................................................................................... 84
4.5.2 Rotor tentative design ................................................................................................................................................... 88
5
Matching of wind turbine rotor and pump ...................................................................................................................101
5.1
Pump characteristics ...................................................................................................................................................101
5.2
Wind turbine rotor characteristics .......................................................................................................................103
5.3
Transmission characteristics ..................................................................................................................................104
5.4
Matching procedure ....................................................................................................................................................104
5.4.1 Original design................................................................................................................................................................104
5.4.2 Transmission ratio........................................................................................................................................................106
5.4.3 Other parameters ..........................................................................................................................................................108
5.4.4 Selected options .............................................................................................................................................................109
5.5
Final design .....................................................................................................................................................................111
6 Conclusions .................................................................................................................................................................................115
7 Reflections ...................................................................................................................................................................................120
8 Recommendations ...................................................................................................................................................................122
References .............................................................................................................................................................................................125
APPENDIX ..............................................................................................................................................................................................131
A.1 SURVEYS ....................................................................................................................................................................................132
A.2 INTERVIEWS ...........................................................................................................................................................................140
A.3 REVERSE OSMOSIS ARRAY PI&D AND LAYOUT .....................................................................................................188
A.4 FEED WATER TEST RESULTS ..........................................................................................................................................191
A.5 PLANT LOCATION IN KILIFI .............................................................................................................................................193
A.6 WIND TURBINE ROTORS PERFORMANCE CURVES ..............................................................................................196
A.7 CURVED PLATES WITH CHORD AT 25% EMPIRICAL DATA .............................................................................198
A.8 ORIGINAL DESIGN BLADE SHAPE .................................................................................................................................200
A.9 THE BEM METHOD ...............................................................................................................................................................202
A.10 PROPCODE RESULTS ORIGINAL DESIGN WITH ADJUSTED CHORD ...........................................................205
A.11 PROPCODE RESULTS FINAL DESIGN .........................................................................................................................207
List of Figures
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List of Figures
Figure 1 - Location of Kenya in Africa (left) and Kenya with its political borders (right) .................................. 19
Figure 2 - Location of Kilifi County in Kenya (left) and location of Kilifi town in the county (right) ............. 19
Figure 3 - Wind driven reverse osmosis desalination system in Kilifi stakeholders map ................................... 31
Figure 4 - Market segments for the designed system in Kilifi, Kenya ........................................................................... 45
Figure 5 - System installed in Somalialand [29] ..................................................................................................................... 63
Figure 6 - Osmosis and reverse osmosis principle [60] ...................................................................................................... 66
Figure 7 - Membrane damaged by biofouling [60] ................................................................................................................ 66
Figure 8 - Membrane damaged by scaling [60] ...................................................................................................................... 67
Figure 9 - Spiral wound membrane configuration [60] ...................................................................................................... 67
Figure 10 - Selected pumps delivered flow at different shaft speeds ........................................................................... 78
Figure 11 - Selected pumps required power at different shaft speeds ........................................................................ 80
Figure 12 - Selected pumps required torque at different shaft speeds ........................................................................ 81
Figure 13 - Overview of the windpump (left) and blade profile detail (right) ......................................................... 85
Figure 14 - Coupling top open gear (left) and bottom open gear (right) ................................................................... 85
Figure 15 - Weibull distribution for the Kilifi wind conditions ....................................................................................... 90
Figure 16 - Blade variables [59] .................................................................................................................................................... 94
Figure 17 - Blade geometry [59].................................................................................................................................................... 94
Figure 18 - Power coefficient vs tip speed ratio curve for the original blade design with constant chord . 98
Figure 19 - Torque coefficient vs tip speed ratio curve for the original blade design with constant chord 98
Figure 20 - Blade diagram ................................................................................................................................................................ 99
Figure 21 - CAT 2531 delivered flow at different shaft speeds .....................................................................................102
Figure 22 - CAT 2531 required power at different shaft speeds ..................................................................................102
Figure 23 - CAT 2531 required torque at different shaft speeds ..................................................................................103
Figure 24 - Power-speed curves for the original wind turbine design with adjusted chord (i = 40) ..........105
Figure 25 - Torque-speed curves for the original wind turbine design with adjusted chord (i = 40) ........105
Figure 30 - Power-speed curves for the selected windpump configuration (i = 32) ..........................................112
Figure 31 - Torque-speed curves for the selected windpump configuration (i = 32) ........................................112
Figure 32 - Power coefficient vs tip speed ratio curve for the final blade design .................................................113
Figure 33 - Torque coefficient vs tip speed ratio curve for the final blade design................................................114
List of Tables
xiv
List of Tables
Table 1 - Trends of drinking water coverage in Kenya [1] ................................................................................................ 22
Table 2 - Required pressures for lower flows (ESPA2-4040 membranes) ................................................................ 70
Table 3 - Required pressures for higher flows (ESPA2-4040 membranes) .............................................................. 71
Table 4 - Selected pumps feed flow at different shaft speeds .......................................................................................... 78
Table 5 - Selected pumps required power at different shaft speeds ............................................................................. 79
Table 6 - Selected pumps required torque at different shaft speeds ............................................................................ 81
Table 7 - Pump selection criteria weighting factors ............................................................................................................. 82
Table 8 - CAT 2531 scores ................................................................................................................................................................ 83
Table 9 - CAT 3531 scores ................................................................................................................................................................ 83
Table 10 - Hydra-Cell G25 scores .................................................................................................................................................. 83
Table 11 - Hydra-Cell G35 scores .................................................................................................................................................. 83
Table 12 - Kilifi monthly average wind speeds in meters per second measured at 10 meters ......................... 89
Table 13 - Kilifi monthly average wind speeds in meters per second transferred to a height of 18 meters
...................................................................................................................................................................................................................... 90
Table 14 - Recommended number of blades for different tip speed ratios [59] ..................................................... 93
Table 15 - Chord and twist distribution of the designed blade ....................................................................................... 96
Table 16 - Chord and twist distribution of the adjusted designed blade (constant chord) ................................ 97
Table 17 - Local lift coefficient of each blade section of the original blade design when the rotor is not
turning....................................................................................................................................................................................................... 99
Table 18 - Starting torque coefficient calculation................................................................................................................100
Table 19 - Required power and torque by the CAT 2531 model at different shaft speeds ...............................101
Table 20 - Chord and twist distribution of the adjusted designed blade (constant chord) ..............................103
Table 21 - Options to be considered in the matching procedure ..................................................................................109
Table 22 - Operational speeds of the selected wind turbine rotor options, at 3 different transmission ratios,
with the selected pump ...................................................................................................................................................................110
Table 23 - Chord and twist distribution of the final design blade ................................................................................113
Nomenclature
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Nomenclature
Latin Symbols
A
a
c
Cd
Cl
CP
CQ
CT
D
dr
FD
FL
FN
FT
g
H
h
i
k
N
P
Pr
Q
q
R
r
T
U
z0
Swept area of the rotor
Scale parameter (Weibull)
Blade element chord
Drag coefficient
Lift coefficient
Power coefficient
Torque coefficient
Thrust coefficient
Wind turbine rotor diameter
Blade element width
Drag force
Lift force
Normal force
Thrust force
Acceleration due to gravity
Head
height
Transmission ratio
Form parameter (Weibull)
Number of blade elements
Power
Pressure
Torque
Capacity, volumetric flow rate
Wind turbine rotor radius, blade length
Blade element radius
Thrust
Wind speed
Terrain roughness
Greek Symbols
α
η
λ
Ω
ω
φ
ρ
σ
θP
θT
Angle of attack
Efficiency
Tip speed ratio
Angular velocity in revolutions per minute
Angular velocity in radians per second
Angle of relative wind
Density
Solidity
Pitch angle
Twist angle
Nomenclature
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Abbreviations
A4A
ADP
BAU
BEM
BoP
CBO
CEO
CCWP
CFA
COAST
CRSP
CWSB
DWL
ERC
EU
FAO
FFA
GLAAS
GDP
HAWT
IDA
IDO
IPCC
JKUAT
JMP
KEBS
KES
KIMAWASCO
MDG
MoE
MTGP
MWI
NGO
NPSH
NWCPC
PI&D
PLAN
PP
PVC
PVDF
R&D
REA
RO
Aqua For All
Area Development Program
Business As Usual
Blade Element Momentum
Bottom of the Pyramid
Community Based Organisation
Chief Executive Officer
Chipande Water Project
Cash For Assets
Collaborative Actions for Sustainable Tourism
Coastal Rural Support Programme
Coast Water Service Board
Dutch Water Limited
Energy Regulatory Commission
Euro (currency)
Food and Agriculture Organization of the United Nations
Food For Assets
UN-Water Global Analysis and Assessment of Sanitation and Drinking-Water
Gross Domestic Product
Horizontal Axis Wind Turbine
International Desalination Association
International Development Organization
Intergovernmental Panel on Climate Change
Jomo Kenyatta University of Agriculture and Technology
Joint Monitoring Programme
Kenya Bureau of Standards
Kenyan Schilling
Kilifi-Mariakani Water and Sewerage Company
Millennium Development Goal
Ministry of Energy
Moving the Goalposts
Ministry of Water and Irrigation
Non-Governmental Organization
Net Positive Suction Head
National Water Conservation and Pipeline Corporation
Piping and Instrumentation Diagram
Plan International
Polypropylene
Polyvinyl Chloride
Polyvinylidene Fluoride
Research and Development
Rural Electrification Agency
Reverse Osmosis
Nomenclature
SWASIP
SWT
TDS
TU Delft
UNESCO
UNICEF
UNIDO
UoN
USAID
USD
VAWT
WASH
WASREB
WFP
WHO
WSB
WSP
WSS
WSTF
WV
xvii
Sombeza Water and Sanitation Improvement Project
Small Wind Turbine
Total Dissolved Solids
United Nations Educational, Scientific and Cultural Organization
United Nations Children's Fund
United Nations Industrial Development Organization
University of Nairobi
United States Agency for International Development
United States Dollar (currency)
Vertical Axis Wind Turbine
Water, Sanitation and Hygiene
Water Service Regulatory Board
World Food Program
World Health Organization
Water Services Board
Water Service Provider
Water Supply and Sanitation
Water Services Trust Fund
World Vision
xviii
Introduction
1
19
Introduction
In 2010 the United Nations declared access to clean water and sanitation a Human Right, and although the
world met the Millennium Development Goal drinking water target in 2010, 5 years ahead of schedule, 748
million people – mostly the poor and marginalized – still lack access to an improved drinking water source
[1]. Climate change is increasing the average temperatures and causing droughts and, due to their already
warm weather, agriculture dependence and low incomes, developing countries are being the most affected
ones by this phenomena [2]. The coastal city of Kilifi in Kenya deals with the consequences of these
problems every day.
In the last national census held in 2009 the total population in Kenya was found to be 38,610,097 [3];
however, considering the population average annual growth rate of 2.7% the country is experiencing since
2010 [4], it is estimated to be around 44 million nowadays.
Situated in Eastern Africa, the Republic of Kenya lies squarely on the equator between latitudes 5° North
and 5° South and between longitudes 34° West and 42° East. It covers an area of 582,646 square kilometres
with lakes occupying about 2% of it [5]. It borders with Somalia and the Indian Ocean on the East, Uganda
on the West, Ethiopia and South Sudan on the North, and Tanzania on the South. A map of the location of
the country in Africa and its political borders can be seen in Figure 1.
Figure 1 - Location of Kenya in Africa (left) and Kenya with its political borders (right)
A new Constitution of Kenya was promulgated in 2010 and the country was divided into 47 counties,
looking to bring decision making closer to the people. One of the recently created Counties is Kilifi, which,
according to the aforementioned census, ranks 8th in population. The system designed in this report will be
installed in the capital of this county, which is also called Kilifi. A map of Kenya where the location of the
county is indicated and a closer picture of it where its capital can also be observed are presented Figure 2.
Figure 2 - Location of Kilifi County in Kenya (left) and location of Kilifi town in the county (right)
Introduction
20
Current proposals to solve the water shortage problem in Kilifi include rainwater collection systems, piping
in water from inland sources and the rehabilitation and construction of water pans/ponds. These solutions
do not always result in clean potable water, are capital intensive and lack the capacity to meet growing
water deficits; therefore, and considering the fact that wind and saline water are freely available in the
region, a wind driven reverse osmosis desalination system is being proposed in this project. This is a costeffective, robust and easy to maintain technology that finds a sustainable and off-grid (stand-alone)
solution to the fresh water problem in the region by using wind energy to pump water through the
membranes of a reverse osmosis array, filtering the impurities and turning brackish salty water into fresh
drinking water for the inhabitants of the region.
The system to be designed will use brackish water stored underground, and it is expected to produce
between 20,000 and 30.000 litres of fresh water every day. The system will be operated and maintained at
a local setting stimulating entrepreneurship activities in the region.
The technological requirements of such a system have been verified, but the system itself has not been
validated in a Kilifi-like environment. The question whether it will indeed produce enough water depends
on the system’s components capacity and their ability to interact with each other, but also on the system’s
acceptance by the local community and their skills to perform proper operation and maintenance tasks,
repairs and usage management. This highlights the other side of the coin there is to technological
development; whether the technology will become a success is highly dependent on the context and the
future it is subject to; therefore, it is important to assess the technology interaction with its context and all
the related actors to find out if it can overcome the expected drawbacks and barriers in order to be of added
value.
In the remaining of the first chapter the problem statement, which has been divided in two sections (water
and energy) will be described. Then the objectives of the research and the methodology used will be
presented.
1.2 Problem statement
The problem statement is divided in the two aspects to be tackled in this project with the system to be
designed: water and energy.
1.2.1 Water
First a description of the severity of the access to drinking water problem in the world, its consequences
and the benefits of tackling it is given, followed by an explanation of the situation in Kenya, the country in
which the system will be installed.
1.2.1.1 Access to safe water
An improved drinking-water source is defined by the WHO/UNICEF Joint Monitoring Programme (JMP) as
one that, by nature of its construction or through active intervention, is protected from outside
contamination, in particular from contamination with faecal matter [6].
In 2012 almost 90% of the global population used an improved drinking water source, which compared
with the 76% of 1990 represents an important progress on the topic; however, lack of access to these
sources still affects almost 750 million people, nearly half of which lives in Sub-Saharan Africa, and it is
estimated that 1.8 billion people use a source of drinking-water that is contaminated with faeces [1]. Dirty
or unsafe drinking water is, along with inadequate sanitation and poor hygiene, linked to transmission of
diseases such as cholera, diarrhoea, dysentery and typhoid. These water, sanitation and hygiene (WASH)
problems are estimated to cause 88% of the cases of diarrhoea in the world, which result in more than 3.4
million deaths each year, nearly all of them in underdeveloped nations [7]. Diarrhoea is the second leading
cause of death among children under five in the world (around 1.5 million each year), only behind
pneumonia, killing more children than malaria, AIDS and measles combined [8]. These children, mostly
from developing countries, represent 90% of the deaths due to diarrheal diseases in the world [9]. In
Introduction
21
addition, it is estimated that 50% of the cases of malnutrition in the world are also associated with repeated
diarrhoea. Underweight children are more vulnerable to almost all infectious diseases and have a lower
chance of full recovery, which brings up the total number of deaths in children under five years of age
caused directly and indirectly by malnutrition induced by unsafe water, inadequate sanitation and
insufficient hygiene to around 860,000 per year. It has been estimated that nearly 10% of the global disease
burden and more than 6% of all deaths could be prevented by improvements related to drinking-water,
sanitation, hygiene and water resource management [7].
Lacking access to safe drinking-water has many other effects, and surveys from 45 developing countries
show that by 2011 women and children, especially girls, beard the primary responsibility for water
collection in 76% of the households [10]. Investing in water and sanitation would yield a better quality of
life for them, and some of the benefits include time saved and used for other activities instead of fetching
water at distant or unsafe facilities risking violence or animal attack; improved school attendance and
completion, especially for girls; fewer days lost in the home, at school or work due to preventable sickness;
greater comfort, privacy and safety, especially for women, children, the elderly and people living with
disabilities; and a greater sense of dignity and well-being in general [11].
Investment in safe drinking water and sanitation also contributes to the economic growth of a country, as
it has been estimated that the benefits of doing so include an overall estimated gain of 1.5% of global GDP
and a USD 4.3 return for every dollar invested due to reduced health care costs for individuals and society;
greater productivity and involvement in the workplace through better access to facilities, especially for
women in the workforce; opportunity for growth of new industries, such as infrastructure, disposal and
use of human waste and materials supply [11]. A World Health Organization (WHO) study shows a total
payback of USD 84 billion a year from the USD 11.3 billion per year investment needed to meet the drinking
water and sanitation target of the Millennium Development Goals [7].
The eight United Nations Millennium Development Goals (MDGs) gather a set of needs of the world’s
poorest that the United Nations, along with governments, leading development institutions, civil society
and other partners, is aiming to solve by the year 2015. A wind driven reverse osmosis desalination system
such as the one proposed in this project can assist countries in working towards achieving several of the
MDGs, from eradicating poverty and hunger, reducing child mortality, improving maternal health and
combating infectious diseases, to ensuring environmental sustainability. It especially tackles Goal 7, Target
7c, which calls on countries to "Halve, by 2015, the proportion of people without sustainable access to safe
drinking-water and basic sanitation" [12]. Despite the fact that since 1990 more than 2.3 billion people
around the world has gained access to improved sources of drinking water and that 116 countries have
met the MDG target for water, this progress has been uneven. Sharp geographic, sociocultural and economic
inequalities in access persist, and in some cases the inequalities became even greater. Substantial
disparities exist between rich and poor, between and within countries, and between those living in rural
areas and those in formal urban settings. According to the last update of the Progress on Drinking Water
and Sanitation of UNICEF and WHO over 90% of the people lacking access to clean water in the World lives
in rural areas [1].
The last UN-Water Global Analysis and Assessment of Sanitation and Drinking-Water (GLAAS) report
shows, among many other results, that global aspirations towards universal access to safe and affordable
water and sanitation are supported by political processes in many countries, and two thirds of the 94
countries surveyed recognized drinking-water and sanitation as a universal human right in national
legislation while more than 80% reported having national policies in place for drinking-water and
sanitation; however, a large gap between aspirations and reality exist and less than one third of countries
have universal access targets for drinking-water [11].
1.2.1.2 Water situation in Kenya
Kenya is, along with other 44 countries -most of them located in the African continent-, not on track to meet
the MDG drinking water target, and nowadays only 62% of the total population has access to improved
drinking water sources [1]; however, there has been some progress in the sector, and a proportion of 26.4%
of the current population gained access to drinking water sources between 1995 and 2010 [13]. In Table 1
the Kenya trends of drinking water coverage are presented.
Introduction
22
Table 1 - Trends of drinking water coverage in Kenya [1]
Drinking water coverage estimates
Source of water
Urban (%)
Rural (%)
Total (%)
1990
2012
1990
2012
1990
2012
Piped onto premises
56
44
10
13
18
20
Other improved source
36
38
23
42
25
42
Other unimproved
4
13
18
16
16
15
Surface water
4
5
49
29
41
23
Despite the fact that most people living in urban areas (82%) have access to drinking water and that the
percentage of people living in rural areas with access to drinking water has increased from 33% in 1990 to
55% in 2012, the total numbers are still very low, and advances in this topic must be done faster as it is
affecting the country in many ways. A WHO study showed that by 2002 almost 10% of the deaths in Kenya
were related to water, sanitation and hygiene problems, being the diarrhoeal diseases the cause of most of
them [7].
Kenya is classified as a water scarce country with only 647 cubic meters of renewable fresh water per
capita, which is far below the 1,000 cubic meters threshold. Population growth is forecast to reduce this
figure to 359 cubic meters by 2020, and could be even less if the resource continues to be depleted [14],
1.2.2 Energy
A brief statement of the urgency of the energy transition, especially in the current scenario of growing
demand and population, and the nexus between energy consumption and water sources is given in the first
part, while in the second part a description of the status of the energy sector and the consequences of
climate change in Kenya, especially in the rural communities, is presented.
1.2.2.1 Clean Energy and Climate Change
Since the industrial revolution the high levels of energy consumption based on fossil fuels have caused an
irreversible damage to the environment. The last Intergovernmental Panel on Climate Change (IPCC)
report concluded that the effects of climate change will be perverse, pervasive and irreversible: flooding
due to rising sea levels will hit millions while the ecosystems are being threatened by the higher levels of
acid in water resulting from the carbon dioxide emissions. The rising temperatures will hurt harvests
causing food shortages and people will be forced to flee some areas due to extreme conditions. In addition,
the changes could indirectly increase the risk of conflict [15]. Nevertheless energy demand is still
increasing, and considering that the current world population of 7.2 billion is also projected to increase
reaching 8.1 billion in 2025 and 9.6 billion in 2050, most if which will occur in developing regions that are
projected to increase from 5.9 billion in 2013 to 8.2 billion in 2050 while the population of developed
regions will remain largely unchanged at around 1.3 billion people [16], the future does not look very
promising for the World unless actions are taken. Keeping business as usual (BAU) will only accelerate the
possibility of severe and very costly consequences [15]. According to the World Bank the annual cost of
adapting to the impacts of an increase of 2°C in global average temperature could range from USD 70 to
USD 100 billion per year until 2050, of which 70% is water-related [17].
Climate change is predicted to have a whole range of impacts on water resources, as the variation in
temperature and rainfall may affect water availability, increase the frequency and severity of floods and
droughts, and disrupt ecosystems that maintain water quality [15]. In addition, collecting water is expected
to become increasingly burdensome as more regions will experience water shortages due to the more
erratic rainfalls, the melting of glaciers and the rise of the seas. People living within 60 miles of a shoreline,
a full third of the world's population, will be hit especially hard, as they are most susceptible to increased
salinity of coastal potable water sources [18].
Water and energy are tightly interlinked and highly interdependent. Demand for energy production is
expected to increase significantly in coming decades, especially in emerging economies, and this will
probably have a negative impact on water resources unless the management and coordination between
both sectors is improved. The management (extraction, transportation and treatment) of water involves a
considerable amount of energy, while at the same time the extraction of fossil fuels and production of
Introduction
23
electricity requires important quantities of water. By 2014, 15% of the water withdrawn in the world was
used for energy production, and this percentage is expected to increase even more due to growing
population, urbanization of rural areas and changing consumption patterns [19].
Climate change is expected to make the management of water and energy resources exceptionally
challenging by causing more water variability and intensified weather events, such as severe floods and
droughts. Of the 7 billion people on Earth today over 2.5 have unreliable or no access to electricity and 2.8
billion live in areas of high water stress, and with population growth and rapidly-expanding economies the
already critical dependence of energy and water is likely to become even sharper. Estimates show that by
2035 the global energy consumption will increase by 35% while water consumption by the energy sector
will increase by 85%, increasing the pressure on the finite water resources, being the developing countries,
which have limited experience in energy projections and associated water consumption, the most
vulnerable ones. Water constraints have already adversely impacted the energy sector in many parts of the
world; however, current energy planning and production is often made without taking this into account.
Planners and decision-makers in both sectors are often not informed enough about the drivers of these
challenges, how to address them, and the merits of different technical, political, managerial and
governmental options. Integrated planning between the two sectors is necessary in order to avoid
unwanted future scenarios, and the exploration of brackish and saline water options is one of the many
ways of tackling this [20].
Besides different efforts to push renewables into the mainstream of power production, thermal power
plants are still responsible for roughly 80% of global electricity production, and as a sector they are a large
user of water. Power plant cooling is responsible for 43% of total freshwater withdrawals in Europe (more
than 50% in several countries), nearly 50% in the United States of America and more than 10% of the
national water cap in China [19].
It has been calculated that 3.5 planets Earth would be needed to sustain a global population achieving the
current lifestyle of the average citizen of a developed country [21].
1.2.2.2 Energy status in Kenya
Climate change has a significant influence on Kenya’s energetic and economic situation, and in the 18 years
period between 1990 and 2008 the temperature of the country has experienced a rise of almost 1.8%, while
rainfall has reduced by more than 5% [5]. Climate change is also at the root of the increased floods and
droughts, which have important socio-economic consequences in the country and are a key factor for
Kenya’s declined economic growth [22].
Rural electrification has been a long-standing goal in Kenya, however still only 4% of the people living in
these communities have access to any kind of electricity, and their energy needs are met by sources such
as traditional biomass (wood fuel and charcoal) and fossil fuels. In addition, the few communities that get
electricity depend on an unreliable grid with increasing prices [23].
Kenya has already suffer the effects of the water-energy nexus explained in the previous part, as a massive
drought decreased hydro generation by 25% in the year 2000. This lost in energy production had to be
replaced by more expensive fuel-based generation. Losses in hydropower generation and industrial
production due to water shortage during 1999/2000 were over USD 2 billion [20].
The increase of the power demand and the scarcity of fossil fuels has also prompted the movement towards
green technologies in Kenya, which is reflected in different ways. The Kenyan government and public are
gaining environmental awareness through increased media attention and international climate
conferences. Also international organizations such as the United Nations and The World Bank are
encouraging Kenya for a transition towards a green economy by various programs, while more western
donor money is being invested in ‘green projects’ through the NGO sector [23].
Introduction
24
1.3 Objectives
The goal of the research done in relation to this project is to find an answer to the following question:
Which is the optimal windpump configuration for a wind driven reverse osmosis brackish water
desalination system to be implemented in the town of Kilifi in Kenya?
In order to find an answer to the above question the following sub-questions were defined:
 Who are the relevant actors involved in the development, implementation, regulation and, more
importantly, usage (operation and maintenance) and consumption, of the designed system in this
specific market niche?
 Who are the possible end-users for the designed system and what is the situation of the different
market segments in Kilifi?
 Which is the best pump option capable of delivering the flow and pressure required by the reverse
osmosis process to produce the expected amount of water?
 Which is the best wind turbine rotor design capable of producing the required power and torque
by the pump with the conditions of Kilifi?
 Which is the better coupling option to transmit the power and torque produced by the wind
turbine rotor to the pump?
1.4 Methodology
As this project involved different topics a methodology that allows the author to combine efficiently various
perspectives was required. It was then decided to divide it in 4 phases, namely theoretical background, field
study, design and matching, some of which happened simultaneously. They are described in the following
sections.
1.4.1 Theoretical background
The theoretical background phase consisted in mainly two parts: literature research and communication
with experts in the different aspects of the project.
1.4.1.1 Literature research
For the study of the context in which the system will be implemented different documents and websites
from the Kenyan government and recognized institutions and organizations that have published useful
information on the country’s characteristics, as well as on its water and energy infrastructure and usage,
were consulted. This information provided insight in established technologies and gave a first incentive for
the need of a wind driven reverse osmosis desalination system for Kilifi.
To make the stakeholders analysis and map and the market research chapters of the project the documents
provided by Sjoerd Dijkstra from Winddrinker Holdings were also often used, as well as the websites of the
company, its partners, Kenyan Government institutions, research institutes located in the country and
organizations working in the area.
For the reverse osmosis process and the pump literature research the material obtained from different TU
Delft courses such as Fundamentals of Water Treatment (CIE4495) and Drinking Water Treatment
(CIE4475), as well as books on the subject such as “Reverse Osmosis” by Jane Kucera, “Pumping” by Frank
Spellman and Joanne Drinan and “Process Pump Selection” by John Davidson and Otto von Bertele was
fundamental.
In the case of the wind turbine rotor the information provided on the TU Delft courses Introduction to Wind
Energy (AE3W02TU) and, more importantly, Wind Turbine Design (AE4W09), was often used, while the
books “Wind Energy Explained: Theory, Design and Application” by Manwell, McGowan and Rogers and
Introduction
25
“Matching of Wind Rotors to Low Power Electrical Generators” by Hengeveld, Lysen and Paulissen were
the main sources reviewed.
1.4.1.2 Communication with experts
Understanding how the reverse osmosis array operates was fundamental for the proper selection of a
pump and consequently the design of the wind turbine rotor; however, this is a topic in which the author
had no previous experience and therefore meetings with TU Delft experts in the area such as Dr. Bas
Heijman from the Water Management Department of the faculty of Civil Engineering and Geosciences
(CEG), and engineers of Hatenboer Water, the Dutch company responsible of the design and development
of the reverse osmosis array to be used, such as Jan Arie de Ruijter, leader of the Process Engineer
Department, were held in order to obtain more specific information. These meetings were used to discuss
not only the reverse osmosis array but also the characteristics of the pump to be installed.
During the pump selection process communication with dozens of pump manufacturers and distributors
was maintained through phone calls and emails in order to discuss the properties of the pump and choose
the better alternatives for further analysis, complementing the information obtained from the literature
research described before. The list of considered providers was long, but especially the conversations with
Ivan Hopchet and Frank Haertjens from CAT Pumps Belgium and with Piet Kopet from PromoTec B.V
resulted in valuable inputs for the project.
The wind turbine properties and characteristics were discussed in meetings with the first supervisor of the
project Prof.dr. Gerard van Bussel, as well as other members of the TU Delft Wind Energy Department Ir.
Michiel Zaayer, Ir. Nando Timmer, Ir. Ruud van Rooij and Ir. Gael de Oliveira. The input obtained from the
meetings and conversations with William Dijkstra, the windpump expert in charge of manufacturing the
provided design, were also of great value, as a different more practical approach was provided by him.
For the social-related studies the most important communication channels where the meetings and emails
exchanged with the second supervisor of the project Dr. Linda Kamp and with Winddrinker Holdings CEO
Sjoerd Dijkstra, who is the most interested person in the success of the project.
1.4.2 Field study
The field study was divided in two phases, first a visit to a windpump in the Netherlands and then a 1month trip to Kilifi, the place where the system will be installed. They are described in the following subsections.
1.4.2.1 Drachten, the Netherlands
There are no wind powered reverse osmosis desalination plants operating in the Netherlands, but there
are many windpumps especially in the countryside. A visit to the only windpump in the Netherlands that
operates 24 hours/7 days a week was done with William Dijkstra, its designer and builder and the person
that will be in charge of manufacturing the design provided at the end of this project. This specific
windpump is located in Drachten, close to Heerenveen, and it consists of a multi-bladed wind turbine rotor
coupled to an Archimedes screw pump type through a mechanical coupling with two open gears.
The main goal of the one-day visit to this windpump was to see in detail how such system operates and to
have a better understanding of how its various components interact with each other.
1.4.2.2 Kilifi, Kenya
As finding reliable data about rural communities of developing countries from the distance is not very
efficient a 4-weeks field study in Kilifi was made between the months of October and November of 2014.
The goal of the visit was to obtain good first-hand information useful to understand the context on which
the system will be installed.
Part of the work performed on place consisted on taking a water sample from the well that will feed the
plant and take it to a laboratory in Mombasa to have it tested, as the characteristics of this water (especially
Introduction
26
its content of total dissolved solids) will have a direct impact on the design of the system. The exact future
location of the plant was also evaluated to decide on the roughness coefficient of the terrain.
In Kilifi different interviews and surveys, which were prepared in the Netherlands, were made to many of
the project stakeholders with the following focus:
Community survey
A survey was conducted on site with the inhabitants of Kilifi with the goal of understanding their current
water situation, as well as to identify the knowledge they have about desalinated water, their willingness
to consume it and how much would they pay for it. The survey was done to two different groups of 25
persons each, one formed by people found at the streets of the town centre and bus station while the other
group was composed by people shopping at Tuskys, the only supermarket that can be found in Kilifi. As
Tuskys has products at higher prices than the small stores and kiosks spread in town the people found
there are expected to have a higher acquisitive power.
Shops survey
A survey was made to different shops/kiosks in town with the goal of finding out if they are selling water,
at what price, how they get it and if they know its source, as well as to know the feedback (positive or
negative) from their customers about the water they sell and the importance this activity has for the income
of their shops. Finally, questions about desalinated water were made to them to know what they think
about it and how they perceive a system such as the one being proposed in this project will be received by
the communities of the area.
Non-governmental Organizations/International Development Organizations workers interviews
Many non-governmental organizations (NGOs) and international development organizations (IDOs) work
closely with the communities of Kilifi that will eventually benefit from the water produced by the system.
These organizations know these communities very well and are usually the link between them and anybody
that wants to develop a project in the area. Interviews were made to some of these organizations with the
goal of having a better understanding of how the communities of the area live, which is the best way to
approach them and what are the main challenges in the process, as well as to know if they think the
proposed system will be accepted by them. Questions about the organizations they represent and their
knowledge about water-related projects in the area were also included in the interview.
Hotel/resort managers interviews
Interviews were held on site with hotel and resort owners and managers in order to find out more about
the current water situation in the tourism industry, the main economic activity of the area. Questions about
the problems they have had with water in the past, how these issues affected them, how they solved them
and what are their expectations for the future in this topic were included in the interviews, which were also
used to evaluate their interest in the final product of the proposed system.
Farmers interviews
Some farmers of the area were also interviewed with the goal of finding out how they use the water, the
quantities they consume, what are the main uses of this water, where it comes from and how much it costs
to them. Their opinion about the quality of this water they are using and its reliability was also asked, as
well as their opinion about desalinated water and what would be an ideal solution for them. Finally, as in
the case of the interviews with the hotel and resort managers, a question about the situation of the farmin
industry was made.
Water service providers interview
An interview was held on site with the Area Manager for Kilifi of KIMAWASCO, the water service provider
of the area, with the goal of finding out more about the company, the products they offer, their market and
the process any organization that wants to start water-related projects in the area has to follow.
Introduction
27
Water desalination companies interview
An interview was done with the General Manager of Dutch Water Limited (DWL) in Mtwapa, a company
set in 2009 with the objective of producing as cheap as possible quality and healthy drinking water to the
Kenyan population, with the goal of obtaining information about the operation of their plant and the
difficulties of the business of selling affordable water in the coast of Kenya, as well to have a better
understanding about the market segments they reach and how they do it.
1.4.3 Design
In this phase the system, which can be divided in four components namely the reverse osmosis array, the
pump, the coupling and the wind turbine rotor, was designed.
1.4.3.1 Reverse osmosis array
The reverse osmosis array to be used in Kilifi was not designed by the author of this report, and a model
developed by the Dutch company Hatenboer Water will be applied in the project; however, as this
component dictates the amount of pressure the pump needs to deliver to the fluid, and therefore the power
and torque required from the wind turbine rotor, it was evaluated in detail. The reverse osmosis array is
the starting point of the design.
In this phase the Integrated Membrane Solutions Design (IMSDesign) program developed by Hydranautics
was used. This program is described by the company as a powerful tool that helps users to design reverse
osmosis (RO) systems based on membrane technology. It also provides many features that enhance the
user's ability to quickly and accurately design and analyse various RO desalination systems.
The characteristics of the water sample obtained in Kilifi, as well as the properties of the reverse osmosis
array to be used in the project, were introduced in the IMSDesign program to calculate the pressures for
different permeate flows, which are product of the changes in the pump shaft due to the varying wind speed
and that are needed to design the rest of the system.
1.4.3.2 Pump
As the system will be located on a rural community it was decided to use an off-the-shelf pump in order to
be able to facilitate the maintenance tasks. For the selection process the first step was to choose the type of
pump to be used in the project and then, knowing the flows and pressures (head) required by the reverse
osmosis array, the size of the pump was decided.
With these two characteristics in mind pumps with good salt protection were searched. Many pump
manufacturers and distributors were contacted to discuss the properties of the pump, and finally the best
four alternatives were selected for further analysis.
As the pump of the system will be powered by a fluctuating source initial calculations were done to evaluate
the selected models performance at different shaft speeds. Based on the data sheets and technical manuals
provided by the manufacturers, relations were derived to calculate the delivered flow rate by the pump
and the required power and torque as a function of the pump’s angular velocity and the feed pressures
needed for the reverse osmosis process. The results of the calculations for the pumps were compared
through curves that allow a better comparison.
Besides these calculations, the selection of the pump also depended on other factors that were thought
considering the way this component will be operated and its location. Extra criterions considered for the
final phase of the selection process were the pump’s price and how easy it is to maintain it as well as its
manufacturer’s experience in reverse osmosis applications and presence on the African continent to
rapidly provide support in case it is necessary. Nevertheless, not every criterion had the same importance
for this project, and therefore weighting factors for each category were introduced to highlight this
difference. The importance of each criterion was defined by giving it a grade when compared to the rest,
and to calculate the weighting factors this maximum value was assumed to have a value of four.
Introduction
28
Finally, scores were given to every pump in each category. These scores were then multiplied by the
weighting factors previously assigned and summed, providing a final or total score for all the pumps. The
scores given to each pump for every category were based on the information and data obtained in the steps
described before and the particularities of the location of the system. The pump with the highest score was
selected for the system.
1.4.3.3 Coupling
The different types of coupling were presented and, considering their advantages and disadvantages of
each and the characteristics of the location where the system will be installed, a specific type was chosen.
The transmission ratio was initially assumed considering recommendations of the manufacturer and then
defined during the matching process between wind turbine rotor and pump.
1.4.3.4 Wind turbine rotor
The procedure used for the design of the wind turbine rotor was based on the approach proposed by
Manwell, McGowan and Rogers in their book “Wind Energy Explained”, which consists on going from the
more general aspects of the turbine design to its details; however, as their book is focused in modern
turbines for electricity generation, the text written by Hengeveld, Lysen and Paulissen, “Matching of Wind
Rotors to Low Power Electrical Generators”, which is focused on the design of wind turbines of smaller size
to be installed in developing countries, was also used as a compliment of the first one.
The procedure suggested in Wind Energy Explained for the wind turbine rotor design consists in three
parts: blade rotor parameters, blade shape and rotor performance. In the first one the choice of various
rotor parameters and an airfoil is done, while in the second one an initial blade shape is determined using
the optimum blade shape. Then, in the third part, the final blade shape and performance are evaluated.
The procedure applied can be summarized as this: first, the wind regime for Kilifi was evaluated, and in this
process a Weibull distribution was applied to the conditions of the location. Then the rated power and the
rated wind speed were chosen, and assuming a power coefficient and a transmission ratio the swept area
of the rotor was calculated. After this, and based on the characteristics of the operation to which the wind
turbine rotor will be subjected to, a design tip speed ratio, the number of blades and an airfoil with known
lift and drag coefficients as a function of the angle of attack were selected. In the second phase a design
angle of attack (and, thus, lift coefficient at which the airfoil will operate) was chosen keeping in mind that
the ratio of drag coefficient over lift coefficient (C d/Cl) has to be minimum in order to try to comply with
the assumption of zero drag coefficient. With this the twist and chord distributions of the blade were
determined; however, the cost and difficulty of fabricating the blade also has to be considered in the design
process as an optimum blade would be very difficult to manufacture at a reasonable cost, and therefore the
next step consists on adjusting the blade shape design. Nevertheless, this step was skipped for the moment,
as the blade was expected to change in the matching-with-the-pump procedure. Finally, the wind turbine
rotor performance was evaluated with the power coefficient-tip speed ratio (CP-λ) and torque coefficienttip speed ratio (CQ-λ) curves.
The CP-λ and CQ-λ curves were used to determine the power and torque produced by the rotor for any
combination of wind and rotor speeds, and for this project the data to build them was obtained through a
Blade Element Momentum (BEM) code based on the Propcode by James Tangler, a horizontal axis wind
turbine performance prediction code, with the formula from the book by Wilson & Lissaman. This code was
facilitated by professors Nando Timmer and Ruud van Rooij from the Wind Energy Department of TU Delft.
The code works by introducing an input file into an executable program. In this input file the blade chord
and twist distributions calculated before were needed, as well as other parameters such as the radius, the
rotational speed, the air density, the number of blades, the thickness of the airfoil and the values of lift
coefficient and drag coefficient for different angles of attack. Nevertheless, as the program had some
limitations, the chord distribution had to be adjusted and assumed constant. The wind turbine rotor
obtained in this section was tested, and varied, in the matching procedure.
Introduction
29
1.4.4 Matching
The matching procedure between the wind turbine rotor and the pump was done using the power-speed
and torque-speed curves of both components, as proposed by Peter Fraenkel in his FAO book “WaterPumping Devices: a handbook for users and choosers”.
In the case of the wind turbine rotor the power-speed and torque-speed curves were drawn for wind
speeds between 1 and 10 meters per second, while in the case of the pump just one power-speed curve and
one torque-speed curve was drawn, indicating the required pressure and torque, respectively, by this
component to deal with the flows and their respective pressures.
The operating point of the system occurs when in the power-speed plot the load (pump) line crosses the
wind turbine rotor curves, and it will only function when this crossing point is to the right of the locus of
maximum power produced by the wind turbine rotor. The same principle applies in the torque-speed
curves. The cut-in wind speed of a wind turbine rotor-pump configuration is given by the highest speed at
which this crossing occurs for both graphs for the first time.
Using the original design of the wind turbine rotor different values for the transmission ratio were tested
and some of them were selected for further analysis; however, other design parameters such as the radius,
the number of blades and the design tip speed ratio also have an impact in the operational speeds of the
system and the matching between both components. Therefore the next step was to try different values for
these other parameters. For this evaluation process each property of the rotor was changed while holding
the others constant.
Considering the results obtained in all the tests and looking to reduce the costs of the wind turbine rotor a
selection of the most promising designs was made for further evaluation. In addition, other designs with
perturbations of the original twist and chord distributions were also analysed, bringing up the total number
to 7 candidates. For each of these 7 final options the solidity was calculated and afterwards they were
matched with the pump using the transmission ratios considered before. The results were presented in a
table to make the comparison simpler, and at the end one of these options, with a slightly adjusted
transmission ratio, was selected for the system.
1.5 Report structure
The report will start with the stakeholders analysis in Chapter 2, followed by the market research in
Chapter 3. These two first chapters describe the results of the social research, and are fundamental for the
decision-making process throughout the entire system design and matching process.
In Chapter 4 the design of the system is detailed, starting by a description of the reverse osmosis array to
be implemented, continuing with the description of the pump selection process and finalizing with the wind
turbine rotor design.
The matching between the components is evaluated in Chapter 5, in which a final design for the wind
turbine rotor and a selection of the transmission ratio is done at the end.
Finally, the conclusions of the thesis are presented in chapter 6, and reflections on what could have been
done better in the research are presented in chapter 7. Chapter 8 is dedicated give recommendations for
future research.
Stakeholders analysis
2
30
Through a stakeholders analysis this chapter is dedicated to answer questions about who are the relevant
actors involved in the development, implementation, regulation and consumption of the system and its
final product in this specific market niche.
The stakeholders are the individuals and organisations that can influence the development of the
technology or that can be affected by it; therefore, the stakeholders are not only the experts on the system,
but also the users, the social organizations, the government, the companies, knowledge institutes and any
other actor that is, in one way or another, related to it [24].
A stakeholders analysis is a helpful tool to identify dead-ends and issues that could interfere with the
successful implementation of the designed system in Kilifi. By finding out who is behind the development
of the technology, who will be its end-users and who is in the middle, it is possible to identify key aspects
such as networks, isolated initiatives, flows for funding, bureaucracy and missing stakeholders to get an
overview of the entire situation. It gives an insight in the players involved in the project.
The chapter is divided in two main sections: first a stakeholders map is presented and then, in the second
part, the actors are described in terms of their interest in the project, their influence and their relationship
to the project and to each other. At the end of the chapter a summary with the results of the stakeholders
analysis is presented.
2.1 Stakeholders map
The stakeholders map is a graphical representation of how the different actors that are currently related
to the project are linked to it and between them. In Figure 3 the map is presented, and afterwards a brief
explanation of it is given.
Figure 3 - Wind driven reverse osmosis desalination system in Kilifi stakeholders map
32
In the stakeholders map the actors are divided in 8 different blocks: technology development, knowledge
development, funding, government, owners, users (operation and maintenance), intermediaries and
consumers. All the blocks are directly linked to the wind driven reverse osmosis desalination system to be
installed in Kilifi, Kenya, which is located at the centre of the map.
In the map connectors are used to link actors with each other representing the existent cooperation
between them. Winddrinker Holdings, which belongs to the technology development and the funding
blocks, is the organization in charge of coordinating and managing the project, and therefore the one linked
to more stakeholders. It is connected to the knowledge developers, namely Hatenboer Water, Bertus
Dijsktra, TU Delft and IHC MERWEDE, as all of them will, through Winddrinker Holdings, provide their
knowledge and expertise to the project, especially during its design phase. It is also connected to the
technology developers CAT Pumps, Hatenboer Water and Bertus Dijkstra, as they will, again after
consulting with Winddrinker Holdings the requirements of the system and details of the project, provide
the pump, reverse osmosis array and wind turbine for the system, respectively. Other stakeholders linked
to Winddrinker Holdings are the organizations that are part of the funding block, as they will financially
support the project through economic contributions and/or their network. These organizations are TU
Delft, IHC MERWEDE, Aqua for All, TEDx and Hivos. In the technology development block a connection can
be seen between CAT Pumps and Hatenboer Water, as these two organizations will have to closely work
together in the project in order to combine the components they are providing. It is important to note that
CAT Pumps was added as a stakeholder after design decisions to be described in Chapter 4 were made.
Winddrinker Holdings is also connected to Organic Essentials Limited, which will be the owner of the
system once it is completely installed, and Choice Humanitarian, which is the NGO that will work as the
intermediary between the installed system and the communities of Kilifi. For this reason Choice
Humanitarian is also linked to community group in the consumers block. This block is completed by
farmers and hotels/resorts, as these three market segments were recognized as the possible end users of
the system. As the community of Kilifi strongly depends in the tourism and farming industry all of the
market segments are connected to each other. Organic Essentials Limited is also connected to the Jua Kali
in the users block, as they will be the people in charge of performing the daily operation and maintenance
of the system.
The government block is divided in two groups: energy and water. Both of these groups have their
respective Ministry at the head. In the energy group the Ministry of Energy (MoE) is connected to the three
institutions presented in the map, namely the Rural Electrification Agency (REA), the Energy Regulatory
Commission (ERC) and the Meteorological Department, but these organization are independent of each
other. In the case of the water sector, the Ministry of Water and Irrigation (MWI) is also connected to all
the institutions in the group, namely the Water Services Regulatory Board (WASREB), the Water Services
Trust Fund (WSTF), the National Water Conservation and Pipeline Corporation (NWCPC), the Coast Water
Services Board (CWSB) and the Kilifi-Mariakani Water and Sewerage Company (KIMAWASCO); however,
inside this group there are also links between some of the institutions, as the WASREB and the CWSB are
both connected to KIMAWASCO. The first one because is the one in charge of approving the tariffs and
standards of quality, service and performance KIMAWASCO has to comply with, while the second one is the
one in charge of its contract.
A more detailed description of the actors and their history and relationship with the project is given in the
following section.
2.2 Stakeholders description
In this section all the stakeholders related to the project are described. Each actor description starts with a
small explanation of its core business followed by its relation with the project and with other actors. Finally,
the history of the organization with the project, if any, is commented.
The stakeholders to be described have been divided in two sections: current stakeholders and possible
future stakeholders. As the name of the groups suggest, the first one includes all the actors that are
currently involved with the Kilifi project and that where already presented to the reader in the stakeholders
33
map of the previous section, while the second group looks into possible interesting stakeholders for the
future of the system.
2.2.1 Current stakeholders
The current stakeholders are divided in the eight blocks: technology development, knowledge
consumers.
Even though most of the actors belong to just one group, there are some cases, namely TU Delft, Hatenboer
Water and Bertus Dijkstra, which are part of two blocks or even more. In these cases the small explanation
of the stakeholder’s core business and its history with the project will be given just the first time the actor
is presented to the reader. Its role on the project will be given in each block the actor is located.
2.2.1.1 Technology development
This block focuses on Winddrinker Holdings as the leader of the project and includes, as a second layer of
technology developers, all the other companies and organizations that are involved on the technology
supply chain, meaning all the technical and strategic partners required for the successful implementation
of the wind driven reverse osmosis desalination system in Kilifi. The financial partners, which also play an
important role in the development of the technology, are described in a separate block called “funding”
(section 2.2.1.3).
Winddrinker Holdings
Dutch registered social enterprise that believes affordable mid-scale decentralized desalination systems
can help solve the problem of coastal water shortages. They have the certainty that their cost effective
solution offers a sustainable market based approach to convert salty water resources into drinkable water.
They focus their projects in developing countries where they partner with qualified local small business
and entrepreneurs, and their final goal is to become the leading supplier of clean and affordable water via
renewable energy powered decentralized desalination systems, first in East Africa and then across the
globe [25].
Winddrinker Holdings is the manager of the Kilifi project, and they will coordinate and provide overall
guidance during the design, construction and testing phases in the Netherlands. They are also in charge of
the selection and purchase of a proper pump for the system. In addition, they will coordinate the
implementation of the system in Kilifi with Organic Essentials Limited, the main local partner (section
2.2.1.5).
In 2012, with the financial and technical support of Hatenboer Water, TU Delft and Aqua for All,
Winddrinker Holdings installed its first operational model near the port of Berbera in Somaliland. Although
at the beginning this system produced high quality drinking water, after some time it suffered two major
breakdowns caused by the poor quality of some of the parts supplied by a South African wind turbine
manufacturer. After this experience Winddrinker Holdings decided that a new design and more reliable
suppliers were needed, and therefore engaged Dutch consortium partners to design and test a new system
in the Netherlands that will be then transferred to Kilifi [25].
Hatenboer Water
Dutch company specialized in water, from the production of drinking water right through to the treatment
of ballast water. A full service player in the water treatment market, Hatenboer Water uses their vast
experience to offer sustainable solutions and supply the right products, spare parts and services to different
industries with a diversity of technologies, including the manufacturing of reverse osmosis systems
powered by renewable energy sources [26].
Hatenboer Water was the supplier of the desalination equipment used in the 2012 Somalialand project, and
is also in charge of supplying the reverse osmosis installation to be used in the Kilifi project. They have
closely work with the provider of the pumping equipment (CAT Pumps) in the past and they will also work
together in this project.
34
Hatenboer Water partnered with TU Delft for the 2008 Curaçao project, but after it was completed they
decided to continue their research on systems with an electrical transmission while TU Delft decided to
focus on the mechanical coupling [27].
CAT Pumps
American company focused on manufacturing and marketing the, according to them, longest lasting most
dependable high-pressure pumps available in the industry. CAT Pumps has over 40 years of experience in
the reverse osmosis/desalination industry in which it has developed a much respected reputation in highpressure positive-displacement pumps [28].
After studying different options for pump providers it was decided that CAT Pumps will provide the
positive displacement pump (model 2531) that will be used in the system to be installed in Kilifi (Chapter
4). Although they have never worked with Winddrinker Holdings before, CAT Pumps is the main provider
of pumping equipment of Hatenboer Water, with whom they have been working in different projects for
several years proving that the components developed by these two companies can be combined.
Bertus Dijkstra
Dutch company specialized in the restoration of traditional Dutch windmills and the design and production
of windpumps [29].
After the design is completed, Bertus Dijkstra will be in charge of manufacturing the wind turbine and the
transmission system. Then they will have the responsibility of coupling the wind turbine to the pump and
test the system in the Netherlands before taking it to Kilifi for its installation [29].
2.2.1.2 Knowledge development
This block is composed by the research institutes that have provided knowledge, in terms of research and
development, to the system. The block is divided in two groups: universities and companies.

Universities
Delft University of Technology (TU Delft)
Dutch university that collaborates with a large number of other educational and research institutes within
the Netherlands and abroad and has a reputation for high-quality teaching and research. TU Delft has
extensive contacts with governments, trade organizations, consultancies, the industry and small and
medium-sized companies. It is known worldwide for, among many other things, playing a leading role in
the research on sustainable energy technologies and water resources management [30].
Through continue researches led by Dr. Bas Heijman from the Water Management Department of the
faculty of Civil Engineering and Geosciences (CEG), TU Delft has been the main knowledge developer for
the design of the system. In addition, through the university the company reaches students interested in
carrying out projects to monitor and evaluate older systems in order to improve them or to provide new
ideas during the design phase of new components. With the support of experts and professors of the
university the author of this report, a TU Delft Sustainable Energy Technology Master student, developed
the conceptual design of the system to be implemented in Kilifi.
Led by Dr. Bas Heijman and with Hatenboer Water as one of the main partners, TU Delft installed in 2008
a mechanically coupled wind driven reverse osmosis system for seawater desalination on the island of
Curaçao, in the Caribbean Sea. After the installation Hatenboer Water decided to continue the project with
an electrically coupled system, while TU Delft was still interested in the direct mechanical coupling option
and how the performance of both systems compare to each other, resulting in the start of the Winddrinker
Holding initiative [27].

35
Companies
Hatenboer Water
Through their continuous research in desalination and water management, Hatenboer Water is the main
knowledge developer for the reverse osmosis process of the system. In addition, they have installed,
through its initiative Dutch Water Limited, a successful jerry can bottling plant in Mombasa whose Manager
was interviewed during the field work phase (section 3.4). The knowledge gained by the company with this
initiative has been of great value for Winddrinker Holdings business plan ideas in Kilifi [29].
Bertus Dijkstra
Before building the system Bertus Dijkstra will be already related to the project in its design phase, as the
company will provide their expertise and practical knowledge in windpump technologies in order to
improve the reliability of the system and build the most efficient plant.
IHC MERWEDE/IHC MERWEDE Foundation
Royal IHC is focused on the continuous development of design and construction activities for the specialist
maritime sector. The IHC Foundation was established to contribute to social, environmental and cultural
activities on behalf of, and in cooperation with, its employees around the world. The overall objective of the
IHC Foundation is therefore to primarily support charitable projects in countries where the company
conducts its business activities and its employees are directly involved in operations [31].
With a great experience in mechanical applications, IHC MERWEDE will advise Winddrinker Holdings in
the design phase of the system in order to make it more resistant against the harsh conditions it will be
subject to in Kilifi [29].
2.2.1.3 Funding
A project like this one needs not only strategic and technical partners, but financial partners as well. This
block includes all the organizations that provide funds, one way or another, to the project.
Winddrinker Holdings
As the manager of the project one of Winddrinker Holdings main activities is to be involved in the fund
raising process, with the goal of financing the Kilifi project and expanding the activities of the company in
the region [29].
Delft University of Technology (TU Delft)
Besides being the main knowledge developer of the project (section 2.2.1.2), TU Delft is also a strategic and
financial partner of Winddrinker Holdings, supporting the company with fundraising activities and
providing them with an important network of actors that could be potentially interested in investing in
their projects [29].
IHC MERWEDE/IHC MERWEDE Foundation
As with the case of the TU Delft, IHC MERWEDE works as both a knowledge developer (section 2.2.1.2) and
funding organization, providing a financial support to Winddrinker Holdings to complete its activities.
Aqua for All
Aqua for All (A4A) is an international development organisation with the purpose of providing access to
clean drinking water and adequate sanitation on a sustainable base to the poorest people in the world [32].
Acting as a networking agent, A4A is a strategic and financial partner of Winddrinker Holdings, connecting
the company to public and private organizations and mobilizing resources, expertise and finances from the
Dutch water sector towards the project [29].
36
Hivos
Netherlands based international development organisation that, together with local civil society
organizations in developing countries and guided by humanist values, wants to contribute to a free, fair
and sustainable world in which everybody has equal access to resources, opportunities and markets, and
can participate actively and equally in decision-making processes that determine their lives, their society
and their future [33]. Hivos partnership with Winddrinker Holdings is strictly financial.
TEDx Amsterdam
TED is a non-profit organization devoted to spreading ideas usually in the form of short and powerful talks.
It began in 1984 as a conference where technology, entertainment and design came together, but today
topics that go from science to business to global issues are covered in more than 100 languages. Meanwhile,
independently run TEDx events help share ideas in communities around the world [34].
Also a strictly financial partner, TEDx Amsterdam awarded a USD 100,000 prize to Winddrinker Holdings
in the 2010 edition of “Ideas Worth Doing” for the company to continue with its operation [25].
2.2.1.4 Government
The Kenyan government plays an important role at a national and a regional level, as they have the interest
of reducing the clean water scarcity numbers and promoting the usage of renewable energies to achieve
the United Nations Millennium Development Goals. This block includes the governmental entities and
policy makers that could influence the development of the project, and they are divided in two groups:
water and energy.

Water
The Kenyan Government made important reforms to its water supply and sanitation (WSS) services sector
through the passage of its 2002 Water Act, which was instrumental in decentralizing Kenya’s WSS services
and creating the current institutional framework. The most important actors are the following:
Ministry of Water and Irrigation (MWI)
The fundamental goal and purpose of the Ministry of Water and Irrigation (MWI) is to conserve, manage
and protect water resources for the socioeconomic development of the Kenyans and the improvement of
its living standards. The MWI is also responsible of developing and monitoring the water policy and overall
sector functions.
The MWI was created in 2003 after the aforementioned 2002 Water Act, following a separation from the
Ministry of Environment and Natural Resources with the aim of consolidating the responsibility for the
management and development of water resources under a single institution [35].
Water Service Regulatory Board (WASREB)
Water Service Regulatory Board (WASREB) is a non-commercial State Corporation established in March of
2003 as part of the comprehensive reforms of the water sector result of the 2002 Water Act. It is in charge
of the regulation of water and sanitation services, including licensing, quality assurance and issuance of
guidelines for rates and fees. It also handles service complaints [36].
Water Services Trust Fund (WSTF)
Water Services Trust Fund (WSTF) is also a State Corporation established under the Water Act, 2002. Its
goal is to assist in financing the provision of water services to areas of Kenya that lack adequate water
services. They are in charge of mobilizing government and donor funds for water supply in poor areas [37].
37
National Water Conservation and Pipeline Corporation (NWCPC)
The National Water Conservation and Pipeline Corporation (NWCPC) is a State Corporation in charge of
developing and managing water infrastructures (i.e. construction of dams and water pans; development of
canals; flood control works and drilling of boreholes) to enhance water security and storage for multipurpose uses, mitigation of drought and flood effects in a sustainable manner [38].
Coast Water Services Board (CWSB)
Seven Water Services Boards (WSBs) are responsible for the efficient and economical provision of water
and sewerage services within their area of jurisdiction. They cover the whole country and are also
responsible of managing (maintaining, planning, and developing) the assets [39].
The Coast Water Services Board (CWSB) is a parastatal under the MWI responsible for the provision of
Water and Sewerage Services in the Coast Region. Its area of jurisdiction coincides with the administrative
boundaries of the Coast Region, covering six counties: Mombasa, Kilifi, Kwale, Taita-Taveta, Lamu and Tana
River [40]. The core functions of the Coast Water Services Board include:
 Development and management of water supply and sewerage infrastructure in the Coast Region.
 Holding or leasing of water and sewerage assets within the Coast Region.
 Contracting Water Service Providers within its area of jurisdiction.
 Ensuring that the Water Service Providers comply with licensing requirements.
 Assuming the responsibility of Water Service Provider as a last resort.
Kilifi-Mariakani Water and Sewerage Company (KIMAWASCO)
The Water Service Provider (WSP) are commercially oriented public enterprises, typically owned by local
authorities, contracted by the WSB to provide the water and sanitation services on performance basis at
town/community level. The WSP operates within the regulatory framework and its tariffs have been
approved by the WASREB, which also establishes standards on quality, service and performance that must
be complied by the WSP [39].
The Kilifi-Mariakani Water and Sewerage Company (KIMAWASCO) is the WSP that operates in Kilifi. Its
water distribution network has a total of 1,342 kilometres of pipes fed from 2 main sources: the Mzima
springs and the Baricho water works. The CWSB manages the main pipelines of these sources and there
are several off-takes along them. The Kilifi water area is supplied by the Lower Silala Mwamkura off-take,
which accounts for 45% of the water supplied to the KIMAWASCO area of operation [41].

Energy
As in the case of the water sector, the energy institutions of Kenya and its framework have also gone
through several changes in the last years. The institutions that can directly affect the development of the
project are the following:
Ministry of Energy (MoE)
The Ministry of Energy (MoE) is responsible for the energy policy development. In addition, to stimulate
the wind energy sector, it has recently begun to collect wind data at several locations throughout the
country that have potential for the installation of wind turbines. Furthermore, the MoE also has an
oversight role over the Rural Electrification Agency and the Energy Regulatory Commission [23].
Rural Electrification Agency (REA)
The Rural Electrification Agency (REA) is in charge of, by either grid extension or off-grid/stand-alone
projects, the rural Kenya electrification. They are also responsible for the promotion of renewable energy
technologies throughout the country. In addition, and as part of their off-grid electrification strategy, they
provided two schools with a wind–solar hybrid system in 2010. The REA also collaborates in the renewable
energy R&D program of Jomo Kenyatta University of Agriculture and Technology (section 2.2.2.2) as three
staff members of the organization will take upon the task of transferring the knowledge to the Jua Kali
(section 2.2.1.6) [23].
38
Energy Regulatory Commission (ERC)
The Energy Regulatory Commission (ERC) is Kenya’s energy regulator. The ERC Renewable Energy
Department is responsible for preparing an indicative energy plan for renewable energies and assisting the
Ministry of Energy (MoE) in the development of regulations for all forms of renewable energy technologies.
Next to setting the regulations and standards, the ERC is also responsible for their compliance [23].
Meteorological Department
The Meteorological Department is the institution responsible for measuring wind speeds in Kenya through
their 33 stations located across the country. Interested parties can buy these wind data sets from them [23].
2.2.1.5 Owner
The goal of Winddrinker Holdings is to develop a technology that after being installed can later be managed
on a local setting by one or many organizations. In the case of the Kilifi project a single company will be in
responsible of this: Organic Essentials Limited.
Organic Essentials Limited
Organic Essentials Limited is a company run by Barney Gasston, a local farmer, engineer, and proven
entrepreneur. The company grows plants, fruits, and vegetables, and produces extracts that are used in the
medical and food/beverage industry. In addition, the company has some experience with renewable energy
projects, as it has developed a large biogas installation and biomass production projects, and is currently
developing a solar farm with a capacity of more than 1 megawatt that will sell energy to the Kenyan grid
[29].
Mr. Gasston leases a plot of farm land in Kilifi which, like many other plots in the Coast Province of Kenya,
sits on abundant reserves of brackish ground water; however, due to its high levels of total dissolved solids
(TDS), this water is currently unusable for agriculture or human consumption. The designed system will
be installed in this land, and Organic Essentials Limited will manage, with the initial support and
consultation from Winddrinker Holdings, the daily financial, marketing, and distribution operations of the
project. Some of the produced water by the system will be used by Mr. Gasston for drip irrigation and water
efficient greenhouses [29].
2.2.1.6 Users (Operation and maintenance)
The system has been designed with the goal of keeping its operation and maintenance tasks as simple as
possible; however, it still comprises some technologies, especially in the desalination process, that are
likely to be unfamiliar to the inhabitants of the rural community of Kilifi. Winddrinker Holdings wants the
system to be operated and maintained by locals, and they predict this will generate employment for around
25 people of which 50% are expected to be women [29].
This block presents the Jua Kali as the locals that are expected to, after trained, be in charge of the daily
operation and maintenance of the system.
Jua Kali
Jua Kali is the local name given to people who work as a carpenter, welder, electrician or car mechanic. It
means “hot sun” in Swahili, and refers to the rough working conditions under which these workers do their
jobs [42]. They are part of the informal sector of Kenya’s economy, also called second economy, which
contributes with over 90% of the new jobs created annually. Despite being ignored by public institutions
and officials Kenya’s informal sector continues to grow [42]
There are various Jua Kali throughout the country that have engaged themselves in the design,
manufacturing and, in some cases, sales of small wind turbines (SWT). They use manual labour and
handmade tools to produce low cost goods that fit the market, and are usually working under materials
constraints [42].
39
Vanheule’s research revealed that Jua Kali initiated their small wind turbine activities more than 15 years
ago. Furthermore, eight individual cases were found of Jua Kali having independently designed a small wind
system from locally available, often scrap, materials. Whereas for some of them it remained an experiment
others have tried or realized to turn their SWT activities into a business [23].
2.2.1.7 Consumers
This block presents a brief description of the possible end-users of the technology, which are the consumers
of the fresh water to be produced by the system. These consumers are divided in three different market
segments that were recognized from the literature research, which are the community, the hotels/resorts
of the area and the farmers. The information regarding the market segments will be further developed in
Chapter 3, in which more detailed descriptions and the results of the on-field research are presented.
Community
Kenya inhabitants, especially in the rural areas of the country, suffer from serious problems of access to
clean drinking water. Central in the stakeholder analysis is the people of Kilifi in need of fresh water.
Hotels/Resorts
Kilifi is known as “resort town”, and much of their income comes from the tourists that visit the region
every year; however, this industry has been affected in the past due to the severe droughts and the difficulty
they have to offer clean water to its customers.
Farmers
Farming is also a very important activity in the coastal towns of Kenya such as Kilifi, and, as in the case of
the tourism industry, they have seen their activities limited due to the lack of access to proper water. They
have been forced to use different methods that increase the costs of their products.
2.2.1.8 Intermediaries
In order to develop a successful project it is necessary to build bridges with the communities in order to
avoid misunderstandings and to make sure the proposed ideas are accepted by the communities that
should not feel invaded or imposed. The best organizations to do this connection between the two parts
and work as their link are the NGO’s. This block includes only Choice Humanitarian, as it is, so far, the only
on-site non-governmental organization related to the project.
Choice Humanitarian
Founded in 1982, the NGO Choice Humanitarian connects motivated villagers to resources and tools that
allow them to change their lives. All of the community development projects that Choice Humanitarian
establishes in Kenya happen as a result of an extensive collaboration process with community and
government leadership. Sustainability and local adoption are the two most important criteria for
establishing development programs, particularly when new technologies are involved [43].
Ever since beginning their work in the Coast Province of Kenya more than 20 years ago, Choice
Humanitarian has been trying to find viable water solutions for the more than 100,000 inhabitants it serves.
Although their communities sit on huge reserves of brackish groundwater so far they have never
considered desalination as an option due to its elevated costs. Nevertheless, Winddrinker Holdings has
provided to them the first viable, affordable solution to serve these communities with fresh water via
desalination [25].
Winddrinker Holdings and Choice Humanitarian have an agreement in place to build up to 10 desalination
plants in the Coast Province of Kenya [29].
40
2.2.2 Possible future stakeholders
This section looks at possible future stakeholders that could be interesting for the further development of
the project. The options are many, but only three blocks will be considered as they could have the biggest
impact in the implementation of the system: technology development, knowledge development and
intermediaries. As in the previous section each actor’s core business will be described, followed by a small
explanation of what its role in the project could be.
2.2.2.1 Technology development
In this technology development section some organizations with which Winddrinker Holdings has already
made contact but that are not part of the project (yet) are presented.
These organizations could have an important impact in the near future of the Kilifi project and in the further
plans of Winddrinker Holdings in the region.
Kijito Wind Power Limited
Kijito Wind Power Limited is a Kenyan manufacturer of multi-bladed wind turbines with more than 20
years of experience, in which they have manufactured and sold over 500 systems [44].
At this moment the standard product of this company are not compatible with the system; however, they
expressed they are willing to adjust their manufacturing processes to be able to construct parts such as the
wind turbine tower and the rotor blades, which would be an important benefit in terms of maintenance
activities and the up-scaling process. In addition, Kijito Wind Power Limited could be a key partner for local
construction, technical assistance and the maintenance of the systems [29].
The WindFactory
The WindFactory is a fully owned Dutch subsidiary of Hoekstra Installatietechniek, a mechanical/electrical
engineering company specialized in sustainable energy installations. The WindFactory develops wind
driven systems and solar pumps that are sold mainly in developing countries.
The solar pumps engineered and sold by The WindFactory could provide an ideal supplement/back up to
the wind driven system designed for Kilifi, making it more reliable and resulting in a higher and more
constant production of fresh water.
2.2.2.2 Knowledge development
Even though the system has been tailored for the Kilifi conditions and that has been designed to be very
robust, failures are still inevitable. When a component fails or breaks down the people in charge of
managing the technology will make the necessary repairs; however, local universities and R&D centres
could be involved in monitoring the system’s operation to improve it if necessary, especially when these
institutes are close to the site where the system is installed and/or have related studies or ongoing
research. In addition, having access to the technology could be a very useful learning experience for the
students and/or researchers, as it would give them the opportunity of gaining some hands-on experience.
This section is divided in two parts: institutes that have related studies or research and institutes that are
close to the implementation site, being the second group considered as a more interesting option.

Related research
University of Nairobi (UoN)
The University of Nairobi, located at the Country’s capital and most populated city, already established a
small wind turbine research program in the seventies, and has also been involved in a community
experiment with locally manufactured wind turbines [23].
41
The UoN is divided in six colleges: Architecture and Engineering, Agriculture and Veterinary Sciences,
Biological and Physical Sciences, Health Sciences, Humanities and Social Sciences, and Education and
External Studies, some of which offer undergraduate and graduate studies related to the system such as a
Certificate in Renewable Energy and Bachelor and Master programs in Climate Change and Development,
Civil Engineering and Mechanical Engineering, In addition, wind energy courses are also provided to the
students [45].
Jomo Kenyatta University of Agriculture and Technology (JKUAT)
Located in Juja, very close to Nairobi, the Jomo Kenyatta University of Agriculture and Technology (JKUAT)
has been involved in wind energy assessments and a demonstration pilot in 2003. Next to the fact that they
offer wind energy teaching, JKUAT is establishing a program to develop and improve their capacity on
renewable energy technologies, including small wind turbines. The JKUAT has the goal of producing
designs that can be locally built, maintained and repaired by rural Jua Kali [23].
The JKUAT is divided in 3 colleges (Engineering and Technology, Health Sciences and Pure and Applied
Sciences), 8 schools (Architecture and Building Science; Human Resource Development; Mechanical,
Manufacturing and Materials Engineering; Civil Engineering and Geomatic Engineering; Electrical,
Electronic and Information Engineering; Law; Open, Distance and eLearning; and Computing and
Information Technology) and a Faculty of Agriculture, some of them offering, as in the case of the UoN,
undergraduate and graduate programs related to different aspects of the wind driven water desalination
plant. In addition, an Institute of Energy and Environmental technology was already established in JKUAT
in 1990 to carry out research and training in energy and environmental technologies [46].

Proximity
Pwani University
More interesting for the system is the option of research centres near to the place where the system will be
operating such as Pwani University, located in the town of Kilifi capital of the Kilifi County and just some
minutes away of the place where the system will be installed.
Since its foundation in 2007 Pwani University has been growing and expanding its array of courses offered
and the general service to the community. Currently it has the following schools:
 School of Humanities and Social Sciences
 School of Pure and Applied Sciences
 School of Agricultural and Environmental Sciences
 School of Education
 School of Graduate Studies
Although there is no specific course on water management or sustainable energy technologies, the School
of Pure and Applied Sciences and the School of Agricultural and Environmental Sciences could be interested
in using the installed system as a learning experience for some of their courses.
The School of Pure and Applied Sciences is divided in 5 departments: chemistry and biochemistry,
biological sciences, mathematics and physics, nursing and public health and biomedical sciences, while the
School of Agricultural and Environmental Sciences is divided in 3 departments: animal science, crop
sciences and environmental science. The environmental sciences department of the School of Agricultural
and Environmental Sciences could be particularly interested in getting involved with the system [47].
2.2.2.3 Intermediaries
Working together with more intermediaries such as Choice Humanitarian would allow Winddrinker
Holdings to reach more communities in the area of Kilifi.
Among the non-governmental organizations working in the area that were interviewed by the author of
this report during the field work for the market research (Chapter 3, section 3.3.1.3) two look like very
interesting options: World Vision and Plan International.
42
World Vision
World Vision (WV) is a Christian humanitarian organization dedicated to working with children, families
and their communities worldwide to reach their full potential by tackling the root causes of poverty and
injustice. This work with needy communities is done in partnership with donors, other humanitarian
development partners, Government bodies, Faith Based organizations, grassroots organizations and actors
and private sector partners. World Vision works in nearly 100 countries around the world, serving all
people, regardless of religion, race, ethnicity or gender [48].
One of these countries is Kenya, in which World Vision has been working for 40 years. World Vision Kenya
implements its activities through Area Development Programs (ADPs) as an entry point within the targeted
communities. The organisation has helped to strengthen the well-being of children and communities in 57
programmes spread across 35 out of 47 counties nationwide, reaching about 3,000,000 Kenyans including
clients of VisionFund Kenya, a microfinance subsidiary of World Vision that provides economic
empowerment to rural communities extending its financial services to 33 ADPs of World Vision Kenya.
VisionFund seeks to build social and financial knowledge among rural communities for both long and short
term financial stability
World Vision’s priority programme interventions in Kenya include Food Security, Economic Development
(Small Scale Enterprise), Education, Health, HIV & AIDS, Nutrition, Public Policy & Advocacy, Humanitarian
Emergency Response and, especially important for the project to be developed in Kilifi, Water, Sanitation
& Hygiene (WASH) [49].
Plan International
With the vision of a world in which all children realise their full potential in societies that respect people's
rights and dignity, Plan International (PLAN) was founded over 75 years ago, and is one of the oldest and
largest children's development organisations in the world. PLAN is independent, with no religious, political
or governmental affiliations, and they work in 51 developing countries across Africa, Asia and the Americas
to promote child rights and lift millions of children out of poverty [50].
PLAN has worked in Kenya since 1982, helping poor children to access their rights to health, education,
sanitation and protection, and today more than 800,000 people in community-based organisations (CBOs)
and children’s clubs, as well as farmers, youth and women’s groups benefit from their work. PLAN Kenya
implements programmes across the Eastern, Nyanza and Nairobi provinces, and their main activities
involve child survival, education, HIV and AIDS prevention, and sanitation, which could be a reason to work
together with Winddrinker Holdings in the Kilifi desalination project, especially because PLAN Kenya has,
besides the Country Office in Nairobi, seven programme units in Kisumu, Bondo, Homa Bay, Tharaka,
Machakos, Kwale and the place where the system will be installed: Kilifi [51].
The Plan Kilifi Programme Unit started operating in 1995 and works with 21 community based
organisations (CBOs) in the Kilifi and Ganze counties. It has sponsored 9,363 children through health,
education, livelihood and protection programmes [52].
2.3 Summary of the stakeholders analysis
From the stakeholders analysis it can be seen that even though this is a project proposed by a small Dutch
social enterprise, there are many actors involved, and Winddrinker Holdings, its initiator, is the most
important one. It is the organization in charge of bringing everything together, and its presence on two of
the presented blocks (technology development, funding) is one proof of that. The stakeholders were
divided in 8 blocks: technology development, knowledge development, funding, government, owner, users,
intermediaries and consumers.
The technology development block is complete, as each component of the wind driven reverse osmosis
system has an actor related to it: Hatenboer Water provides the reverse osmosis array, CAT Pumps is in
charge of the pumping equipment (added after design decisions to be described in Chapter 4 were made),
and Bertus Dijkstra is responsible of the wind turbine and the transmission system. Winddrinker Holdings
is, one more time, in charge of coordinating the project and putting all the pieces together.
43
A similar situation can be found in the knowledge development block, in which Hatenboer Water and
Bertus Dijsktra play important roles once again by providing their expertise and continuous research on
reverse osmosis and windpumps, respectively, to improve the system’s operation, while another
stakeholder must be highlighted: Delft University of Technology (TU Delft).
After its 2008 Curaçao prototype, developed together with Hatenboer Water, TU Delft researchers decided
to continue exploring ways of driving a reverse osmosis pump with a wind turbine using only mechanical
components. This idea resulted in the start of the Winddrinker Holdings initiative. Other actor in the
knowledge development block is IHC MERWEDE, whom experience in mechanical applications will be used
during the system’s design and assembling phases. Interestingly, all the actors of this block are also part of
other blocks, namely technology development or funding.
Winddrinker Holdings is a social enterprise, and therefore getting financial support is vital for the success
of the projects they develop. In the funding block there are some actors already mentioned in other blocks
such as Winddrinker Holdings, which is the main fund raising organization, TU Delft, which organizes
fundraising activities and provides an important network, and IHC MERWEDE, which, through its
Foundation, provides an economical support. In this block also strictly financial partners such as Aqua for
All, which was already involved with Winddrinker Holdings in the Somalialand project of 2011, Hivos, and
TEDx Amsterdam can be found. More stakeholders in this block would always be beneficial for the project.
In the stakeholders analysis it is also very important to consider the Kenyan Government, which plays an
important role in any project to be developed in the country, as it happens in most African countries. The
proposed wind driven reverse osmosis desalination system it’s not the exemption. The Government’s block
is divided in two parts: energy and, more importantly, water.
On the energy side there is the Ministry of Energy responsible for the energy policy development, the Rural
Electrification Agency in charge of powering the isolated communities of Kenya by either grid extension or
off-grid/stand-alone projects and the promotion of renewable energy technologies throughout the country,
and the Energy Regulatory Commission in charge of setting the regulations and making sure they are
complied, including those for renewable energy technologies. Finally, the Meteorological Department is
responsible for measuring wind speeds throughout the country.
On the water side there have been many changes since the 2002 Water Act, which was instrumental in
decentralizing Kenya’s water supply and sanitation services and creating the current institutional
framework. Currently the highest authority is the Ministry of Water and Irrigation, which was created in
2003 following a separation from the Ministry of Environment and Natural Resources with the aim of
consolidating the responsibility for the management and development of water resources under a single
institution. Then there is the Water Service Regulatory Board in charge of the regulation of water supply
and sanitation services, the Water Services Trust Fund in charge of mobilizing government and donor funds
for water supply in poor areas, and the National Water Conservation and Pipeline Corporation in charge of
the development and management of water infrastructures.
In Kilifi, any water-related project will have to go through the Coast Water Service Board (CWSB), one of
the seven Water Services Boards, which is a government subcontractor responsible for water distribution
and sanitation in the Coast Region of the country. Finally, the Kilifi-Mariakani Water and Sewerage
Company (KIMAWASCO) is the water service provider of the area, the organization in charge of providing
the water and sanitation services on performance basis at the town/community level. Its pipes are fed from
2 main sources: the Mzima springs and the Baricho water works.
As it can be seen, there are lot of governmental institutions that can affect the development of the project,
which in a country with high levels of corruption, bureaucracy and mistrust, is not an ideal situation;
however, if things are done correctly no problems should arise. The most important governmental actors
for the Kilifi project are KIMAWASCO and the CWSB, as they are the entities that will finally approve or
reject the proposed system.
Even though Winddrinker Holdings will be closely related to the system’s installation and operation,
especially at the beginning, is Organic Essentials Limited, the local partner, who will own the system, and
is therefore the only actor in the owners block. They will manage, with the initial support and consultation
from Winddrinker Holdings, the daily financial, marketing and distribution operations of the project. The
44
people in charge of operating and maintaining the system will be local Jua Kali, who will be trained on how
to work with all the components. As in the case of the owners block, the users block is composed by only
one actor, but this does not have to be seen as a negative aspect.
The possible end-users of the system, the consumers of the fresh water, are divided in the three market
segments presented in this block: the community, the hotels and resorts, and the farmers. The unreliable
and not always clean water provided by the municipality affects the health of the inhabitants of Kilifi as
well as the operation of the hotels/resorts and the farms, which are the most important economic activities
of the region. A more detailed explanation of the consumers block can be found on the market research to
be presented in Chapter 3.
Finally there is the intermediaries block, which also has, so far, only one stakeholder. Choice Humanitarian
will operate as the link between Winddrinker Holdings and the communities Kilifi, as they have been
working in Kenya for more than 20 years. The two organizations have an agreement in place to build up to
10 desalination plants in the Coast Province of the country. If Winddrinker Holdings wants their product
to reach more communities in the area, a bigger group of intermediaries organizations such as nongovernmental organizations or international development organizations are definitely required in this
block.
A study of possible interesting future stakeholders was also developed in this chapter, but only the
technology development, the knowledge development and the intermediaries blocks were considered. In
the technology development block two actors can be found: Kijito Wind Power Limited and The
WindFactory. Kijito is a Kenyan manufacturer of multi-bladed windmills that could be a key partner for
local construction, technical assistance and the maintenance of the systems, while The WindFactory is a
mechanical/electrical engineering company specialized in sustainable energy installations that develop
wind driven systems and solar pumps that are sold mainly in developing countries, and which could
support the designed system making it more reliable.
The knowledge development block was created with the purpose of looking for local universities and
research centres that could be interested in getting involved with the project to monitor its operation and
do the necessary improvements and repairs while having a hands-on learning experience in the process.
This block is divided in two sections: related research and proximity.
In the related research part the institutions considered were the University of Nairobi (UoN) and the Jomo
Kenyatta University of Agriculture and Technology (JKUAT), both of them located in the capital of the
country, Nairobi, or its surroundings. The UoN already established a small wind turbine research program
in the seventies and has been involved in a community experiment with locally manufactured turbines,
while JKUAT has been involved in wind energy assessments and a demonstration pilot in the past. Next to
the fact that they offer wind energy teaching, JKUAT is also establishing a program to develop and improve
their capacity on renewable energy technologies, including small wind turbines, and has the goal of
producing designs that can be locally built, maintained and repaired by rural Jua Kali.
The only institution considered for its proximity to the installation place was the Pwani University, which
has been growing since its foundation in 2007 and expanding the array of courses offered. Although there
is yet no specific course on water management or sustainable energy technologies, the School of Pure and
Applied Sciences and especially the School of Agricultural and Environmental Sciences could be interested
in using the installed system as a learning experience for some of their courses; however, the involvement
of any of these institutions has to be further studied and consulted with Winddrinker Holdings and other
related actors.
In the intermediaries block two organizations were considered as possible future stakeholders: World
Vision and Plan International, both of them were interviewed for the market research (Chapter 3).
Although they have different approaches, the two organizations focus in helping the children of the
developing world, and have been working in Kenya, and specifically Kilifi, for many years, developing and
supporting projects in, among many other things, water, sanitation and hygiene. A partnership between
these organizations and Winddrinker Holdings could be beneficial for all the parts involved.
Market research
3
45
Market research
In this chapter the market for the fresh desalinated water produced by the system is studied, through a
literature research and then with interviews, surveys and observations held on the place where the plant
will be installed.
The reason behind this market research is the interest of knowing if there is a real need for the product, if
it will be accepted and if people will be willing to pay for it, as it would be useless to install the system if no
customers are expected. It has been proven that dumping a technology on a developing country without a
proper assessment of its possibilities brings more harm than good.
As some values to be found throughout the chapter are in Kenyan schillings, the national currency of the
country, it is important for the reader to know the conversion to an international currency (20/09/2014):
1 𝐾𝑒𝑛𝑦𝑎𝑛 𝑠𝑐ℎ𝑖𝑙𝑙𝑖𝑛𝑔 = 0.0089 𝐸𝑢𝑟𝑜𝑠
At the beginning of the chapter the market segments are presented, in which the different groups of
possible customers are described first from the literature research and then from the field work. Then a
section is dedicated to describe Kilifi-Mariakani Water and Sewerage Company (KIMAWASCO), the local
water service provider, which was interviewed on site. In the third part of the chapter alternative projects
that have been initiated to solve the water problem in Kilifi are described, and in the fourth the results of
the interview held on site with Dutch Water Limited (DWL), the biggest company on water desalination in
the area of Mombasa, is presented. Finally, in the last section, a summary of the chapter is used to
concentrate all the information gathered.
3.1 Market segments
Through different reports, articles and websites the context in which the system will be implemented was
studied, and three different market segments were identified: community, hotels/resorts and farmers.
They are presented in Figure 4.
Figure 4 - Market segments for the designed system in Kilifi, Kenya
Each market segment is presented in this section with a description that resulted from the aforementioned
literature research and the first-hand information obtained from different interviews and surveys and the
observation held on site during the field-work phase of the project.
Market research
46
3.1.1 Community
Climate change is increasing average temperatures and causing draughts and, due to their already warm
weather, agriculture dependence and low incomes, developing countries are being the most affected ones,
and Kenya is not the exception.
In 1974, the Kenyan government put in place plans to install drinkable water facilities within walking
distance of every Kenyan home by the year 2000; however, this goal was not achieved and today almost
50% of Kenyans living in the rural areas do not have access to it. This problem is particularly bad in the
Coast Province in which in 2013, due to water shortages, only about 35% of the area’s population got water
from the Coast Water Services Board (described in section 2.2.1.4) [29].
Coastal urban centres have sparse piping systems, and those that are in place loose nearly 50% of the water
due to leakages along the way. This lack of proper infrastructure results in most of the residents being
forced to collect water from contaminated sources or purchase expensive bottled water.
Aware of this critical situation the water sector underwent through a reform when the Water Act No. 8 of
2002 was passed. This Act decentralized the water provision and created a new institutional framework
with the goal of increasing the access to clean water for the Kenyans.
To find out more about the situation of the water in the communities of Kilifi three different methods were
used on the on-field research: a survey with the community, a survey with local shops and interviews with
NGOs and IDOs. Different things were learned from each, and the results are presented in the next sections.
3.1.1.1 Community survey
In order to find out the expectations Winddrinker Holdings should have with the local communities of Kilifi
a survey was conducted on site with the goal of understanding the current water situation of the inhabitants
of this part of the country, as well as to identify the knowledge they have about desalinated water, if they
would consume it and how much would they be willing to pay for it.
The survey was done to two different groups of 25 persons each: the first group was formed by people
found at the town market and the bus station, while the second group was formed by people found at
Tuskys, the only supermarket that can be found in Kilifi. As Tuskys has products at higher prices than the
small stores and kiosks spread in town the people found there are expected to have a higher acquisitive
power. For convenience these groups will be called Group 1 and Group 2, respectively.
The results of the surveys (Appendix 1) show that the big majority of the Group 1 gets their water from the
tap, which is provided by the Municipality through KIMAWASCO at a very low price, while some of them
fetch it from a close well or river and some buy it from the store (mineral and desalinated). Most of the
people also claimed to know the source of the water, and those who did not are apparently interested on
finding out. Even though the general recommendation was not to drink water from the tap still 18 of the 25
respondents (72%) said that they are satisfied with the quality of the water they are getting. The ones that
are not satisfied mentioned dirtiness as the main reason.
Most of the people from this group did not know what desalinated water is, but when the process was
explained to them 20 out of 25 (80%) said they would consume it, while the rest would not do it because
they do not trust on it. The amount of money they would be willing to pay for it, in comparison to what they
are paying right now, was the question with the more balanced answers, as “paying the same amount” was
the most repeated response, but was followed very close by “less” and also “more”.
In group 2 the results were surprisingly similar, but still some differences can be found. Once again the tap
was the most common option of getting the water, but none of the surveyed of this group was fetching it.
Also in this case most of the people, in a less amount than in the first group, claimed to know the source of
the water they are getting, but the ones that did not were less interested in learning than in the previous
case. One more time most of the people (19 out of 25) were satisfied with the quality of the water they are
getting, but the ones that are not added “salty” and “unreliable” as some of the reasons.
Market research
47
The bigger differences between the answers of this group in comparison to Group 1 were in the desalinated
water questions, as in this case most people knew what it is and absolutely all of them said that they would
consume it. Most of the people from this group are willing to pay for the desalinated water the same price
they are currently paying for their tap water.
3.1.1.2 Shops survey
Ideally some of the produced water by the system will be sold to the inhabitants of Kilifi through different
shops or kiosks located in the town.
The survey with the shops was held with the goal of finding out if they are selling water, at which price,
how they get it and if they know its source. Also, the feedback they have had from the customers regarding
the quality of the product and the importance of selling water for their shops was asked. Finally, questions
about desalinated water were made to hear their opinion in the subject. Shops know, better than anyone,
how the water market moves in Kilifi, and they can provide a perspective of it that cannot be found in the
literature research.
The initial idea was to interview different shops; however, the owners were usually not there and for some
reason most of the employees refused to be recorded. In addition, the shops were in very noisy places at
the town, which interfered with the proper recording of the conversation. Also, as they are small kiosks,
they did not have the time to sit and go through all the questions with detailed answers, so at the end it was
decided to transform the interviews into a new questionnaire.
The respondents include small shops (P.C.I, Sunshine Digital, Taquaa Shop, Mwireri, Al-Iman Shop and
Jumbe) as well as Tuskys, the only supermarket in town.
All the surveyed shops are selling water (results in Appendix 1): 3 of them are selling “regular” mineral
water and 4 are selling desalinated water, mainly from the Dutch Water Limited and Pride brands. In all of
the cases a distributor brings the water to the shop and then they put it on sale, and most of the polled do
not know the source of it. The question regarding the market segments had similar answers, as 4 of the
respondents said they could identify different types of buyers but 3 said they could not. From the 7
respondents 5 claimed to know what desalinated water is, and the majority thinks people would be willing
to pay for it the same price in comparison to what they are currently spending. None of the surveyed knew
about any water-related project being developed in the area.
3.1.1.3 Non-Governmental/International Development Organizations interviews
Interviews were done with different organizations that work closely with the communities of Kilifi that will
eventually benefit from the water produced by the system. These organizations know the communities very
well and tend to work as the link between them and any company that wants to develop a project in the
area.
The interviews were made with the goal of having a better understanding of how the communities of the
area live, how to approach them and what challenges are to be expected, as well as to try to find out if, in
the opinion of these interviewees, the communities will accept the system and will be interested in its
product. Questions about the organizations they represent and their knowledge about other water-related
projects in the area were also included. The interviewed organizations were: Moving the Goalposts (MTGP),
World Vision (WV), Plan International (PLAN) and KOMAZA, and the transcriptions of the interviews can
be found in Appendix 2.
The organization MTPG has been working in the area since 2001, WV since 2007, PLAN since 1995 and
KOMAZA has been around for the last 8 years. All the interviewed organizations have different goals and
different ways of doing things. From this group only WV and PLAN are doing, among many other things,
water-related projects, while MTGP and KOMAZA are focusing their efforts on the girls and young women,
and the farmers, respectively; however, water is still in their agenda, as MTGP uses football to teach the
girls about WASH while in the KOMAZA activities water plays a fundamental role. All the organizations
mentioned the municipality tap and the wells as the main sources of water for the communities, but they
acknowledged it is not a reliable source and it does not reach everybody, highlighting the necessity of
developing projects to help the people that do not have access to clean water.
Market research
48
With funding from international donors PLAN is extending the main pipeline at three different points to
send water to some communities in need. Once the pipelines are built a water committee, which will
manage the water distribution, is installed by the community. In the case of WV different approaches are
being used to tackle the water problem: in the sanitation and hygiene aspects awareness around issues
such as the proper use of toilettes, hand washing and treatment of water is being created, while in the water
access topic water kiosks have been recently built. WV provides the community with materials to build the
kiosks in exchange of the land where it will be placed and the labour required to build the infrastructure.
As in the case of the PLAN pipe extension project, after the structure is completed the community itself will
be in charge of managing the water distribution. None of the interviewed organizations knew anything
about other important water related projects besides the ones already mentioned.
In the way of approaching the communities all the organizations highlighted the importance of involving
and communicating with the community since the beginning of the project and throughout the entire
process, as well as using the community elders, chiefs or leaders, or even other important community
members such as the community health workers, to reach the rest of the people. Communities are very
receptive, said Ms. Amakobe from MTGP, while Ms. Moseti from WV emphasize the importance of not
assuming things, training the community on the different required skills and supervising them
continuously. Mr. Baya from PLAN claimed that the meetings with the community are very important and
that having a Swahili translator for a better exchange is vital. Finally Mr. Axe, acknowledging they have
some gaps in this aspect, is trying a different approach with KOMAZA and is currently looking at using a
platform of communication with the farmers over feature phones,
In the difficulties of approaching the communities the responses were various, and all of them very useful.
Ms. Amakobe from MTGP claimed that, especially when a mzungu (Swahili word for white person) is in
charge of the project, communities will be constantly asking for money, which can lead to stressful times.
In the opinion of Ms. Moseti the biggest problem is getting rid of what she called the “dependence
syndrome”, referring to the communities looking at the organizations as the big brother that has to take
care of everything without their support and without them being held responsible of the ownership. For
Mr. Baya from PLAN the biggest problem is related to the commitment of the communities, as he gave the
example of the situation in which some men are the ones in charge of making decisions but at the same
time they are not willing to leave the farms to go to a project meeting, and this interferes with the whole
process complicating the completion of projects. Finally Mr. Axe said the biggest challenges he has been
faced to is gaging expectations and maintaining the patience of the communities.
As barriers for the business of affordable water the lack of funding from the government, the scarcity of
rains, the personalization of the projects, the lack of regulations, restrictions and enforcement, and the
poverty of the communities were mentioned, while as drivers the organizations talked about the passion
and the willingness to work hard of some of the members of the communities as well as the good amount
of water that can be found in the area.
Finally, in the question about their opinion of the system’s product and if they think it will be
accepted/consumed by the communities, the responses can be summarized in: as long as the community is
educated, involved and informed and awareness is created with the support of local leaders, the
introduction of the product should have successful results.
3.1.2 Hotel/Resorts
Hosting over 1 million visitors every year tourism is a major industry in Kenya. Particularly along the coast
of the country it is the most important economic activity.
In 2010 a drought near the city of Mombasa forced hotel owners to ask the government to not include them
in the rationing plan they set up and to give them a regular water supply in order to avoid closures and
operational problems. These coastal water shortages continue to threaten the Kenyan tourism sector
nowadays, and they are in need of solutions.
To find out more about the water situation this industry faces interviews were held on site with hotels and
resorts owners and managers. In the interviews questions about problems they have had in the past with
the access to clean water, how these problems affected them, how did they solve these issues and what are
their expectations for the future in this topic were also done. The interviews were also used to evaluate
Market research
49
their interest in the product of the system and to find out the impact of the delicate political situation of the
country. Are hotels and resorts a possible end-user of the system?
The results of the interviews are explained in the next section, while a complete transcription of them can
be found in Appendix 2.
3.1.2.1 Hotel managers interviews
The interviewed hotels includes a big range that goes from the small Water Gate Hotel located in town to
Mnarani Club, the biggest hotel in the area. The Bofa Beach Resort Kilifi, the Kilifi Bay Beach Resort, whose
owner also runs the Baobab Sea Lodge, and the Eco-lodge Backpackers Distant Relatives were also part of
the interviews.
The water consumption of each hotel depends very much on its size and the season, going from 0.5 cubic
meters a day in the case of Bofa to 100 cubic meters a day in the case of Mnarani Club. The use is very
similar in all the cases: cooking, cleaning, showers, pool, laundry and garden. Just in the case of the Distant
Relatives the toilettes were not included, as they use compost toilettes. Water Gate does not have a pool.
All the hotels receive water from the municipality pipes, which is metered and paid on a monthly basis, and
also have a safe tank to cover some of their needs when the water is not coming, which in some cases, such
as Bofa Hotel, is between 3 and 4 days per week. Water Gate and Distant Relatives also have their own well
that can be used when there is some water scarcity, and the latter one has also a system to collect rain
water. All of the interviewed knew the source of the water that comes through the pipes.
After having some problems with the water supply and some complains about its quality Mnarani Club
decided to invest, two years ago, in their own desalination plant. This installation provides them between
75 and 80 cubic meters of fresh water every day, which is supplemented in a small amount with water from
the municipality. Mr. Venter, the manager of the hotel, claims that they are saving a very big amount of
money and also that the quality is better now (confirmed by tests).
When the other four hotels were asked for the quality of the water they are getting from the municipality
and how they have solved the water supply cuts in the past different answers were obtained. In the case of
Bofa they are satisfied with the quality of the water, but they also acknowledge not knowing too much of
the topic. They also claim not to have too many problems with the provision of water. When they had an
issue a couple of weeks before the interview they just had to call the municipality who sent their people to
fix it, probably a blockage, according to its manager Mr. Karanja. However, Kilifi Bay Beach Resort
experience has been completely different, as they have suffered a very unreliable system that has let the
hotel without water very frequently forcing them to use water bowsers that cost too much money,
especially because, according to the general manager of the hotel, Mr. Njoroge, the cuts are usually
happening during the high season. In the interview Mr. Njoroge also expressed that the water that comes
from the pipe is not treated and therefore they have to put chlorine on it before pumping it to the
installations to make sure the hotel clients are satisfied. In the Water Gate they are also not satisfied with
the quality of the water which they claim to be too dirty to use, forcing them to use chemicals that also
involve more costs. In the case of Distant Relatives they think the quality of the water is fine, although every
once in a while it blocks the filters at the entrance of the pipes which means it is not very clean; however,
they have had several water scarcity problems in the past, including a water shortage of 3 months in 2013.
They claim that continuing the hostel normal operation during those days is a huge challenge, as they are
forced to order over-priced water bowsers on a daily basis; and the problem does not stop there as, due to
low amount of private bowser in the area, they have to chase the bowser to make sure it does not get
stopped by other people that is looking for water.
The interviewees were asked what would be, in their opinion, an ideal solution to solve the water problem
of the hotels, and the answers were, once again, different. In Bofa Hotel they replied that the only solution
was to get a bigger tank to save more water when it is entering, while in Kilifi Bay Beach Resort they have
already tried different things such as boreholes, but all they got was a very salty water that damaged some
of the pipes of their facilities. Mr. Njoroge claimed they are always advocating for water-related projects in
the area. Now they do not know how to solve the water problem, but they think the government, at a county
and a national level, should look at this. He claims that the water problem is not only affecting the hotels,
but also all the Kilifi inhabitants. He said the town is growing but the infrastructure is very old and incapable
of serving everybody, that when water is pumped from its source it usually takes 3 to 4 days to arrive and
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that when it finally does it is at a very low pressure. In this topic Mr. Venter from Mnarani Club said that
there are areas, especially in the Baobab side, where people have not had water for more than a year, and
that the people from the Municipality does not know the exact place where the pipes are running, as they
were laid in the late 60's or 70's and by then the area was under-developed. Now houses have been built in
the area and everything is more confusing. The people from Water Gate agreed with Mr. Njoroge in the fact
that the capacity of KIMAWASCO is not enough for the growing population, but they also proposed
integrating the private sector into the water provision business. The owners of Distant Relatives think the
problem is the disorganization of KIMAWASCO, as nobody knows who is in charge of what, the structure is
terrible and there is a lot of diverting. It's a private company at the end and not a public service, they
claimed.
For Mr. Venter the answer is easy: desalination. As it was already mentioned, Mnarani Club picked up 2
years ago that the water supply in the area was not very steady and they decided to solve this by having
their own desalination plant. The water that enters the plant comes from a big mixing tank which receives
water from two boreholes located on the resort; one is 20 meters deep while the other one is 50 meters
deep. From the mixing tank the water goes through some filtering process and into another holding tank,
and from there it goes to the reverse osmosis array where it is divided in fresh water and waste water. The
fresh water goes straight into an underground tank and from there to the rooms, while the waste water is
sent back to the ocean. The plant is powered by electrical motors which need to be replaced every 2 to 3
years, however the cost of this in comparison to the amount of money they save is minimum. When asked
about other desalination projects in the area he said that Mandarini, another hotel that is just opening, also
got a big desalination plant, and that he believes that in Vipingo, an area near to Kilifi, they are also looking
at this process as an option.
In Bofa and Water Gate they did not know what desalinated water is, but when the process was explained
to them both said they would be open to give it a try and that they can pay the same money they are
currently paying, but if the price is lower it would be even better. In the Bofa Hotel they think that if the
plant is powered by renewables it would not affect the price they are willing to pay for it, but in Water Gate
they think that there should be a reduction in the price as the power used comes from the nature. In Kilifi
Bay Beach Resort they knew what desalination is, and they said they would be more than willing to use it
and even pay more than what they are paying right now, as long as it is a reliable source. The fact that the
plant would be powered by renewables does not affect their answer, as Mr. Njoroge highlights again that
they would support such idea, or any other idea, that helps them with the water situation. In Distant
Relatives they recognized the process when they heard the explanation, and they would definitely be
interested in something like that, they claimed, especially if they can do it with their own well water which
is currently too salty. To the question about if the price they are willing to pay for it would change because
of the fact the plant is powered by renewable sources they say that they would like to say yes because it
goes with the philosophy and ideology of the place, but that because their business is so young anything
that is going to cost more to them is a difficult thing to approve. They would have to do some calculations
before giving a definitive answer.
Finally questions about the tourism industry were asked, and everybody talked about the complicated
situation the industry is facing right now and that severely affects the population of Kilifi. Mr. Njoroge from
Kilifi bay Beach Resort and Mr. Venter from Mnarani Club were the ones with more knowledge in the topic,
which makes sense as they are running the biggest hotels in the area. The only one that is still doing fairly
good considering the context is the Distant Relatives Eco-lodge Backpackers, as they are quite a unique
business and the type of travellers that go there pay less attention to the travel warnings and the general
issues that affect other hotels; however, they also acknowledge that it has been a terrible time for the
industry since Westgate (Westgate is the name people uses to talk about the terrorist attack that happened
in a shopping mall with that name in Nairobi in 2013).
According to Mr. Njoroge from Kilifi Bay Beach Resort 70% of the people in Kilifi depends, directly or
indirectly, on tourism. When the hotels are full the entire town is active, as the guests need transport, food,
entertainment and more. Even construction is related to tourism. Therefore when there is no business in
the hotels everybody in town suffers. In Kilifi there are no walk-in walk-out businesses like in Mombasa or
Nairobi. In Kilifi Bay Beach Resort the solution they found was to partner with conferences organizers, and
now they are getting a lot of domestic tourism that has resulted in a really important income for them.
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Apparently the hotels in the area were doing quite well in the previous years, but since last year it has been
really bad and now they are struggling badly. The reasons for this situation are many, being the Euro-zone
crisis one of them. According to Mr. Njoroge a lot of Italians used to go to the Kenyan Coast, especially to
places like Malindi, but not anymore. The only European market that is still strong is Germany, but even
they are starting to look to other, cheaper, destinations, because the high prices are, according to Mr.
Njoroge, other problem for the industry. He thinks the Government should do something about it. Other
important problem is the security, as many terrorism-related activities have occurred in the country,
especially the last few years after the Kenyan Government decided to fight the Somalis that were terrifying
the people, tourists included, at the north of the country in their shared border. The 2013 terrorist attack
at the Westgate shopping mall in Nairobi had really bad consequences for the industry. As Mr. Njoroge
explained, when people goes on holidays they want to relax, and not to be thinking that something bad can
happen in the streets. He also thinks the media has been part of the problem because, looking to sale more
than the competition, they tend to highlight news that give a bad image to the country and scare away the
possible tourists. Finally, he thinks more marketing is required, as it is important to show to the people
what the country, and in this particular case the coast, has to offer.
Regarding the numbers Mr. Venter from Mnarani Club said that pre-travel ban, or travel advisory, their
hotel was in a 50% occupancy and they had about 15,000 guests per year. Kilifi Bay Beach Resort and
Baobab Sea Lodge were also busy, as well as smaller hotels that attract more locals than international
tourists. Then Mr. Venter talked about Distant Relatives, which attracts a different crowd with their Ecolodge philosophy and, as it was already mentioned, has not suffered as much as the other hotels in the area.
He thinks that in total there were probably around 50,000 visitors in Kilifi per year. Now they see how, as
in the case of Kilifi Bay Beach Resort, the number of local guests is starting to peak up, and they need to rely
more on this. “Is always a blessing to have the local interest”, he claimed.
3.1.3 Farmers
Agriculture is, just behind tourism, the second most important activity in the coast region of Kenya;
however, farmers are dealing with the problem of not being able to expand their productivity due to the
lack of access to proper water. Groundwater is too salty and the frequent draughts makes them unable to
depend on rainwater collection; therefore, larger farmers are forced to invest in efficient green houses, drip
irrigation systems and other water efficient methods to produce water and fight the shortages, which
increases the price of their products. At times when water becomes particularly scarce and expensive these
farmers are forced to pay between USD 10 and 15 for a cubic litter of water. Even when in rainy seasons
farmers could still increase their yields with more affordable sources of consistent water [29].
Interviews were held on site with some farmers of the area with the goal of finding out their usage of water
(how much, what for, where it comes from, how much it costs, etc.), their opinion about the quality of this
water, its reliability and what would be an ideal solution for them. They were also asked about their opinion
about desalinated water. Finally, as in the case of the hotels and resorts interview, a question about the
industry situation was made.
In the next section the most important aspects of the interviews are presented, and a transcription of them
ca be found in Appendix 2.
3.1.3.1 Farmers interviews
The interviewed farmers were Warren Wilson (Kilifi Plantations), Ja Maina Wanjohi (Patbon Farm),
Chokkie Rama (Ramar Farm) and Robert Clarke (REA Vipingo Plantations Limited).
The amount of water used in the farm depends strongly on its size and the product. From this group REA
Vipingo Plantations Limited is the bigger farm, and it counts with 3 decorticator machines that use up to
60 cubic meters of water per hour, followed by Kilifi Plantations, Patbon Farm and ending up with Ramar
Farm, which is a small-scale farm that uses just 2 cubic meters per day.
Most of the farms use borehole water: Mr. Wilson has 6 wells and 80% of the water is consumed by the
animals while the remaining 20% is used on the decorticator machines. Mr. Wanjohi has 2 boreholes that
he uses for the agro-farming activities. Mr. Rama also has 2 boreholes that he is still not able to use, but
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once they are active they will be destined for irrigation purposes. Mr. Clarke has 15 boreholes, the biggest
one producing 40 cubic meters per hour. The water from 7 of the wells go to the factories and the remaining
go to the camp and housing, as they have around 6,000 people living there. Mr. Wilson and Mr. Clarke
clarified that the fact that the water comes from a borehole does not mean it is completely free, as there is
a price they have to pay for the license to pump out the water, which has a cost of 15 cents per cubic meter.
Besides the borehole water Mr. Wanjohi also collects rain water and buys around 400 cubic meters of water
per month from KIMAWASCO for human as well as cattle and poultry consumption, while Mr. Rama is still
using only municipality water, which he claims is too expensive for him. He is already making the necessary
arrangements to start using his boreholes, which he claims he already tested and are good for direct use.
When asked about the quality of the water they are using Mr. Wilson acknowledge that his wells have
brackish water. He says that a lot of the boreholes he uses have been in existence for a very long time and
the quality of the water has deteriorated. They did new boreholes recently and found that the quality is far
superior to the old ones. In other words, he is not satisfied, especially from a dairy point of view, as the
better the quality of the water the better the produced milk as well. In addition, this high salinity is also
affecting the machines, and he explained that every year they are forced to spend a lot of money in the
replacement of components that are corroded or rusted out by this water that eats everything very quickly.
He claimed that the suspended solids in the water are not an issue. He thinks it is certainly not the best
water, but at the same time is what they have and they have learned to live with it. In the case of Patbon
Farm Mr. Wanjohi said that, even though he knows the water is not very good, so far they do not have any
complains about it. Mr. Rama shares the same opinion. Mr. Clarke thinks the water is good for his
decortication machines, but not for human consumption. Before sending the water to the camps they are
adding chlorine to it, but he thinks is still not good enough and they are looking at the option of piping in
water from the Municipality.
Due to their high amount of wells Mr. Wilson and Mr. Clarke have never had water scarcity problems in the
past, although Mr. Wilson acknowledge that sometimes they got pushed against the wall. However, smaller
farms such as Patbon and Ramar do suffer from the water shortages, especially during the dry season. Mr.
Wanjohi said the these water supply cuts did not affect them because so far the collected rain water was
enough, but this is not the case of Mr. Rama, who basically could not produce the quality he is used to and
had to wait for KIMAWASCO to start pumping water again. He loses a lot of money when this happens.
Each of the interviewees has its own idea of an ideal solution for this water problem. Mr. Wilson said that
they have never considered cleaning the water until recently that they started discussing the possibility of
putting in a reverse osmosis plant, mainly because they are starting to process milk again; however, in his
personal opinion, the way he would deal with the water situation is through drilling lots of boreholes in the
farm spreading out the volume uptake across a much bigger area rather than relying on a few wells. He also
said that he would love to do recharge of the wells, but the problem is that this activity requires storing
water, which is very expensive considering the very large tanks and containers that would have to be built
in order to hold the massive water they get in the very short period of time of heavy rains (3 months). He
likes the idea of putting all back into the water table, directly: “Is not great, but in some ways you are
replenishing back”, he claimed. In Mr. Wanjohi’s opinion the Government should promote a policy that
supports the activity of collecting rain water, as he thinks the amount of water they get this way would be
more than enough but so far it is getting wasted. Mr. Rama only thinks on activating his 2 boreholes to not
have problems anymore, and Mr. Clarke is, as it was already mentioned, thinking on piping in water. He
said they have talked about reverse osmosis, but the discussion never went any further than that because
it was too expensive.
All the interviewees but Mr. Wanjohi knew what desalinated water is, and only Mr. Wilson said directly he
would not use it because it is too expensive to produce and at the moment the improvement of water quality
is not important enough to make him pay that difference, which, after doing some calculations, he
concluded was too big, If it would be for human consumption is different, but to pump it for the animals is
not worth it and they do not feel the urgency of making any changes, he claimed. He would have to do a cost
analysis to come up with a price he would be willing to pay for it, and the fact that the plant would be
powered by renewable energies does not affect his answer. He highlighted that, at the end of the day he is
a business man.
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Mr. Wanjohi said that he would try it and would pay for it in the case KIMAWASCO water starts being more
unreliable and his economic activity grows. He feels that the fact that the plant would be powered by
renewable energies should decrease the price of the water making it more affordable, while Mr. Rama
thinks desalination would be a good fit for him and, considering he is a small-scale farmer, the lower the
price the better, regardless of the source of energy used to power the plant. Also Mr. Clarke said he would
use it because in that way they would reach the standards of water they are aiming for. He is willing to pay
for it the same amount of money in comparison to the KIMAWASCO tap water, and he liked the idea of the
renewable energy powered plant, as he thinks that in their farm they have a lot of potential to produce
clean energy from biomass.
Finally the farmers were asked about the importance of their industry for the area and Mr. Wilson was very
clear: “Farming for Africans is everything”. He claims that 90% of the agriculture in Kenya is from smallscale farmers, and if an African has a farm he is happy, otherwise he is not. Agriculture is the life of an
African.
As it was already mentioned the largest and most important farm in Kilifi is REA Vipingo, which is doing
sisal. It has 10,000 acres, employs 1,300 permanent workers and have two nursery schools for the workers.
The second largest is, with 3,000 acres and 300 people employed, Kilifi Plantations. Everyone else is smallscale and they are doing subsistence farming, Mr. Wilson expressed.
Mr. Wanjohi feels farming is very important for Kilifi, as he believes one of the things that determine the
progress of a region is how well they do agriculture. Good farming could reduce the poverty index, he
highlighted, while Mr. Rama described the Kilifi farming industry as “quite big”. He has noticed that the
people in the area are very interested in farming, but he feels there should be a better communication
between the farmers.
3.2 Kilifi-Mariakani Water and Sewerage Company
As it was explained in section 2.2.1.4, the Kilifi-Mariakani Water and Sewerage Company (KIMAWASCO) is
the Water Service Provider (WSP) operating in Kilifi. The WSP’s are commercially oriented public
enterprises, typically owned by local authorities, contracted by the Water Service Board (WSB) to provide
the water and sanitation services on performance basis at town/community level. They operate within the
regulatory framework and its tariffs have been approved by the Water Service Regulatory Board
(WASREB), which also establishes the standards on quality, service and performance that must be
complied by KIMAWASCO and any other WSP.
The WSBs are responsible for the efficient and economical provision of water and sewerage services within
their area of jurisdiction. There are seven WSB which cover the whole country and are responsible of
managing (maintaining, planning, and developing) the assets [39]. The Coast Water Service Board (CWSB)
is a parastatal under the Ministry of Water and Irrigation (MWI) responsible for the provision of Water and
Sewerage Services in the Coast Region of the country. Its area of jurisdiction coincides with the
administrative boundaries covering six counties, namely Mombasa, Kilifi, Kwale, Taita-Taveta, Lamu and
Tana River [40].
The water distribution network of KIMAWASCO has a total of 1,342 kilometers of pipes fed from 2 main
sources: the Mzima springs and the Baricho water works. The CWSB manages the main pipelines of these
sources and there are several off-takes along them. The Kilifi water area is supplied by the Lower Silala
Mwamkura off-take, which accounts for 45% of the water supplied to the KIMAWASCO area of operation
[41].
During the interviews with the market segments described in the previous section the name of
KIMAWASCO was very often mentioned, as most of the people from Kilifi depends on this organization to
get their water; however, some complains about its reliability and the quality of the water it provides were
also heard,
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An interview was held on site with Mr. Cornelious Mutai, KIMAWASCO Area Manager for Kilifi, with the
goal of finding out more about the organization, their products, customers, and what has to be done by any
organization that wants to start water-related projects in the area (the transcription of this interview can
be found in Appendix 2).
Mr. Mutai explained that the goal of KIMAWASCO, founded in 2006, is to supply water from Kilifi to
Mariakani, including the operation and maintenance of the water supply systems. They should be doing
sanitation and sewerage as well, but they have not started with it yet.
During the interviews with the different market segments it was mentioned several times that KIMAWASCO
charges its clients depending on their consumption, but nobody knew the scale they use by heart. Mr.
Cornelius confirmed this information and also clarified that they own the meters in the connections to each
client, which allows them to know the exact amount of consumed water. He also explained that
KIMAWASCO has domestic rates, commercial rates, institutional rates and kiosks rates. In the case of
domestic rates a system of blocks is used: if the consumption goes from 0 to 6 cubic meters a total of 300
schillings is charged, as this bracket serves mainly the poorer people. Then, from 7 to 20 cubic meters, 75
schillings per unit are charged, and from 21 to 50 cubic meters the unit has a price of 97.5 schillings. From
51 to 100 they charge 120 schillings per unit, and so on. The more you consume the more you pay. The
KIMAWASCO customers are therefore various, and they provide water to institutions, industries, schools,
communities and individual consumers. Anybody that wants to become a KIMAWASCO client has to go to
their offices and do an application procedure before getting the connection. The bulk number of water users
is, of course, the community, but meeting the bills is a very big challenge for a lot of them.
KIMAWASCO is in constant communication with its customers, Mr. Mutai claimed, as they are constantly
posting messages through their bills and giving them questionnaires. The company also has a website and
a hotline that can be used by the customers to solve any issue. Mr. Mutai also emphasized the fact that they
reach the communities through their local leaders. Communities also have different stations in the radio in
which, using their local language, KIMAWASCO communicates with their customers, and although not all
the interviewees were completely satisfied with the water service Mr. Mutai claimed that so far the
feedback has been very positive, especially in terms of complains, as they have been able to solve them in
very short periods of time. People are, in general terms, satisfied with their service, and their number of
clients increases every day.
The business plan of KIMAWASCO has suffered some changes since its foundation. Before 2006, when they
started to operate as a semi-private company, it was the government who was in charge of the water
services in the area. Now that they operate as a company, even though they are still under the government
policy, they need to cover other costs, so the water prices have increased. They have also become very strict
in the revenue collection because they do not get any subsidy from the government anymore. Everything
that enters is used to pay the operation of the company. Nevertheless, KIMAWASCO is not the most
important water authority in the area, as they have to respond to the Coast Water Service Board (CWSB),
a Government entity. The CWSB owns all the infrastructure on the coast and any water-related project or
development in the area has to go through them.
There are no other water service providers in Kilifi besides KIMAWASCO, Mr. Mutai said. There are some
organizations such as World Vision and Plan International, as well as some proposals from the
communities, private donors, the CDF (local parliament fund) and the County Council Government pushing
for projects, but at the end everything has to go through them and the CWSB. Anybody that wants to start
a project in the area needs to do it like this. If an organization that wants to start a project is going to use
tap water they might own the infrastructure, but they still have to communicate with KIMAWASCO. The
same process is required even if this organization will start a project that does not use the water flowing
through the pipes. Every water-related project is under the rules of KIMAWASCO and has to pay a fee.
When asked if he thinks the people in Kilifi is open to new products or services Mr. Mutai said that if the
proposal is prepared correctly and is explained in details to the people that will be affected by it there
should be no problems, and he highlighted the importance of communicating with the leaders of the
communities. Finally Mr. Mutai explained that the water they use comes from the Sabaki River and that
before the pumping it is filtered and chemicals are added to make sure the water is safe and consumable.
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3.3 Alternative water projects
From the literature research it was found that several organizations are already planning or developing
different projects to try to help the inhabitants of the county of Kilifi to solve their water problem. In this
section a brief explanation of these initiatives, including the organization behind it and the technology or
method used, are presented.
3.3.1 Chipande Water Project
The United Nations Industrial Development Organization (UNIDO), via its Collaborative Actions for
Sustainable Tourism (COAST) initiative, has partnered with the Slovenian Government to develop the
Chipande Water Project (CCWP) in the Chipande-Matsangoni area of the Kilifi County, Kenya, Watamu
Demo Site Area. The project aims not only to provide a solution to the clean water problem but also to be a
source of income to a marginalized community, representing an investment opportunity that combines a
highly attractive return on investment with social value [53].
The project consists of a reverse osmosis water purification plant housed in a shipping container and
powered by a wind turbine and solar panels mounted on the container. This makes the renewable-resource
system cost-effective while reducing the endemic waterborne diseases in the area. The systems consists of
a reverse osmosis purification system, a micronic filtration, 10 solar panels of 100 watts, a 2.4 kilowatts
wind turbine, a 20 Deep-Cycle (solar) battery bank of 159 ampere hours and a 5 kilo-volt-ampere backup
generator. It is expected to produce up to 130 litters per hour [54].
3.3.2 Musichovweka Water Project
Initiated by the Kilifi programme area branch of the NGO Plan International (PLAN), the project consists
on the installation of water tanks to benefit schools in Kilifi. So far this project that operates as a Community
Based Organisation (CBO) has erected 5 water stands benefiting 4,000 people and a new phase is under
construction. At the water standpoints women sell the water to sponsor children for education, and they
have been able to paid examination fees for over 800 children and to purchase textbooks for secondary
school students. The CBO has also employed a metre reader for collecting data on a weekly basis to ensure
that what is sold tallies with the amount of water consumed for accountability [55].
3.3.3 Cash-Food for Assets
Cash For Assets (CFA) / Food For Assets (FFA) is a joint initiative between the World Food Programme
(WFP) and the Government of Kenya, in which communities under certain circumstances, such as Kilifi,
receive incentives in form of food or cash, which is aimed to work on household or community
assets/projects that improve their resilience to common shocks/hazards such as droughts or floods that
can result in hunger periods. One of the project goals is to improve access to water for both human and
livestock consumption as well as agricultural use. In the Kilifi region they have been doing this through the
rehabilitation (36,000 cubic meters in total) and construction (382,188 cubic meters in total) of water
pans/ponds from 3,000 to 15,000 cubic meters [56].
3.3.4 Sombeza Water and Sanitation Improvement Project (SWASIP)
The goal of the SWASIP is to improve the health status and living conditions of rural populations in the arid
and semi-arid areas of Kinango, Kaloleni and Kilifi districts in the Coast Province. SWASIP expands upon
Coastal Rural Support Programme (CRSP) of the Aga Khan Foundation interventions in the water sector by
focusing on projects about water for domestic and productive use as well as the introduction of a sanitation
component, both in terms of infrastructure for improved sanitation and health and hygiene promotion.
Designing, installing and ensuring appropriate use of sustainable infrastructure for domestic water use and
sanitation, including small farm reservoirs, rock catchment, roof water harvesting tanks and ventilated
improved pit "V.I.P" latrines are among SWASIP goals, which also focuses on enhancing community capacity
to manage and utilise water resources and assist in the mobilisation, training and enabling of local
organisations to administer, operate and maintain water supply and sanitation infrastructures [57].
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3.4 Opportunity
In Kilifi and its surrounding towns people can buy mineral bottled water at locally run kiosks and grocery
stores; however, this water is usually sold at a price that is not affordable for most of the inhabitants of
these rural communities.
In the coastal town of Mtwapa, between Mombasa and Kilifi, Dutch Water Limited (DWL) has had great
success in selling desalinated clean water in 10 litter reusable jerry cans at a considerable lower price per
litter in comparison to the aforementioned mineral bottled water.
Dutch Water Limited was set with the objective of producing as cheap as possible quality and healthy
drinking water to the Kenyan population. Due to its low prices (10 to 20 times lower than the regular
bottled water), DWL has seen an important growth in sales since 2009, and its aim is now to set up 8 plants
in Kenya within the next 10 years [58].
Winddrinker Holdings intends to replicate and scale elements of the Dutch Water Limited success, and
therefore an extensive interview with their General Manager Michael Dubelaar was held on their offices on
Mtwapa with the goal of finding out more details about the operation of the plant, the difficulties of the
business of selling affordable water in Kenya and the behaviour of the different market segments. A
complete transcription of the interview can be find on Appendix 2.
In the interview Mr. Dubelaar clarified that Dutch Water Limited goal is to supply affordable healthy
drinking water for the people. They are a social enterprise but need profits to sustain their business, and at
the moment they are breaking even. DWL started as a small business in 2009 when just 6 people had to do
all the work: producing the clean water, filling up the bottles and taking them to the customers. In 2011
things changed and they started growing, going big scale. They had to stop looking at it as a hobby to start
treating it as a business.
The 10 litter jerry cans are the most common DWL product presentation, but Mr. Dubelaar clarified that
they also distribute water to schools in bulks of 1,000, 2,000, 4,000 and 6,000 litters. In those cases the
water has a cost of 5 shillings per liter including transport and the maintenance of the tanks, while in the
case of the 10 litter jerry cans the price of the water depends, due to the transport cost, on the location: in
Mtwapa, where it is produced, it costs 60 shillings (6 schillings per litter), while outside of Mtwapa people
has to pay 70 schillings. If the customer is farther away the price can reach 80 schillings. For the expense
of the bottles DWL has a deposit system, and the first time somebody buys the 10 litter jerry can an extra
payment of 150 schillings needs to be done. Afterwards every time the customer wants more water he/she
exchanges the empty 10 litter jerry with one that does have water, but now only its content, the fresh water,
has to be paid.
Although the business model of DWL is business-to-consumer they have a two-step delivery system in
which they put the water from the plant to the trucks and then take the trucks to the shops, which are then
in charge of selling it to the people, Mr. Dubelaar explained. Currently they have no profit margin and are
breaking even. When asked about increasing the prices to create more profit Mr. Dubelaar responded that
this was not possible because the competition is already 10 shillings cheaper. The last 2 years around 56
competitors, selling the same product DWL offers -at least in theory- have started operations in the area.
Mr. Dubelaar claimed that there are some honest and good competitors and that there is no problem with
that, but that most of them are just stealing the jerry cans, consuming the water, filling the bottles back with
any other water (mostly from the tap) and selling it to the people with a different sticker. Even the honest
competition is stealing the DWL cans; however, they are still the biggest one. Mr. Dubelaar assured that if
a question about which is the best 10 litter jerry can is asked in any shop most of the people would answer
DWL, without hesitating. Trust is a big issue in Kenya, and Africa in general, and people trust in DWL as
they were the first ones in the business and have been around for a long time, doing things the good way.
People know they will be there the next year, and they survive of that branding. They had a monopoly at
the beginning and were able to wrap the market, so now they just have to maintain themselves. They have
seen a lot of brands coming into the market and fading out, and then a new brand comes in and the same
happens. Nevertheless, Mr. Dubelaar recognized that the competition has stolen 30% of the market to DWL,
and according to him one of the reasons is that in Kenya people is not interested in quality, and they just go
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for price. At some point of the interview Mr. Dubelaar said: “For Kenyans water is water. If it’s packed and
looks nice then is probably OK for them”.
Mr. Dubelaar is sceptic on the idea of entering a market like this right now, as there is already too much
competition in the coast, or at least in the area around Mombasa. He thinks that it would be complicated to
put a new brand now, and that if somebody tries to do it the others, bigger ones, will push it out. The new
brand will not have the capacity to fight against the already established ones, he expressed.
When asked about DWL’s final customers Mr. Dubelaar was very clear: is not possible to reach the bottom
of the pyramid (BoP), even with these low prices. It is simply not possible to compete against the prices of
the water from KIMAWASCO or the brackish water they can get from other sources (i.e. wells), for free.
People add a bit of water guard (a chemical) to this low quality water and they have drinking water for a
lower price. Mr. Dubelaar explained that DWL market is the lower end of the middle class. When asked
about the tourism industry as a possible market Mr. Dubelaar said that Hatenboer Water has tried to sell
machines to the hotels, or even lease them, but it never happens. He thinks they are not a market now, as
they are not in a good moment and are only interested in revenue, which they need desperately. He
expressed that hotels are now in the business of selling bottled water to the customers and they cannot do
that with jerry cans. Only if you can sell them desalinated bottled water with their logo they might do
something about it, but that requires a production line or a big investment. For other activities the borehole
water is good enough. He said that DWL has talked to hotels before about desalinated water and they liked
the idea until they had to pay for it. There are a few, such as Mnarani Club, with desalination plants, but this
water is not used for drinking purposes.
As it was already mentioned DWL started with a small group of people delivering water directly to the
customers, however this is not possible anymore, as they would not be able to reach the volume they need.
There is simply not enough time. They had to change that business model because it would not allow them
to compete. They run on business hours and people in Kenya is used to go to the shops in the evening. The
availability of the water is a very important factor. Now they are testing the usage of distributors instead of
depots, as the distributor’s business starts at 7:00 in the morning and runs until 10:00 in the evening. DWL
cannot compete with that. As part of their new activities they are also introducing 20 liter bottles for the
upper market and looking at small volume packaging.
Mr. Dubelaar warns that starting operations in Kenya is not easy, as their law system is based on the English
model but with the difference that in the African country they do not really understand it. Nevertheless, if
you miss something they will get you. Therefore during the interview Mr. Dubelaar also highlighted the
importance of being very organized with the procedures (bills, certificates) or otherwise the authorities
will be all over you putting pressure, asking for money and even putting you in jail if they want to. They will
find any opportunity to make some money, so you have to stay out of trouble. Government corruption is
also very high. In addition there is also the problem of mistrust with your own staff. Everybody wants
something and short-term vision is a very common problem. If you can reach high volumes, being well
organized and having your distribution in order you can survive and also make some money, but is a huge
challenge, Mr. Dubelaar expressed.
According to Mr. Dubelaar the company is also heavily affected by the politics of the country. With the last
Constitution promulgated in 2010 the country was divided in counties following the American model.
Suddenly, from one day to the other, DWL trucks, and any other truck, had to pay 4,500 shillings (1,000
after negotiations) to enter the town of Mombasa, which multiplied by the 12 to 16 trucks they sent every
day results in a very important amount of money. Mr. Dubelaar complained that they (the county
governments) did not prepare the people for this, and that things like this can happen every day. Every
county has their own government and their own parliament and they are all trying to make some money.
In addition Mr. Dubelaar claimed that if you miss one thing they will fine you or you will pay and they will
let you go, but once you pay for the first time you are promoting corruption and they will look for you every
day asking for more.
In the interview questions about the impacts of their products were also asked. Mr. Dubelaar said that since
DWL started to operate in Mtwapa the health of the people in the area has improved and that they would
like to think they are in part responsible of that. About the environmental impact he expressed that caring
for the environment is what made them start the reusable jerry cans system, which is actually a big
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headache for the company. The country is much polluted and plastic can be seen everywhere, so they
decided not to add to that mess and not to have a negative impact.
The plant requires continuous maintenance which is performed by DWL employees who receive an inhouse training. Most of the materials required for the maintenance activities can be found locally, but due
the fact they have a Hatenboer Water installation in a metric system and the country uses imperial system,
some other things, such as the piping, have to be imported. Mr. Dubelaar also highlighted that the
employees of the company are not “just locals” without preparation, as they need qualified people to run
the plant properly or otherwise they would lose too much money.
Asked about the jerry cans Mr. Dubelaar said that they cost 150 schillings to DWL, which is the same price
the customers have to pay for it. The company is not making any money there. Now they have their own
moulding machine which required a huge investment.
3.5 Summary of the market research
The observation made in place coincides with the literature research: Kilifi depends strongly on their
farming industry, but even more in the tourism. There is basically no other industry, and the walk-in walkout businesses barely exist in this place. Three market segments are clearly identifiable: communities,
hotels/resorts and farmers.
Most Kilifi inhabitants get their water from the tap, which is provided by the Municipality through the local
water service provider KIMAWASCO at a very low price. Most of the people knows where this water comes
from and, in general terms, they are satisfied with its quality. Not many people is aware of what desalinated
water is, especially in the bottom of the pyramid, but most people is willing to try it as long as its quality
fits the standards and the price they have to pay for it is the same (or less) of the water they are currently
consuming.
Desalinated water can be already found at the shops of Kilifi, mainly from two brands: Dutch Water Limited
(DWL) and Pride. The shops do not know the source of the water as it is brought by distribution trucks and
they are only in charge of re-selling it. According to them, and coinciding with the results of the other
surveys, the people from Kilifi would be willing to try desalinated water and pay the same price in
comparison to what they are spending now. None of the surveyed knew anything about water-related
projects being developed in the area.
Rural communities get their water from the tap or from wells, but not all the communities have access to
these sources. Some organizations such as Word Vision and Plan International are therefore developing
water-related projects in the area, but more initiatives are needed in order to help other communities that
are struggling. World Vision is extending pipes and Plan International is building water kiosks. In both cases
the community will be in charge of managing the water source once the structure is finished.
To develop projects in the area it is important to involve the communities and keep constant
communication with them, especially with their leaders. Communities know better what they need and
what their capacity is. It is important to train them and also make them realize that they will be the owners
of the project once it is completed, and therefore the ones responsible of keeping it running. To really help
the communities it is important to get rid of the “dependence syndrome”, as Ms. Moseti called it, referring
to the communities looking at the western organizations as the big brother that has to take care of
everything for them. They need to understand how these projects will help them to commit to its proper
management. When introducing a new product, such as desalinated water, educating, informing and
creating awareness are key aspects to its success.
Tourism, as the major economic activity of the area, plays a very important role in the water consumption
scheme. Some of the hotels are satisfied with the quality of the water they are getting from KIMAWASCO,
at least for what they are using it for, but most of them have complains about the reliability of the water
provision system and they are forced to complement the water coming from the tap with alternatives such
as boreholes or rainwater collection systems, or even their own desalination plant as in the case of the
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Mnarani Club. Hotels are also using tanks to store water when it is entering and use it later when it is cut,
however sometimes the water they are able to store is not enough, and looking for water in those periods
is difficult and very expensive. It usually requires buying over-price water from bowsers that are scarce
and not easy to find. Continuing normal operation during these periods is a huge challenge for them, and
some of the hotels want more participation of the government to fix this situation as this water problem is
not only affecting the hotels but also all the Kilifi inhabitants.
According to the hotels the problem with the water is caused by several reasons: on the one hand the
population of the town is growing and KIMAWASCO does not have the capacity of covering the new demand
as their infrastructure is too old. The pipes were laid in the 60’s and 70’s when the area was underdeveloped and now new houses were built and KIMAWASCO does not know the exact place of these old
pipes. On the other hand hotels complain KIMAWASCO is too disorganized and nobody knows who is in
charge of what.
As in the case of the communities everybody is willing to try the desalinated water, even though some of
them did not know it. The fact that the plant will be powered by renewable energy sources does not affect
the price they are willing to pay for it. The industry is going through very difficult times. In a town were
around 70% of the people depends, directly or indirectly, on tourism, the numbers have been very low for
the last two years. Some of the reasons mentioned in the interviews are the crisis that affected Europe, their
main customers, and the lack of marketing, but the most important one is the complicated political situation
of the country, as travel bans to Kenya were published by several governments due to the terrorist attacks
that have been occurring in the country since the Kenyan government decided to fight the Somalis that
were terrifying the people, tourists included, in the north of the country close to the common border.
Farming is a very important activity for Kenyans and Africans in general, and Kilifi is not different; however,
most of the people (90%) is doing it at a small-scale. Opposite of the hotels most farmers use their own
borehole water as the main source and then complement it with the one sent by KIMAWASCO. Some of
them are also collecting rainwater. However, the borehole water in these farms is too salty and therefore
not good for human consumption, animals or even some agricultural activities. This water is sometimes so
salty that it cannot even be used in the machines.
The fact that the farmers own the boreholes, which is also important to note that deteriorate with time,
does not mean the water they get from it is completely free and there is a price for the license to pump it
out; however, the costs are still considerable lower than those from KIMAWASCO, which is an especially
important factor when consuming big amounts of water as the farmers do. At the end of the day the water
is not ideal, but is what they have.
Because it is not their main source of water the cuts in the KIMAWASCO service do not affect the farmers
as bad as it affects other industries such as the tourism; however, they do are pushed against the wall
sometimes, especially in the case of the small farms which, as it was already mentioned, are the big majority.
Most farmers know what desalinated water is, but it is too expensive for them to produce it. They feel such
an investment is not worth it considering the use they are giving to (most of) the water. The boreholes are
still the best solution in their opinion. As in the case of the hotels, the fact that the designed desalination
plant will be powered by renewable energy sources would not affect the price they are willing to pay for
the water. They are in the business of producing, and the cheapest the water the better.
KIMAWASCO is the governmental water service provider for Kilifi. They have different rates (domestic,
commercial, institutional and kiosks) for the variety of customers they service. In the case of domestic rates
a system of blocks is used in which the more water you consume the more you pay for every unit of it.
KIMAWASCO owns the meters on all the connections, which are used to calculate the exact amount of water
consumed. Anybody that wants to start receiving water from KIMAWASCO has to go their office to apply
for a connection.
KIMAWASCO is, through different channels, in constant communication with their customers, and although
people from each studied market segment complained about the water service in KIMAWASCO they say the
feedback they get from the customers has been, so far, very positive, and that people are, in general terms,
satisfied with their service. Their number of clients increases every day.
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Before 2006, when they started to operate as a semi-private company, it was the government who was
operating the water services in the area. Since then different changes have been made: prices went up (no
subsidies) and they became stricter in the collection of revenues. Everything that enters is used to pay the
operation of the company.
Any water-related project or development that wants to be started in area, regardless of if it uses tap water
or not, has to go through KIMAWASCO and the Coast Water Service Board (CSWB), a Government entity
which is the highest authority in this topic in the coast region. They are in charge of approving or denying
the project and a fee will have to be paid to them, as it will operate under their rules.
Different projects have been proposed to try to help solving the water issue in Kilifi, especially focusing on
the rural communities that do not have any source of clean water nearby. The Chipande Water Project uses
renewable energy sources to desalinate water, the Musichovweka Water Project is installing water tanks
for schools, in the Cash-Food for Assets Project water ponds/pans are being rehabilitated and constructed
and in the Sombeza Water and Sanitation Improvement Project they are installing sustainable
infrastructure for domestic water use and sanitation and ensuring its appropriate use. Interestingly none
of these projects were mentioned by any of the interviewees.
Desalinating water in the coast of Kenya is not something new, and since 2009 Dutch Water Limited (DWL)
is doing it at a plant in Mtwapa, a town located between Kilifi and Mombasa. Their goal is to supply
affordable healthy drinking water for the people, producing enough profits to continue their operations.
They sell 10 litter jerry cans that have a price depending on the location of the customer: 60 shillings in
Mtwapa, 70 schillings in the nearby towns and 80 schillings when the client is farther away. They use a
deposit system for the bottles in which the customer has to do a payment of 150 schillings plus the cost of
the water the first time it is bought and then only the content water when the jerry can is exchanged has to
be paid. They also sell water in bulks of 1,000, 2,000, 4,000 and 6,000 litters to schools, and in this case they
sell their product at a price of 5 schillings per litter, including its transport and the maintenance of the tanks
where it is stored. The way DWL reaches its customers is through a two-step delivery system in which they
put the water from the plant to the trucks and then in the shops, which are the ones in charge of selling it
to the people.
During the last couple of years a lot of competitors offering the same product have started operating in the
area. Some of them are honest, but most are not and they are just stealing the DWL jerry cans and filling
them back with tap water to sell it again with a different sticker; however, due to the fact that they were
the first ones in the market and have been doing things good for a while, people trust on DWL and, even
though the competition stole 30% of their market, they are still the biggest company. They can live of that
brand they have made while many others that try to enter the market just to fade away in a short period of
time. The reason why so much competition has started recently lays in the fact that most Kenyans do not
care about the quality of a product but only about its price. Now the market looks saturated, and trying to
enter to it from scratch could be very difficult as bigger companies will push the new brand away, which
will not have the capacity to fight back. Other reason that complicates the entrance of a new brand to the
market is the difficulty of starting operations in Kenya, as they have a law system based on the English
model which they do not seem to understand. In addition, there is all the stealing, cheating and corruption
which are very frustrating to deal with, and also a political instability that produces changes from one day
to the other with no preparation for the people. However, if high volumes can be reach, being well organized
and with a distribution system in order, money can be made, but is a huge challenge.
Is not easy to find customers, and the bottom of the pyramid is not an option. The prices of KIMAWASCO
are too low and impossible to compete with. DWL’s market is the low end of the middle class. Mr. Dubelaar
is sceptic on counting with the tourism industry as a possible market, as they are currently going through
a very difficult time and do not want to spend any money they do not absolutely have to. They rather make
money by selling water to their customers. For other uses borehole water, which is of course cheaper, is
good enough.
DWL is looking at expanding their business in different ways: they are testing the usage of distributors
instead of depots, introducing 20 liter bottles for the upper market, looking at small volume packaging and
building new plants. Innovating is always necessary.
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Selling affordable desalinated water has had a positive impact on the health of the residents of Mtwapa. At
the same time DWL is trying to take care of the environment with the reusable jerry can system they use,
which is not easy to manage and requires important expenditures. The maintenance of the plant is done by
DWL employees who receive an in-house training. Most of the materials required to perform the
maintenance activities can be found in the local market, but still some of them have to be imported.
System design
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System design
A wind driven reverse osmosis desalination system consists in mainly four components: the wind turbine,
the coupling, the pump and the reverse osmosis array.
The design of such system must start from the reverse osmosis array, which is the component that dictates
the amount of pressure the pump needs to deliver to the fluid in order for it to go through the membranes,
and therefore the power and torque that the wind turbine needs to produce.
The wind driven reverse osmosis desalination system to be designed is expected to produce an average of
25 cubic meters of fresh water per day from a brackish water underground reservoir in the coastal town of
Kilifi in Kenya, where there is an average wind speed of 3.8 meters per second.
It is important to note that the system is meant to operate in a rural area of a developing country, and
therefore the components to be used must be able to withstand a harsh environment and a rough operation.
This means that the system must be robust, cost effective and easy to maintain, and it also needs to be
independent of high-tech or advanced skills as its daily operation and maintenance will be done on a local
setting. This was confirmed with a visit to Kilifi and the interviews and surveys held with its inhabitants.
In this chapter the components that comprise the wind driven reverse osmosis desalination system to be
installed in Kilifi are detailed, but first the design premises and an overview of the system operation are
presented.
4.1 Design premises
In this section the design premises are divided in four parts: first a summary of the thesis developed by
Carla Generaal is given, as her work was fundamental for the initiation of the project in Kilifi. Then a small
description of the Somalialand project, the predecessor of the one of Kilifi, is provided. A third part is
dedicated for the innovations this project has and finally some design constraint factors, namely the
climate, the site and the environment, and how they affect the current project are described in the last part.
4.1.1 Wind driven reverse osmosis desalination for small scale standalone applications
In 2011 Carla Generaal developed the SIMULINK Wind2Water model as part of her Master Thesis on Wind
Driven Reverse Osmosis Desalination for Small Scale Stand-Alone Applications [27]. In this section the main
results obtained in this research are presented.
The Wind2Water model is a tool designed to select the optimal wind driven reverse osmosis system
configuration for a specific site. It consists of four main blocks: the wind turbine block, the transmission or
coupling block, the pump block and the reverse osmosis array block; and two main configurations: a
mechanical coupling with different gearbox ratios and an electrical coupling with a battery. The first
configuration was validated by means of the experimental data obtained from a prototype built by TU Delft
in Curacao while the second one was validated by means of a prototype built by the Dutch company
Hatenboer Water that was later installed in Indonesia.
During her research Carla Generaal used the Wind2Water model to analyse system configurations for
brackish and sea water desalination in regions with a mean wind speed of 5.9 meters per second and 7
meters per second. The evaluated configuration types were a multi-bladed and a three-bladed wind turbine
with a mechanical coupling and a three-bladed wind turbine with an electrical coupling. The effect of
different pump sizes and transmission ratios were also considered in the simulations. The water output for
each configuration was estimated and the water cost defined. The total score of each configuration was
based on the weighted score of four design criterions: cost, maintenance, life and reliability.
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According to this research the optimal configuration type for brackish water desalination is, based on the
aforementioned design criteria, the mechanically coupled multi-bladed wind turbine, which is also the best
option in terms of water cost; however, at a higher mean wind speed -higher than 7 meters per second-,
the other analysed configurations become cost competitive. In the same research it was also found that the
best configuration from a water output point of view depends on the mean wind speed: at high mean wind
speeds the three-bladed wind turbines, either mechanically or electrically coupled, are favourable, while at
low mean wind speeds a well-chosen mechanical coupling with a multi-bladed wind turbine is a better
option. Also for sea water desalination the mechanical configuration with a multi-bladed windmill was
found to be the solution with the highest score.
4.1.2 Somalialand project
The work developed by Carla Generaal in her thesis was later used to select the components of a wind
driven reverse osmosis desalination system to be installed near the port city of Berbera in Somalialand.
Led by the Dutch social enterprise Winddrinker Holdings and with the financial and technical support of
Hatenboer Water, TU Delft and Aqua for All the prototype was developed in 2011. It was successfully built
and initially fresh quality water was produced and distributed to the local community nearby; however,
the system suffered two major breakdowns caused by the poor quality of the parts supplied by the wind
turbine manufacturer. This experience proved to the company that a new design and more reliable
suppliers were needed to build a commercially viable product [29]. A picture of the installed system can be
observed in Figure 5.
Figure 5 - System installed in Somalialand [29]
4.1.3 Project innovation
In order to avoid the problems that affected the Somaliland project in this case the system will be tailored
to the Kilifi conditions. This means not only that the wind data and the water properties will be applied, but
also that the results of the research developed in Chapter 2 and Chapter 3 will be considered throughout
the entire design process. The context on which the system will be operated will affect the different
components of the system.
Although it was mentioned before that the reverse osmosis array is the starting point of the design, the
most important component for this project will be the wind turbine; however, as it will be used to power a
pump instead of producing electricity, as more wind turbines in modern applications, the design process
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learned during the different TU Delft courses will have to be adapted and a different matching process
between components will be necessary.
In the case of a pump, as it will be explained later in the chapter, a high start-up torque is required;
therefore, a wind turbine capable of producing enough torque to start the pump to be selected at a certain
wind speed to be determined needs to be designed. Same for the rated power. In addition, it is important
to highlight that this pump is used for a reverse osmosis process, and therefore its behaviour is different to
the one of the pumps used to move water from one level to other.
Regarding the pump it is also important to note that in the starting phase of the project it was decided to
make a couple of changes to the conceptual design of the system in comparison to the one installed in
Somalialand:
 Two pumps instead of one: in the previous design just one pump was used for the entire process,
meaning that this one pump was in charge of pumping the water out of the underground reservoir
and then pressurize it to go through the membranes of the reverse osmosis array. These two
processes require very different amounts of pressures and therefore it was decided to separate
them.
 No submersible pumps: Another important aspect to consider is that, although they are frequently
used in windpumps, submersible pumps (also called “sumps”) will not be taken into account. A
submersible pump was used in the Somalialand project, but they are very difficult to reach. This
complicated any maintenance task that wants to be performed on it, and therefore just surface
pumps will be evaluated.
4.1.4 Design constraints factors
As it is discussed in Wind Energy Explained by Manwell, McGowan and Rogers, a general design process is
also influenced by some specific external factors such as the climate, the location and the environment [59],
some of which affect just the wind turbine while others the entire system. They are briefly explained in the
next sub-sections.
4.1.4.1 Climate
Particularly important for the wind turbine, as they have to be stronger when they are designed for more
energetic or turbulent places instead of “conventional” sites. In addition, climate can also affect the design
in other aspects. For example, if the place where the wind turbine will be installed is too warm extra cooling
might be needed, while if the place is too cold heaters, special lubricants, or even different materials might
be required. Turbines to be installed in marine climates, such as Kilifi, need protection from salt and
therefore corrosion-resistant materials should be used wherever it is possible. This is important for the
manufacture process, which is not the scope of this report.
4.1.4.2 Site-specific
This factor applies for the system as a whole, as limited availability of expertise and equipment for
installation and operation is of particular importance for systems in stand-alone operation, especially
applicable for remote areas in developing countries as the case of Kilifi, in which case will be very important
to keep the system simple, modular and designed to require only commonly available mechanical skills,
tools and equipment.
4.1.4.3 Environment
The implementation of a system such as the one being designed in this project will always impact the
immediate environment around which it is installed, and not all of these impacts will be appreciated by the
people. The most commonly environmental impacts are noise, visual appearance, effects on birds and
electromagnetic forces. Careful design can minimize some of these effects; however, this is more applicable
for big turbines installed in wind farms, which is not the case of the current project.
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4.2 System operation overview
In order for the reader to have a better understanding of how the complete system works an overview of
its operation is presented in this section.
The four components of the proposed wind driven reverse osmosis desalination system, namely the wind
turbine, the coupling, the pump and the reverse osmosis array, are interconnected to each other; however,
as it has already been mentioned, the reverse osmosis array is the starting point of the design.
Reverse osmosis arrays are designed for a maximum flow that, depending on certain properties of the
water (i.e. TDS and temperature) and the array’s characteristics, require a specific amount of pressure to
go through the membranes. As most of the pumps used for delivering water to reverse osmosis arrays are
driven by an electric motor that can provide constant values of power, torque and speed, achieving the
required conditions to produce a fixed pre-defined amount of water is not a problem. Nevertheless, in the
case of directly coupled mechanical systems that use the wind as the source of power these parameters are
not constant.
In a reverse osmosis process the required pressure is determined behind the pump. The membranes have
a constant resistance, but the driving force is linearly related to the flux; therefore, more flow will result in
an increase of the pressure required from the wind turbine. An electrical resistance can be used as an
example: the resistance has a constant value, but an increase in the driving force (the voltage) will also
linearly increase the current. Therefore, when the flow varies due to the changes in the pump’s shaft speed
as a consequence of the different wind speed the needed pressure also does it. This means that for the
current project also the pressure will not have a fixed value, as in the case of an electrical motor powered
system, but a range that has a value close to the osmotic pressure of the fluid as a minimum and a
maximum/optimal pressure that depends on the membranes used.
The varying pressure also influences the required power by the pump, which depends on the pressure to
be applied to the fluid and the pump’s shaft speed, and the needed torque, which is a function of the power
and, once again, the velocity at which the shaft of the pump spins.
Most of the times the wind turbine rotor will, with the help of the tail vane(s), face the wind to extract of it
as much energy as possible, and just when the wind is extremely high it will turn in another direction to
avoid any damages. The wind turbine rotor and the pump shaft are connected through a coupling system,
and therefore the faster the rotor turns the faster the pump shaft will spin and the more fluid will be
available to be pumped towards the array; however, the required pressure will also go up, increasing the
required power and torque from the pump to the turbine. The wind turbine’s rotor angular velocity will
vary due to the influence of the wind speed and the torque required by the pump until these two
components (wind turbine and pump) converge to an operating point.
4.3 Reverse osmosis
This section is divided in four parts: first a theoretical background and then a brief description of the
reverse osmosis array to be applied in the system are given. After that the properties of the brackish water
underground reservoir to be used in Kilifi are explained and finally the pressures required by the different
flows, as a consequence of the varying wind speeds, are presented.
In an osmosis process water molecules diffuse naturally through a semi-permeable membrane from the
side that contains purer water to the one with the higher salt concentration to equalize the differences
between them. If both sides of the membrane contain water with the same concentration and at the same
temperature and pressure there will be no flowing. In a reverse osmosis process pressure is applied to the
side with the higher salt concentration, resulting in a flow of water in the opposite direction through the
semi-permeable membrane, which allows water to pass but not the dissolved matter. This process results
in permeate or product (fresh water) and concentrate or brine (saline water) flows. The salt concentration
System design
66
in the permeate flow is lower than the salt concentration in the feed flow while in the concentrate flow it is
higher [60].
The driving force for this process is the applied pressure minus the osmotic pressure, which is a fluid
property dependent on the number of total dissolved solids (TDS) and the temperature, and independent
of the presence of a membrane; therefore, the energy consumed in the reverse osmosis process is directly
related to the salt concentration in the water (higher salt concentration means higher osmotic pressure).
This pressure difference is called transmembrane pressure [60]. The principle of the reverse osmosis
process is graphically presented in Figure 6.
Figure 6 - Osmosis and reverse osmosis principle [60]
The reverse osmosis membrane filtration process is commonly used in the treatment of drinking water,
more specifically for the desalination of sea water or brackish water, the removal of dissolved trace
compounds such as arsenic, the disinfection of microbial contaminated water, the removal of dissolved
natural organic matter and the partial removal of organic micro-pollutants such as hormones and
pesticides [61].
Due to the capacity of a reverse osmosis process to remove very small particles from water a problem
arising with it is the fouling of the membrane due to biofouling or scaling. In the first one matter particles
are retained in the membrane and biomass is produced, while in the second salt precipitates are formed.
Even though the membrane fouling is almost inevitable, an effective pre-treatment of the feed water to
remove the particulate matter should be performed to reduce its effects. This pre-treatment can be a
conventional coagulation, flocculation, sedimentation, or filtration, or it can also involve more complicated
processes such as the ultrafiltration [60]. An example of damages in the membranes caused by biofouling
and scaling can be seen in Figure 7 and Figure 8, respectively.
Figure 7 - Membrane damaged by biofouling [60]
System design
67
Figure 8 - Membrane damaged by scaling [60]
To obtain the necessary permeate production without a large footprint membranes with high area per
volume (high specific area) are used instead of large flat membranes. Almost all membranes used in reverse
osmosis process are of the spiral-wound configuration (specific area of 1,000 m2/m3), in which the feed
water enters the element and is distributed via the spacers, which are the supporting layers between
membrane sheets. See Figure 9 for more details.
Figure 9 - Spiral wound membrane configuration [60]
A membrane element, which usually has a length of one meter, is composed by a number of membrane
sheets twisted around a central tube that collects the permeate water. A disadvantage of spiral-wound
membranes is that rapid fouling of the spacer channels with particulate matter can occur.
To withstand the high pressures required in the process a pressure vessel must be used; however, it is too
expensive to use one for each membrane element, and therefore using, membrane modules containing
groups of membrane elements (generally six) connected in series are a common practice [60].
Reverse osmosis modules are always operated in cross-flow mode, and only between 1% and 10% of the
feed flow that enters a membrane element is recovered as permeate flow. Most of the feed water flows
System design
68
along its surface and leaves the membrane element as concentrate flow. This recovery gives the
relationship between permeate and feed flow and it indicates the overall production of the system, which
for sea water desalination has a maximum value of about 50% while for groundwater recoveries up to 95%
can be obtained. Higher recoveries could result in a very high salt concentration of the brine water
producing scaling as a consequence [60].
Among the advantages of reverse osmosis over thermal processes are the low energy requirement, the
achievement of higher conversion ratios, the enhancement of membrane lifetime leading to improved plant
availability, the simplicity and the modularity of plant design and operation, the limited installation space,
the short delivery times and the lower environmental impact [62].
4.3.2 Project reverse osmosis array
The reverse osmosis array to be used in the system was designed and developed by the Dutch company
Hatenboer Water in 2010. An interview with the leader of the Process Engineer Department of the
company, Jan Arie de Ruijter, was held in the offices of the company in Schiedam in May of 2014 to discuss
the characteristics of the system, which are briefly presented in the next paragraphs.
The reverse osmosis array to be implemented operates with a pump that is used for the pre-treatment of
the brackish water as well as for the desalination phase. Usually these two processes are separated and
different pumps of different capacities are used, but in order to have a rugged system that requires fewer
parts, the less maintenance possible and no electricity, it was decided to apply just one pump.
The pre-treatment filtration process to remove contaminants of the feed water before it enters the RO
module consists of two stainless steel high pressure cartridge filters of 30 inches in which the water suffers
a pressure drop of around 1.5 bars. Then the feed water is directed to two membrane modules connected
in parallel, each consisting of six membrane elements of spiral-wound configuration that are connected in
series. The membrane elements that can be applied in this specific array are the ESPA2-4040 or the ESPA44040, and the fact that they are connected in series means that the concentrate of an element is the feed of
the one that follows.
To withstand the high pressures each membrane module has two 600 pounds per square inch pressure
vessels (3 elements/vessel), but they operate as just one vessel per module. The modules will operate
together just when the wind speed, and therefore the flux, is too high for just one of them. The high pressure
piping used in all the system is made out of PVC.
The system has a recovery of 50% and the maximum volumetric flow of water the array can operate with
is 5 cubic meters per hour, meaning that the flows of the product and the brine leaving the membrane
modules have a maximum value of 2.5 cubic meters per hour each.
As the system has been designed to be as simple as possible the setup will not have extra components such
as energy recovery devices or booster pumps. In addition, no concentrate recirculation, permeate blending
or permeate throttling will be applied. It is also important to highlight that because the recovery was set to
be 50% no acids or anti-scaling are needed.
The total product and brine pipes are connected to each other with another pipe in which a safety valve can
be found. This valve is usually closed, but it would open to avoid an over pressure in the system if the
product outlet is closed. A PI&D and a layout (1:22 scale) of the reverse osmosis array can be found in
Appendix 3.
4.3.3 Kilifi water
The system will desalinate water from an underground reservoir in Kilifi. Groundwater is the major source
of water across much of the world, and it is likely to play an even greater role in the future under the
changing climatic conditions. The extraction of groundwater is very unevenly distributed across the globe,
as it differs not only from country to country but also inside their borders. By 2010 the world’s aggregated
groundwater extraction was estimated to be approximately 1,000 cubic kilometres per year, 67% of which
was used for irrigation, 22% for domestic purposes and 11% for industry. The global groundwater
System design
69
abstraction rate has at least tripled over the last 50 years and is still increasing at an annual rate of between
1% and 2%. Groundwater supplies almost half of all drinking water in the world and 43% of the global
consumptive use in irrigation [63].
Sea water has a total dissolved solids (TDS) number in the order of 30,000 parts per million (ppm), while
in the case of brackish water, as the one to be found below the ground, this number is usually around 5,000
ppm. As it was previously explained in section 4.3.1 the osmotic pressure is directly related to the salt
concentration of the water, meaning that the energy requirements for the desalination of brackish water
are lower than the ones for sea water.
At the moment of starting the calculations to design the system no water quality tests had been performed
to the Kilifi underground reservoir to be used in the project, and therefore a TDS of 6,000 ppm and a
temperature of 25 degrees Celsius, common values for brackish water, were assumed. These properties
were introduced in the osmotic pressure calculator developed by the Dutch company Lenntech [64] and
values of 4.73 bar and 14.18 bar for the osmotic and the operational pressures, respectively, were obtained.
The operational pressure indicates the optimal pressure that should be applied to the water in order to
have a high quality product.
However, the author had the opportunity of going to Kilifi where it was possible to collect water from the
well and take it to Mombasa to have it tested. After the water tests were completed it was found that the
value for the TDS of the groundwater to be used is 5,020 milligrams per litter, which is equivalent to almost
5,026 ppm instead of the 6,000 ppm that were assumed before. It was then decided to repeat all the
calculations applying the new –and real- values. The values for the osmotic and operational pressures of
this water are 3.89 bar and 12.24 bar, respectively. The results of the TDS test can be found on Appendix 4.
4.3.4 Pressures
In order to calculate the pressures required for the different flows the Integrated Membrane Solutions
Design (IMSDesign) program developed by Hydranautics, part of Japan's Nitto Denko Corp, was used.
Hydranautics describes their program as a powerful tool that helps users to design reverse osmosis (RO)
systems based on membrane technology. It also provides many features that enhance the user's ability to
quickly and accurately design and analyse various RO desalination systems [65]. The program can be
downloaded from the Hydranautics website [66] and was used to simulate a reverse osmosis array with
the properties of the Hatenboer Water system to be applied in the Kilifi project.
The first step in the design tool is to add the TDS and temperature of the water which, as it was just
discussed, have values of 5,026 ppm and 25 degrees Celsius, respectively. Then in the RO design window a
product recovery of 50% was fixed, and before starting the simulations the system specifications were
defined in the program.
Two different membranes can be used in this specific array, namely the ESPA2-4040 and the ESPA4-4040.
The first one is a low pressure composite with a rejection of 99.6% while the second one is a lowest
pressure composite with a rejection of 99.2%. Both elements have the same size (4.0 x 40.0). As they have
the higher rejection between the two options it was decided to use the ESPA2-4040 membranes, and even
though this means that slightly higher pressures are required it also means that the system will operate
more efficiently.
Then the number of elements per vessel and the amount of total vessels needs to be defined. Despite the
fact that the current project RO array has two membrane modules with two pressure vessels each and three
membrane elements per vessel, due to its configuration the system will operate as having two vessels in
total (one per module) with six elements connected in series each, resulting in a total of twelve elements
in the system. Nevertheless, the two modules will operate together only when the flow is too high to be
treated by only one module, which will be indicated by the average flux rate. According to Dr. Bas Heijman
from the Water Management Department of the faculty of Civil Engineering and Geosciences of TU Delft,
this average flux has an ideal value of 20 litters per square meter of membrane surface per hour.
The highest average flux rate accepted in the IMSDesign program is around 30 litters per square meter per
hour, and through different simulations it was found that, regardless of which of the two possible element
types was used, a permeate flow higher than 1.4 cubic meters per hour would result in an average flux rate
System design
70
higher than this upper limit as long as just 1 of the modules is in operation. This means that when the
permeate flow is lower than 1.4 cubic meters per hour, or in other words, when the feed flow is lower than
2.8 cubic meters per hour, just one of the modules will be necessary, but when this flow is exceeded the
second membrane module starts to work until the feed flow reaches the system’s maximum value of 5 cubic
meters per hour. An average flux rate above this limit could damage the membranes.
Once the usage of the modules and its boundaries were defined the IMSDesign tool was used to calculate
the pressures for different permeate flows, which are product of the changes in the pump shaft due to the
varying wind speed. The results are presented in Table 2 and Table 3. Permeate flows between 0 and 1.4
cubic meters per hour were evaluated with 1 vessel while the flows between 1.5 and 2.5 were analysed
with the two modules working in parallel.
Table 2 - Required pressures for lower flows (ESPA2-4040 membranes)
Permeate flow
[m3/hour]
Number of
vessels
Average flux
rate
[l/m2-hour]
Feed pressure
[bar]
Concentrated
pressure
[bar]
Concentrate
osmotic
pressure
[bar]
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
1.05
1.1
1.15
1.2
1.25
1.3
1.35
1.4
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1.1
2.1
3.2
4.2
5.3
6.3
7.4
8.4
9.5
10.6
11.6
12.7
13.7
14.8
15.8
16.9
17.9
19
20.1
21.1
22.2
23.2
24.3
25.3
26.4
27.4
28.5
29.5
0
4.7
6.4
7
7.3
7.6
7.8
8
8.3
8.5
8.8
9.1
9.4
9.7
10
10.3
10.6
10.9
11.2
11.5
11.8
12.1
12.4
12.7
13
13.4
13.7
14
14.3
0
4.7
6.3
6
7.2
7.4
7.6
7.8
7.9
8.1
8.3
8.6
8.8
9
9.2
9.4
9.6
9.8
10
10.3
10.5
10.7
10.9
11.1
11.4
11.6
11.8
12
12.2
0
6.3
7
7.3
7.5
7.6
7.7
7.7
7.7
7.8
7.8
7.8
7.8
7.8
7.8
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
System design
71
Table 3 - Required pressures for higher flows (ESPA2-4040 membranes)
Permeate flow
[m3/hour]
Number of
vessels
Average flux
rate
[l/m2-hour]
Feed pressure
[bar]
Concentrated
pressure
[bar]
Concentrate
osmotic
pressure
[bar]
1.45
1.5
1.55
1.6
1.65
1.7
1.75
1.8
1.85
1.9
1.95
2
2.05
2.1
2.15
2.2
2.25
2.3
2.35
2.4
2.45
2.5
2.55
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
15.3
15.8
16.4
16.9
17.4
17.9
18.5
19
19.5
20.1
20.6
21.1
21.6
22.2
22.7
23.2
23.7
24.3
24.8
25.3
25.9
26.4
26.9
10.1
10.3
10.4
10.6
10.7
10.9
11
11.2
11.3
11.5
11.6
11.8
11.9
12.1
12.3
12.4
12.6
12.7
12.9
13
13.2
13.4
13.5
9.3
9.4
9.5
9.6
9.7
9.8
9.9
10
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
11
11.1
11.2
11.4
11.5
11.6
11.7
7.8
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
7.9
The feed pressure indicates the amount of pressure required by the flow at the beginning of the process in
order for it to go through the array, and it can be seen in the tables that it increases when the amount of
permeate flow goes up. The concentrated pressure and the concentrate osmotic pressure are measured at
the end of the process.
When the concentrate osmotic pressure is higher than the concentrated pressure (or even when it is
slightly lower) it means that, due to the low flux, there will be not water production at the last element(s)
of the array and that all the production will be done at the beginning, resulting in a very inefficient operation
and poor quality water.
In the reverse osmosis process the level of TDS in the water is decreased from its original amount to, ideally,
a level below 500 ppm (in the water tests results –Appendix 4- the Kenya standard specification for
drinking water maximum value of 1,000 milligrams per litter can be found). When the feed flow is very low
the quality of the resultant permeate is less because the ions are diluted in a smaller amount of water, and
the opposite applies to high flux’. This is a real problem for seawater desalination, where a factor of about
100 is needed to decrease the salinity of the water to the right level. In the case of brackish water this factor
is about 10, which means that membranes with rejection above 90% are enough. As it was mentioned
before the ESPA2-4040 membranes elements selected in this project have a rejection of more than 99%.
For these reasons when the very low values of flow were simulated in the program a warning message was
given stating that the design limits were exceeded (values in red in Table 2); however, it does not mean
that the permeate water will not be produced, but that it will not have the optimum quality. In these cases
when the flow is too low there are 4 possibilities:
 Stop the wind turbine.
 Disconnect the feed flow from the reverse osmosis array.
 Discharge the low quality permeate.
 Blend the low quality permeate with the high quality permeate produced at higher wind speeds.
System design
72
As it is the simplest one it was decided to opt for the 4th option. The wind turbine will start producing
permeate water at low wind speeds and the result will be mixed with that one produced during high wind
speeds, which does not only has a very high quality, but is also produced in bigger amounts. The TDS
average of the mix of permeates in the final vessel will be below the 500 ppm. The last value in Table 3 is
in red because, although the program does not give any error message, it exceeds the permeate flow limit
of 2.5 cubic meters per hour. Actually, there is no warning sign until the permeate flow reaches a values of
2.9 cubic meters per hour (feed flow of 5.8 cubic meters per hour); nevertheless, the limit of 5 cubic meters
per hour established by the manufacturer will be respected for safety reasons.
4.4 Pump
It has been decided to separate the two pumping processes: a first pump will be used to pump out the water
from the brackish water underground reservoir into a storage tank and a second pump, of considerable
bigger size, will be in charge of pumping the water through the reverse osmosis array. The first pump is not
part of this research and just the second pump, which will be driven by the power of the wind, is going to
be evaluated.
The section starts with a brief theoretical background, and then the type and size of the pump to be used in
the project is explained. Then the different pump options considered and its respective calculations are
presented, they are compared and finally, following a selection criteria described later in the chapter, a final
selection is made considering the results of the observation on site and the study of the context in which
the system will be operated.
A pump is a hydraulic machine characterized by the interrelations of its head, flow or capacity, efficiency
and power. Pumps can be operated in series or parallel. Series pump operation is achieved by having one
pump discharge into the suction of the next to increase the discharge head, while parallel operation is
obtained by having two pumps discharging into a common header to have more flow while keeping the
head of the working pump. Series or parallel arrangements allow the operator to be flexible enough in
pumping capacities and heads to meet requirements of system changes and extensions [67]. In general, two
main categories of pumps can be distinguished: kinetic (hydrodynamic) or centrifugal pumps and positive
displacement pumps.
Centrifugal pumps are, due to its broad application possibilities in combination with relative low
maintenance and high efficiency, the most widely used type of pumping equipment. They have an axle in a
bearing with one or more (multi stage pump) impellers sealed in a casing (volute). The impellers are
connected to a drive unit that supplies the energy to make them rotate inside the volute casing, creating an
area of low pressure (partial vacuum) in the centre of the impeller that allows outside forces to push the
water into the impeller eye and out of its periphery. The spinning action of the impeller transfers energy to
the water and accelerates it. Then, due to the way the volute casing is designed, the water loses velocity and
the energy is converted into pressure head that supplies the required energy to transfer the water from
one point to other. According to the way the impeller imparts energy to the fluid the centrifugal pumps can
be classified in axial flow impellers, mixed flow impellers and radial flow impellers, being the latter the
most common type [67].
Positive displacement pumps discharge a given volume for each stroke or revolution. They act to force
liquid into a system regardless of the resistance that may oppose the transfer. The discharge pressure
generated by this pump type is, in theory, infinite [67]. These pumps are commonly used for applications
in which the fluid is very viscous or in case that a high pressure is needed [68]. Within the group of positive
displacement pumps there is further classification based on the mechanisms that cause the displacement
[69]:
 Rotary type: a rotating motion causes the displacement within the fixed chamber.
 Linear type: a lifting device moves the chamber itself through a suction pipe.
 Reciprocating type: a reciprocating motion of a piston or diaphragm in a fixed chamber causes the
displacement.
System design
73
4.4.2 Type
The first step in the pump selection process is to decide the type of pump to be used. Centrifugal pumps are
the most used type for reverse osmosis applications, and some of the advantages they have is that these
pumps are easy to operate and maintain, can be constructed from different materials and in a wide range
of sizes, and they have small space requirements, a wide tolerance for moving parts and a self-limitation
for pressure; however, this is not a standard reverse osmosis plant driven by an electric motor, and
therefore other aspects must be considered.
Centrifugal pumps have a narrow range of speeds in which they operate at a high efficiency, and matching
the speed of the wind turbine rotor at different wind speeds with this range is a very demanding task. It is
also important to note that centrifugal pumps require high revolutions per minute and that its speed is not
easily adjusted as additional equipment is necessary for this. The rotor of a wind turbine turns at low
speeds, and when centrifugal pumps are operated outside the aforementioned optimum range its efficiency
is greatly reduced. In addition, centrifugal pumps do not have a high torque, meaning that the production
of water at low wind speeds could be a serious problem.
Other disadvantages of centrifugal pumps are the fact that the suction side air leaks can reduce its capacity
and that they do not have the built-in capability to prevent flow from moving through the pump in the
opposite direction, resulting in increased consumption of the already intermittent provided power.
Centrifugal pumps also lack the capacity of self-priming, so if for any reason the water in the casing and
impeller drains out the pump would cease pumping until this area is refilled.
Centrifugal pumps provide a rather constant flow but have a certain flow/pressure curve where there is a
physical, relatively low, maximum in pressure at very low flow and pressure dropping as admitted outflow
increases. They are designed to act at a constant shaft speed. With closed discharge port pump pressure
will not be dangerously high, but enclosed fluid will heat up. Positive displacement pumps have a linear
relation between shaft speed and delivered flow, but at very low rpm opening/closing times of in and outlet
valves might shift in the cycle resulting in a deviating flow. They do not have a physical maximum pressure
(except breaking pressure) and generate pressure according to the admitted discharge flow. They generally
need a device that acts as a pressure regulator or safety valve. For reverse osmosis applications the
pressure is regulated at the ‘concentrate outlet’ of the membranes instead of at the pump discharge.
The capacity of a positive displacement pump is relatively low and the water flow will not be constant;
however, it is cheap to manufacture and easy to use. A positive displacement pump can produce large head
even with low rotation speeds, which means that they can provide a discharge pressure that is generally
higher than the one provided by a centrifugal pump even when the input power is low. In addition, they
can deal with different power inputs and rotational speeds better than the centrifugal pumps.
Considering all these advantages and disadvantages of both pump types and the context in which the
system will be operated it was decided to opt for a positive displacement pump for the reverse osmosis
array of the project. This decision is backed up by the fact that other researches on the topic of wind driven
desalination, such as the one of Liu and the one of Miranda, have also worked with this type of pump. In the
case of the wind-driven reverse osmosis system for aquaculture wastewater reuse and nutrient recovery
designed by Liu it was decided to use a Dempster Inc. piston pump [70], while in the project lead by Miranda
a Clark pump was applied [71].
4.4.3 Sizing
To find the size of the pump to be used in the system it is necessary to know the flow it will be required to
process, the pressure to be delivered to this flow and the total differential head, which is the difference
between the discharge and suction heads, expressed in meters [67].
In this project the flow, and therefore the required pressure and head, will vary; however, the maximum
flux of 5 cubic meters per hour and a pressure of 15 bar (slightly above the maximum pressure found in
Table 2 and Table 3) will be considered in the sizing process.
System design
74
To calculate the total differential head the Bernoulli equation was used, which requires knowing the density
of the fluid to be pumped. Pure fresh water has a density of 1,000 kilograms per cubic meter while salt
water density is about 1,025 kilograms per cubic meter. Brackish water can have any of the densities
between these two points, and for this project a density of 1,012 kilograms per cubic meter was assumed.
Calculating the head:
𝐻=
∆𝑃𝑟
=
𝜌∗𝑔
15 ∗ 105 𝑃𝑎
= 151.09 𝑚 ~ 150 𝑚
𝑘𝑔
𝑚
1,012 3 ∗ 9.81 2
𝑚
𝑠
Provided that there is sufficient power available the positive displacement pump to be used in the system
has to be able to withstand the conditions of Kilifi and the way it will be operated, deal with saline water,
and pressurize a flow of 5 cubic meters per hour with 15 bar or 150 meters of head.
4.4.4 Options
In addition to the type of pump and the sizing discussed in the previous sections, as well as its capacity to
deal with saline water, it is important to highlight that just off-the-shelf pumps will be considered.
Standard components are cheaper than custom-made and have been already tested, meaning that fewer
problems are expected to arise during the operation of the system. In addition, they are easier to fix and
the replacement of its parts can be done quicker, which considering the lack of industry and people with
proper knowledge in pumping equipment in Kilifi, as observed during the research presented in Chapter 3,
are important aspects to take into account.
During the pump selection process dozens of pump manufacturers and distributors were contacted in
order to select the better alternatives for further analysis. The list of considered providers included:
Aquatec, Bornemann, CAT Pumps, Danfoss, DP, FEDCO, Flowserve, FMC, Grundfos, KSB, MONO helical rotor
pumps, NUERT rotary vane pumps, PENTAIR, PROCON, Speck, Sultzer, Wanner Engineering, and Xylem.
The chosen pumps for further analysis were the 2531 and 3531 models of CAT Pumps and the Hydra-Cell
G25 and G35 of Wanner Engineering.
4.4.4.1 CAT Pumps 2531 and 3531
CAT Pumps is an American company with over 40 years of experience in the Reverse Osmosis/Desalination
industry, in which it has developed a much respected reputation in high-pressure positive-displacement
pumps. Although they do not have an official location in Africa, their CAT Pumps International Group office
located in the United States is in charge of the relationship with the customers located in that continent.
CAT Pumps manufacture and market the, according to them, longest lasting and most dependable highpressure pumps available in the industry [28].
With an emphasis on immediate product availability and customer service, some of the benefits of using
their services are [28]:
 Energy-efficient, extremely dependable, little maintenance required, very versatile.
 High quality components are used ensuring the longest lasting pump available in the marketplace.
 Immediate Product Availability and Delivery.
o 99.7% fill rate, year after year of world-class inventory management.
o 95% of orders ship within 24 hours.
 Knowledgeable Distribution
o Hundreds of distributors worldwide.
o Highly trained and experienced sales representatives.
 Industry Leading Customer Service.
o Experienced staff assistance.
o Live support available.
System design
75
Their stainless steel pumps line for reverse osmosis applications offers corrosion-resistance, strength, and
long life even in the harshest environments. They also claim to reach an efficiency of 85 - 95% in their
pumps which, according to their description, are designed in such a way that providing field service will
require only standard tools, with parts available worldwide [28]. In addition, Jan Arie de Ruijter from
Hatenboer Water explained in a meeting that CAT Pumps are the main providers of equipment for this
company, which is the one behind the development of the custom made reverse osmosis array to be used
in the system, which means that it has been already proved that these two components can work together.
The partnership between them could also decrease the purchase cost of the pump.
In a phone call with Frank Haertjens from CAT Pumps Belgium he explained that in their triplex plunger
pumps the plungers are driven by a crankshaft with 3 cranks at 120 degrees intervals. At any position of
the shaft a running pump has always 1 or 2 plungers in suction or pressure stroke while the other(s) are in
opposite stroke. Plungers in ‘suction stroke phase’ might help driving the crankshaft if the pump has a
significant inlet pressure. If the inlet pressure is negative gauge pressure (< 1 bar absolute) these plungers
will add extra load to the crankshaft.
The CAT Pumps models to be evaluated are the 2531 and the 3531. The 2531 model has a maximum
capacity of 95 litters per minute -equivalent to 5.7 cubic meters per hour- in a pressure range from 7 to 70
bar. The 3531 model has a higher maximum capacity of 136 litters per minute or 8.16 cubic meters per
hour in a pressure range between 7 to 85 bar. The price of the 2531 model is 2,738.00 euro while for the
3531 model is 5,282.00 euro.
4.4.4.2 Wanner Engineering Hydra-Cell G25 and G35
The Hydra-Cell seal-less pumps are a product from the American company Wanner Engineering, Inc., and
they are sold and serviced worldwide including Africa, where they have trained pump distributors located
in South Africa. According to Wanner Engineering these pumps are designed and built, above all else, for
precise performance and long life in order to keep plant and equipment running on a daily basis without
interruption. Among the advantages of their Hydra-Cell pumps they highlight [72]:
 Seal-less design: no dynamic seals, cups and packings that require maintenance are used. It also
means that it does not need the pumped fluid to lubricate and it can run dry all day without
suffering damages.
 Energy efficient.
 The multiple diaphragm design in a single pump head achieves steady low pulsing flow.
 Easy installation.
 Robust, reliable, and highly tolerant to operation errors.
 Low cost.
 Needs hardly any maintenance.
The Hydra-Cell pump, which is promoted by Wanner Engineering as ideal for RO applications, is a pulsating
pump, but due to its construction with three diaphragms overlapping each other the pulsation grade is very
low.
The models to be evaluated are the G25 and the G35. The G25 is the biggest pump of the line that can be
built in both a metallic and a non-metallic head. With the metallic head a maximum pressure of 69 bar is
achievable while the non-metallic head pump can deliver a discharge pressure of maximum 24 bar if it is
made of Polyvinylidene fluoride (PVDF) and 17 bar if it is made of Polypropylene (PP). Regardless of the
selected option a capacity of 5 cubic meters per hour is achievable. The G35 can be built only with a metallic
head, and maximum values of 103 bar for the pressure and 8.28 cubic meters per hour for the flow rate are
achievable.
The price of the G25 model is 4,920.00 euro while for the G35 model it is 17,428.00 euro; however, these
pumps need a stuck of safety valves that cost 1,122.00 euro, raising the total price of the G25 and G35
pumps to 6,042.00 and 18,550.00 euro, respectively.
System design
76
4.4.4.3 Other options
In the first place Danfoss looked like a very good option. It is a very well-known Danish manufacturer with
presence in North East Africa countries such as Djibouti, Eritrea, Ethiopia and Somalia, and also South
Africa, guaranteeing easy access to spare parts and technical support whenever it is necessary [73].
The APP 5.1 model seemed to be the one that better fits the system requirements, as it is capable of dealing
with a flow of 5 cubic meters per hour in a range between 20 and 80 bar; however, the pump is not suitable
for direct drive with a belt, as it has no roller bearings and therefore it cannot take any force on the shaft.
Danfoss pumps with energy recovery systems were already investigated by Carla Generaal during her
research on wind driven RO systems [27]. An energy recovery system is a device that allows re-using the
pressure of the brine to get the feed water to the necessary pressure and reduce the system’s energy
requirements. Nevertheless, as it was already explained before, one of the goals in this project is to have a
very robust system, and energy recovery devices require an electrical motor for its operation. There are
ways of powering it mechanically, but they have not been tested enough. In addition, due to the lower
salinity and therefore lower osmotic pressure, the energy requirements of brackish water are less than
those of sea water, meaning that these mechanisms, that increase the expenses of the water treatment, are
not really necessary in this case.
The series of Franklin Electric Orbit GW positive displacement pumps were also analysed by Carla Generaal
in her study for brackish water, as this was the pump series used by TU Delft researcher Bas Heijman in the
system designed for Curacao [27]. It is a medium pressure pump with good salt protection that is based on
the helical rotor technology and suitable to drive directly by means of a rotary windmill. Nevertheless,
when Franklin Electric was contacted an answer stating that they are now producing only centrifugal
pumps was received.
4.4.5 Calculations
As the pump will be powered by a fluctuating source initial calculations were done to evaluate the selected
models performance at different shaft speeds. Based on the data sheets and technical manuals provided by
the manufacturers relations were derived to calculate the delivered flow rate by the pump and the required
power and torque as a function of the pump’s angular velocity and the feed pressures for the reverse
osmosis process.
4.4.5.1 CAT 2531/CAT 3531
Both CAT Pumps models are from the same line and use the same equations to relate the different
parameters. First, to calculate the delivered flow, which is the feed flow entering the reverse osmosis array,
the next equation was used.
𝐹𝑒𝑒𝑑 𝑓𝑙𝑜𝑤 [𝑙𝑝𝑚] = 𝑎𝑛𝑔𝑢𝑙𝑎𝑟 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 [𝑟𝑝𝑚] ×
𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑑 𝑣𝑜𝑙𝑢𝑚𝑒
[𝑙𝑖𝑡𝑒𝑟𝑠] × 𝜂𝑣𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 × # 𝑝𝑙𝑢𝑛𝑔𝑒𝑟𝑠
𝑝𝑙𝑢𝑛𝑔𝑒𝑟
To calculate the delivered flow by the pump in litters per minute, the shaft speed in revolutions per minute
were multiplied by the displaced volume by the 3 plungers of the pump at a volumetric efficiency of 97%,
obtained from the manufacturers. The displaced volume of each plunger is a function of the bore and the
stroke of the pump, which in the case of the 2531 model are 32 and 38.5 millimetres, respectively, while in
the case of the 3531 model are 40 and 48 millimetres. The pump’s bore and stroke were obtained from the
technical manuals of the pump that are available in the company’s website. Then, to calculate the required
power, the following equation was applied.
𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑝𝑜𝑤𝑒𝑟 [𝑘𝑊] =
𝑓𝑒𝑒𝑑 𝑓𝑙𝑜𝑤[𝑙𝑝𝑚] × 𝑓𝑒𝑒𝑑 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒[𝑏𝑎𝑟]
600 × 𝜂𝑚𝑒𝑐ℎ𝑎𝑛𝑖𝑐𝑎𝑙
System design
77
The mechanical efficiency (ηmechanical) was fixed in 90% for both models. Finally, with the power already
calculated, the needed torque was found using with the next equation.
𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜𝑟𝑞𝑢𝑒 [𝑁𝑚] =
𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑝𝑜𝑤𝑒𝑟[𝑘𝑊]
× 9550
𝑎𝑛𝑔𝑢𝑙𝑎𝑟 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 [𝑟𝑝𝑚]
Both efficiency values were provided by Frank Haertjens, engineer of CAT Pumps, who also approved the
results presented in next sections. In addition, the flow calculations matched the results of real
measurements obtained in a test bank in the United States and that were provided by Ivan Hopchet, also
from CAT Pumps Belgium.
4.4.5.2 Wanner Engineering Hydra-Cell G25/Hydra-Cell G35
In the case of the Hydra-Cell G25 diaphragm pump the delivered flow at different shaft speeds was
calculated using a 0.0721 litters per revolution relationship provided in the technical manual, while in the
case of the Hydra-Cell G35 this shaft speed/delivered flow relationship is given by a rate of 0.1314 litters
per revolution. For the G25 pump the required power was calculated with the following formula:
50 × 𝑎𝑛𝑔𝑢𝑙𝑎𝑟 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦[𝑟𝑝𝑚] 𝑓𝑒𝑒𝑑 𝑓𝑙𝑜𝑤 [𝑙𝑝𝑚] × 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒[𝑏𝑎𝑟]
+
84,428
511
While for the G35 it was slightly different:
100 × 𝑎𝑛𝑔𝑢𝑙𝑎𝑟 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦[𝑟𝑝𝑚] 𝑓𝑒𝑒𝑑 𝑓𝑙𝑜𝑤 [𝑙𝑝𝑚] × 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒[𝑏𝑎𝑟]
+
84,428
511
Both of the equations were obtained from the technical manuals of the pumps, and they consist on two
parts: the first one calculates the absorbed power for the mechanical, or so called parasitic, losses in the
pump (friction in bearings, pistons, springs, etc.), while the second part is used to calculate the fluid power
of the pump. This fluid part is rather conservative and probably the exact power consumption is lower, but
most manufacturers are rather conservative with these formulas. Finally the required torque by both
pumps was calculated using the next equation:
𝑅𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑡𝑜𝑟𝑞𝑢𝑒 [𝑁𝑚] =
𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑝𝑜𝑤𝑒𝑟[𝑘𝑊]
× 9550
𝑎𝑛𝑔𝑢𝑙𝑎𝑟 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 [𝑟𝑝𝑚]
This torque formula is standard and is the same one used for the calculations of the CAT Pumps models;
however, it can also be divided in two parts: by changing the capacity (and speed) of the pump it can be
observed that the torque for the mechanical losses will not change. This torque is considered to be the
starting torque of the pump. As soon as the pump speeds up, the hydraulic losses (and also the hydraulic
torque) will be added to this, and therefore the higher the speed the higher the hydraulic –and total- torque
will be.
4.4.6 Results
The results of the calculations for each pump are presented in the next tables and then compared through
curves that allow a better understanding of the performance of the selected pumps at different revolutions
per minute.
4.4.6.1 Delivered flow
The first important calculation is about the delivered flow at different shaft speeds, which will be a
consequence of the fluctuating behaviour of the wind. In Table 4 the results are displayed and in Figure 10
they are compared.
System design
78
Table 4 - Selected pumps feed flow at different shaft speeds
Feed flow [m3/hour]
Shaft speed [rpm]
CAT 2531
CAT 3531
Hydra-Cell G25
0
0.00
0.00
0.00
50
0.27
0.53
0.22
100
0.54
1.05
0.43
150
0.81
1.58
0.65
200
1.08
2.11
0.87
250
1.35
2.63
1.08
300
1.62
3.16
1.30
350
1.89
3.69
1.51
400
2.16
4.21
1.73
450
2.43
4.74
1.95
500
2.70
5.27
2.16
550
2.97
5.79
2.38
600
3.24
6.32
2.60
650
3.51
6.85
2.81
700
3.78
7.37
3.03
750
4.05
7.90
3.24
800
4.32
8.43
3.46
850
4.60
8.95
3.68
900
4.87
9.48
3.89
950
5.14
10.01
4.11
1000
5.41
10.53
4.33
1050
5.68
11.06
4.54
1100
5.95
11.58
4.76
1150
6.22
12.11
4.97
1200
6.49
12.64
5.19
Hydra-Cell G35
0.00
0.39
0.79
1.18
1.58
1.97
2.37
2.76
3.15
3.55
3.94
4.34
4.73
5.12
5.52
5.91
6.31
6.70
7.10
7.49
7.88
8.28
8.67
9.07
9.46
The pumps are evaluated until a shaft speed of 1200 rpm as this is the first speed, considering the used
scale, at which all the selected pumps deliver more flow than the allowed by the RO array. From now on all
the results will be evaluated until this point.
The CAT 2531 reaches the maximum array capacity between 900 and 950 rpm, while the CAT 3531, the
one that is delivering more fluid at each revolution, does it between 450 and 500 rpm. With a number
between 1150 and 2000 rpm the G25 is the one that takes more revolutions per minute to reach the
maximum array capacity. The G35 needs between 600 and 650 rpm.
Figure 10 - Selected pumps delivered flow at different shaft speeds
System design
79
In volumetric pumps the delivered flow varies with changing speeds, and due to the fact that all the
evaluated pumps are of the positive displacement type it can be seen in Figure 10 that there is a linear
relationship between flow and shaft speed in the four models. As it was just explained, it can also be seen
in the same figure that the 3531 and the G35 have bigger capacities than the 2531 and the G25 at the same
speed, and therefore they reach the RO limit at lower shaft speeds.
4.4.6.2 Required power
To calculate the required power the results of Table 4 were used, as the delivered flows at the each
evaluated speed of every considered pump were introduced in the IMSDesign tool explained in section 4.3.4
in order to calculate the feed pressure for each case. With this feed pressure the required power by the
pump was calculated, and the results can be observed in Table 5 while in Figure 11 they are presented
graphically for a better comparison.
Table 5 - Selected pumps required power at different shaft speeds
Required power [kW]
Shaft speed [rpm]
CAT 2531
CAT 3531
Hydra-Cell G25
0
0.00
0.00
0.00
50
0.06
0.12
0.08
100
0.13
0.29
0.16
150
0.21
0.51
0.26
200
0.30
0.79
0.36
250
0.41
1.12
0.47
300
0.53
1.02
0.59
350
0.67
1.29
0.72
400
0.82
1.57
0.86
450
0.99
1.89
1.00
500
1.17
2.24
1.16
550
0.94
2.07
1.33
600
1.06
2.36
1.52
650
1.19
2.68
1.71
700
1.33
3.00
1.43
750
1.49
3.36
1.57
800
1.64
3.72
1.70
850
1.80
3.45
1.86
900
1.97
3.77
2.01
950
2.16
4.14
2.16
1000
2.34
4.49
2.33
1050
2.54
4.85
2.49
1100
2.15
5.22
2.67
1150
2.30
4.90
2.84
1200
2.46
5.23
3.03
Hydra-Cell G35
0.00
0.15
0.33
0.54
0.78
1.05
1.35
1.69
1.55
1.82
2.10
2.39
2.70
3.04
3.39
3.14
3.44
3.74
4.05
4.37
4.73
5.08
5.43
5.09
5.40
The values presented in Table 5 show that while the G25 and the CAT 2531 have similar power needs, the
CAT 3531 and the G35 will require almost the double of the kilowatts for every revolution per minute.
System design
80
Figure 11 - Selected pumps required power at different shaft speeds
Every peak in each curve indicates the introduction of a new module in the operation of the system;
however, as it was already presented in the section describing the project RO array, it will only operate
with 1 or 2 modules, meaning that everything in each curve from the 3rd peak onwards is not possible.
As in the case of the flow, a linear relationship between power required and shaft speed can be observed
for the four pumps (Figure 11), at least between peaks. The power requirements of the CAT 2531 model
and the G25 are very similar, with the main difference given by the speed at which the second module starts
to operate: while in the CAT2531 this happens at around 500 rpm, in the case of the G25 this occurs at
around 650 rpm. This similarity can also be seen between the CAT3531 and the G35 models, which follow
a very similar path with peaks at different shaft speeds.
4.4.6.3 Required torque
The required torque for each pump at each evaluated speed was calculated using the values obtained in
Table 5, which means that, once again, the feed pressure value for every case was considered; however, the
formulas presented in section 4.4.5 do not work for the starting torque (torque at a shaft speed of 0 rpm),
which is a very important aspect to take into account in this project as the wind turbine design must be
able to produce at least this torque at a low wind speed.
Several e-mails were exchanged with people from CAT Pumps in Belgium and the United States, but no one
could give a correct answer about the start-up torque of the evaluated models or even on how to calculate
it, which was a surprise. They only had the data of some tests made in Japan for a 15 frame model which
resulted in a start-up torque of 7 Newton meters. Although the pumps evaluated in this project are bigger,
this is the value that will be considered for the calculations. In the case of the Hydra-Cell pumps a formula
was facilitated by the company and used to calculate this parameter, and a start-up torque of 5.7 Newton
meters was found for the G25 while for the G35 it almost doubled this value reaching a total of 11.3 Newton
meters.
In Table 6 the required torque by the pumps to pressurize the feed flow at different shaft speeds is
presented. In Figure 12 these values are displayed in a graphical way for a better visualization.
System design
81
Table 6 - Selected pumps required torque at different shaft speeds
Required torque [Nm]
Shaft speed [rpm]
CAT 2531
CAT 3531
Hydra-Cell G25
0
7.00
7.00
5.70
50
11.00
23.59
14.41
100
12.27
27.94
15.63
150
13.23
32.59
16.30
200
14.34
37.56
16.97
250
15.62
42.84
17.78
300
16.89
32.59
18.73
350
18.33
35.08
19.53
400
19.60
37.56
20.48
450
21.03
40.04
21.29
500
22.31
42.84
22.23
550
16.25
36.01
23.17
600
16.89
37.56
24.12
650
17.53
39.42
25.06
700
18.17
40.98
19.53
750
18.96
42.84
19.94
800
19.60
44.39
20.34
850
20.24
38.80
20.88
900
20.87
40.04
21.29
950
21.67
41.60
21.69
1000
22.31
42.84
22.23
1050
23.11
44.08
22.63
1100
18.64
45.32
23.17
1150
19.12
40.67
23.58
1200
19.60
41.60
24.12
Hydra-Cell G35
11.30
29.24
31.45
34.15
37.10
40.04
42.99
46.18
37.10
38.57
40.04
41.52
42.99
44.71
46.18
40.04
41.03
42.01
42.99
43.97
45.20
46.18
47.16
42.25
42.99
The required torque is directly related to the required power, and therefore similar trends can be identified.
While the CAT 2531 and the G25 models have similar values, the CAT 3531 and the G35 models require
almost the double of this.
Figure 12 - Selected pumps required torque at different shaft speeds
As in the case of Figure 11 in this graph two groups can also be easily identified, the first one composed by
the CAT 2531 and G25 models and requiring considerable less torque that the second group, formed by the
CAT 3531 and the G35 pumps. In both groups the two pumps that are part of it have similar values;
System design
82
however, an important difference can be observed in this figure in comparison to the one presenting the
required power, and this is related to the slope of the lines: while in both cases the line is increasing the
growing rate of the required torque is lower than the one of the required power, and therefore more
constant, or at least closer, values are obtained,
4.4.7 Pump selection
This section is divided in three parts: first the weighting factors are described, then the scores of each pump
are calculated and at the end the pump for the system is selected.
4.4.7.1 Weighting factors
Besides the calculated performance of the pumps presented in the previous sections, the selection of this
component will also depend on other factors that have been thought considering the way the system will
be operated and its location.
Kilifi is a county in the coast of Kenya where, as it was already explained din Chapter 3, no industry besides
the tourism and farming exists. There is no knowledge related to the components of the system, and any
provider is located kilometres away. It has a tropical climate with average monthly temperatures sitting
between 20 and 33°C throughout the entire year, and the fact that is located in the coast also means that
there is salt everywhere affecting the equipment. In addition, the market research also reflected that people
in Kilifi is not willing to pay high amounts of money for the produced water, and building a high-tech system
would not be a good decision. Therefore, extra criterions considered for the final phase of the pump
selection process are its cost and how easy it is to maintain it, as well as the manufacturer’s experience in
RO applications and its presence on the African continent. Nevertheless, as not every criterion has the same
importance weighting factors for each category were introduced. They are defined by comparing one
criterion with the other and grading the importance, assigning two points for the most important one and
zero to the other. If they are considered to be equally important each category receives one point. In total
there are five criterions considered, meaning that if one of them is more important than all the others it
will get a maximum score of 8 points. To calculate the weighting factor this maximum was assumed to have
a value of 4. The final results of the comparison between the criterions are shown in Table 7.
Table 7 - Pump selection criteria weighting factors
Criterion
Pe
C
M
E
Pr
Performance (Pe)
Cost (C)
Maintenance (M)
Experience (E)
Proximity (Pr)
0
1
0
0
2
2
0
0
1
0
0
0
2
2
2
1
2
2
2
1
-
Total
Score
7
4
7
1
1
Weighting
Factor
3.5
2
3.5
0.5
0.5
From the results of the table and the previous sections it can be concluded that an off-the-shelf positive
displacement pump capable of pressurizing an amount of fluid of 5 cubic meters per hour with 15 bar (or
a total head of 150 meters) is an absolute priority. In addition, a reliable, robust and easy to maintain pump
to avoid stand stills due to failed or damaged parts is also a very important aspect, especially considering
the Kilifi harsh conditions and that the system will be operated at a local setting. Finally, affordable pumps
from manufacturers with experience in reverse osmosis applications and presence in the area of operation
are preferred in order to easily and quickly find spare parts or get technical assistance in case it is
necessary.
4.4.7.2 Scores
In this section scores from one to four (1 for bad, 2 for regular, 3 for good and 4 for very good) will be given
to every pump in each category. Then these scores will be multiplied by the weighting factor assigned in
Table 7 and summed, providing a total score for all the pumps. The scores of each pump for every category
are based on the information and data presented in the previous sections. The total scores are presented
in next tables, and after them an explanation of the reasons behind their values.
System design
Table 8 - CAT 2531 scores
Performance
Cost
S
WF
T
S
WF
4
3.5 14
4
2
83
T
8
Maintenance
S
WF
T
3
3.5 10.5
Experience
S
WF
T
4
0.5
2
S
2
Table 9 - CAT 3531 scores
Performance
Cost
S
WF
T
S
WF
3
3.5 10.5 2
2
T
4
Maintenance
S
WF
T
3
3.5 10.5
Experience
S
WF T
4
0.5
2
Proximity
S
WF T
2
0.5
1
Table 10 - Hydra-Cell G25 scores
Performance
Cost
S
WF
T
S
WF
4
3.5 14
2
2
T
4
Maintenance
S
WF
T
4
3.5 14
Experience
S
WF
T
2
0.5
1
S
3
Proximity
WF
T
0.5 1.5
T
2
Maintenance
S
WF
T
4
3.5 14
Experience
S
WF T
2
0.5
1
S
3
Proximity
WF
T
0.5 1.5
Table 11 - Hydra-Cell G35 scores
Performance
Cost
S
WF
T
S
WF
3
3.5 10.5 1
2
Proximity
WF
T
0.5
1
TOTAL
35.5
TOTAL
28
TOTAL
34.5
TOTAL
29
The performance of the pump is the most important factor, as it is necessary that it is capable of producing
the expected amount of fresh water and withstand the fluctuating property of the power source. As it was
already discussed in section 4.4.6 the performance of the CAT 2531 and the Hydra-Cell G25 are very similar,
while the CAT 3531 and Hydra-Cell G35 calculations resulted in higher values close to each other. While
this second group provides more flow at lower speeds, the power and torque requirements are
considerable higher than those of the pumps of the first group, and therefore it was decided to give a better
score to the CAT 2531 and the G25 pumps.
The project budget is limited by the fact that, as it was described in Chapter 2, Winddrinker Holdings, the
social enterprise that initiated the project, does not have many funds. Therefore and affordable pump is
fundamental. With a price of less than 3,000 euro the CAT 2531 is considerable cheaper than any of the
other options. The Hydra-Cell G25, which has a similar performance, costs almost the double and is even
more expensive than the CAT 3531, which has a considerable higher capacity. The Hydra-Cell G35 price is
extremely high.
The system will be in continuous operation, and maintenance tasks will have to be performed with
regularity. Kilifi is a small where expertise in the components of the system is not easy to find. Ease of
maintenance is a key aspect of the pump selection process, and although both CAT Pumps and Wanner
Engineering Inc. claim that their pumps are robust, require little maintenance and are designed to
withstand harsh conditions, the seal-less design of the Hydra-Cell G25 and G35 pumps, which decrease the
amount of maintenance required by the pumps and eliminates the necessity of lubrication, is an important
advantage over the CAT models, and therefore a better score was assigned to these pumps.
Just one reverse osmosis plant owned by Mnarani Club (section 3.1.2) was found during the research in
Kilifi showing that, even though this is not a new technology, they are not very familiarized with it. A pump
suited for this type of application is needed to make sure the system keeps running with the characteristics
of the water to be used. Both manufacturers promote their pumps as ideal for reverse osmosis applications,
but CAT Pumps has been in the industry for a longer period of time and it is a very well-known company
among reverse osmosis users. In addition, as it was explained in the stakeholders analysis presented in
Chapter 2, they also are the main providers of pumping equipment of Hatenboer Water with whom they
have been working in different projects for several years proving that the components developed by these
two companies can be combined.
The system will be designed specifically for the Kilifi conditions; however, failures are inevitable, and a
pump manufacturer located in the area would be very important to obtain spare parts and receive technical
support as fast as possible, especially considering that there will be people in Kilifi relying in the water
provided by the system. None of the selected pump manufacturers are located in Kenya; however, Wanner
Engineering have a team of trained pump distributors located in South Africa while CAT Pumps does not
count with any offices in the region. They do support their clients in Africa, but this is done from their offices
System design
84
in the United States, and even though they claim to have immediate product availability and delivery, these
long distances complicate the response times, Therefore it was decided to appoint a better score to the
manufacturers of the Hydra-Cell line.
4.4.7.3 Selected pump
Considering the scores presented in the previous section (Table 8, Table 9, Table 10 and Table 11) it was
decided to select the CAT 2531 model as the pump to be applied in the project.
The reasons behind the selection of this pump, which were thought considering how the pump will be used
and some characteristics of Kilifi studied in Chapter 2 and Chapter 3 of the report, are the low power and
torque requirements to reach the desired flows, the very low cost in comparison to the other alternatives,
the robustness of the pump and the little maintenance required to keep it functioning, the experience of the
manufacturer in reverse osmosis applications and with Hatenboer Water, and the fast support they provide
to its clients even if they do not have an office in the country.
From now on this will be the pump used for all the calculations to be performed throughout the remaining
parts of the design process and the matching with the wind turbine rotor to be presented in Chapter 5.
4.5 Wind Turbine Rotor Design
In this section the wind turbine rotor that will power the selected reverse osmosis pump will be designed.
The procedure to be used applied will be based on a mix between the approaches proposed by Manwell,
McGowan and Rogers in their book “Wind Energy Explained” and the procedure exposed on the book
“Matching of Wind Rotors to Low Power Electrical Generators” by Hengeveld, Lysen, and Paulissen.
Manwell, McGowan and Rogers approach consists on going from the more general aspects of the turbine
design to its details; however, as their book is focused in modern turbines for electricity generation, the
text written by Hengeveld, Lysen and Paulissen, which is focused on the design of wind turbines of smaller
size to be installed in developing countries, will also be used as a compliment.
Fist the design premises, which consist on determining the application, reviewing previous experience and
selecting the topology, will be explained, and then a tentative rotor design will be executed.
4.5.1 Design premises
The first steps of the procedure proposed in the Wind Energy Explained book consists on determining the
application, reviewing similar projects and selecting the wind turbine topology. These steps are described
in this section and they are a very important part of the process as they allow, and even force, the designer
to take all the aspects of the project into account from the beginning.
4.5.1.1 Determine application
The application the wind turbine will have an influence on its size, control method and how it will be
installed, operated and maintained.
As it has been already explained the wind turbine to be designed in this project will be used to power the
pump of a reverse osmosis desalination plant that will be located in Kilifi, a coastal rural town in Kenya;
therefore, a wind turbine rotor capable of producing high torques at low wind speeds and that is easy to
install, maintain and operate are important design considerations.
4.5.1.2 Review of previous experience
In this step of the design process previous projects with similar characteristics are reviewed. It should
consider, in particular, wind turbines built for similar applications.
System design
85
As there are not wind powered reverse osmosis installations in operation in the Netherlands a visit to a
windpump located in Drachten, close to Heerenveen, was held in company of its designer and builder
William Dijkstra. This windpump located at the north of the country is the only one in the Netherlands that
still operates 24/7, and it consists of a multi-bladed wind turbine connected to an Archimedes screw that
is used to pump water from one level to a higher level. The coupling between the wind turbine rotor and
the pump consists of two open gears, one at the top and one at the bottom of the transmission shaft. The
goal of the visit to the windpump was to closely see how it operates in order to have a better understanding
of how its components interact with each other. In Figure 13 the wind turbine and a detail of one of the
blades profiles is presented, while in Figure 14 a detail of the aforementioned open gears used for the
power, torque and speed transmission, are shown.
Figure 13 - Overview of the windpump (left) and blade profile detail (right)
Figure 14 - Coupling top open gear (left) and bottom open gear (right)
System design
86
4.5.1.3 Select topology
There are several possible topologies to evaluate for a wind turbine, the most important ones being:
 Rotor axis orientation: horizontal or vertical
 Power control: stall, variable pitch, controllable aerodynamic surfaces, and yaw control
 Rotor position: upwind of tower or downwind of tower
 Yaw control: driven yaw, free yaw, or fixed yaw
 Rotor speed: constant or variable
 Design tip speed ratio and solidity
 Type of hub: rigid, teetering, hinged blades, or gimbaled
 Number of blades
The selection of the wind turbine topology will be done considering the characteristics of the system and
the way it will be operated as well as the conditions of Kilifi observed during the on-field work.
The most important topologies for this report are those related to the rotor design and that directly affect
the power and torque produced by the wind turbine, namely the design tip speed ratio and solidity and the
number of blades.
4.5.1.3.1 Rotor axis orientation
The first decision to make in the design process is the orientation of the rotor axis. Nowadays most wind
turbines have a horizontal axis rotor (HAWT), and two of its most important advantages over vertical axis
wind turbines (VAWT) are:
 The rotor solidity is lower, which tends to decrease costs on a per kilowatt basis.
 The average height of the rotor swept area can be higher above the ground, which tends to increase
the productivity on a per kilowatt basis.
The most important advantage of the VAWT is the fact that it does not need a yaw system and it can accept
and produce with wind coming from different directions. In addition, the blades can have a constant chord
and no twist, simplifying the manufacturing process and lowering its costs. Finally the drive train can be
located on a stationary tower, close to the ground. However, and despite these advantages, the VAWT have
presented fatigue damage in the blades and incompatibilities between structure and control, and therefore
they have not been widely applied. As the system to be installed in Kilifi must be robust and reliable no
experiments will be made and a HAWT will be installed.
4.5.1.3.2 Power control
There are different options for controlling the wind turbine power aerodynamically (stall, pitch, yaw,
aerodynamic surfaces), and its selection will affect the design of the system in different ways.
Although stall and pitch control are the most common options in modern wind turbines, in this project the
design will be, considering where it will be located and how it will be operated, very robust, and no
electrical components that are difficult to find in a place like Kilifi and its surroundings will be included.
Therefore it has been decided to apply a mechanical yaw control system in which the rotor is faced away
from the wind to reduce the power and torque produced and avoid damaging components of the system.
When designing such yaw control system it is important to consider that the hub must be able to withstand
the gyroscopic loads produced when the rotor is turned; however, the structural design of the wind turbine
is not the scope of this research and it will not be evaluated in detail.
4.5.1.3.3 Rotor position
In a HAWT the rotor may be upwind or downwind from the tower. In a downwind configuration the turbine
can have a free yaw, which is simpler to apply than an active yaw and it allows an easier usage of centrifugal
forces to reduce the blade root flap bending moments; however, when the wind goes through the rotor a
wake is produced in the downwind direction. This wake the blades have to pass through in every revolution
is a source of loads that can result in blades fatigue.
System design
87
This condition affects particularly slow turning machines as the one to be designed in this project to
produce higher torques, and therefore it was decided to use an upwind configuration.
4.5.1.3.4 Yaw control
The wind direction changes and the turbine must have a way of orienting the rotor to extract from it as
much power as possible. Downwind configurations usually work with a free yaw, but in the case of upwind
configurations, such as the one to be applied in this project (section 4.5.1.3.3), turbines normally have an
active yaw control.
It is important to highlight that towers supporting active yaw control must be able to withstand the
torsional loads produced; however, as it was already explained, the structural analysis of the wind turbine
is not going to be evaluated in this report.
4.5.1.3.5 Rotor speed
Most rotors of grid-connected wind turbines operate at a nearly constant speed; however, one of the most
important aspects of the wind driven reverse osmosis desalination system to be designed in this project is
the fact that it is not going to be connected to the power grid, which is known to be very unreliable in Kenya
and especially in the rural communities such as Kilifi.
Therefore it was decided that the system will produce all the energy that it needs to operate, and in this
stand-alone configuration the wind turbine rotor speed will be allowed to vary with the wind.
4.5.1.3.6 Design tip speed ratio and solidity
The design tip speed ratio of a rotor is the tip speed ratio at which the turbine’s power coefficient is at its
maximum. Its value will impact various aspects of the design.
There is a direct relation between the design tip speed ratio and the rotor’s solidity, which is the area of the
blades relative to the swept area of the rotor. A high-speed rotor has less blade area than the rotor of a
slower machine. For a specific number of blades the chord and thickness decrease when the solidity
decreases, but there is a lower limit given by structural constraints. Therefore usually when the solidity
decreases the numbers of blades decreases as well.
As there will be a reduction on the weight of the blades decreasing this solidity of the rotor also reduces
the costs of the turbine,; however, and even though the low solidity increases the tip speed ratio and the
rotational speed, it also decreases the produced torque, which is a very important aspect to consider for
the design of wind turbines connected to pumps.
Wind turbine rotors designed for high speed and low torque have a solidity of around 0.1, while rotors
designed for low speed and high torque tend to have a solidity close to 0.8 [74]. A relatively high solidity
with a low tip speed ratio will be applied in the current design, and their values will be evaluated later on
the chapter.
4.5.1.3.7 Type of hub
The main options for the hub are teetering, rigid or hinged. Most of the wind turbines use rigid rotor, which
means that the blades cannot move in the flap-wise and edgewise directions. This does not include systems
with variable pitch blades, but as it was already discussed this is not the case of the current design.
As other hub types would add unwanted complexity to a system that will be designed to be as simple and
easy to maintain as possible it was decided to use a rigid rotor.
4.5.1.3.8 Number of blades
Most modern turbines used for electricity generation have three blades, although in some designs they have
been installed with two or even just one blade. In this case only multi-bladed and three-bladed
configurations were considered.
System design
88
Three-bladed wind turbines produce less torque at small tip speed ratios than rotors with more blades.
This might not be a problem when coupled to generators, but it is a disadvantage for applying them directly
to a pump with a relatively high start-up torque such as the model selected for this project and any positive
displacement pump in general. Therefore a multi-bladed wind turbine capable of providing the necessary
torque and power to the pump will be designed for the current project.
4.5.2 Rotor tentative design
A procedure suggested in Wind Energy Explained for rotor design consists in three parts: blade rotor
parameters, blade shape, and rotor performance. In the first one the choice of various rotor parameters
and an airfoil is done, while in the second one an initial blade shape is determined using the optimum blade
shape. Then, in the third part, the final blade shape performance is evaluated [59].
The procedure to be followed can be summarized as this: First, the wind regime for Kilifi will be evaluated
and then, considering this wind regime and the power required by the pump, the rated wind speed and the
rated power of the wind turbine will be chosen and assuming a power coefficient and a transmission ratio
the swept area of the rotor, and therefore the rotor radius, will be calculated. After this, and based on the
characteristics of the operation to which the wind turbine rotor will be subjected to, a design tip speed
ratio, the number of blades and an airfoil with known lift and drag coefficients as a function of the angle of
attack will be selected. In the second phase a decision about the design angle of attack (and, thus, lift
coefficient at which the airfoil will operate) will be made, keeping in mind that C d/Cl has to be minimum in
order to comply with the assumption of zero drag coefficient. With this the twist and chord distribution of
the optimum blade can be determined; however, the cost and difficulty of fabricating this blade also have
to be considered in the design process as an optimum shape would be very difficult to manufacture at a
reasonable cost. Therefore the next step consists on adjusting the blade shape design, which will result in
a new design. Finally, the wind turbine rotor performance with the designed blades will be evaluated with
the CP-λ and CQ-λ curves. Each of these steps is further explained in the following sections.
4.5.2.1 Basic rotor parameters
In this section the basic rotor parameters will be determined. This includes the calculation of the rated
power for a rated wind speed of the wind turbine, the design tip speed ratio, the number of blades and the
airfoil to be used on the blades.
4.5.2.1.1 Power
The first step is to decide the power needed from the wind turbine for a particular wind velocity. The effects
of a probable power coefficient and the efficiencies of various components have to be included. The rotor
radius will also be estimated at the end of this section.
4.5.2.1.1.1 Wind regime
Unequal heating of the earth by the sun creates different pressure levels that make the wind move from
higher to lower pressure areas. Furthermore, the wind direction and speed are influenced by other factors
such as the rotation of the earth, local topographical features and the terrain roughness [75]. Kenya is
located within the equatorial region, which generally does not result in strong winds; however, due to the
country’s topographical features and varying height levels, in addition to its many lakes, significant winds
can be found throughout the country [76].
Kilifi wind
Ideally locally measured hourly averages of the wind velocity would be used for the calculations; however,
in most cases, especially on the rural areas of developing countries, only mean monthly or annual wind
speeds are known.
Despite the fact that efforts have been made to understand the Kenyan wind potential through two wind
measurement campaigns by the Ministry of Energy, namely the 2003 wind atlas from meteorological data
and the 2008 SWERA map from Geospatial mapping, there is still a lack of sufficient and reliable wind data
and its proper assessment [23], and therefore other methods to obtain wind data are required.
System design
89
RETscreen is an Excel-based clean energy project analysis software tool developed by Natural Resources
Canada. It helps decision makers to quickly and inexpensively determine the technical and financial
viability of potential renewable energy, energy efficiency and cogeneration projects. The software has
climate database that includes the meteorological data required in the model. If climate data is not available
from a specific ground monitoring station data is then provided from NASA's satellite/analysis data [77].
In the case of Kilifi the NASA satellite information had to be used, and in Table 12 the average monthly wind
speeds in meters per second for this location are presented.
Table 12 - Kilifi monthly average wind speeds in meters per second measured at 10 meters
Jan
Feb
Mar
April
May
June
July
Aug
Sept
Oct
3.6
3.3
2.9
3.3
3.9
4.2
4.4
4.5
4.3
4.1
Nov
3.5
Dec
3.2
The average monthly speeds result in a yearly average of 3.8 meters per second, which gives a rough
indication of the available wind energy potential of the location; however, for a detailed analysis more data
is necessary.
As it was already explained time series measured data are not available for Kilifi, and therefore a statistical
analysis of wind data for resource estimation approach was required. In general, two probability
distributions (or probability density functions) are used in wind data analysis: Rayleigh and Weibull. The
first one only uses the average wind speed as a parameter, while the second one is based on two parameters
and therefore can better represent a wider variety of wind regimes.
Weibull distribution
To approximate the wind that will reach the wind turbine rotor the Weibull distribution was applied. This
is a model used to estimate the frequency of different wind speeds at a location with a certain mean wind
speed. The Weibull probability density function and the cumulative distribution function are given,
respectively, by the following equations:
𝑃(𝑈) =
𝑘 𝑈 𝑘−1
𝑈
( ) exp(−( )𝑘 )
𝑎 𝑎
𝑎
𝑈
𝐹(𝑈) = 1 − exp(−( )𝑘 )
𝑎
The scale factor a, and the shape factor k, are characteristic of the studied wind locations. These parameters
are correlated by the next formula:
𝑎=
𝑈𝑎𝑣𝑔
1
𝛤(1 + )
𝑘
Therefore the wind regime can be described by two main parameters: the average speed of the wind (Uavg)
and the shape factor k, which depends on the climate:
 k = 1; polar
 k = 2; temperate maritime
 k = 4; trade wind
As the value of the shape factor k increases the Weibull distribution curve has a sharper peak, indicating
that the variation of the wind speeds are lower.
Kilifi has a temperate maritime climate and therefore the shape factor k will have a value of 2. This
assumption results in a simplification of the Weibull distribution commonly known as the Rayleigh
distribution. The new value of the scale factor a, is given by the next equation:
𝑎=
𝑈𝑎𝑣𝑔
2
=
𝑈𝑎𝑣𝑔
1
𝛤(1 + ) √𝜋
𝑘
System design
90
Using these values the Weibull distribution curve was created with the Kilifi yearly average wind speed of
3.8 meters per second and the resultant probability curve is presented in Figure 15.
Figure 15 - Weibull distribution for the Kilifi wind conditions
Vertical wind profile
The speed of the wind not only varies with space and time, but also with the height. The vertical wind profile
depends on the “roughness length” of the surface, and at higher altitudes more wind energy potential can
be found. Therefore, for the proper assessment of the winds that will reach the wind turbine rotor, the wind
speeds values must be “transferred” from the height they were measured to the height of the centre of the
wind turbine rotor, which can be done with following formula:
ℎ
ln( )
𝑧0
𝑈(ℎ) = 𝑈(ℎ𝑟𝑒𝑓 ) ∙
ℎ𝑟𝑒𝑓
ln(
)
𝑧0
In this formula href is the reference height at which the wind speed is known and z 0 represents the terrain
roughness. The wind speeds were measured by the NASA satellite at 10 meters high, and in coastal areas
on land such as the case of Kilifi the z0 is estimated to have value of 0.03. Just the height of the rotor would
be necessary to complete the calculations, and assuming it will be at a common height of 18 meters the new
wind speed values were calculated. The results are presented in Table 13.
Table 13 - Kilifi monthly average wind speeds in meters per second transferred to a height of 18 meters
Jan
Feb
Mar
April
May
June
July
Aug
Sept
Oct
Nov
4.0
3.6
3.2
3.6
4.3
4.6
4.8
5.0
4.7
4.5
3.9
Dec
3.5
The new average monthly speeds result in a slightly higher yearly average of 4.2 meters per second.
However, after the author of this report had the opportunity of going to Kilifi to visit the exact place where
the system will be installed it was decided to not scale up the wind speeds and work with the original
measured values.
The reason for this is because even though the place is indeed close to the coast it is surrounded by trees
that can disturb the wind approaching the wind turbine rotor, especially considering that machines such
as the one to be designed are particularly vulnerable to performance reduction due to obstructions due to
its small height. It was decided that it is not fair to take the benefits of upscaling the wind regime and not
consider the fact that the terrain roughness is higher than expected in these cases. Therefore the rotor will
be dimensioned for a lower wind speed regime and be prepared for the “worst-case” scenario. Pictures of
the location and the pump and well that are currently in place can be found in Appendix 5.
System design
91
4.5.2.1.1.2 Power coefficient
Wind turbine power production depends on the interaction between the rotor and the wind approaching
it. The power that can be extracted from the wind is given by the next equation.
1
𝑃𝑤𝑖𝑛𝑑 = 𝜌𝐴𝑈 3
2
This formula expresses that the wind power is proportional to the density of the air, the area swept by the
rotor blades and, more importantly, the cube of the wind velocity; therefore, the power output predictions
are very sensitive to errors in collecting wind speed data.
The function of the rotor is to slow down (disturb) the wind velocity, converting part of the kinetic power
to mechanical power at its shaft. Wind turbine rotor performance is usually characterized by its power
coefficient CP, which is given by next equation.
𝐶𝑃 =
𝑃𝑟𝑜𝑡𝑜𝑟
𝑅𝑜𝑡𝑜𝑟 𝑝𝑜𝑤𝑒𝑟
=
1 3
𝜌𝑈 𝐴 𝑃𝑜𝑤𝑒𝑟 𝑖𝑛 𝑡ℎ𝑒 𝑤𝑖𝑛𝑑
2
The non-dimensional power coefficient represents the fraction of the power in the wind that is extracted
by the rotor. The Betz limit is the maximum theoretically possible rotor power coefficient, and is given by
the following formula.
𝐶𝑃,𝑚𝑎𝑥 =
16
= 0.5926
27
Therefore, the theoretically maximum available mechanical power at the rotor shaft is, as derived by Betz,
given by the next equation.
𝑃𝑟𝑜𝑡𝑜𝑟 =
16
𝑃
27 𝑤𝑖𝑛𝑑
If an ideal rotor were designed and operated such that the wind speed at the rotor were 2/3 of the free
stream wind speed then it would be operating at the point of maximum power production, which is the
maximum power possible.
In practice three effects lead to a decrease in the maximum achievable power coefficient:
 Rotation of the wake behind the rotor
 Finite number of blades and associated tip losses
 Non-zero aerodynamic drag
For the system to be installed in Kilifi a slow running wind turbine (with a low rotational speed and a high
produced torque) will be designed. These designs experience more wake rotation losses than high-speed
wind machines with low torque, and therefore for the initial calculations a typical power coefficient C P for
multi-bladed wind turbines of 0.3 will be chosen. This value comes from the wind turbine rotor
performance curves presented in Appendix 6.
4.5.2.1.1.3 Transmission efficiency
Besides the losses produced by the fact that the amount of power the turbine from the wind has a limit, the
windpump also has to deal with the mechanical transmission losses,
For the current project the transmission losses will be assumed to be 12%. This value was obtained from
the report on the wind driven reverse osmosis desalination the Delft University of Technology installed
with Hatenboer Water in Curaçao [78].
System design
92
4.5.2.1.1.4 Radius
To calculate the rotor radius the next equations can be used:
𝑃=
1
𝐶 𝜂 𝜌𝐴𝑈 3
2 𝑃 𝑇𝑟
𝐴=
𝑃
1
𝐶 𝜂 𝜌𝑈 3
2 𝑃 𝑇𝑟
4
𝐷 =√ ∙𝐴
𝜋
To solve these equations it is necessary to include the effects of the potential power coefficient C P and the
transmission efficiency previously described. It is also noticeable the necessity of deciding what power is
needed to be produced at which specific wind velocity. It was then decided to do this with the rated values,
resulting in the next equation.
𝑃𝑟𝑎𝑡𝑒𝑑 =
1
𝐶 𝜂 𝜌𝐴(𝑈𝑟𝑎𝑡𝑒𝑑 )3
2 𝑃 𝑇𝑟
Rated power
The power produced by the wind turbine has to be greater than the one needed to drive the pump or
otherwise the system will not work. The rated power will be defined as the amount of power required to
produce the maximum capacity of the reverse osmosis array to be used in this project.
Using the IMSDesign tool it was calculated that a feed flow of 5 cubic meters per hours requires a pressure
of 13.4 bar to go through the membranes of the desalination unit (Table 3). Then, using the equations
described in section 4.4.5 it was calculated that the power required by the CAT 2531 pump to deliver this
flow is 2.07 kilowatts; however, the efficiency of the transmission also needs to be considered, and this will
increase the value of the power to be produced by the wind turbine to 2.32 kilowatts.
Rated wind speed
With the rated power already defined it is still important to select the wind speed at which the rotor is
expected to produce it. There are three important design speeds in a wind turbine [79]:
 Ucut-in: wind velocity at which the wind turbine starts to produce.
 Urated: wind velocity at which the wind turbine reaches its maximum output.
 Ucut-out: wind velocity above which the wind turbine is stopped to prevent damage.
The Ucut-in will be given by the matching procedure between the wind turbine rotor and the pump to be
explained in Chapter 5.
For wind speeds higher than U rated the power output of the wind turbine remains constant due to control
devices, which in this case consists, as defined in the topology (section 4.5.1.3), of a yaw system that turns
the rotor out of the wind direction. Increasing Urated and Ucut-out and decreasing Ucut-in looks like the ideal
solution to extract more power from the wind, but this simple choice will lead to impractical solutions.
In most climates the energy contribution of wind speeds higher than 3 times the average value is negligible
and therefore it is common practice to use this wind speed as the Ucut-out on automatic systems, while for
manual furling the wind turbine is stopped when a storm is expected. A third possibility is to make the
construction strong enough to withstand the maximum wind velocity expected in about 30 years, avoiding
stopping the wind turbine during its lifetime. As in the current project the system will be operating as long
as the wind is strong enough to produce water it was decided to apply the first option, which also allows
the system to operate without having somebody constantly in place.
System design
93
The choice of the other two speeds (Ucut-in and Urated) is not that simple, as they are related and therefore
one fixes the other. Due to the cubic relationship between power and wind speed the ratio between
Urated/Ucut-in should not be higher than 3.
For temperate maritime climates (Weibull k = 2) such as the one of Kilifi the wind speed is higher than 0.7
times the average wind speed during 70% of the year (6,100 hours), and higher than 0.5 times for 80% of
the year (7,000 hours); however, the amount of energy gained from wind speeds between 0.5 and 0.7 times
the average wind speed is less than 1% of the yearly output. Recommended values for the aforementioned
design speeds are:
 Ucut-in: 0.7 times Uavg
 Urated: 1.5 - 2 times Uavg
 Ucut-out: 3 times Uavg or higher
As it was previously presented the average wind speed (Uavg) of Kilifi is 3.8 meters per second, and to start
the calculations a rated wind speed of 1.6 times this will be considered. This results in a rated wind speed
of 6.1 meters per second.
Area and diameter
Applying the rated power and rated speed to the following equation:
𝐴=
𝑃𝑟𝑎𝑡𝑒𝑑
1
𝐶 𝜂 𝜌(𝑈𝑟𝑠𝑡𝑒𝑑 )3
2 𝑃 𝑇𝑟
A rotor swept area of 63.73 square meters was found, resulting in a rotor diameter and radius of 9 meters
and 4.5 meters, respectively.
4.5.2.1.2 Design speed tip ratio
The selection of a tip speed ratio depends on the application of the wind turbine. For a water windpump,
in which a greater torque is needed, the tip speed ratio is usually between 1 and 3.
The higher speed machines use less material in the blades and have smaller gearboxes, but require more
sophisticated airfoils. To start the iterations and considering the torque values obtained in section 4.4.6 for
the selected pump a low tip speed ratio of 1 will be applied.
In Table 14 recommend numbers of blades for different values of design tip speed ratio are presented. This
information was obtained from Wind Energy Explained [59].
Table 14 - Recommended number of blades for different tip speed ratios [59]
λ
B
1 8 - 24
2 6 - 12
3
3-6
4
3-4
>4 1 - 3
The fewer the blades the lower the possible power coefficient CP at the same tip speed ratio. Considering
the fact that the tip speed ratio might move from 1 to 3 an initial guess of 24 blades was made; however,
different amount of blades will be considered in future steps of the design and matching process.
4.5.2.1.3 Airfoil
Wind turbine blades use airfoils to develop mechanical power. These airfoils, which give shape to the crosssection of the blades, generate lift by virtue of the pressure difference across them.
System design
94
A wind turbine blade has a length R, which is also called the rotor radius, and it consists of N blade elements.
The radius, which is the distance from the hub to an element, is defined by r, while dr is the blade element
width and the chord c is its length. The blade has an angular velocity Ω. These variables are illustrated in
Figure 16.
Figure 16 - Blade variables [59]
The airfoil is the aerodynamic cross section of the blade, which creates lift as it moves through the air. Its
shape may vary from root to tip, and it strongly affects the amount of lift it produces. A schematic overview
of its geometry can be seen in Figure 17.
Figure 17 - Blade geometry [59]
In Figure 17 it can be observed that the angle of attack α is a function of the angle of relative wind Φ and
the pitch angle θP. The pitch angle is the summation of the blade twist angle θT and the pitch angle at the tip
θP,0. The incremental lift force is given by dFL and the incremental drag force by dFD, while the incremental
force contributing to the thrust and normal to the plane of rotation is given by dF N and the incremental
force creating useful torque and tangential to the circle swept by the rotor by dFT.
As a low tip speed ratio multi-bladed wind turbine rotor is being designed for the current project (tip speed
ratio below 3) the aerodynamics of the blades are not a priority, and therefore simple curved plates with a
tube at a quarter chord will be applied.
System design
95
4.5.2.2 Blade shape
In this step of the design process the design lift coefficient and design angle of attack are chosen and then
the blade shape is defined. Finally, if necessary, the blade shape is adjusted to make it easier to manufacture
and lower it costs.
4.5.2.2.1 Design lift coefficient and design angle of attack
The aerodynamic properties of the airfoil, i.e. the Cl vs α and the Cd vs α curves, can be obtained from
literature or by means of computer programs. In the current study data from literature was used.
As in Carla Generaal research the blades were assumed to be curved plates with a tube at quarter chord
[27]. The empirical curves, measured at a Reynolds number of 100,000, were obtained from the
experimental results of the Wind Energy Group of the Eindhoven University of Technology [80]. The values
of the curves can be found in Appendix 7.
The design aerodynamic conditions (αdesign = 8° and Cl,design = 1.2) were chosen such that Cl,design / Cd,design is
maximum.
4.5.2.2.2 Blade shape
As it has been previously explained the blades are divided in N elements. To estimate the shape of the blade
at each section the local tip speed ratio (λr), local pitch (θP,r), local twist angle (θT,r) and local chord (cr) can
be obtained from equations obtained from the Wind Energy Explained book, and in which wake rotation is
assumed.
Usually wake rotation is not considered in the design process of modern wind turbines, but the lower the
design tip speed ratio the more important this phenomena becomes. Considering the design tip speed ratio
chosen in section 4.5.2.1 is very low (1) then wake rotation is certainly important and must be evaluated.
In the equations R is the rotor radius, r is the local rotor radius and B the number of blades. The design
aerodynamic conditions Cl,design and αdesign are found as described in the previous section.
𝜆𝑟 = 𝜆(𝑟/𝑅)
𝛷𝑟 = (2/3) tan−1 (1/𝜆𝑟 )
𝑐𝑟 =
8𝜋𝑟𝑖
(1 − cos 𝛷𝑟 )
𝐵𝐶𝑙,𝑑𝑒𝑠𝑖𝑔𝑛
𝜃𝑝,𝑟 = 𝛷𝑟 − 𝛼𝑑𝑒𝑠𝑖𝑔𝑛
𝜃𝑇,𝑟 = 𝜃𝑝,𝑟 − 𝜃𝑝,0
The values obtained from the previous steps and used for the blade shape design are the following:
 Design tip speed ratio (λdesign): 1
 Radius (R): 4.5 meters
 Number of blades (B): 24
 Design lift coefficient (Cl,design): 1.2
 Design angle of attack (α): 8 degrees (0.14 radians)
 Pitch angle at the tip (θp,0): 0 degrees (0 radians)
In Table 15 the chord and twist distribution for the designed blade are presented. The blade was divided
in 10 sections and an extended version of this table with all the intermediate calculations required can be
found in Appendix 8.
System design
96
Table 15 - Chord and twist distribution of the designed blade
r/R
θt [degrees]
0.05
50.1
0.15
46.3
0.25
42.6
0.35
39.1
0.45
35.8
0.55
32.8
0.65
30.0
0.75
27.4
0.85
25.1
0.95
23.0
c/R
0.0206
0.0545
0.0798
0.0977
0.1095
0.1166
0.1202
0.1211
0.1203
0.1183
The designed bladed has a higher twist than modern three-bladed wind turbines and a large and roughly
constant chord, at least in the outermost part of the blade, was obtained. The reason behind this last aspect
is that, due to the fact that in multi-bladed wind turbines with low tip speed ratio aerodynamics are less
important than other factors such as the produced torque, these rotors tend to have blades with a shape
opposite to the one seen in modern wind turbines.
It is also important to highlight that according to William Dijkstra, the expert windmill manufacturer, these
type of rotors have a twist between 45 and 23 degrees, which means that the results obtained (from 50 to
23 degrees) are very close to what was expected.
4.5.2.2.3 Blade shape design adjustment
In this step, and using the optimum blade shape designed in the previous steps as a guide, a blade shape
that promises to be a good approximation is selected.
For ease of fabrication linear variations of chord, thickness and twist might be chosen; however, for the
moment this step will not be considered, as some of the values of the designed blade might still be adjusted
during the matching between wind turbine rotor and pump.
4.5.3.3 Rotor performance
The parameters commonly used for presenting the performance of wind turbine rotors are the power
coefficient CP, the torque coefficient CQ and the rotor tip speed ratio λ. These dimensionless coefficients are
related with each other through the next equation.
𝐶𝑃 = 𝐶𝑄∙ ∙ 𝜆
With these coefficients the multitude power-speed and torque-speed curves of the wind turbine can be
transformed into single CP-λ and CQ-λ curves.
4.5.3.3.1 The CP-λ and CQ-λ curves
Once the blade has been designed for optimum operation at a specific tip speed ratio the performance of
the rotor over all expected tip speed ratios needs to be determined.
The CP-λ and CQ-λ curves are used to evaluate the power and torque produced by the rotor for any
combination of wind and rotor speeds. The data for such a relationship can be found from tests or
modelling, and in either case the results depend on the lift and drag coefficients of the airfoils which may
vary as a function of the flow conditions.
The BEM code
For this project the data to build the CP-λ and CQ-λ curves was obtained through a BEM code (BEM method
explained in Appendix 9) based on the Propcode by James Tangler [81], a horizontal axis wind turbine
System design
97
performance prediction code, with the formula from the book by Wilson & Lissaman [82]. This code was
facilitated by professors Nando Timmer and Ruud van Rooij from the Wind Energy Department of TU Delft.
The code works by introducing an input file into an executable program. In this input file the blade chord
and twist distributions calculated in the previous design steps are needed, as well as other parameters such
as the radius, the rotational speed, the air density, the number of blades, the thickness of the airfoil and the
values of lift coefficient and drag coefficient for different angles of attack.
All these properties but the thickness were already discussed in previous sections. In this case the thickness
refers to the percentage of the largest camber of the blade to the chord, and for the selected airfoil it has a
value of 10% [80]. Nevertheless, the program has some limitations that are important to discuss, being the
following two the most important ones:
 No design tip speed ratio sweep: This limitation does not affect the results, but makes of the
process a very inefficient one. Instead of making a straightforward sweep of design tip speed ratios
a rotational speed is fixed in each simulation and then a wind speeds sweep is performed to
calculate the tip speed ratios and its respective power and torque coefficients. To have a range of
values that allows the construction of proper C P-λ and CQ-λ curves the process has to be repeated
several times for different rotational speeds.
 No increasing chord distribution: This limitation has a direct impact on the results of this and the
following sections, and it refers to the fact that the program does not allow the user to introduce
in the input file a chord distribution that goes from a smaller value in the hub to a higher value in
the tip, as it is the case of the current design and many other multi-bladed wind turbine rotors. As
Propcode is a very old code written in fortran language it was not possible to debug it. With the
support of Gael Oliveira Andrade of the TU Delft Wind Energy Department a fortran compiler had
to be used in order to make the code usable with modern operative systems, but the blade chord
still had to be adjusted. A constant chord is however easier to manufacture and also cheaper, which
are advantages for the system.
One of the consequences of using the Propcode program is then the fact that the blade, and more specifically
its chord distribution, had to be adjusted to it, resulting a blade shape design different to the optimum blade
shape whose twist and chord distributions are presented in Table 16.
Table 16 - Chord and twist distribution of the adjusted designed blade (constant chord)
r/R
θt [degrees]
0.05
50.1
0.15
46.3
0.25
42.6
0.35
39.1
0.45
35.8
0.55
32.8
0.65
30.0
0.75
27.4
0.85
25.1
0.95
23.0
c/R
0.1201
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
With the new constant chord distribution the program was used to build the aforementioned C P-λ and CQλ curves to calculate the performance of the wind turbine rotor. These curves can be seen in Figure 18 and
Figure 19, respectively.
System design
98
Figure 18 - Power coefficient vs tip speed ratio curve for the original blade design with constant chord
Figure 19 - Torque coefficient vs tip speed ratio curve for the original blade design with constant chord
The shape of the power coefficient vs tip speed ratio curve (Figure 18) is similar to what was expected;
however, it is important to note that due to the fact that the chord distribution was varied in order to
introduce the design in the program the maximum power coefficient (0.307) is not found at the design tip
speed ratio of 1 used in the original design, as it should, but at a value close to 1.35. The value of the
maximum power coefficient coincides with what was expected from the literature. The change in the blade
shape increased the speed of the machine.
In the case of the torque coefficient vs tip speed ratio plot (Figure 19) there is a difference between the
starting torque coefficient value obtained with the program and the one expected from the literature
research, where values between 0.5 and 0.6 were found [74]. With the Propcode a starting torque
coefficient of 0.224 was calculated. The values obtained from the program and used to build both curves
can be found in Appendix 10.
This difference between starting torque coefficients is mainly caused by the change in the shape of the
blade, meaning that the different chord distribution also decreased the amount of torque produced by the
rotor. To confirm this an analysis of the torque produced by the original design at zero rotational speed
was performed with a different methodology.
System design
99
Starting torque coefficient
When the turbine is just starting up there is no induction. Thus, in the diagram presented in Figure 20, ‘a’
is zero, and the incoming wind speed is equal to the undisturbed upstream wind speed.
Figure 20 - Blade diagram
Furthermore, as the torque needs to be determined with the rotor standing still, the local velocity (‘Ωr’) is
also zero. With this information the velocity/force diagram for the start-up situation can be drawn, and this
diagram shows that the resultant velocity is equal to the wind velocity (‘V res = U’). Because the twist of the
blade is already known and considering the fact that the local wind direction is perpendicular to the plane
of rotation, the angle of attack for this situation is also known. Therefore, for the calculations the lift (and
drag) coefficients for large angles of attack also need to be known.
In this situation all the lift of the blade is in the plane of rotation, and it is therefore the force causing the
start-up torque (the drag is perpendicular to it). The contributions of all blade elements to the torque need
to be integrated. Applying these properties to the original designed blade Table 17 was created.
Table 17 - Local lift coefficient of each blade section of the original blade design when the rotor is not turning
Local angle of relative wind
Local angle of attack
Local lift coefficient
Blade
φr [degrees]
αr [degrees]
Cl,r
section
1
90.0
39.9
1.34
2
90.0
43.7
1.27
3
90.0
47.4
1.24
4
90.0
50.9
1.21
5
90.0
54.2
1.14
6
90.0
57.2
1.06
7
90.0
60.0
0.98
8
90.0
62.6
0.90
9
90.0
64.9
0.82
10
90.0
67.0
0.76
As the wind turbine rotor is not turning the angle of relative wind will be 90 degrees for each blade section,
perpendicular to the plane of rotation, to which the local twist has to be subtracted in order to find the new
angle of attack. With this angle of attack known the empirical curves of Hageman [80] were used to find the
lift coefficient of each blade section at stand-still. With the local lift coefficients the produced torque by each
blade section at wind speeds between 1 and 10 was calculated using the next equation.
1
𝑑𝑄 = 𝜌𝐶𝑙 𝑈 2 𝑐𝑟𝑑𝑟
2
The results of the local torque produced by each blade section at the aforementioned wind speeds are
presented in Table 18, followed by the calculations of the torque produced by the entire rotor and the one
transmitted to the pump. At the end of the table the calculated torque coefficient is also included.
System design
100
Table 18 - Starting torque coefficient calculation
Wind speed (relative velocity) [m/s]
1
2
3
4
5
6
7
8
9
10
0.38
2.84
6.79
11.27
15.32
18.53
20.86
22.25
23.00
23.22
0.49
3.71
8.86
14.72
20.01
24.20
27.24
29.07
30.04
30.33
0.62
4.69
11.22
18.62
25.32
30.62
34.48
36.79
38.01
38.38
0.77
5.79
13.85
22.99
31.26
37.81
42.57
45.42
46.93
47.39
188.66
238.77
294.77
4527.74
5730.41
7074.59
86.66
113.19
143.26
176.86
0.40
0.40
0.40
0.40
Produced torque [Nm]
0.01
0.06
0.14
0.23
0.31
0.38
0.43
0.45
0.47
0.47
0.03
0.23
0.55
0.92
1.25
1.51
1.70
1.82
1.88
1.90
0.07
0.52
1.25
2.07
2.81
3.40
3.83
4.09
4.22
4.26
0.12
0.93
2.22
3.68
5.00
6.05
6.81
7.27
7.51
7.58
0.19
1.45
3.46
5.75
7.81
9.45
10.64
11.35
11.73
11.85
0.28
2.09
4.99
8.28
11.25
13.61
15.32
16.35
16.90
17.06
Produced torque by each blade [Nm]
2.95
11.79
26.53
47.16
73.69
106.12
144.44
Produced torque by the rotor [Nm]
70.75
282.98
636.71
1131.93
1768.65
2546.85
3466.55
Transmitted torque by the rotor [Nm]
1.77
7.07
15.92
28.30
44.22
63.67
Torque coefficient
0.40
0.40
0.40
0.40
0.40
0.40
The produced torque by each blade was calculated by adding the torque produced by the different blade
sections, while the torque produced by the entire rotor was calculated by multiplying the produced torque
by each blade times the number of blades evaluated (24). The transmitted torque was calculated with a
ratio of 40; however, this value does not have any impact in the calculation of the torque coefficient, which
was calculated with the following equation.
𝐶𝑄 =
𝑄𝑟𝑜𝑡𝑜𝑟
1 2 3
𝜌𝑈 𝜋𝑅
2
An indication that the calculations were done correctly is the fact that the torque coefficient does not vary
with the wind speed. The value of 0.40 differs with the 0.224 calculated with the code and it is closer to the
value found in the literature. Nevertheless, the design with the constant chord will be used for the matching
procedure, and just if the starting torque coefficient becomes a problem in the next chapter a deeper look
will be given to it.
Matching of wind turbine rotor and pump
5
101
In this chapter the reverse osmosis pump selected in section 4.4 and the wind turbine rotor designed in
section 4.5 will be matched with each other, considering the conditions of Kilifi and the expected amount
of water to be produced. As described in its selection process the pump is an off-the-shelf component and
no changes will be done to it; however, as the wind turbine has not been built yet variations to this
component are still possible.
In this chapter first the pump, wind turbine rotor and transmission characteristics are given. Then the
matching procedure starts with the original wind turbine rotor design developed in the previous chapter.
After the results are obtained different characteristics are changed in order to try to improve the operation
of the system, first varying the transmission ratio and then other parameters such as the radius, the number
of blades and design tip speed ratio. From all this simulations a small group is selected for a more detailed
analysis, and based on this a final design of the wind turbine rotor design is done.
5.1 Pump characteristics
In chapter 4 performance curves of four pre-selected pumps were evaluated at different shaft speeds, as
this velocity affects the amount of fluid the pump delivers and therefore the pressure needed to be applied
in the system, which at the same time has consequences on the required power and torque. The results
were plotted for a better comparison in Figure 10, Figure 11 and Figure 12, and the CAT 2531 model was
ultimately chosen as the pump for the system to be installed in Kilifi.
Due the fact that the system operates with a reverse osmosis array with 2 membrane modules that work in
parallel at high flows (feed flow higher than 2.8 cubic meters per hour), the required pressure and torque
do not have a completely linear behaviour as it could have been expected, but a curve that has a sudden
drop when the second module starts operating. In Table 19 the required pressures for the different
delivered flows by the pump, consequence of the varying shaft speed, are presented, as well as its related
power and torque requirements. In this case the performance of the pump will be evaluated just until 950
rpm as this is first speed, considering the used scale, at which the pump delivers more fluid than what the
RO array can take, which was defined as the system rated power.
Table 19 - Required power and torque by the CAT 2531 model at different shaft speeds
Shaft speed
Delivered flow
Feed pressure
Required power
[rpm]
[m3/hour]
[bar]
[kW]
0
0.00
0
0.00
50
0.27
6.9
0.06
100
0.54
7.7
0.13
150
0.81
8.3
0.21
200
1.08
9
0.30
250
1.35
9.8
0.41
300
1.62
10.6
0.53
350
1.89
11.5
0.67
400
2.16
12.3
0.82
450
2.43
13.2
0.99
500
2.70
14
1.17
550
2.97
10.2
0.94
600
3.24
10.6
1.06
650
3.51
11
1.19
700
3.78
11.4
1.33
750
4.05
11.9
1.49
800
4.32
12.3
1.64
850
4.60
12.7
1.80
900
4.87
13.1
1.97
950
5.14
13.6
2.16
Required torque
[Nm]
7.00
11.00
12.27
13.23
14.34
15.62
16.89
18.33
19.60
21.03
22.31
16.25
16.89
17.53
18.17
18.96
19.60
20.24
20.87
21.67
102
From the table it can be seen that the second module starts operating when the pump reaches a speed
between 500 rpm and 550 rpm as the feed pressure, and therefore the required power and torque by the
pump, decrease suddenly at this point to then start increasing again. In Figure 21 the output flow as a
function of the rotational speed of the pump shaft is displayed.
Figure 21 - CAT 2531 delivered flow at different shaft speeds
The CAT 2531 is a volumetric pump and the delivered flow varies with changing shaft speeds. Due to the
fact that it is a positive displacement pump type it has a linear relationship between these two parameters.
To deliver the reverse osmosis array maximum capacity of 5 cubic meters per hour the shaft of the pump
has to reach a speed of 925 rpm. In Figure 22 the required power associated with the pressures needed by
the flow to go through the array is presented.
Figure 22 - CAT 2531 required power at different shaft speeds
In this curve the peak, which indicates the starting of the operation of the second module, is clearly visible
at the speed of 500 rpm. Finally, the required torque for each shaft speed of the pump is shown in Figure
23.
103
Figure 23 - CAT 2531 required torque at different shaft speeds
In this figure it is important to note how the torque does not start from zero, but from a value of 7 Newton
meters. This starting torque was obtained from tests made in Japan by the manufacturer. It will be
important for the designed wind turbine to be able to overcome this starting torque in order to start the
water production. As in the case of the required power curve the peak that indicates when the second
module starts to operate is easy to identify.
5.2 Wind turbine rotor characteristics
In the previous chapter a wind turbine rotor with optimal blade shape was designed; however, the code
used to calculate its performance does not allow the introduction of a blade that has an increasing chord
distribution, as it is the case of the original design, and therefore the wind turbine rotor had to be adjusted
to this limitation by applying a constant chord.
Considering this code will be used in the matching procedure to test different designs, the adjusted version
will be used as the starting point of the calculations. Besides the chord and twist distribution to be
presented in Table 20 this design has the following characteristics:
 Design tip speed ratio (λdesign): 1
Table 20 - Chord and twist distribution of the adjusted designed blade (constant chord)
θt [degrees]
r/R
0.05
50.1
0.15
46.3
0.25
42.6
0.35
39.1
0.45
35.8
0.55
32.8
0.65
30.0
0.75
27.4
0.85
25.1
0.95
23.0
c/R
0.1201
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
0.1200
104
5.3 Transmission characteristics
Different methods of coupling between wind turbine rotors and pumps are possible, being the most
common ones the following:
 Mechanical coupling with a gearbox
 Direct electrical coupling
 Electrical coupling with battery
 Hydraulic coupling
As it has been discussed before after visiting Kilifi, studying the context and interviewing some of its
inhabitants (Chapter 2 and Chapter 3) it was decided that one of the focus of the design was to make a
system that is simple, robust and with components available off-the-shelf near the place where the system
will be installed.
On the one hand hydraulic couplings are complex and more common to modern systems, and therefore
were not considered for the Kilifi project. On the other hand the transformation of intermediate electricity
increases the equipment investment and the battery waste pollution. In addition, the usage of batteries has
other disadvantages such as the required maintenance and the limited lifetime [83]. It was therefore
decided to work only with mechanical couplings with a gearbox.
The gearbox consists of a transmission system with a certain transmission ratio, and its efficiency depends
on the type used. In conversations with William Dijkstra, a specialist in the restoration of traditional Dutch
windmills and the design and production of windpumps, as well as the person in charge of building the
provided design, a decision of using only standard gearbox was made. According to his experience a
maximum ratio of 1:4 is possible, and common values in multiple stations are:
 1st gear: 1:1, to 1:3
 2nd gear: 1:2, 1:3, 1:4
 3rd gear: 1:2, 1:3, 1:4
Considering these recommendations initial values of 1:2.5, 1:4 and 1:4 for the 1st, 2nd and 3rd gears,
respectively, will be assumed, resulting in a total transmission ratio of 40; however, these values are
expected to suffer some changes during the matching procedure until reaching a new and optimal
transmission ratio.
5.4 Matching procedure
The matching procedure between the wind turbine rotor and the pump will be done using the power-speed
and torque-speed curves of both components, as proposed by Peter Fraenkel in his FAO book “WaterPumping Devices: a handbook for users and choosers” [74] and always considering the conditions of Kilifi,
the place where the system will be installed.
First the original design made in Chapter 4 will be matched to the selected pump to evaluate the operational
speeds of the system and then, depending on the obtained results, the transmission ratio will be varied.
After this step other parameters, namely the radius, the design tip speed ratio and the number of blades,
will also be tested. Based on the outcomes of these sections a selection of promising configurations will be
made before a final design is decided.
5.4.1 Original design
In the case of the wind turbine rotor the curves will be drawn for wind speeds between 1 and 10 meters
per second which, according to the Weibull distribution presented in section 4.5.2.1, combine for more than
99% of the wind speeds that are probable to occur in Kilifi. These curves represent the power and torque
that the wind turbine rotor provides at those wind speeds at a specific transmission ratio. In the case of the
pump there will be just one power-speed curve and one torque-speed curve which indicate the power and
105
torque, respectively, required by this component to deal with the flows and their respective pressures at
the different shaft speeds.
In the power-speed plot a line that goes through the maximum point of each wind turbine rotor curve can
be drawn to indicate the locus of maximum power. The system will only function continuously when the
operating point, which occurs when the pump line crosses a wind turbine rotor curve, is to the right of this
line of maximum power, as under this condition any slight drop in wind speed causes the machine to slow
and the power absorbed by the shaft to increase resulting in a stable operation. The operating point can
only remain to the left of the maximum power locus under conditions of increasing winds, but this is not
possible to evaluate in this case.
In a few words, the operating point has to be to the right of the maximum power point of each curve. The
same applies in the torque-speed curves. The cut-in wind speed of a configuration will be given by the speed
at which this occurs for both graphs for the first time [74].
In Figure 24 and Figure 25 the power-speed and torque-speed curves are presented for the original wind
turbine rotor design with the adjusted chord and the initial assumption of a transmission ratio of 40,
superimposed on the pump curve.
Figure 24 - Power-speed curves for the original wind turbine design with adjusted chord (i = 40)
Figure 25 - Torque-speed curves for the original wind turbine design with adjusted chord (i = 40)
The matching shows that above 5 meters per second the system produces, as it can be seen in the graphs
that the first time the components cross each other in the power-speed curve at the right of the locus of
maximum power is at a wind speed of 5 meters per second, while in the torque-speed curve this happens
at a wind speed of 4 meters per second.
To extract the maximum power from a wind turbine rotor all the time a load which causes the operating
point to follow close to the locus of maximum power would be required, but this is not the case of the
106
reverse osmosis pump. At high wind speeds only a portion of the maximum power that could be produced
by the wind turbine rotor is used by the pump because its load line diverges from the cubic maximum
power curve. This discrepancy is a mismatch between the wind turbine rotor and the load (the pump). The
proportion of the power available from the rotor in a given wind speed which is usefully applied is known
as the “matching efficiency” [74]. The figures presented before illustrate how this mismatch becomes
progressively worse as the wind speed increases; however, this mismatch is less serious than it may seem,
as the time when the best efficiency is needed is at low wind speeds, when it is actually achieved. When a
wind turbine rotor is running fast enough to be badly matched with its pump it means that the wind is
blowing more strongly than usual and probably the output, although theoretically reduced by bad
matching, will be good enough as the extra speed will compensate for the reduction in efficiency.
When looking at this it may be thought that a centrifugal pump would match better with the wind turbine
rotor than a positive displacement pump such as the one selected, but in practice, and as it was already
explained in section 4.4.2, their efficiency falls rapidly below a specific threshold. In other words,
centrifugal pumps do not run with adequate efficiency over a wide range, as it will be required when
connected with wind turbine rotors. Therefore they are not generally used for these applications unless an
intermediate electrical transmission (with or without batteries) that can modify the relationship between
both components at varying wind speeds is used. To avoid using electrical components that require special
components and knowledge that is difficult to find in a place such as Kilifi it was already decided that no
electrical transmission will be applied (section 5.3).
When as in most modern wind turbines generators are used as a load, instead of pumps, a much better
match between the two components can be obtained, and therefore these systems tend to have a superior
matching efficiency over their whole range of operating speeds than windpumps [74].
5.4.2 Transmission ratio
It is important to note from Figure 24 and Figure 25 that the wind turbine rotor is producing much more
power and torque than the required by the pump, especially at high wind speeds, which means that the
rotor has, at it was described in the previous section, a low matching efficiency. This means that the rotor
is over-dimensioned for these wind speeds, but at the same time it also means that the system runs stable.
It can also be observed in the figures that the maximum array capacity, given by the end of the pump line,
or to be more exact slightly to its left, is being achieved at a wind speed below 6 meters per second;
however, as it was already explained in section 4.5.2.1, the rated wind speed for the original design is 6.1
meters per second, which means that ideally at this wind speed is when the pump achieves the array’s
maximum.
Therefore the next step is to start changing the value of the transmission ratio taking the recommendations
given in section 5.3 into account, keeping the same wind rotor design and looking to achieve the desired
production. Different transmission ratios were tested, but the one that better reached the maximum RO
array capacity at 6 meters per second, under the given circumstances, is a slightly reduced transmission
ratio of 36 (with 1:2.25, 1:3 and 1:4 gears). The results are presented in Figure 26 and Figure 27.
107
Both the pump power-speed and torque-speed curves cross the wind turbine rotor curves at the right of
the maximum point at 4 meters per second, meaning that the system will start producing water at a lower
wind speed than in the case of the original design with the adjusted chord, which is a desired characteristic.
However, the wind speed at which the wind turbine rotor starts producing could be further decreased by
lowering the transmission ratio even more; nevertheless, this will also impact the rated wind speed,
increasing its value, and a decision has to be made regarding this very important trade-off. In Figure 28 and
Figure 29 the power-speed and torque-speed curves are presented for the same wind turbine rotor but
now with a considerable lower transmission ratio of 24 (with 1:2, 1:3 and 1:4 gears).
108
In this case the system starts producing at 3 meters per second, as in both plots this is the speed at which
the pump starts crossing the wind turbine rotor curves at the right of the point of maximum power;
however, the speed at which the system starts producing the reverse osmosis maximum capacity, or the
wind turbine reaches its rated power, occurs at a wind speed of more than 8 meters per second, which is a
considerable higher rated wind speed in comparison to the previous cases.
Looking at the Weibull distribution presented in section 4.5.2.1 it can be observed that the wind speed of 8
meters per second is not very probable to occur in Kilifi, and that the wind speed of 6 meters per second is
expected around 60 hours more in the year. In addition, as the average wind speed of Kilifi is 3.8 meters
per second, the wind speed of 3 meters per second is predicted to occur only for 15 more hours per year
than the wind speed of 4 meters per second, which means that the “negative” effect of increasing the cut-in
wind speed is lower than in other scenarios. Nevertheless, and before taking the final decision on the
transmission ratio, the design of the rotor has to be finished, for which other parameters must be tested. In
the following section different radiuses, design tip speed ratios and number of blades are evaluated.
5.4.3 Other parameters
The transmission ratio is not the only parameter that can be varied to impact the operational speeds of the
system and therefore the matching between the pump and the wind turbine rotor. In this section other
parameters are considered, namely the radius, the number of blades and the design tip speed ratio.
The section is divided in two parts, first an explanation of the reasons behind the values chosen for each
parameter is given and then the results obtained from the tests are discussed, allowing the recognition of
some trends that are important to consider before deciding on the final design.
5.4.3.1 Parameters
In this section each parameter will be tested while holding the others constant. First the radius will be
varied while keeping the design tip speed ratio at 1 and the number of blades at 24, and then the design tip
speed ratio will be increased while maintaining the radius and the number of blades at 4.5 and 24,
respectively. Finally the number of blades is decreased without changing the values of the original design
for the radius (4.5 meters) and the design tip speed ratio (1).
5.4.3.1.1 Radius
As presented in section 4.5.2.1 the selection of the radius and the rated wind speed are linked to each other
in order to produce a certain rated power at a specific rated wind speed. In the original design the selection
of a rated wind speed of 1.6 times the average wind speed (recommended range of 1.5 to 2 times the
average wind speed [79]) resulted in a radius of 4.5 meters.
In this section radiuses of 3, 4 and 4.5 meters were tested, as all of them are close to the original value and
still maintain the rated wind speed in the desired range.
5.4.3.1.2 Design tip speed ratio
Low values of design tip speed ratio are common in multi-bladed wind turbine rotors [59], and that is why
a value of 1 was selected for the original design.
In this section higher values for the design tip speed ratio, which result in faster machines, of 1.1, 1.2, 1.3,
1.4, 1.5, 1.6, 1.7, 1.8, 1.9 and 2 will be evaluated in order to understand the consequences this parameter
has in the power and torque produced by the rotor and how this affects the matching process.
Too many blades will not allow the wind to go through the rotor and will have a negative impact in the
amount of power and torque produced by it. As it can be seen in Table 14 of section 4.5.2.1 the original
selection of 24 blades is the maximum amount recommended by Manwell, McGowan and Rogers [59]. In
the same table it can also be observed that the recommended number of blades for a design tip speed ratio
of 1 is between 8 and 24, while for a design tip speed ratio of 2 this range goes from 6 to 12.
109
Therefore rotors with less blades will be evaluated in this section. Particularly rotors with 6, 8, 10, 12, 14,
16, 18, 20 and 22 will be tested, as tip speed ratios between 1 and 2 were tried in the previous section.
5.4.3.2 Results
For each test (23 in total) the new chord and twist distribution were calculated using the same
methodology applied for the original design presented in Chapter 4. Then the chord distribution of each
design was adjusted in order to make it fit the Propcode and calculate the rotor’s performance. It is
important to note that when the design tip speed ratio was increased the blade chord distribution was
going from a minimum value at the hub to a maximum value somewhere in the blade (close to the root), to
then start slowly decreasing until reaching the tip, as in modern wind turbines. In these cases a constant
chord throughout the entire blade was not necessary as in the other designs; however, as in the innermost
part of the blade the values were smaller than in the rest of it (and as it was explained before the program
does not allow this type of chord distribution), a constant chord with the maximum value found in the blade
was assumed until reaching the specific section where this maximum value was originally located. From
this point onward the obtained results for a decreasing chord distribution were used as given by the code.
From these simulations, in which just one of the three parameters was varied while the other two were
kept as in the original design, some trends can be identified:
 When the radius decreases the local chords also decrease, while the chord distribution and the
twist distribution remain equal. The power and torque produced by the wind turbine rotor
decreases with its diameter. The opposite happens when the radius is increased.
 When the design tip speed ratio increases the local chords decrease, as well as both the chord and
twist distributions. The power and torque produced by the wind turbine rotor decreased with the
higher design tip speed ratio, which result in faster machines.
 When the number of blades increases the local chords decrease. The chord distribution also
decreases, but the twist distribution remains constant. With more blades the power and torque
produced by the wind turbine rotor increases.
5.4.4 Selected options
Considering the results obtained in the previous section and looking to reduce the costs of the wind turbine
rotor a selection of 4 of the designs was made to further evaluate how they match the selected CAT 2531
pump. As it was shown before, these designs do not change drastically in comparison to the original rotor,
but some variations in the operational speeds are expected to arise.
In addition, two other designs with linear perturbations were analysed, one with 10% of the chord and the
other one with 10% on the twist. Also, and although its results were already discussed, the values for the
original design will be presented again in this section for a better comparison with the new options, raising
the number of selected configurations to be further evaluated to 7. They are summarized in Table 21.
Table 21 - Options to be considered in the matching procedure
Option
Characteristic
1
Original rotor design
2
Rotor with a radius of 4 meters
3
Rotor with 18 blades
4
Rotor with design tip speed ratio of 1.4
5
Rotor with design tip speed ratio of 1.2
6
Rotor with linear perturbation of -10% of chord
7
Rotor with linear perturbation of +10% of twist
Being option 1 the original design, option 2 has radius of 4 meters, option 3 has 18 blades, option 4 has a
design tip speed ratio of 1.4 and option 5 has a design tip speed ratio of 1.2. Option 6 has a linear
perturbation of -10% of chord and option 7 has a linear perturbation of +10% of twist.
For each of these options the solidity was calculated, and afterwards all the options were matched with the
pump using the 3 transmission ratios considered in section 5.4.2, namely 40, 36 and 24. The graphs are not
included because they are too many, but the results are presented in Table 22.
Table 22 - Operational speeds of the selected wind turbine rotor options, at 3 different transmission ratios, with the selected pump
Transmission ratio: 40
Property
Option
Solidity
Power
Torque
Power
Torque
Power
Torque
Wind speed [m/s]
Cut-in
Rated
Cut-in
Rated
Cut-in
Rated
Cut-in
Rated
Cut-in
Rated
Cut-in
Rated
1
0.92
5
5-6
4
5-6
4
6
4
6
3
8-9
3
8-9
2
0.92
5
6
6
6
5
6
5
6
4
8
4
8
3
0.92
5
5-6
4
5-6
4
6
4
6
3
8-9
3
8-9
4
0.62
6
5-6
6
5-6
5
5-6
5
5-6
4
7
4
7
5
0.76
6
5-6
5
5-6
5
5-6
5
5-6
4
7-8
4
7-8
6
0.83
5
5-6
5
5-6
4
6
4
6
3
8-9
3
8-9
7
0.92
4
6
4
6
4
6-7
4
6-7
3
9 - 10
3
9 - 10
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In Table 22 the seven options considered with its respective solidity and operational speeds (cut-in and
rated) for both properties (power and torque) and the 3 different transmission ratios (40, 36 and 24) are
presented. It can be seen that in some cases just one number was used for the speed while in others two
numbers are found. The reason for this is the fact that in some cases the pump line, which finishes at the
reverse osmosis array maximum capacity, was ending between two of the evaluated wind speeds. This does
not mean that in the other cases the values were exact, but they were considerable closer to one of the
speeds than to the other.
Although savings in materials are important when the radius is decreased to 4 meters (option 2) the results
are not good. The rated wind speeds are very close to the original design, but the cut-in wind speeds are
higher. In the case of option 3 the results are identical to those of the original design, as it has less blades
(18 instead of 24) but their chords are bigger, resulting in the same solidity. The manufacturing process of
this rotor might require less work than the original design because of the less cutting, but the amount of
material used and the total weight of the rotor will remain the same. This option does not result in
important improvements over the original design.
In the case of option 4 the design tip speed ratio was increased too much, resulting in a solidity of 0.63 far
from the optimal value of 0.8 found in the literature. It has the advantage of having the lowest rated wind
speeds of the entire group of options considered, but at the same time it has the highest cut-in wind speeds,
which is not what is required from the design. The production with this wind turbine rotor would not be
enough to comply with the goal of the system.
With a design tip speed ratio of 1.2 option 5 results are, as expected, between the original design and option
4. Its rated wind speeds are very similar to those of the original design, but the cut-in wind speeds are
slightly higher; however, with a solidity of 0.76 it is an interesting option to explore more, as it has smaller
chords that could result in important savings.
In option 6 the rotor was evaluated with linear perturbation of -10% of the chord, and similar results to
the original design can be observed; however, when the chord is linearly decreased like this other aspects
of the design might be affected. The same occurs with option 7, in which a rotor with linear perturbation of
+10% of twist was evaluated. In this case the results look very promising for the transmission ratio of 40,
but they are not very good for the other two options, as a high twist makes the rotor less productive at high
rotational speeds.
5.5 Final design
In the process of matching the two components there is a very important trade-off between the starting
torque and the power produced by the wind turbine rotor, and therefore it is important to decide if a system
that starts producing at lower wind speed is wanted over one that works more efficiently when the wind
speed reaches higher values, or vice versa.
Looking at the results obtained in the previous section, option 5 (design tip speed ratio of 1.2) was
recognized as an interesting alternative and possible improvement over the original design, and therefore
it was decided to try it with a transmission ratio of 32 (with 1:2, 1:4 and 1:4 gears) for a better coupling
between wind turbine rotor and pump and to improve the operational speed (increase the rated wind
speed and decrease the cut-in wind-speed). The results are presented in Figure 30 and Figure 31.
112
Figure 30 - Power-speed curves for the selected windpump configuration (i = 32)
Figure 31 - Torque-speed curves for the selected windpump configuration (i = 32)
The operational speeds of this configuration are equal to those of the original design with a transmission
ratio of 36, and it will therefore start producing at a wind speed of 4 meters per second (cut-in wind speed)
while the rated wind speed is at 6 meters per second as wanted. Now the chords are smaller to those of
most of the previously evaluated designs resulting in a solidity of 0.76, which is very close to what was
initially expected. Finally, the increase in the design tip speed ratio (1.2) allows to reduce costs in materials
for the rotor, which will now have a lower weight. Saving money was one of the main goals of the matching
process, especially considering that, as it was described in the stakeholders analysis presented in Chapter
2, the project is being promoted by a social enterprise to which funds are a limitation.
The system will produce until the cut-out wind speed, which still has to be determined from the structural
analysis (not evaluated in this report), is reached; however, its value is, as it was previously described in
section 4.5.2.1, usually around 3 times the average wind speed. According to the Weibull distribution
presented in the same section wind speeds between 4 and 12 meters per second have a probability of occur
in Kilifi almost 43% of the time, which means that the system is expected to produce for around 3,750 hours
every year reaching the expected amount of fresh water determined at the beginning of the project. The
information about the expected amount of hours of operation can also be used to prepare a more detailed
maintenance plan and ensure the system is constantly running.
Considering these results it has been therefore decided to keep this design option as the wind turbine rotor
to be used in the system to be installed in Kilifi. The final characteristics of the rotor are the following:
 Design tip speed ratio (λdesign): 1.2
113
It is very similar to the adjusted version (constant chord) of the original design, and just the design tip
speed ratio has been increased from 1 to 1.2; however, with the new design tip speed ratio also some blade
characteristics, presented in Table 23, have changed.
Table 23 - Chord and twist distribution of the final design blade
θt [degrees]
r/R
0.05
50.1
0.15
46.3
0.25
42.6
0.35
39.1
0.45
35.8
0.55
32.8
0.65
30.0
0.75
27.4
0.85
25.1
0.95
23.0
c/R
0.1001
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.0900
The twist distribution has remained equal to the one of the original design, but the chord distribution did
change. It decreased from a constant value of 0.1200 (original version with adjusted chord) to a value of
0.1000 that, as it was already explained, results in savings on material and a lower (closer to what was
found in the literature) solidity.
The performance of the wind turbine rotor is once again described by the following CP-λ and CQ-λ curves,
which are used to determine the power and torque produced, respectively, for any combination of wind
and rotor speeds. They are presented in Figure 32 and Figure 33.
Figure 32 - Power coefficient vs tip speed ratio curve for the final blade design
114
Figure 33 - Torque coefficient vs tip speed ratio curve for the final blade design
As in the case of the original design with the adjusted chord distribution described in Chapter 4 the power
coefficient vs tip speed ratio curve presented in Figure 32 has a shape that resembles what was expected
from the literature, with a curve that starts from a power coefficient of zero at a tip speed ratio of zero and
then starts to grow until drastically increasing the steep of the curve at a tip speed ratio close to 1, reaching
a maximum value of almost 0.4 at a tip speed ratio of 1.4. This difference between the design tip speed ratio
(1.2) and the tip speed ratio at which the maximum power coefficient is achieved (1.4) is due to the fact
that the chord distribution had to be adjusted to introduce the design in the Propcode.
The torque coefficient vs tip speed ratio curve plotted in Figure 33 has, once again, a different shape to
what was expected from the literature, especially in terms of the starting torque.
The rotor was expected to have a starting torque between 0.5 and 0.6 were found [74], but a value of less
than 0.2 was obtained. The divergence between these two values is again due to the different shape of the
blade. The values obtained from the Propcode that were used to build both performance curves can be
found in Appendix 11.
This wind turbine rotor will be mechanically coupled to a positive displacement CAT 2531 pump with a
transmission ratio of 32 (with 1:2, 1:4 and 1:4 gears), delivering brackish water to a Hatenboer Water
reverse osmosis array with two modules in parallel with six ESPA2-4040 membranes connected in series
and a maximum capacity of 5 cubic meters per hour with a recovery of 50%.
Conclusions
6
115
Conclusions
The primary objective of this project was to find the optimal windpump configuration for a wind driven
reverse osmosis brackish water desalination system to be installed in the town of Kilifi in the coast of
Kenya. In this chapter concluding remarks are given by answering the five complementing sub-questions
elaborated to solve the main problem of the research.
Who are the relevant actors involved in the development, implementation, regulation and, more importantly,
usage (operation and maintenance) and consumption, of the designed system in this specific market niche?
The stakeholders of the project are divided in 8 different blocks: technology development, knowledge
consumers.
The stakeholder analysis illustrates Winddrinker Holdings, the initiator and manager of the project, as the
actor with the biggest influence on its success. Winddrinker Holdings, which belongs to the technology
development and the funding blocks, is the organization in charge of coordinating the project from the
design phase of the system until its installation in Kilifi, and therefore it is linked to many other actors
involved in different phases of the project. In 2012 and with the financial and technical support of
Hatenboer Water, TU Delft and Aqua for All this organization installed a similar system near the port of
Berbera in Somalialand.
The technology development block is completed by Hatenboer Water, CAT Pumps and Bertus Dijkstra, as
they will provide the reverse osmosis array, the pump and the wind turbine and transmission system,
respectively. These three organizations play therefore very important roles for the project. Hatenboer
Water is a Dutch company that partnered with TU Delft for the installation of a similar project in Curaçao
in 2008, but after it was completed they decided to continue their research on systems with an electrical
transmission while TU Delft decided to focus on mechanical couplings. The American company CAT Pumps
is the main provider of pumping equipment of Hatenboer Water, with whom they have been working in
different projects for several years proving that the components developed by these two organizations can
be combined. They will have to work together in the Kilifi project. Finally Bertus Dijkstra, a Dutch company
specialized in the restoration of traditional Dutch windmills and the design and production of windpumps,
will not only be in charge of manufacturing the wind turbine and the transmission system once the design
is completed, but they will also have the responsibility of coupling the wind turbine to the pump and test
the system in the Netherlands before taking it to Kilifi for its installation.
The knowledge developers, namely Hatenboer Water, Bertus Dijsktra, TU Delft and IHC MERWEDE,
provide their expertise and continuous research in different fields that have a direct impact on the project,
especially during its design phase. In the funding block Winddrinker Holdings is joined by TU Delft, IHC
MERWEDE, Aqua for All, TEDx and Hivos, as all these organizations financially support the project through
economic contributions or their network, which is fundamental for its success, especially considering that
Winddrinker Holdings is a social enterprise with limited funds.
In the stakeholders analysis it is also very important to consider the Kenyan Government, which plays an
important role in any project to be developed in the country. The Government’s block is divided in two
parts, namely energy and, more importantly, water. The actors of this block with the biggest influence in
the project are the Coast Water Service Board (CWSB), responsible for the efficient and economical
provision of water and sewerage services in the coast region of the country, and KIMAWASCO, which,
contracted by the CWSB, is in charge of providing the water and sanitation services on performance basis
at town/community level, These two institutions will finally approve or reject the proposed system.
Organic Essentials Limited is the local company that will own the system once it is installed in their land.
They will manage, with the initial support of Winddrinker Holdings, the daily financial, marketing and
distribution operations of the project. They will also be in charge of working with the Jua Kali, who are the
locals that are expected to, after trained, be in charge of the daily operation and maintenance of the system.
Jua Kali is the local name given to people who does manual labour and handmade tools to produce low cost
goods that fit the market, and are usually working under materials constraints. Some Jua Kali have already
engaged themselves in the design, manufacturing and even sales of small wind turbines.
Conclusions
116
Finally, the non-governmental organization Choice Humanitarian will work as the intermediary between
the project and the communities the system will serve. This organization has been working in the coast of
Kenya for more than 20 years trying to, among other activities, find viable water solutions for the
inhabitants of the region. Winddrinker Holdings has provided to them the first viable and affordable
solution to serve these communities with fresh water via desalination and now have an agreement in place
to build up to 10 desalination plants in the Coast Province of Kenya.
An analysis of possible future stakeholders was also performed, and Kijito Wind Power Limited, a Kenyan
manufacturer of multi-bladed wind turbines with more than 20 years of experience that could be a key
partner for local construction, technical assistance and the maintenance of the systems, and The
WindFactory, a Dutch engineering company specialized in sustainable energy installations that could
provide a solar pump ideal to back up to the wind driven system designed for Kilifi, were recognized for
the technology development block. For the knowledge development block the local universities and R&D
centres that are close to the installation site (Pwani Universty) or have related studies or ongoing research
(the University of Nairobi and the Jomo Kenyatta University of Agriculture and Technology) were
considered, as the students/researchers of these institutions could monitor and improve the system while
gaining hands-on experience. Finally the future of the intermediaries block was also evaluated and two
organization that are already operating in the area for many years developing WASH projects were
included: World Vision and Plan International.
Who are the possible end-users for the designed system and what is the situation of the different market
segments in Kilifi?
The possible end-users of the system are divided in the three market segments, namely the community, the
hotels/resorts and the farms. The unreliable water service provided by the municipality affects the
inhabitants of Kilifi in many ways, as well as the operation of the hotels/resorts and the farms, which are
the most important economic activities in town.
Most Kilifi inhabitants get their water from the tap, which is provided by the Municipality through the local
water service provider KIMAWASCO at a very low price. They have the monopoly of the water in the area.
Although Kilifi inhabitants are, in general terms, satisfied with the quality of the water they get, some
complains about the service, especially in terms of reliability, are still heard, particularly from the most
rural communities that sometimes are forced to fetch water from wells and other sources. Partnering with
non-governmental organizations or international development organizations that already have experience
in the area and are looking to help the communities of Kilifi to have access to drinking water could be a way
of finding a market for the product of the system within the communities.
There are already some alternative projects in Kilifi county that are focused on the production of clean
drinking water, most of which are trying to help the most isolated and affected communities. While some
of them are aiming to use traditional solutions such as the construction and/or rehabilitation of water tanks
and water pans, others are looking for more innovative solutions, such as the one being proposed in this
project. None of the organizations behind these projects will solve the problem by itself, but a good
coordination between the different initiatives can bring positive results to the most vulnerable
communities at the coast of Kenya.
Dutch Water Limited (DWL) has a plant in Mtwapa where desalinated water that is sold at an affordable
price to the inhabitants of Kilifi is already being produced. The market of this company is the low end of
the middle class, and this is probably the same market for the system designed in this report as long as the
product wants to be put on sale in shops or kiosks. To reach the bottom of the pyramid the prices would
have to be too low to compete with the tap water and the company would not be able to sustain itself.
Kilifi lacks of walk-in walk-out businesses as other bigger cities in the county, and tourism is, by far, the
major economic activity of the area. Some hotels and resorts, which play a very important role in the water
consumption scheme, have had several problems with water in the past and are complaining about the
reliability of the provision of water. Running their business during those periods of time when the water
service is cut is a very challenging task for them, as the complementary sources they use (boreholes,
rainwater) are not enough and the water bowsers they have to reach are very expensive. Hotels and resorts
are interested in the product of the proposed system; however, they might not be the best market segment
Conclusions
117
to aim at the moment, as the complicated situation they are going through for the last couple of years,
especially since the Westgate terrorist attack in 2013, is obliging them to save money wherever they can.
Farming is the second most important industry in Kilifi, and most farmers in the area use their own
boreholes as the main source of water which is then complemented, if necessary, with the one sent through
the tap by KIMAWASCO. Some of them are also collecting rainwater. Although the borehole water in these
farms is too salty and therefore not good for human consumption, animals or even some agricultural
activities, they have been able to operate with it for many years. They get it for a very low price as just a
small amount of money has to be paid to KIMAWASCO for the license to pump it out. Farmers like the idea
of desalinated water, but the prices would have to be very low, especially considering the big amounts they
consume, in order for them to be really interested. They are a difficult market to reach.
Which is the best pump option capable of delivering the flow and pressure required by the reverse osmosis
process to produce the expected amount of water?
The system will have two pumps, the first one will be used to pump out the water from the brackish water
underground reservoir into a storage tank while the second pump, of considerable bigger size, will be used
to pump the water through the reverse osmosis array. Only the second pump, which will be driven by the
power of the wind, was evaluated in the project.
Considering the conditions of Kilifi, in terms of available industry, knowledge and expertise in pumping
equipment, it was decided to select an off-the-shelf pump. Standard components are cheaper than custommade parts and have been already tested, meaning that fewer problems are expected to arise during their
operation. In addition, they are easier to fix and the replacement of its parts can be done quicker, which
considering how isolated is Kilifi are important aspects to take into account.
Centrifugal pumps are, due to many advantages such as its ease of operation and maintenance and its
versatility, the most used pump type for reverse osmosis applications; however, centrifugal pumps also
have a narrow range of speeds in which they operate at a high efficiency, and matching this range with the
wind turbine rotor at different wind speeds is a very demanding task. In addition, these do not have a high
torque, meaning that the production of water at low wind speeds could be a serious problem. The capacity
of a positive displacement pump is relatively low and the water flow will not be constant; however, these
pumps are cheap to manufacture and easy to use. A positive displacement pump can produce large head
even with low rotation speeds, which means that they can provide a discharge pressure that is generally
higher than the one provided by a centrifugal pump even when the input power is low. In addition, they
can deal with different power inputs and rotational speeds better than the centrifugal pumps. It was
therefore decided to opt for a positive displacement pump for the reverse osmosis array of the project.
As it will be used to pump brackish water the equipment also has to be salt resistant. The water from the
underground reservoir (well) to be used in the project has a total dissolved solids (TDS) contents of 5,020
milligrams per litter, equivalent to almost 5,026 ppm, and the values for the osmotic and operational
pressures of this water are 3.89 bar and 12.24 bar, respectively. In an optimal reverse osmosis process the
level of TDS in the water is decreased from its original amount to, ideally, a level below 500 ppm.
The reverse osmosis array to be used in the project was designed and developed by Hatenboer Water, and
it is the starting point of the design. This specific array contains two membrane modules that are connected
in parallel, each consisting of six membrane elements of spiral-wound configuration connected in series
and in which the concentrate of an element is used as the feed of the one that follows. From the two
membrane elements that can be applied in this specific array (ESPA2-4040 and ESPA4-4040) it was
decided to use the ESPA2-4040 membranes, as they have a higher rejection and even though this means
that slightly higher pressures are required it also means that the system will operate more efficiently. To
withstand the high pressures each membrane module is equipped with two 600 pounds per square inch
pressure vessels (3 elements/vessel), but they operate as just one vessel per module. The modules will
operate together when the feed flow provided by the pump is higher than 2.8 cubic meters per hour, as in
this moment the average flux rate exceeds the limit of the first module (30 litters per square meter per
hour) and could damage the membranes. The system has a recovery of 50% and the maximum volumetric
flow of water the array can operate with is 5 cubic meters per hour, meaning that the flows of the product
and the brine leaving the membrane modules have maximum values of 2.5 cubic meters per hour each. The
maximum pressure required by the RO array maximum is almost 15 bar.
Conclusions
118
Considering the fact that Kilifi is a county in the coast of Kenya with a harsh environment for any machine
and where no industry besides the tourism and farming exists and also that the system will be operated at
a local setting, extra criterions besides the pump performance were considered for the final phase of the
pump selection process. Nevertheless, as not every criterion has the same importance, weighting factors
for each category were introduced, and it was concluded that an off-the-shelf positive displacement pump
capable of pressurizing an amount of fluid of 5 cubic meters per hour with 15 bar (total head of 150 meters)
is an absolute priority for the project. In addition, a reliable, robust and easy to maintain pump to avoid
stand stills due to failed or damaged parts is also a very important aspect. Finally, affordable pumps from
manufacturers with experience in reverse osmosis applications and presence in the area of operation are
preferred in order to easily and quickly find spare parts or get technical assistance in case it is necessary.
Among the four options selected for further analysis (CAT2531, CAT3531, Hydra-Cell G25 and Hydra-Cell
G35) it was decided that the CAT2531 model was the pump that better fits the system to be installed in
Kilifi. The power and torque requirements to reach the desired flows is low, the price is very good in
comparison to the other alternatives, it is robust and easy to maintain and its manufacturer has years of
experience in reverse osmosis applications. In addition, they are recognized for the support provided to its
clients, wherever they are. It is also important to highlight that CAT Pumps is the main provider of pumping
equipment to Hatenboer Water, the company behind the development of the custom made reverse osmosis
array to be used in the Kilifi project, which means that it has been already proved that these two
components can work together.
Which is the best wind turbine rotor design capable of producing the required power and torque by the pump
with the conditions of Kilifi?
A wind turbine rotor had to be designed to power the reverse osmosis array pump under the Kilifi wind
regime; however, before designing this component its topology had to be defined, for which the conditions
of Kilifi and the characteristics of the system were taken into account. It was then decided to use a
horizontal axis wind turbine with a rigid rotor upwind from the tower and an active yaw control system.
As the system is not going to be connected to the power grid the wind turbine rotor will have a variable
speed. A multi-bladed high solidity with a low tip speed ratio is desired to increase the produced torque.
There is no detailed wind data of Kilifi and therefore monthly averages obtained from a NASA satellite at a
height of 10 meters were used to have a rough indication of the available wind energy potential of the
location. With an average wind speed of 3.8 meters per second not very high wind speeds should be
expected in Kilifi; however, its temperate maritime climate indicates that a low variation of the wind speed
is expected, which is beneficial for the design and the operation of the system.
The specific place where the system will be installed is indeed close to the coast; however, it is also
surrounded by trees that can disturb the wind approaching the rotor. Slow machines are particularly
vulnerable to performance reduction due to obstructions and it would not be fair to take the benefits of
upscaling the wind regime and not consider the fact that the terrain roughness is higher than expected. It
was therefore decided to dimension the rotor for a lower wind speed regime and be prepared for the worstcase scenario.
A flow of 5 cubic meters per hour needs a pressure of 13.4 bar to go through the membranes of the
desalination unit to be used in the project. The power required by the selected pump (CAT 2531) to deliver
this flow is 2.07 kilowatts, but considering a transmission efficiency of 12% (obtained from the report on
the wind driven reverse osmosis desalination plant TU Delft installed in Curaçao) the power that must be
provided by the rotor in this case reaches 2.32 kilowatts. This was defined as the rated power of the wind
turbine. The rated wind speed was decided to have a value of 1.6 times the average wind speed of Kilifi
(recommended range of 1.5 – 2), which results in 6.1 meters per second. Using these values the rotor radius
was calculated and 4.5 meters were obtained.
Considering the torque requirements initial values of 1 for the design tip speed ratio and 24 for the number
of blades were chosen. As aerodynamics are less important in this project than other factors the blades
selected are curved plates with a tube at quarter chord with design aerodynamic conditions of 8 degrees
for the design angle of attack and 1.2 for the design lift coefficient.
Conclusions
119
Using a code to calculate the performance through power coefficient-tip speed ratio (CP-λ) and torque
coefficient-tip speed ratio (CQ-λ) curves different wind rotor designs were tested varying parameters such
as the design tip speed ratio, the number of blades and the radius. After selecting some options for further
analysis in which they were matched to the chose pump a design very similar to the original one but with
a design tip speed ratio of 1.2 instead of 1 was finally decided.
In this multi-bladed wind turbine rotor with a radius of 4.5 meters, a design tip speed ratio of 1.2 and 24
blades, the twist angles go from 50.1 degrees at the hub to 23 degrees at the tip, while the chord distribution
has a value very close to 0.10 throughout most of the entire blade. The final solidity of the selected wind
turbine rotor is 0.76, which is very close to the value of 0.8 found in the literature.
Which is the better coupling option to transmit the power and torque produced by the wind turbine rotor to
the pump?
Considering the context in which the system will be operated it was decided that one of the focus of the
coupling was to have one that is simple, robust and with components available off-the-shelf near Kilifi, the
place where the system will be installed.
Hydraulic couplings are complex and more common to modern systems, while the transformation of
intermediate electricity increases the equipment investment and the battery waste pollution. In addition,
the usage of batteries has other disadvantages such as the required maintenance and the limited lifetime.
The system will be operating in stand-alone mode.
It was therefore decided to have a mechanical coupling with a multiple stages gearbox, and after several
tests a total transmission ratio of 32, with ratios of 1:2, 1:4 and 1:4 for the 1 st, 2nd and 3rd gears, respectively,
was selected as the best way of transmitting the power, torque and speed from the designed wind turbine
rotor to the selected reverse osmosis pump.
Reflections
7
120
Reflections
In this chapter the author wants to reflect on the work developed throughout all these months and the
process used to answer the formulated sub-questions. The reflections will therefore include the main
problems encountered during the research.

Each part of the project was difficult on its own way, but combining all the different topics involved
in a logic structure was the most challenging part of it.

When the project started there was no assessment of the wind data of Kilifi, the properties of the
water or the characteristics of the well to be used, and only after the field work was done, several
months after the project was started, (some of) these were obtained.

The layout of the plant also suffered some changes after the project was initiated, when it was
decided that the system was going to have two pumps instead of one as in the Somalialand project.
This obliged the author to do adjustments and research on aspects that were not initially in the
plans.

The initial idea was to do the field trip at the beginning of the project, but it was then decided to
postpone it several months in order to go there once the design was (almost) finished. However,
and even though these decision had some advantages, the field work also allowed the author to
study the context in which the system will be installed and collect some data. Both of these
activities ended up affecting the original design.

As long as the research is conducted only in the Netherlands some numbers are difficult to process.
Having the opportunity of going to the place where the system will be installed, meet the people
that will eventually benefit from it and understand the positive impact it will have on the
communities completely changes the perspective on the project.

English is one of the official languages of Kenya, but people in the coast does not use it very much.
They are not use to it, and even though there was always a way of communicating with each other
the language barrier was still very present during the interviews and especially in the surveys,
where the help of a translator was required. The transcription of the interviews was therefore a
more demanding task than what was initially expected.

The support of a local was fundamental for the realization of the field work, not only for the
language barrier described in the previous reflection, but also for the provided network and the
support with the transportation. Especially when a short trip is programmed, as in the case of this
project, a person that can introduce you to the culture of the country becomes essential for a faster
adaptation, otherwise a more detailed preparation would have been required.

Finding information from the distance about rural communities of developing countries is always
a difficult task, but surprisingly even web pages from the Kenyan Government were out of date,
complicating the process of gathering valid information. It was found that, for example, some
governmental websites still have information from before the last Water Act, which was declared
in 2002. Interviews with governmental institutions should have been organized.

Some of the information found on the literature research phase was not possible to confirm when
in place. This is particularly the case of the alternative water projects, on which information was
obtained through different websites but nobody knew about their existence when they were asked
in the interviews and surveys. This might be due to a lack of promotion of these projects, but it also
increases the confusion and mistrust on the collected information. The organizations behind these
projects should have been contacted before going there, as a lack of communication between
projects could lead to interference and less efficient water distribution.

There is plenty of information for designing modern three-bladed wind turbines connected to
generators for electricity production, but not that much for traditional multi-bladed windpumps.
A combination of different books had to be used to come up with a valid methodology.
Reflections
121

The starting torque of the pumps had to be assumed, and this could potentially affect the final
design of the wind turbine rotor. Constant communication with the pump manufacturers was
maintained, but they never were able send the starting torque values and there was no way of
calculating this.

Initially the Wind2Water model developed by Carla Generaal was going to be used for evaluating
the wind turbine performance and doing the matching procedure, but the code had some problems
and it was therefore decided to quit this idea. Other ways of calculating the performance of the
designs were used, but they involved the combination of different spreadsheets created by the
author and a very BEM code.

The BEM code used is based on the Propcode by James Tangler, a horizontal axis wind turbine
performance prediction code, with the formula from the book by Wilson & Lissaman. The code is
very old, and was written in fortran language. A fortran compiler was used to make it usable with
modern operative systems, but it was not possible to debug it. Two main limitations where
encountered when using this code. In the first place it does not allow a tip design speed ratio
sweep, and therefore a rotational speed had to be fixed in each simulation and then a wind speeds
sweep was performed to calculate the tip speed ratios and its respective power and torque
coefficients. To have a range of values that allows the construction of proper C P-λ and CQ-λ curves
the process had to be repeated several times for different rotational speeds, which consumed a lot
of time, especially because each design had to be introduced in the code separately. Secondly, and
more importantly, the code does not allow chord distribution that goes from a smaller value in the
hub to a higher value in the tip, as in the case of the original design and many other multi-bladed
wind turbine rotors. This obliged the author to adjust the design and continue the calculations like
this, but the rotors used did not have the optimal shape.

The matching procedure between the wind turbine rotor and the pump was done graphically
through the power-speed and torque-speed curves of both components. In these plots it was very
difficult to see the exact crossing point, and therefore it was not possible to do precise calculations
on the water to be produced by the system.
Recommendations
8
122
Recommendations
Based in the work done in this report and the reflections described previously recommendations for future
research in the topic are given in this chapter. These recommendations are also important for Winddrinker
Holdings and any other stakeholder involved, although it is considered with some modesty that there is a
probability that some of these have already been implemented, or at least considered, by them.

In projects in which many topics are involved a detailed work schedule determined at the
beginning of the process is fundamental for the development of the research, especially when there
is field work planned. It is very important to have the objectives of the research very clear since
the starting phase.

A good preparation before making the field work is crucial. It is important to make sure the
information obtained in the literature research is trustworthy, and if there is any doubt the related
organization or government institution should be contacted before going there in order to arrange
a meeting.

Developing a new program or working on improving/completing the Wind2Water code developed
by Carla Generaal in her thesis could be very beneficial for future research on wind driven reverse
osmosis desalination systems, as it would allow researchers to save a lot of time in the testing of
the different components and designs as well as in the matching process.

It is very important to assess the wind regime and solar radiation (in case solar pumps are
considered in the future) of the location. This will allow a better estimation of the amount of water
to be produced using a wind turbine and/or with the implementation of solar panels, allowing a
better decision on what technology to use and other characteristics of the system.

A proper study of the source of water that will be used to feed the system is extremely important,
not only to know the properties of the water it contains, which will impact the pressures required
by the system and therefore the design and selection of all the components, but to assess its
capacity. This is especially important in the case of wells, as their salinity increases drastically
when water is pumped out of it, meaning that if the well is not deep enough it will simply not be
able to provide important quantities of water. In the case of seawater the salinity is constant, but
its high levels of total dissolve solids require higher pressures and therefore much more power. To
go through the membranes of the array.

A structural analysis of the designed wind turbine rotor is absolutely necessary before the machine
is built. Yawing the wind turbine rotor early might reduce the amount of water produced, but it
will also reduce the gyroscopic loads on the hub, which caused the system implemented in
Somalialand to fail. This structural analysis also has to include the design of the vanes that will be
used to move the rotor.

Before the project reaches its implementation stage it is fundamental to do a deeper analysis the
impact the system will have, as it could highlight a number of key areas that were not evaluated in
this project and that could be highly important for consideration in the context of this project (or
any other project to be developed in similar circumstances). Some of these are determining how
the fresh water produced by the system is to be distributed among the different market segments,
balancing the potentially intermittent supply and preparing for the follow on effects from
(probably, and hopefully) improving the health of the population.

A proper assessment of the capacity of the locals to solve failures the system might present, the
availability of materials in the area and the response time of the components providers should be
evaluated before taking a definitive direction in future designs.
Recommendations

123
The water market in the coast of Kenya looks difficult to enter to, especially with all the obstacles
mentioned in the report. If there are no customers for the product it does not matter if the system
has the capacity of reaching its production goals. Therefore, and with the market research
developed in this report as a base, a more in depth study on the strategies, prices, competition,
possible alliances, local laws, etc. should be performed before implementing the project.
124
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Appendix
131
APPENDIX
Appendix
132
A.1 SURVEYS
Appendix
133
Survey 1 - Community
Introduction
In order to find out the expectations Winddrinker Holdings should have with the local communities a
survey was conducted on site. The goal was to find out what is the current water situation for the
inhabitants of Kilifi and if they have knowledge about desalinated water, if they would consume it and how
much are they willing to pay for it.
The survey was done to two different groups of 25 persons each: the first group was formed by people
found at the town market and the bus station, while the he second group was formed by people found at
Tuskys, the local supermarket. As Tuskys has products of higher quality and at prices than the small stores
and kiosks in town, the people found there are expected to have a higher acquisitive power.
Questions
1. How do you get your water?
 Tap
 Fetch at well/river:
 Mineral (bottled)
 Desalinated (bottled)
 Other:
Specify:
2.
Do you know its source? (where it comes from)
 Yes:
 No:
3.
If not, are you interested in knowing it?
 Yes:
 No:
4.
Are you satisfied with its quality?
 Yes:
 No:
5.
If not, why? (Mark as many options as you want)
 Dirty:
 Salty:
 Expensive:
 Unreliable:
 Time-consuming:
 Other:
Specify:
6.
Do you know what desalinated water is?
 Yes:
 No:
7.
Would you consume it? (if the standards of drinkable water are met)
 Yes:
 No:
8.
If not, why?
 Dirty:
 Salty:
 Expensive:
 Unreliable:
 Time-consuming:
 Other:
Specify:
Appendix
9.
134
How much would you be willing to pay for high quality desalinated water? (in comparison to what
you are currently paying)
 More:
 Less:
 Same:
Appendix
135
Results Survey 1 - Community Group 1
1.
How do you get your water?
 Tap: 18
 Fetch at well/river: 2
 Mineral (bottled): 2
 Desalinated (bottled): 3
 Other:
Specify:
2.
 Yes: 16
 No: 9
3.
 Yes: 8
 No: 1
4.
 Yes: 18
 No: 7
5.
 Dirty: 5
 Salty: 1
 Expensive:
 Unreliable: 1
 Time-consuming:
 Other:
Specify:
6.
 Yes: 9
 No: 16
7.
 Yes: 20
 No: 5
8.
If not, why?
 Dirty:
 Salty:
 Expensive:
 Unreliable:
 Time-consuming:
 Other: 5
Specify: I don’t trust it (5)
9.
 More: 7
 Less: 8
 Same: 10
Appendix
136
Results Survey 1 - Community Group 2
1.
How do you get your water?
 Tap: 17
 Fetch at well/river:
 Mineral (bottled): 5
 Desalinated (bottled): 2
 Other: 1
Specify: RO plant (1)
2.
 Yes: 15
 No: 10
3.
 Yes: 7
 No: 3
4.
 Yes: 19
 No: 6
5.
 Dirty: 2
 Salty: 2
 Expensive:
 Unreliable: 2
 Time-consuming:
 Other:
Specify:
6.
 Yes: 13
 No: 12
7.
 Yes: 25
 No: 0
8.
If not, why?
 Dirty:
 Salty:
 Expensive:
 Unreliable:
 Time-consuming:
 Other:
Specify:
9.
 More: 6
 Less: 4
 Same: 15
Appendix
137
Survey 2 - Shops
Introduction
Ideally, some of the produced fresh drinkable water will be sold, at affordable prices, to the inhabitants of
Kilifi through different shops located in the town.
The survey with the shops was held with the goal of finding out if they are selling water, at which price,
how they get it and if they know its source. Also, the feedback from the customers about the quality of the
product and the importance of selling water for their shops was asked. Finally questions about desalinated
water were made to find out their opinion in the subject. Shops know, better than anyone, how the water
market moves in Kilifi, and they have a different perspective of it in comparison to the community.
The initial idea was to interview different shops, but it was difficult to reach the owners that were usually
not there and for some reason most of the employees refused to be recorded. In addition, the shops were
in very noisy places, which interfered with the proper recording. Also, as they are small kiosks, they didn’t
have the time to sit with us and go through all the questions with detailed answers, so it was decided to
transform the interviews into a new questionnaire.
The respondents include small shops (P.C.I, Sunshine Digital, Taquaa Shop, Mwireri, Al-Iman Shop, Jumbe)
as well as Tuskys, the only supermarket that can be found in Kilifi town.
Questions
1. Do you sell water at your shop?
 Yes:
 No:
2.
Which type?
 Mineral:
 Desalinated:
3.
How do you get it?
 They bring it:
 I buy it somewhere else:
4.
 Yes:
 No:
5.
Have you heard any complain about its quality?
 Yes:
 No:
6.
Is selling bottled water an important income for your shop?
 Yes:
 No:
 Not directly, but it bring clients:
7.
Could you identify different market segments for the water business? Different types of buyers?
 Yes:
 No:
8.
 Yes:
 No:
Appendix
9.
138
How much do you think they would be willing to pay for desalinated water? (compare to what they
are paying right now)
 More:
 Less:
 Same:
10. Do you know about any water-related project in the area?
 Yes:
 No:
Appendix
139
Results Survey 2 - Shops
11. Do you sell water at your shop?
 Yes: 7
 No: 0
12. Which type?
 Mineral: 3
 Desalinated: 4
13. How do you get it?
 They bring it: 7
 I buy it somewhere else: 0
14. Do you know its source? (where it comes from)
 Yes: 2
 No: 5
15. Have you heard any complain about its quality?
 Yes: 0
 No: 7
16. Is selling bottled water an important income for your shop?
 Yes: 3
 No: 2
 Not directly, but it bring clients: 2
17. Could you identify different market segments for the water business? Different types of buyers?
 Yes: 4
 No: 3
18. Do you know what desalinated water is?
 Yes: 5
 No: 2
19. How much do you think they would be willing to pay for desalinated water? (compare to what they
are paying right now)
 More: 1
 Less: 2
 Same: 4
20. Do you know about any water-related project in the area?
 Yes: 0
 No: 7
Appendix
140
A.2 INTERVIEWS
Appendix
141
Recommendations
The lessons and guidelines for future field work presented by Lynn Vanheule after her research in Kenya
were used for the preparation of the interviews and the work on site [23]. These are summarized in the
following points.
 Spend enough time on the field research
Literature sources are valuable, but they are not always up to date. Field work leads to insight in
developments and brings up information that is not easy to find through other means.
 Be persistent in approaching your potential interviewees
A persistent attitude is necessary to arrange meetings. In the Kenyan context, calling is much more
appropriate than sending an email, and sometimes it is necessary to visit some actors even without having
a previously arranged appointment.
 Prepare well for an interview
Second chances are not easy to get in Kenya, and therefore a good preparation is very important. Maybe
some interviewees will be located in remote areas that will not be possible to visit more than once while
some of them provide only one chance.
 Arrange a local companion
A local companion is of great help for getting to know the country and the way of doing things, as well as
for getting safely and on time to the interviews. In addition, it can also be helpful in the process of
translating and interpreting when necessary.
 Adjust your interview questions to the education and language level of your interviewee
The differences in society influence the actual interview. The interview questions and the way to ask them
as well as the behaviour during the process need to be adjusted to each interviewee. It is important to be
flexible during the interviews.
 Ask direct questions
Interviewees will not understand the question if they are not specific enough and only very direct questions
will result into valuable information.
 Be critical on the analysis of your data sources
It is important to be careful and critical during the analysis of the retrieved data, as many of the literature
sources provide incomplete or even false information. This is also the case for the interviews, as some of
the them might answer the questions based what the interviewer wants to know, hiding information and
even lying in some cases.
 Take into account that a field research in Kenya takes more time and comes with uncertainties
Research in Kenya takes more time than in a western country. Allocating enough time for the research and
adapting a flexible planning to deal with the uncertainties are very important considerations.
Appendix
142
List of interviews
This table presents a summary of the interviewees, and do not reflect the order in which the interviews
were done.
Interview
1
Darcas Amakobe
2
Easterlina Moseti
Organization
Moving the
Goalposts
World Vision
Emmanuel Baya
Plan International
4
Travis Axe
KOMAZA
5
Joseph Karanja
3
Group
NGO’s
6
7
8
Peter Njoroge
Hotels/Resorts
9
10
11
12
Farmers
13
14
15
Name
Paul Omam
Henk Venter
Thomas Atkinson
and Romain Mari
Warren Wilson
Ja Maina Wanjohi
Chokkie Rama
Robert Clarke
Water
desalination
companies
Municipality
water providers
Bofa Beach Resort
Kilifi
Kilifi Bay Beach
Resort
Water Gate Hotel
Mnarani Club
Distant Relatives
Limited
Kilifi Plantations
Patbon Farm
Ramar Farm
REA Vipingo
Plantations
Limited
Position
Programme
Manager
Project Officer
Project
Implementation
Officer
Technology
Manager
Manager
General Manager
Manager
Resort Manager
Managers
General Manager
General Manager
General Manager
Estate Manager
Michael Dubelaar
Dutch Water
Limited
General Manager
Cornelious K.
Mutai
KIMAWASCO
Area Manager Kilifi
Appendix
143
Group #1 - NGOs/International Development Organizations
Introduction
Interviews were done with non-governmental organizations and international development organizations
that work closely with the communities of Kilifi that will eventually benefit from the water produced by the
system. These organizations know the communities very well and tend to work as the link between them
and any company or organization that wants to develop a project in the area.
These interviews were made with the goal of understanding the communities better in order to know how
to approach them and what challenges are expected, and to try to find out if, in the opinion of these
organizations, the communities will accept the system and be interested in the product. Questions about
the organization were also included in order to find out more about what is being done in the area. The
interviewed organizations were: Moving the Goalposts, World Vision, Plan International and KOMAZA
Interview
The following questions will guide the interview:
1.
2.
3.
4.
What is the goal of your organization?
How long has your organization been operating in the area?
What are the main activities your organization develops in the area?
Do you provide clean water for the communities?
a. If so:
i. How do you obtain the water?
ii. How do you get the water to them?
iii. How much do they pay for it?
iv. How do they pay for it?
b. If not:
i. How do they obtain the water?
ii. How much do they pay for it?
iii. How do they pay for it?
5. Could you differentiate market segments within the communities? If so, does that mean different
strategies must be taken to approach each?
6. How do you communicate properly with the communities on the area?
7. What are the main difficulties when approaching the communities on the area?
8. What do you consider the largest barriers and drivers of the business of affordable water in Kenya?
9. Would you consider that a technology such as the one being proposed will be accepted by the
communities of the area? If not, why?
10. Do you know about other actors selling affordable water in the region?
Appendix
144
Interview 1: Darcas Amakobe (Moving the Goalposts)
Interviewee: Darcas Amakobe
Organization: Moving the Goalposts
Position: Programme Manager
Contact: +254 722 315 223 / [email protected]
1.
Our goal is to empower girls and young women through sports.
2.
How long has your organization been operating in the area?
The organization started in 2001.
3.
We use football as an entry point and in the process we discuss issues of reproductive health. We also give
girls a chance to improve their livelihood.
4.
Do you provide clean water for the communities?
No, we don’t provide clean water directly, but the girls that we work with are affected of course by issues
of water and, through football related activities, we teach them about WASH, so the water contributes with
the outcomes of the program. In the facilities we use piped water from KIMAWASCO and we have storage
tanks.
5.
Could you differentiate market segments within the communities?
Well, yes. KIMAWASCO sends water to different people. Members of the communities require licenses, but
for example schools sometimes get it for free (with the support of NGO’s). There is also people taking water
illegally.
6.
How do you communicate properly with the communities on the area?
Communities are very receptive, and the best way of getting to them is through the village elders and the
chiefs.
7.
What are the main difficulties when approaching the communities on the area?
Because you are a mzungu* people will ask you for money, which might be a very stressful experience. You
have to avoid giving them anything because otherwise they will continue asking. Tell them you’re a student,
and give them all the info.
8.
What do you consider the largest barriers and drivers of the business of affordable water in Kenya?
More funding from the government is needed. More pipelines are needed. Water infrastructure is very
expensive, very costly. There is a lot of depletion of forest, which are now almost gone. Rains are too scarce.
9.
Would you consider that a technology such as the one being proposed will be accepted by the
communities of the area?
As long as you educate the community it should work. Is better to start with a pilot project and then expand.
Maybe at the beginning the water could be used for irrigation purposes.
Appendix
145
10. Do you know about other actors selling affordable water in the region?
KIMAWASCO is the main provider, but I know other organization such as Plan and World Vision are
developing projects related to water.
*mzungu: swahili word for white person.
Appendix
146
Interview 2: Easterlina Moseti (World Vision)
Interviewee: Easterlina Moseti
Organization: World Vision
Position: Project Officer
1.
What is the goal of World Vision?
World Vision mainly works with the poorest and most vulnerable communities. We try to go to those
communities and transform their life in different ways by empowering them so that they can be able to
improve their livelihood. We do this through different sectors depending on the area we are working with.
2.
Since when is World Vision working here in Kilifi?
In Kilifi the main program area is in Bamba, so this office is just a part of that one. We started working in
Bamba in 2007.
3.
Within Bamba program we have sponsorship, which is the main World Vision project and is how usually
we come into the communities. Then we have WASH (water, sanitation, and hygiene), education, and we
have a project in maternal and new-born child health.
4.
Is part of your activities to provide clean drinking water to the community?
5.
Can you tell me a little bit about it?
Yes.
As I mentioned one of our projects is a WASH project, which has various components. In the sanitation and
hygiene aspect of it we create awareness around sanitation issues, which include the proper use of toilettes,
hand washing, and treatment of water, and then there is the construction component of it, the technical
part of it, where we try to see how we can increase the access to the different households. There are various
ways: you can either provide tanks if there is already a pipeline through which the water is there or in some
areas where is completely no access we do assess and support the personnel of the Ministry of Water to
construct a pipeline for water.
6.
When you do these projects with the community, how do they get the water?
It depends on the area, because the region that we serve is quite big. There are some areas that have an
issue with access, there are some areas that have an issue with storage, and there are some areas in which
there is need for a pipeline to be there. What would happen is that before we do anything we have to consult
with the community, carry out community dialogues, which are basically community meetings in which
you sit with them and inquiries what the issues are around water, and based on what the community says
and based maybe on the technical assessment we decide on what approach we want to use.
7.
When you do these projects, are the communities paying in some way?
It depends; most recently we did what you call water kiosks. We contribute with the materials and the
community contribute one with the land where the water kiosk could be placed and then then they also
contribute with the labour to build it. Then afterwards the community is responsible to maintain whatever
structure or whatever project that we have implemented there, so they have to go through training on how
to maintain the structures that we have installed.
8.
And how is that working so far? It has good results?
Yes, mostly. The issue usually is just handling over things to the community without properly preparing
them, but we have seen them that if you take them through the capacity building, making them get used to
Appendix
147
the idea of taking ownership -the most important thing with the community is letting them know that once
is handled over to them is their responsibility, they have the responsible to maintain it-, it has actually
worked so far.
9.
What would you say is the best way to communicate with the communities?
The best way is first to always keep the community informed and involved in everything that you do. You
should never go in and assume that the community needs a tank. Maybe that is not what they need. So,
what you call community involvement and dialoguing with the community is very important, because they
themselves know what the priority issues are in that community in terms of water usage, water issues,
anything. Then they should be able to guide you. And then also, I think capacity building and preparing
them is important. There are many skills that they need to be capacity build on so they can be able to
operate. Another important thing is follow-up, right after that, to ensure that they do what they’re supposed
to be doing. Let’s say you go and build a toilette maybe, we have to ensure they are continuously using that
toilette the proper way. Continuous supervision and follow-up is very important.
10. What would you consider are the main difficulties when approaching a community here?
I think the “dependence syndrome” is huge. They always look at organizations as the big brother. They
expect you to do everything and they don’t want to make any contributions. On the other hand which is
also related to that is the ownership. Let’s say you come and you build a pipeline. If that pipeline gets
damage they expect you to come and fix it, even though it is their project. So that ownership, which is
related again to that dependence syndrome, is a very big issue. That mental preparation and also just the
awareness, increase knowledge on how to run their own projects, how to independently be able to maintain
those projects once they’re completed.
11. Considering this business of affordable water, this distribution of water that can be sold at a low
price, what would you consider are the biggest barriers or challenges and what would be the
biggest drivers?
What I have seen is people personalizing the water kiosks. There is usually what we call rural water usage
committee in the area where we build our water kiosk, which is responsible of it; however, we have
experienced in some area people personalizing the kiosks and instead of the water being used for the whole
community it becomes personal. Somebody puts a pipe and the water is connected maybe to their farm and
it ends up benefiting that farm instead of the whole community, so you see a lot of the times that something
you think is good for the community actually ends up being a conflict because of that personalization, but
again, it goes to how you prepare these communities at the beginning, that is why so essential to build the
capacity on a lot of things like leadership, transparency, and what you call advocacy, so they can be able to
voice any issues that they have. The preparation part is key, really an important factor.
12. Are the communities willing to really learn all these skills? What I see and hear is that the
communities have maybe their own way of doing things, and then there is an organization like you
with all the good intentions, doing a good thing for them because they really need water, and then
there is a guy that connects his pipe and steals the water. At the end all the nice idea becomes, as
you’re saying, a conflict in the community. Have you seen a change during your experience? Are
the communities really engaging all these trainings?
That’s why I mentioned, back to how you approach with these projects, if you keep the community involved
in the whole process, right from the inception of carrying out the needs assessment, the community is
already aware, this is what World Vision wants to support. Now, when World Vision identifies a need
somewhere, we will call a very big meeting, we involve also the administration, the chiefs, so is transparent
from the beginning what is happening, everybody knows the persons responsible, everybody knows who
the committee are, is that preparation of the community to be able voice issues, is that openness, is that
continuous cooperation from World Vision in many issues. We come together; we have a very good
relationship with the administration in terms of handling disputes. So there is a bunch of mechanisms that
we use in different approaches to hopefully make the thing sustainable, which is of course the goal.
Appendix
148
13. Do you think that the product of a technology such as the one being proposed would be accepted
by the communities? That people would actually use it and drink it?
I’m not sure. It all depends on the awareness, on how sensitive is the community to it. On the project that
I’m working on we are having a challenge in changing perceptions. I work a lot with community health
workers, and they distribute the water purifiers, which surprisingly was received quite well when the
communities were approached, at a household level, by these community health workers. Community
health workers are people who live within the community. They are people who are chosen from the
community, so if a community health worker comes to your household every month to see the progress of
your sanitation and your hygiene, and the health of your babies and everything, you develop a relationship
with this person because is somebody that you know, so people from the community will listen to them
much easier than maybe a chief doing it, or a doctor from town, or a person of World Vision. For us, we
really utilize the community health workers to create and increase awareness because is people from their
community, they act as role models, and people will do what they do, so if they use the purified water people
will do it. If you create awareness with these people they are familiar with, if they buy the idea, it’s very
easy for the people within the neighbourhood and their villages to buy the idea. The communities respect
more the introduction of a new product if they are being part of the introduction and is not just somebody
else from outside coming to explain something.
14. You are building these water pans and there is KIMAWASCO bringing water through the pipelines.
Do you know about any other water projects here in Kilifi?
The main ones is what KIMAWASCO is doing and the water pans. There is nothing else. You will hardly ever
hear about water wells because everybody, I don’t if its true cause I don;t know much about wells either,
but everybody says that the well water is salty.
15. (After explaining the desalination process) Do you think these communities would be willing to
pay for that water or is something they would do just if it is given to them?
Just depends on the approach. In the water kiosk people are willing to pay. Why wouldn;t they do it with
the well water? As long as it is water they can consume.
16. Can you tell me a little bit more about these water kiosks? What is the idea behind it?
Water kiosks are there mostly because water sources are so far away, so you may find that there is a
pipeline that is connected to the main source of water, but this pipeline is very far from the households, so
we develop like water shops in different parts to decrease the distance people needs to walk to get to one
source. You create small pipelines in different point. What happens is that there is a certain amount they
have to pay, and that money goes back to running that water kiosk.
17. What is the price of the water you’re selling in these water kiosks?
We had one somewhere, but then there were issues with pipelines so that stopped. We recently build
another one but we are waiting for the water source. Normally if you want to go and buy water somewhere
in Bamba the price is 10 schillings for a 20 litters jerry can. If you have a water kiosk you have to lessen the
price, to make it available for as many people as possible. Ideally we are looking to reduce the price to
somewhere around 2 shilling for the 20 litter jerry can. The water is already available now, but the persons
have to go a long distance to fetch it.
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Interview 3: Emmanuel Baya (Plan International)
Interviewee: Emmanuel Baya
Organization: Plan International
Position: Project Implementation Officer
Contact: emmanuel.baya@plan_international.org
1.
This is the CCD, Child Centre De-nutrition, and our main goal is to make sure children reach their potential
within the communities.
2.
How long has your organization been working in the area?
Since 1995.
3.
We are doing health projects, livelihood, education, inclusion, and protection. All of them focused on
children.
4.
Is part of your activities to provide clean water for the communities?
Yes, we had 3 projects last year to extend pipelines to communities and provide them with clean water.
5.
And in these projects of extending the pipelines for the communities where were you getting the
water from?
We are getting it from the main pipeline that is called Baricho and goes from Malindi to Mombasa. We
extended the pipes at 3 different points: one at the north, one at the south, and one at the east to serve
different communities.
6.
In this project, where you going to charge some money to the community or were you just going
to give them the water?
Once the pipeline is constructed, a water committee is installed, and they are the ones who set the
(affordable) prices for the water. If they sell it too high we stop sending them water. The community has to
be able to afford it.
7.
How did you fund this project?
The projects are funded from the support of other countries, from donors.
8.
Inside the communities you are doing these projects for are there different market segments?
Yes, there are different markets segments. Farmers need additional water, so for them we do some sort of
water catchment, like small dams, and water is collected for different purposes, however, the water from
the main pipeline is used just for drinking purposes.
9.
What would you say is a proper way of approach a community here in Kilifi?
You have to go through the people who are committee leaders. They are the ones that can introduce you to
the community, so contacting them you normally request for some sort of a meeting and you agree on the
date and the terms. When the time for the meeting comes normally people comes a little bit late, so is better
to make the appointment early. Once everybody is gathered and ready the committee leader is the one that
will introduce you the community members and you will give them a brief explanation of your project. If
you don’t know Swahili you just talk to them in English and somebody will be translating.
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10. What would you say are the main difficulties in the process of approaching these communities?
The major difficulties that I see in these communities are related to the commitment. For example, getting
the people from their farms is a problem. They might say they will be there tomorrow for the meeting and
at the end nobody comes because they are busy with their farms, so the people are not easily available.
Another problem is that here, men, who are the household head, are normally the decision maker. They
give permission to the wife or the boy to go to the meeting to listen, and even if they told them what to do,
a decision (of accepting or rejecting the proposal) will not be taken. It is a problem because men don’t come
to the meetings very often but they are the decision makers. Women come to the meeting but they cannot
take the decision.
11. What would you consider are the main barriers and drivers of the business of affordable water in
Kenya?
Barriers:
The communities are poor, very poor, so before you set the project you tell them what will your
organization do (A-B-C-D) and you agree how much they will give, something like 10%, which is normally
through skill labour, like cutting the bushes, digging trenches and filling out the trenches, but when the
time comes for the closure of the project comes, certain community members will ask (demand) for money.
Even when you agreed they will pay a part of the project with labour they ask for payment. Another
problem is that we are lacking role models in the communities.
Drivers:
In some areas we have people who are very keen, they have the passion and they are hard-working. They
go and do with no problem. They are very supportive with these projects.
12. In your opinion how can you bring these different groups of people (those who are keen and
helpful and those who don’t care) together?
Whenever we have this type of implementations, we call for a meeting and the natural leaders, those with
the passion, will come and we use them as natural leaders to go and somehow and get all of their colleagues
who might not be that supportive to try to convince them. Secondly, when there is a committee that is not
very active or successful, we tell them to work with other more active committees to learn from their
colleagues the benefits of the active work and how to also become a successful committee. Some of them
have improved because they saw that their colleagues are doing it good, so they catch up and manage their
program well.
13. Would you consider that a technology such as the one being proposed will be accepted by the
communities of the area? If not, why?
Yes, as long as some parameters are met. Once the water is clean and potable then people will take it.
14. Besides yours, do you know if there is any other water project being developed in the area?
Yes, there is a project to provide water to arid and semi-arid areas. They normally dig dams and water pans,
which are a bit smaller water catchement areas that allow people to get water 2 or 3 months after the rainy
season. But for the big projects they provide dams, and when it rains they can collect a lot of water that
lasts up to 3 years without being dry again. Even though they normally between 3 and 7 months they can
collect all this water. Dams are OK, but the issue is how you take that water from it. The problem is that
during that period of time the water can get dirty for different reasons and stops being drinkable. One thing
is providing water and another one is to make sure it is clean for the community.
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Interview 4: Travis Axe (KOMAZA)
Interviewee: Travis Axe
Organization: KOMAZA
Position: Technology Manager
1.
The ultimate goal of the organization is to collaborate with rural farmers throughout the coast region of
Kenya, and to plant trees with them, not only providing a supplementary income but, in theory, alleviating
them from poverty.
2.
How long has your organization been working in the area?
KOMAZA has been around for 8 or 9 years.
3.
What are the main activities you are developing?
I’m building and monitoring the evaluation system and several business management systems as well.
4.
Is part of your activities to provide clean water?
No, we don’t have any hand in providing water.
5.
And do you know how do they get their water?
Most of them are from wells, almost all of them. Some get water of river systems, seasonal/annual river
systems. Modern wells boreholes.
6.
Have you come up with a proper way to communicate with them? What do you think would be the
best way to do it?
There are several ways. We do hold a lot of community sessions where we collaborate with chiefs and
influential members of the community, and we hold different gatherings as far as just explaining a lot of
what we do and this might be part of the recruitment process. A lot of our communication is disseminated
down throughout our field network which is called the facilitators, and we have 70 or 80 of those. They are
the ones that work side by side with the farmers. I believe there is probably gaps of communication in that
process, so one of my objectives, one of the things I’m looking at, is how to provide the farmers with a
platform of communication over feature phones, because most of them have feature phones, so could be a
system similar to M-PESA* or something like that, just basic SMS codes. Even if we are just sending out
basic info, some sort of channel of communication.
7.
What would you say are the main difficulties in the approaching process?
Gaging expectations is one. Also maintain patience. These trees, depending on their growth rate, could take
5 to 10 years to harvest. That’s a long investment, so maintaining that patience and not been able to rely on
the farmer not to just cut down a tree or maybe sell one on the side or something like that, and to really
help them understand that the longer that thing is on the ground the more money is going to be worth when
it pulls out, that’s a very tough one. Also finding stigma, we plant eucalyptus and there has been outcry that
eucalyptus takes too much of the water. I’m sure that’s true with a lot of species, but with the particular
strain we plant is not the case.
8.
In your opinion what do you think are the largest barriers and drivers for the business of affordable
water here in Kilifi and Kenya?
A lot of the barriers are lack of proper regulations and restrictions on water rates, and more importantly
the lack of enforcement. The drivers, well, there is good rain. It comes, there are decent water sources. The
water is here.
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152
Would you consider that a technology such as the one being proposed will be accepted by the
communities?
Yes, I do. I honestly do believe that it would be accepted. I feel that Kilifi, and the entire coast region, is an
eclectic mix of people. Definitely the majority of the population is Kenyan, and moreover Giriama**, but
there is a lot of different Kenyan tribes, there is a lot of expats, and there is a lot of foreigners as well, so I
think on the coast you have a really good chance. The far the inland you move the more difficulties you’re
going to have in installing that new idea.
10. Do you know about any other water project in the area of Kilifi and its surroundings?
To be honest with you I’m not familiar.
*M-PESA is a mobile money transfer solution that enables the users of the Kenyan mobile network operator
Safaricom to do transactions safely and conveniently.
**Giriama are one of the nine ethnic groups that make up the Mijikenda ("the Nine Tribes"), which are nine
Bantu ethnic groups inhabiting the coast of Kenya.
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Group #2 - Hotels/Resorts
Introduction
Tourism is the most important activity for the Kenyan Coast economy, and, according to the research done
in the literature, the sector has been affected by water scarcity problems in the past.
Interviews were held on site with hotels and resorts owners and managers to find out their water situation
and the problems this industry has had in the past with the water access, how did these problems affect
them, how did they solve them and what are their expectations for the future in this aspect. The interviews
were also used to evaluate their interest in the product of the designed plant and to find out the impact of
the delicate political situation of the country. Are hotels and resorts a possible client for the produced
water?
The interviewed hotels includes a big range that goes from the small Water Gate Hotel located in town, to
Mnarani Club, the biggest hotel in the area. The Bofa Beach Resort Kilifi, the Kilifi Bay Beach Resort, and
the Eco-lodge backpackers Distant Relatives were also included in the interviews.
Interview
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
How much water does your hotel/resort consume?
What is its main use?
How do you get it?
What do you have to do to get it?
How much do you pay for your water? (price/unit)
Are you satisfied with the water you are getting? If not, why?
Have you had water scarcity problems in the past?
How did they affect you?
How did you solve these problems?
In your opinion, what would be an ideal solution?
Would you use it? If not, why?
How much would you be willing to pay for desalinated water? (compare to what they are paying
right now)
15. Would the fact that it is produced from renewable energy sources affect the amount of money you
are willing to spend on it?
16. Can you provide me some numbers of the industry? (Role in economy, number of tourists, etc.).
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Interview 5: Joseph Karanja (Bofa Beach Resort Kilifi)
Interviewee: Joseph Karanja
Organization: Bofa Beach Resort Kilifi
Position: Manager
Contact: +254 720 209 516
1.
How much water do you consume here in the hotel?
A day might be maybe 500 litters.
2.
What is the main use of the water?
Cooking, washing, showers, toilettes.
3.
How do you get this water?
We got them from KIMAWASCO. We are normally charged through the meter. We have 2 meters, so all the
clean water we consumer is reflected there.
That's from the pipes, but we also have a safety tank. We normally pump water on it when they're empty.
The water is normally supplied I think 3 days per week, so the tank is used for the days without water.
4.
Do you know the source of this water?
In Mombasa we are normally supplied from Tahita Hills, but I'm not very sure in Kilifi where they get them
from. In Tahita there is a spring called Mzima. Kilifi I'm not very sure. In Mtwapa we have the main pipe on
the right side from Kilifi.
5.
KIMAWASCO provides water to all this area?
Yes, KIMAWASCO is Kilifi Mariakani Water and Sewerage Company. And the water comes from this Mzima
spring.
6.
How much are you paying or the water?
The water is not very expensive; actually, it is very cheap. I just saw one our monthly bills which amounts
to 16,000 schillings, but I think we had a balance of last month, September, so let's say like 5,000 to 6,000
schillings per month. When the hotel is empty you can't use 500 litters, it is less, so it depends. For the last
4 days we have been very quiet, so actually I have not been using the water, like we need when there are
people.
7.
Are you satisfied with all the water service? Its quality?
Yes, I'm satisfied. Well, according to my knowledge is OK, and is very cheap.
8.
Yes, when the pipe bursts, sometimes we have problems, not only here but in the whole region.
About 2 weeks ago we had a problem, because we actually we didn't have water, so we had to call them to
come and service the pipes. I think there was a blockage somewhere, so they came and they repaired and
we got the water back, but is not something that happens very often.
9.
Even though these problems are not very often. Do they affect you?
In that process we didn't have a problem with water, but in the past when I was working in another hotel,
many years back, `there was a problem with water because the clients used to get diarrhoea. We didn't
actually know if there was a problem with water or maybe it was food poisoning, so I can't tell about that.
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10. When you had this pipe problem 2 weeks ago, how did you manage to still provide water in the
hotel?
Well, we have a safety tank upstairs and it still had water so we used it. It was enough. I never had a problem
I couldn't solve with the tank.
11. In your opinion, what would be an ideal solution for the water situation? Although from what I
understand you really haven't had that many problems with the water
Actually the only solution that you can do is to get a big enough safe tank, so that when you get water you
can save more water. A bigger tank would be good.
Is that treated water?
13. Yes, basically is a process in which you take salty water and using membranes you removes the
impurities so at the end you have good quality water, with the difference that it didn't come from
a spring but from under the surface, or the sea. I was wondering if that's something you would use.
I have never head of that process, because actually in Mombasa we have enough water.
14. The concept of desalinated water is something you would approve or you wouldn't like to use it?
We can give it a try.
15. The fact that is desalinated and not from a spring would that mean you're willing to pay, more, less,
or the same than what you're currently paying?
If it would be less it would be much better.
16. If renewable energy sources are used to power the desalination process. Would that somehow
affect the price you're willing to pay for it?
I don't think so.
17. Can you tell me more about the tourism industry in Kilifi?
I'm very new in Kilifi, I have been here just for a month, so actually I live in Mombasa and for the last 15
years I have been working there, in various hotels. I have been in that area. In Kilifi I can't tell.
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Interview 6: Peter Njoroge (Kilifi Bay Beach Resort)
Interviewee: Peter Njoroge
Organization: Kilifi Bay Beach Resort
Position: General Manager
Contact: +254 722 605 803
1.
How much water does your hotel consume?
It depends. Our business is distributed in 3 segments: the first segment is the low season, which comes in
between May and about August. Then we have the second season, which is now, and goes in between
September and about November. From November is the peak season and it starts getting very busy until
about Easter, April. It's when the season is good. This year has been not very practical because of what has
been happening around.
I operate two hotels here: I have this one and Baobab. This is 50 rooms and a bed capacity 112. Baobab is
30 rooms and a bed capacity of 65.
In this hotel the consumption is quite high, and the main areas are the kitchen, the rooms, and laundry. In
my storage tank I have a capacity of 150,000 litters, and normally when we are busy, this lasts only 3 days.
You can see the level of consumption.
During the second seasons, when is not so busy, the tank can go for like a week, but when we are busy we
consume a lot of water. The reason is that this is a hot area and people need water all the time. We have to
refill the pools all the time. I have 2 swimming pools and they also consume a lot of water.
I hope this answer the question.
2.
So the main use for this the water is...
The pool, the kitchen, the laundry, and the rooms.
3.
Normally we are supplied by the municipal council. The water that gets into the hotel is metered and then
we pay to the council on a monthly basis.
4.
How wave you experienced the service?
It is very unreliable, and that's why we have always advocated for water-related projects here. In fact two
days ago I was discussing with somebody and we were thinking that if you can get an organization that is
able to bring a desalination plant for the water here so we can make use of it, it would solve a lot of
problems. Not just for the hotels, but also for the communities around because, like I was about to tell you,
I normally have a water bowser here to supplement the water which comes from the council. Why do they
have to do that? Because you will find that every November of the year, I have here now almost 7 year, and
between November and about April, which is supposed to be peak season, there is no water in Kilifi, and
even if there is might be for just 1 or 2 weeks in a month, and that is when everywhere there is people,
tourists are here, the villages are occupied, the holiday hubs are occupied, and there is no water. The supply
system fails, and all the time we are complaining to the authorities, and that has been the trend. I have made
that observation, and normally if they have to supply you with the trucks like I was doing last week, I was
buying one truck, 20,000 litters, 13,000 schillings, so to service a hotel like this one, you need in a day at
least 5 trucks, so 13,000 times 5, what business are you doing? I spoke to my boss and we agreed on having
our own truck which can be able to bring the water for us.
5.
Where does that water come from?
It comes from a spring called Barisho, which is something like 200 - 300 kilometres from here, very far.
Number two they (the municipality water provider) always have issues with the Kenya power, because
Appendix
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they have the water but they need the power, so when they have issues among themselves, not having pay
bills and all that, then they disconnect it, and once it gets disconnected everybody suffers. That has been
the case, for quite some time now. Also, the Kilifi population has really grown, so they need to re-do the
piping. We still have the old infrastructure, is what we're still using, and that must be looked at because you
find that one they start pumping water there, it takes like 3 or 4 days to get here, and when it gets here the
pressures are very low. A solution must be looked at, and this is what I was telling to the county
government, that they really need to look at that, because there is a very serious need for that.
6.
Do you know by any chance the source of the water from KIMAWASCO?
Barisho is also the source of the piped water, but when you're buying the trucks sometimes they go as far
as Mariakani. The other supply from Mombasa comes from Mzima springs.
7.
How much do you pay for the water comes from the pipes?
We are paying for the metered water about 0.20 schillings per cubic meter.
8.
Are you satisfied with the quality of the water you're getting?
This is not treated water. In our case what we normally do, taking care of our clients, we have to put chlorine
in the water before we pump it. We treat it in our reservoirs, because we are very sensitive with the health
of the clients.
9.
A lot of them, in fact, as we speak now, I have device a system where they have to bring me all the water
readings every morning, so I know the level and I make sure I get prepared. As at this morning, the level
was 5 foot, which means it is enough to be pumped 3 times, and in a day we do like 3 times, so there is only
enough for one day. So I have today, but I'm not sure about tomorrow. You can see the situation.
10. How these water scarcity problems affected you? How did you solve the problems?
Customer service is very important, and sometimes you're forced to do things like spending a lot of money
just to make sure you're clients are OK. In our case we have this truck subsidized with what comes through
to the meter, but the other day it had an accident and now we're in the process of trying to get another from
Nairobi. In fact I was discussing with my boss today in the morning on the same topic, because I can't be
without it. Otherwise, you’re not very sure of what will happen next. The volume of water I have today I'm
not very sure if it will last till tomorrow. You can see the kind of uncertainties we are doing business with.
Number two, as I told you I'm running two hotels, and when there is no water at all, like it was happening
last week, I buy 3 trucks for this hotel, this is for a day, and 2 trucks for the other hotel. Those are 5 trucks,
at 13,000 schillings, is a big amount of money I'm spending just to make sure that the people don't complain,
people don't notice this problem, but it is really difficult to make business in this kind of environment.
11. In your personal opinion, what would be the ideal solution for all these water problems?
We have tried many things. First of all I tried the borehole, which I did for this hotel and the other one, but
what I got was salt water, which instead of solving my problem, it added more problems because I had to
renovate the hotel because we used to have pipes that got rotten and now we had to renovate the 2 hotels.
Now, the solution, the county government and the national government, they must try and see a way of
solving this problem, because it is really not only affecting the hotels, it is also affecting the community. I
have my staff, they don't stay in the hotel, they rent accommodation outside and they will tell you that they
haven't had water for 2 weeks, so is not just the hotels, but also the community.
In my opinion, this is something that needs to be looked at. The government, bot the national and the county
government they must sit together and see if they can be able to either contract or partner with an
international organization that can be able to get water, enough water for all of us, because the town is
growing very fast but the infrastructure is still the old system, so it is not able to serve the community and
that's something that needs to be looked at urgently.
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12. Do you know what desalinated water is? Would you be willing to use it?
Yes, we would be more than willing, because we tried to discuss the investment with my boss, but bringing
a machine was too expensive for us, and that's why I'm saying that if the government can come together
there is a possibility. We have a lot of water here.
Alternatively, drill a borehole or a dam, and this would help us, but even if we try to harvest water, you
can't use it for the room. You can only probably use it for the kitchen.
13. In the eventual case you could get desalinated water. How much would you be willing to pay in
comparison to what you're paying now?
We don't have a problem with paying because, if I'm buying for 13,000 a truck, and if you tell me you charge
the same; I would be more than happy. If the supply will be there and is enough, then there is no problem.
14. If this desalination process is powered with renewable energy sources. Would that affect the price
you're willing to pay for the water?
I don't think price would be a big issue here, because what we're talking about now is availability, and
everybody is filling that. They don't mind paying 20 or 50 schillings per jerry can, but they must get the
water. Sometimes they want to pay and the water is not even there. I think coming up with that kind of idea
I'm sure all of us would be more than willing to support that.
15. Can you tell me more about the tourism industry here in Kilifi?
I don’t want to talk of Kilifi as a county but about Kilifi town. We have 3 major tourist class hotels. I run this
two, which as I told you, my hotel here is 112 beds and Baobab is 65. Mnarani has 80 rooms and I believe
that with 80 rooms the highest capacity that can handle is probably 160. This is a total of 337 when they're
operating at full capacity, and it is never the case, so take something like 70%, this would give you
something around 235.
16. And I can see Kilifi town is very dependent on the tourism industry
I want to tell you that when I walk around in Kilifi people ask me when is business coming because most of
the people you see around here, 70% depends on the tourism. When these two hotels are full, the whole
town wakes up, because my guests would need transport to go to the town, so they will use boda-boda or
tuk-tuk or taxi or whatever and when they get to town. I buy my vegetables from the local people here and
I buy fish from the local guys, so when there is no business in the hotels then everybody cries, even
construction work, which is also directly related to tourism. That is how bad it is. I was telling the
government here in another day, when they were launching a website, and I was telling them I would like
to be introduced to their colleague in Kwale county, because Kwale and Kilifi counties they have something
in common, and is that we don't have this walk-in walk-out business. Is not like Mombasa or Nairobi. This
is almost 100% tourism. Go to Watamu now, and when tourism is this low, hotels are closed out. Malindi is
the same. Here is very different to Mombasa and Nairobi, and that's why they have to be very careful in the
way they do things.
17. In this year, has there been a downturn in tourists?
Normally, at this time of the year I operate with 198 members of staff, 198 for the 2 hotels. As we speak I
have 100, meaning that 98 are at home. That's how bad it is, and in fact what is keeping us, because what
we have done now, we have partnered to these conferences for domestic tourism. Today I'm almost full, in
fact I'm almost doing 80%, but this is contract market, just the locals, and this is what I have been doing for
the last 3 weeks. Other than that, if you don't have these local conferences, then you will close down,
because there is nothing. Last week I had only 15 tourists, they checked out and now I have 4, and we're in
November, I'm supposed to be doing almost 85%, so you can see how bad it is.
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18. When did this start to happen?
Last year and this year it has been happening. We were doing quite well the previous years but from last
year to now we have been really struggling. A lot of cancellations.
19. What are the main reasons for this situation?
There are many reasons, because the stocks market, they are also having their own problem. Italy used to
bring a lot of people here, but you know what is happening in Italy. The only market which is a strong
market remaining now is Germany, within the Euro-zone, but they can't support everybody. Now, because
of the recession, they also go for cheaper destinations. That's why the government must come in and look
at this and remove of the taxes so that we are able to attract numbers. Then you can compete on price. If
you have to keep somebody on a hotel and that person is paying you 50 euros, and this is all inclusive, 50
euros is 5,000 schillings! And this is all inclusive. It becomes very difficult unless you have 1,000 rooms in
the hotel for you to be able to operate. If you operate with 50 rooms you can't even break even, and this
person wants bacon in the morning. It has really been really difficult for us. Sometimes we sit down with
the agents to negotiate 1 euro, because everybody is after that 1 euro.
The other things you see around is insecurity. Today we have this, tomorrow we have that. We don’t need
all these things because one wants to go on holiday you want to go where you can enjoy, relax. You don’t
want to go where you’re told there is a bomb there. We don’t want that. All these problems are there.
Then, cheaper destinations have come. We thought we could benefit from all that's happening in Egypt.
After their problems we thought people would come down because of the problems now the Europeans
wouldn't go there, but now they go to Zanzibar or other places. I was discussing with somebody and he was
telling me that the airlines are flying from Addis straight to Kilimanjaro fast, and then to Zanzibar, then it
comes to Mombasa. From Addis is full, and when it gets to Mombasa there is only 20 people, and with all
these hotels, each hotel gets one and some don't even get one. You can imagine, is very difficult.
We were in a meeting and somebody was discussing and saying that the people from the coast themselves
also must be careful because if you to Mara, if you go to Nairobi, business is the same, but the coast is dead,
because all of these things that have been happening here. When you start threatening people and killing
people all around you're messing up with your own economy. Mombasa is a very good holiday destination,
the beaches are very good, and you can combine with safari with beach holiday because Tsavo is very near
from here, but then, you don't want to come on holidays and live in the bushes all the time. You also want
to come to the beaches and if it's not safe then you go to Masai Mara and fly back. This is the problem. We
really have to see what to do.
Our media is another problem. They don’t know that we have what we call "domestic issues". Things that
are not for everybody. They are competing and they come with these funny stories, they highlight them and
put them on the headlines. They don't know they are gaining money at the detrimental of others. We have
messes ourselves up. Kenya is a nice country, and everybody likes the country, peaceful, people are very
welcoming. You will walk freely doing your own things and nobody cares. People are very hospitable.
Weather is always very nice, but we put a lot of emphasis on bad politics.
I hope top guys will sit down and look at those things because really the future of tourism in Kenya does
not look very good. We have to do something about the marketing, people must know the kind of product
you have, and the only way they can know is by you coming out telling them what you have. Improve prices
and standards and people will come. People really want holidays after working for a whole year, they want
to relax.
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Interview 7: Paul Omam (Water Gate Hotel)
Interviewee: Paul Omam
Organization: Water Gate Hotel
Position: Manager
Contact: +254 722 739 482
1.
How much water does your water consume?
I would say around 1.5 cubic meters per day.
2.
What is the main use for that water?
The main use is the rooms. Mostly cleaning and guest’s bathing.
3.
There is a water company in Kilifi (KIMAWASCO), so we get it from there and I pay on a monthly basis on
consumption. We have the meter, so we pay what we consume. We also have our own well, so if the other
one is not coming we use ours.
4.
How often does the KIMAWACO water come?
It can come continuously for six months, but it can suddenly stop for a week and then comes back. And it
happens in specific months, like December, but in the other months is usually OK.
5.
Do you know the source of the water?
I have been told there are some dams. There is a spring also, Mzima springs.
6.
How much are you paying for the water?
It has a scale. For the first cubic meter meters, from 1 to 6, is a standard rate of 350 schillings. Then in the
next ones the rate is up, but I don’t know completely rate. Then there is also a monthly charge of 50
schillings for the meter.
7.
Are you satisfied with the quality of the water you're getting?
No, sometimes, is not that clean, especially when it rains. Is very dirty and we have to treat it, which also
includes a cost.
8.
What about the process? Do you think it is convenient the deal you have with KIMAWASCO?
Yes, so far is reliable enough. I haven't had many problems.
9.
Have you had any water scarcity problems in the past?
Yes, but not for too long, maybe 3 to 4 days and then is back.
10. And how do you do in those situations?
It forces us to use the borehole. The first times we didn't have it. Now we have water for the days that they
stop sending it.
11. In your opinion, what would be the best solution for the water situation?
I think we have to replace the capacity because KIMAWASCO is not enough for all the population. If possible
even integrate the private sector into provision of water.
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No.
13. (After explaining the process) Would you use this water?
No, the water from the well we just use for bathing, but specifically for drinking we use the KIMAWASCO.
14. Even if the water from the well can be purified?
Then we can use it.
15. Would you be willing to pay more, less, or the same price for it in comparison to what you're paying
now?
I can pay the same, as long as it is clean.
16. If this desalination process is done with renewable energy sources. Would that affect you’re willing
to pay for the water?
I think there must be a reduction because they're from the nature.
17. Could you tell me more about the tourism industry in Kilifi? Maybe the number of your hotel
The average guests in this hotel are 10, but we have some branches in different parts. They also have an
average of 10.
I can just try to guess about the number of tourists coming to Kilifi. I would say that annually there are
around 2000 people coming.
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Interview 8: Henk Venter (Mnarani Club)
Interviewee: Henk Venter
Organization: Mnarani Club
Position: Resort Manager
1.
On a busy month, December, peak season, our water consumption is anything between 2,900 to 3,200 cubic
meters per month.
2.
What do you use this water for?
That's being used by the whole resort: laundry, swimming pools, gardens, the guests, everybody.
3.
How are you getting this water?
We have a desalination plant on site. We developed that 2 years ago. We get anything between 75 and 80
cubic meters of water per day. And we just supplement that on a monthly basis with some municipality
water. If we see that we start run low on reserves, or the plant is not producing as it should, or we are using
more water than we planned, we just supplement that with municipality water.
4.
Where does the water you’re desalinating come from?
That's coming from two boreholes on the resort. One borehole is 20 meters deep, which give us the fresher
water, and one is 50 meters deep. Those go into 3 big mixing tanks and from there through the desalination
plant.
The maximum with use per month from the municipality is 200 cubes. The rest is all home-made.
5.
How much are you paying for this water you're getting from the municipality?
Before the desalination plan it was anything in the range from 650,000 to 750,000 schillings per month.
Now, on a month that we use the 200 cubes we pay anything between 18,000 and 20,000 schilling per
month. We are saving a big amount of money.
6.
Do you feel a difference between the water you’re getting from the desalination and the one from
the municipality?
Yes, we do tests on a quarterly basis, from the desalination plant and from the municipality water. The
water from the desalination is pure. There are absolutely no impurities, while in the municipality water
you actually do get sometimes some matter coming through and stuff like that.
We also have now the confidence to tell our guests: "if you want to use the water you can", because we
know where it is coming from. The mixture of what we get in the tanks from the municipality and the
desalination we know is pure and there is minimal chance that you get sick from using it.
7.
Why did you start to desalinate your own water?
I was having problem with water, and the price of water as well.
8.
These problems with water are just about the quality?
Also water supply.
Appendix
9.
163
How were these water problems affecting you? How were you solving them before the desalination
plant?
We got a big water tank that has a capacity of 4,500 cubes of water and that can lasts us up to a week. First
of all we make sure that our tanks are full the whole time, so when there was no municipality water coming
in we knew we had a week supply. Then we didn't do any water of the gardens, we cut down on laundry...
just basically doing water saving. Even now with the desalination plant sometimes when the hotel is busy
and we have to supplement we don't get any municipality water because of water supply problems. The
problem is still there.
10. Did you use to truck it in?
No, it was delivered here. We got a point here. I know that Mnarani, being at the south of the creek, has got
a much better water supply than the north side of the creek. North side is rotten. The guys are complaining
immensely. People from that side come at least once or twice a week to ask us if we can give them water,
and we give them water out of jerry cans. We help where we can. Even the local guys come with 40 cans
because they don't have water in the village, so the guys at the main gate just open the taps for them.
11. What would be an ideal solution to solve these water problems? Do you think the desalination
process is the ideal solution?
Yes, with us desalination, definitely. In Kilifi town you have to solve the water supply. Yes, I understand it's
a lot of money just to get all the pipes ready, the infrastructure planning, but if just do a little bit at the time
it helps to fix the problem over time.
12. How are you powering your desalination plant?
It's got electrical motors, so basically what happens is that the water from the boreholes mix in 3 holding
tanks, then go through a filter system into another holding tank, and from there to reverse osmosis, where
it is divided in fresh water and waste water. Fresh water comes straight into the underground tank and the
waste water we just send it back to the ocean. The fresh water goes from the underground tank to our level
tanks and from there to the rooms. The coordination process happens between the underground tank and
the high level tank, so we know that once the water goes into the high level tank is 100% correct.
13. Do you have to change the membranes of your reverse osmosis system often?
The company that installed the system for us said that you have to change the membranes every 3 years.
We actually have, after 2 years of using them, the plans to change the motors that a pushing the water due
to the salt content of the water. It just breaks down the seals. But still, one motor in 2 years, we're talking
about 13,000,000 (schillings) saving just on water, 20,000 schillings for a motor is nothing. I rather do that
way instead of the other way.
14. Can you tell me more about the tourism industry in Kilifi?
Pre-travel ban, or travel advisory, that was now in May, we were in a 50% occupancy. We had about 15,000
guests for the year, so we were fairly busy. Kilifi bay and Baobab beach on that side also busy, but not as
busy as we are. Then the smaller ones in Titanic for example they attract more your local guys than
international tourists. There is now Backpackers which is on the other side of the creek. They attract a
different crowd because they are an eco-lodge and they put more backpackers. I would say in total probably
around 50,000 visitors per year.
Also Kilifi is still a hidden gem. People don't about Kilifi, because they either go to Mombasa, or Watamu,
or Malindi, so people don’t know us here, but now there are quite some people that want to get away from
Mombasa, and get away from Malindi, so now they're discovering us. We can definitely see how our local
guests are starting to peak up, starting to come through, so is always a blessing to have the local interest.
It’s much more stable.
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15. I did some interviews with other hotels already and they were having problems with the water,
but I guess you found a good solution with your desalination plant
Yes. You know, we actually picked up 2 years ago that the water supply is not so steady, because they might
have a big breakdown, so we thought it doesn't have to get in our way and we get this plant done. I know
they are areas, especially in Baobab side, where people haven’t had water August last year, so that's more
than a year now that they haven't had water. It's just really unreliable, and even though the guys are trying
to find the fault is taking time. They don't exactly know where the pipes are running, because they were
laid in the late 60's, 70's, and by then the area was under-developed. And now houses have been built over
the area. It’s a very interesting situation.
16. Population has been increasing, so if you have this 40-year old infrastructure is really hard to
match this increasing demand, so I do think that solutions such as the desalination plant you
installed make a lot of sense. How much does it cost to run it?
At the end of the day, our running costs for the desalination plant per month is 35,000 - 40,000 schillings,
and that includes the water that I get and the electricity bill. That's my total running costs. Those machines
take a minimal amount of electricity, equivalent to 5 air conditioners running.
17. What about using renewable energies?
We are all looking at going totally green, but the thing is that at the moment solar is still very new in Kenya,
so very expensive. Everything is imported into Kenya now, so there is no manufacture of solar panels in the
country. If they could have done that would have been great. Same as wind.
We did have a look at wind power here, and the guy said our wind here is not constant enough to make it
worth it. It would have cost us 50,000,000 schilling to put up a decent wind power source to produce our
own electricity, but they said it would have been a waste of money because wind isn't constant enough. You
need a constant wind between 15 and 18 knots an hour and over here we have 8 - 9 knots.
18. Winds here are not very string, but the solar...
We have solar for our water heater on the side, so at least that is cutting some costs, but for the general
power you would need big battery packs as there are no feed-in tariffs. We have in Kilifi 350 days with the
sun every year, so it would make a lot of sense to do it.
19. Have you heard about more desalination projects?
I know that Mandarini, that is opening, they also got a big desalination plant as well, and I believe that
Vipingo is also looking at desalination plants.
20. Do you know the salt content in your water before the desalination process?
I can find it out. I do know that the creek is more salty than the ocean outside. Before we did the desalination
plant our idea was to run water directly from the creek and then we had it tested, and we found out is very
salty.
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Interview 9: Thomas Atkinson and Romain Mari (Distant Relatives Ltd.)
Interviewee: Thomas Atkinson and Romain Mari
Organization: Distant Relatives Ltd.
Position: Owners
Contact: +254 787 535 145 (Thomas) +254 770 885 164 (Romain) / [email protected]
1.
T: We can find out. Of the top of my head I wouldn't know, but I have all of our water bills, so I can give you
an average.
R: Combined with the rain, trucks...
T: Yes, that would be a bit more complicated. It would be an estimate. I'll get back to you with that.
2.
T: Pool is the biggest one I would say. We have compost toilettes, so we don't use any water there.
R: Pool used to be because it was leaking, so there was huge water consumption there, but now is just in
operation and once in a while we use the well, but the well is salty and we don't want. Is OK for the pool,
but is not good for the garden.
T: Yes, quite a bit goes to the pool because we backwash, send a lot out, but it’s supplemented by well with
the saline, so we use both. Other than that is kitchen, cleaning the showers in all of the rooms. We have 7,
8, 9, 12 showers, and sinks in all of the rooms as well, but we use cold water to discourage long showers.
Our restaurant uses quite a lot of water, but I couldn't really say how much.
3.
So you are getting all of the water from the well and the municipality pipes?
R: And from the rain.
T: We have 500 square meters to collect it and it’s all centralized. For example, the last two days we filled
up maybe 60,000 - 70,000 litters from the roof, but this is the short rainy season. For most of the year we
use municipal water, so you rely heavily on them.
4.
In the case of the water you're getting from the municipality, do you know its source?
R: It's from the Sabaki River, which is north of Malindi.
5.
How much do you pay for it?
R: It's a scaling system. It gets more expensive the more you buy.
T: Yes, it's an ascending scale. On the top of my head I wouldn't know the exact numbers.
6.
What do you think of the water you're getting from the municipality? Are you satisfied with its
quality?
R: Its fine, but I've just heard that every once in a while it blocks the filters at the entrance of each property,
and they get clogged, so that means it is not very clean. But we consider it drinkable, but we don't tell guests
it is drinkable. We tell them they can do what they want. It's up to them. We can't guarantee is clean, but
we drink it and it's OK.
T: Generally people buy bottled water or they drink purified water.
Appendix
7.
166
But do you treat the municipality water when it enters here?
T: No, because everybody has the option of drinking filtered water that we purchase in bottles. We hear all
these stories about what happens to people diverting the line, breakages in pipes, contamination, all sort
of stuff, so we try not to advertise it.
8.
Have you had any water scarcity problems?
T: Yes, definitely. Romain had an incredible mission. When was that?
R: Exactly last year. There was a water shortage for 3 months. We weren't getting any water from the
municipality.
T: To get something done about it you have to be militant. You have to draw yourself a diagram of how the
supply chain works, which individual to target. It's a full time job working out what's going on.
9.
How did this affect you? How did you solve the problem?
T: Every day we had to order water bowsers, but there are not many private water bowsers available in
this area. As soon as there is any scarcity of water everyone targets these bowsers and creates this massive
conflict between businesses because we need water to operate. So as I was saying before you call a bowser
and you hunt them down, you chase them because people is trying to stop them along the road and buy his
water before it gets to you. And then the price... they just start to inflate it, multiplying by 10. It’s a
nightmare. They can charge anything.
10. In your opinion, what would be a way of solving this water problem?
T: KIMAWASCO is a very disorganized. Nobody knows who is in charge of what. It was very difficult to
pinpoint just who to approach to get an answer. It’s a nexus of individuals and is very hard to work out
what's going on. Romain did a map at some point with all the individuals involved and it was just a a mess,
and now it’s probably change, or double or tripled...
R: It's a private company at the end. It's never public service. That private company buys water from the
government, so it's from the government until certain area and then it gets diverted to this various
companies. They buy at a certain price from the government and then re-sell at a certain price.
T: The structure is terrible. Diverting happens a lot. For example, there is a pipe that runs through our
garden here which has water in it, and you could just dig a hole and put a tap there, and you could just get
water like that. I think that happens a lot.
11. You know what desalinate water is?
T: Yes. Well I understand the word, but nothing else.
12. (After explaining the process) Would you use it?
T: Yes, they're doing it in this island from Mozambique. It is the only way they can get water.
R: Probably run by petrol for the generator.
13. Yes, probably, especially because to desalinate sea water you need much more power. How much
would pay for desalinated water? In comparison to the what you're paying for the water you’re
getting already
R: We have the water now, we have the well, which is 10 times too salty based on what they say the soil can
tolerate. We mainly want to use this water for the garden because we have a huge need for it there. The
well water now is too salty. It just kills the soil. So if we could desalinate that water for us it would be great.
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14. If this desalination process is done with renewable energy sources instead of a petrol engine.
Would that mean that you're willing to pay a different price for it or it wouldn't affect?
T: We would like to say yes, because it’s part of our mandate. If we can put that stamp on our product and
on our business would be important for us, more than for a normal hotel because this is part of what we
want to achieve and how do we want to present ourselves. So I would say yes, but because this is such a
young business anything that is going to cost us more is difficult.
R: In the same way we would install solar panels but we are never going to do it because is too expensive
for us.
T: But also if we're paying 10 times the pure price of water by buying bowsers when there is scarcity, there
might be worth, if you look at our expenditure over a year, to pay a bit more for desalinated water. It could
compensate for that larger expense of the bowsers. If we have a regular source of water it might balance
that out.
So yes, from and ideological point of view, we are willing to pay a bit more for a better technology than is
cleaner and more sustainable.
15. Can you tell me about the tourism industry in Kilifi?
T: We are quite a unique business, so our information might not be all that useful to describe the tourism
industry in a more general perspective. The type of travellers that come here pay less attention to the travel
warnings and more general issues that affect hotels. It has been a terrible since Westgate*, in Kenya in
general, but maybe we haven't been as badly affected as other business'.
R: In terms of numbers you can look at these reports on tourism, but now they are hard to get. There they
give more statistics, stats counting. I think now you have to pay for them, but we have the reports from two
years ago.
T: They want you to buy that information. The government is not producing it in a digestible form, so
private companies create digestible versions and then they charge you.
R: I think Business Monitor International (BMI) publishes reports quarterly, and if you can find them they
are very useful. Recently I try to find recent ones but I couldn't, but for the 2012 you will be able to. They
give quarterly and annual reports on growing groups. Last one said that it was the Chinese and the UAE
that are growing the fastest, how has been growing, and the type of clientele and where they go, how much
they spend, and just the whole thing.
T: You would hope that the government would do something about it through their tourism organization,
but they didn't. You want to invest and you want to see entry, you want to find useful information and you
can't. You have to buy that.
* Westgate: Terrorist attack in the Westgate shopping mall in Nairobi in 2013
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Group #3 - Farmers
Introduction
From the literature research a third market segment was identified: the farmers. They are in a similar
situation to the hotels and resorts in the area, as they also represent an important activity for the economy
of Kilifi and also have seen their production affected by the water scarcity problems.
Interviews were held with some farmers of the area with the goal of finding out their usage of water (how
much, what for, where it comes from, how much it costs, etc.), their opinion about the quality of this water,
its reliability and what would be an ideal solution for them, and their opinion about desalinated water
(would they use it?). Finally, as in the case of the hotels and resorts interview, a question about the industry
situation was made.
The interviewed farmers were Warren Wilson (Kilifi Plantations), Ja Maina Wanjohi (Patbon Farm),
Chokkie Rama (Ramar Farm), and Robert Clarke (REA Vipingo Plantations Limited).
Interview
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
How much water does your farm consume?
What is its main use in your case?
How do you get it?
What do you have to do to get it?
How much do you pay for your water? (price/unit)
Are you satisfied with the water you are getting? If not, why?
How did they affect you?
How did you solve these problems?
In your opinion, what would be an ideal solution?
Would you use it? If not, why?
How much would you be willing to pay for desalinated water? (compare to what they are paying
right now)
15. Would the fact that it is produced from renewable energy sources affect the amount of money you
are willing to spend on it?
16. Can you provide me some numbers of the industry? (Role in economy, products, etc.)
Appendix
169
Interview 10: Warren Wilson (Kilifi Plantations)
Interviewee: Warren Wilson
Organization: Kilifi Plantations
1.
How much water do you consume in the farm?
Probably about 250 cubic meters per day.
2.
What is the main use for this water?
It’s almost all for the animals. A dairy cow would be taking in 100 litters of water a day. We have 800 dairy
cows, plus we have an additional 1,200 animal which would be taking in another 50 litters of water a day.
So the main bulk is for the cows, as obviously they can't drink salt water, so they have to have a relatively
good quality of water. For dairy the better the quality of water the more milk you get from them as well. So
let's say 80% is for the animals and then we do sisal decortication, for which we pump pure saline water
because there is no need for fresh water. We dug a well and it just gives us pure salt water.
3.
How are you getting the water for the animals?
We have 6 boreholes on the farm, and each of those is responsible for pumping to groups of animals around
the place.
4.
But isn't that water brackish?
Yes, a lot of these wells have been in existence for a very long time, from my grandfather's time, so over
time the quality of the water has deteriorated. We did new boreholes recently and we found that the quality
is far superior to the old ones, but I think is to be expected. You're pumping out of that borehole 20 to 30
cubic meters every day, year after year after year, so the quality goes down.
5.
That means that so far you're not paying for water as you're pump out all the water you need?
We pay for licenses and obviously we pay for the cost of pumping it, but I don't buy water. We don't pay
any water.
6.
Are you satisfied with the quality of the water you're using in the farm?
No. it could be better, especially from a dairy point of view. The better the quality of the water the better
your produced milk as well. Milk is 90% water. When a cow gives you a lot of milk the first thing she wants
to do is go and drink because she has obviously lost a lot of her weight in liquid, and if it is not palatable
water, it’s not clean is not cold is not fresh, she is going to limit her intake to a certain amount. The more
you can get her to have the more milk she will produce.
7.
So it is salty and dirty?
Forget the dirt. Suspended solids in the water are not so much of an issue. The salinity of the water is really
the kicker.
8.
Have you ever had any water scarcity problems?
Yes, we have always had water, but sometimes you really get pushed against the wall.
9.
Besides the dairy cows production. Is this salty water affecting you?
It affects the machines. Every year we spend a lot of money replacing all of the bits. Everything has to be in
brass or stainless steel otherwise they corrode or rust out. If you put this water into your tractor it kills the
Appendix
170
radiator. When you wash your tractor with it, it pulls apart. It is a very destructive water. It will eat
everything very quickly, so it certainly is not the best but is what we have and I think you just learn to live
with it. We have never really considered cleaning our water or trying to get the quality better.
Well, I'm considering it now, maybe putting in a RO plant, but mainly because we're starting to process milk
again and at the beginning (of the process)` you have to pasteurize and stuff like that. If you put salt water
or suspended particles in your machines you're really going to damage them very fast.
10. In your opinion what would be an ideal solution for this water problem?
If you ask me how I would deal with it I would drill lots of boreholes but I would spread out the volume
uptake across a much bigger area rather than relying on 2, 3, 5 or 6 wells to give us all of it. I would love to
do recharge of the wells.
The problem is that water storage is very expensive. You have to build very large tanks and containers in
order to hold the massive water. We get a phenomenal amount of water during a very short period of time.
Within 3 months you have your whole year water supply. More than 1 meter worth of water comes down
on you. How do you hold that? You can't contain that amount of water.
One way would is then to recharge your wells. You have all going back into the water table, so is direct. Is
not great, but in some ways you're replenishing back, you're putting the water directly back in to the well.
I think those are the only two things: I would spread the wells and I would try to put back some of the runoff that is going to waste.
11. Would you use desalinated water for your system?
No. I wouldn't. It’s too expensive. If you're going to give me the water for free yeah, I'll use it, but if you ask
me to pay for it I wouldn't. No way. The cost of producing a litter of desalinated against what it costs me to
produce now is too much. Water quality is not that important that I would be prepared to pay the extra.
Although I don't know how much a litter of desalinated is but I assume is pretty expensive.
12. Not really. The idea is to make a system that can actually sell the water at an affordable price
What price?
13. In DWL they are selling the 10 litter jerry cans for around 60 schillings
That's 6,000 schillings per cubic meter, and at the moment it costs me 140 shillings per cubic meter. It’s
quite a big difference. I couldn't afford that. It is just economics, pure economics. If it would be for human
consumption or something like that is different, but if you're pumping it into animals is not worth it. They
are ATM's: whatever you put into the cow you have to get from the cow. Otherwise you're losing money. So
it’s just a money game more than anything.
14. How much would you be willing to pay for it?
I would have to do a cost analysis on the units of production and stuff like that. At the moment we don't feel
the cost of watering our animals mainly because we don't buy it. We produce it and even though its quality
is not so good is not a major factor. I don't look at the water and think "wow I have to find a way of reducing
the cost of that". I look at the quality and I think that if I could improve the quality I could probably get more
volumes and therefore more money, but cost of production is not an issue for me.
15. If this desalination process would be powered by renewable energy would that affect the cost
you're willing to pay for it?
You are the water expert. You will have to tell me that. I have no idea. If it brings down the cost of production
and I was able to realize that extra revenue in increase in production of course, I need to make money at
the end of the day. I'm a business man. I consider all the options, but I would have to take a group of animals.
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Test them on this new water, see if they gave me the extra production required, and then do a little a
feasibility study to see if it’s worth it.
16. How important is farming for the region of Kilifi? Do you know what is being produced in the area
or how important is farming for the economy of the region?
Farming for Africans is everything. 90% of your agriculture here is from small-scale farmers. So if you and
me we all have 5 acres and we all plant maze on its happiness. An African, if he has a farm he is happy, if he
doesn't he is not. Agriculture is the life of an African.
In terms of Kilifi, we are the second largest agriculture industry here. The largest one is the sisal guys off
the road, REA Vipingo. They have 10,000 acres and employ about 3,000 people. We are 3,000 acres with
300 people, so is quite a big step down.
Their water usage is pretty big, probably around 500 to 1,000 cubic meters per day. They run about 4 of
these machines to compare to our 1, and their water is very fresh. They're putting down some very good
water. They are a major player. Everyone else I hate to say is small-scale. It is subsistence farming.
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Interview 11: Ja Maina Wanjohi (Patbon Farm)
Interviewee: Ja Maina Wanjohi
Organization: Patbon Farm
Contact: +254 722 414 079
1.
How much water are you consuming?
Of KIMAWASCO we are using something like 400 cubic meters per month.
2.
We have water from two sources: one is from KIMAWASCO and we also have borehole water. We also
collect some water from the rain.
We use borehole water for farming only, agri-farming. The KIMAWASCO water I use it for human
consumption, households and also poultry and cattle consumption.
3.
Do you know the source from the water that comes from the KIMAWASCO?
Not really. I just trust it is good.
4.
Do you know the price of the water?
Is it 200 (schillings) per cubic meter? They have a list. For every 50 you pay this, for every 100 you pay
that.
5.
Are you satisfied with quality of the water you're getting from KIMAWASCO?
So far we are not complaining about water, although the quality is not that good. As at now we didn't get
any drastic negative issues like somebody getting a disease like cholera.
6.
Did you ever experience any water scarcity problems?
Sometimes during the most dried times, like from January to March, they ration water.
7.
Did that affect your activities?
In our unique setting we haven't been affected in a big time because when they don't send water we use
the rain water we have collected.
8.
In your opinion what would be an ideal solution for the water situation?
My suggestion to KIMAWASCO is that, along with the Government, a policy in collecting rain water should
be promoted and supported. We don't have it so far. It has always been an issue that we have never solved.
I think this would be more than enough. The rain is decent even in the upper region of this country. That
water from the rain is mostly wasted, but then when we are hit by the dry season we are complaining.
They should support this as they are supporting the coming enterprises and companies who are selling
water. I think such policy should be supported by the Government. It would be better.
9.
Not very well.
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10. I'm assuming the water you're getting from your borehole has a high content of salt…
What we usually do is that we drill and take out water to do analysis in toxic levels, and if it’s too high we
seal that borehole. The one that we have running now is within the standards, the accepted limits.
11. If you receive water that has been treated in the sense that they have decreased the level of salt in
the water. Would you consume it?
Why not? We would take that water. We don't do it because even that desalination sounds very serious.
For now we just treat our water.
12. Would you be willing to pay a different price for the desalinated water in comparison to the water
you're getting from the tap pf KIMAWASCO?
If I'm not getting regular supply of water from KIMAWASCO and have a very serious economic activity, and
then there is this alternative supply that has acceptable levels of toxic substances. Why not?
People are not complaining about the quality, but about the reliability of it. Same challenges with the
energy.
13. If this plant that is providing you with desalinated water is powered by renewable energy sources.
Would that affect the price you're willing to pay for the water or would it be the same?
Renewable energy like solar? I expect that if you're using renewable energy it might even be easier and
cheaper, more affordable.
14. What are you farming? What are the main activities in the area? How important is the farming
industry in Kilifi?
My take is that it is very important for the economy. One of the things that determine the progress of a
region is how well they do agriculture. That is my observation. Now I'm in the agriculture business, so my
take is that if Kilifi people are shown properly how to farm and harness water I think we would be talking
about a different poverty index.
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Interview 12: Chokkie Rama (Ramar Farm)
Interviewee: Chokkie Rama
Organization: Ramar Farm
Contact: +254 724 942 481
1.
How much water do you consume here in the farm?
Approximately 2000 liters per day.
2.
What are you using it for? What is the main use of the water?
It’s mainly for irrigation. Here we have spinach, amaranth, and cassava. We have also capsicums, which
needs a lot of water. We also do hot chili and banana.
3.
How are you getting the water you are using?
At the moment I'm using tap water from KIMAWASCO, but it is very expensive for me. I have a well, and I'm
planning on using that water.
4.
How much are you paying for the water that comes from the municipality?
I’m paying about 20,000 schillings per month, so it is very expensive. I have to start using the well water.
5.
Are you satisfied with the quality you are getting from the municipality?
No, I'm not satisfied, because sometimes we can spend one week without water.
6.
Are you going to use the well water for the irrigation process?
7.
Is it good for direct use in irrigation?
Yes.
It’s good. I already tested the water, and is like normal drinking water. Later on if I want to treat it I will
have to.
8.
Have you experience any water scarcity problems?
As I said before, once in a while I don't get the water.
9.
How has that affected you so far?
You know if there is no water, and you have a lot of greens, it really affects your work because I'm selling
them. If there is no water to irrigate the quality of the products is poor, and people look for the quality.
10. In the moments you did not get the water, what did you do to solve the problem?
I had to wait for them to start pumping again because there was no other option.
11. In your opinion, what would be an ideal solution to solve this problem?
To have a well, and I have two in total. I have this one (he points to a well very close to us) and the second
one is right behind, which will be enough for me. Now I'm trying to bring the power so at least I can pull
out the water from the well.
Appendix
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Yes, I know.
13. Would you use it for the irrigation process?
I think it would be better for me.
14. Would you be willing to pay more or less for this water?
If what I have to pay its less for me is also better!
15. If this water is produced with renewable energy sources; would that affect somehow the price you
are willing to pay for it?
It depends on how much they charge per unit.
16. Do you have any comment about the farming industry in Kilifi? Do you know, for example, how big
is farming in this area?
I can see is quite big, it’s only that we have never met other farmers, but there are many people interesting
in farming at the moment. I can see people farming around, but is not exactly what I'm doing. Myself I really
want to go pure farming. I mean, produce things I can sell all over the country.
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Interview 13: Robert Clarke (REA Vipingo Plantations Limited)
Interviewee: Robert Clarke
Organization: REA Vipingo Plantations Limited
Position: Estate Manager
1.
How much water does your farm consume?
You can do the math: we have 3 decorticator machines, and each one uses 60 cubic meters per hour.
2.
Boreholes. We have 15 boreholes.
3.
So you have 15 boreholes and then you send all this water to a main vessel?
Yes. About 7 of them go to the factories and the others go to the camp and housing. The biggest one does
40 cubic meters per hour. It was a well and they put a pump on it.
4.
Do you also use some extra water for other activities?
Yes. We have 6,000 people living here, so it is also a lot of housing, but still the decorticators are the ones
that use the most of the water.
5.
So you don’t have to pay anything for the water?
Yes, we have to pay. Government charges us 15 cents per cubic meter. Is a license thing, so we have to pay
a little bit, and that’s everywhere in Kenya. If you irrigate from a dam or you use dam water or borehole
water there is a charge.
6.
Are you satisfied with the quality of the water you are getting and using?
Yes, for what we do, but is not fit for human consumption.
7.
And how do you do with the water for human consumption?
We don’t put it through reverse osmosis, but we do have chlorination plants on the drinking water.
However it still doesn’t pass the drinking water standards. It is still too salty. We are looking at taking it off
the pipeline for the domestic consumption, but we haven’t done that yet. They are quoting us I think
1,000,000 bobs* to take it to one camp and 600,000 to take it to the other camp, so we might do it, but then
maybe I’ll charge for the water, because I don’t what they charge per cubic meter.
8.
Have you ever experience water scarcity problems on the farm?
No, never.
9.
In your opinion, what would be an ideal solution? Are you completely happy using the system you
have right now or would you like to change it?
I’m happy with factory side of it, but the drinking water needs to be improved. We are talking to
MARIAKIANI water to tap into the pipeline, because the pipeline goes through the farm, just at the top of
the hill, so we are talking, we are talking to them now, the giving us a quotation.
10. Besides the piping have you ever considered any other option?
No, not really. We have talked about reverse osmosis, but it has never really gone further than that. It was
always decided it would be too expensive.
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11. So are you aware of what desalinated water is?
Yes.
12. Would you use it?
Yes, because you have to reach certain standards. There has been a lot of talking about improving it.
13. The fact that it is desalinated, would it affect the price you are willing to pay for it? In comparison
to the water that comes from the MARIAKANI pipeline.
The same.
14. If this desalination plant is powered by renewable energy sources, would that affect somehow your
perspective?
Yes, because we have a lot of biomass that we could use. We have potential of producing biogas from all the
waste material.
15. Can you provide me some details of the industry? What are you doing on your farm and how
important it is farming for this area?
We grow sisal. We have 4,300 hectares. Employing 1,300 permanent workers and we have 6,000 people
living on the state. We have our own clinic and schools. We have two nursery schools for the workers. So I
think we are a little bit important for the income in the district. Total is about 10,000 acres.
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Group #4 - Water desalination companies
Introduction
Since 2009 Dutch Water Limited has seen an important growth in their sales, and their experience could
be very valuable for the Winddrinker Holdings project. An interview was held with the objective of learning
more about DWL operations and business plan as well as to have a better understanding of the different
markets segments they are reaching.
Interview
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
How long has your organization been providing clean water?
What are the main activities/products offered by your organization?
How much do they cost? What is your profit margin?
Who are your customers?
How are they divided (market segments)? How do they behave?
How do you find your customers?
How do you get your products to your customers?
Do you get any feedback from your customers? How?
Has it been positive? Are your customers (in general terms) satisfied with you product?
Do you experience reaching and communicating with your customers as a problem? Why?
Has your business plan changed? How?
Is your organization developing a new product or strategy? Is there any change you are adapting
to?
What do you consider are the largest barriers and drivers for the business of affordable water in
Kilifi?
Are your activities affected by the political situation in Kenya?
How do you evaluate the impact of your product on your customers?
How do you evaluate the environmental impact of your activities?
Do you know about other actors selling affordable water in the region?
Is there any regulation or law that has affected the introduction of your product to the market?
Do you receive any funding for your activities?
Are your activities affected by the political situation in Kenya?
What is the main maintenance activities performed in the plant?
Are these activities performed by DWL employees or a third party?
In case it is performed by DWL employees, is there a training they go through?
If yes, how is this training? How long it takes?
Are all the materials and tools required for the maintenance activities available locally?
How much does a jerry can cost? (cap, seal, no water)
How much does the machinery to mould the jerry cans costs?
Appendix
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Interview 14: Michael Dubelaar (Dutch Water Limited)
Interviewee: Michael Dubelaar
Organization: Dutch Water Limited
1.
What is the goal of DWL?
To supply affordable healthy drinking water, and although we call ourselves a social enterprise, we are
limited. We need profits to sustain ourselves, and at the moment we are running just to break even, but we
will run on profits next year. We are expanding our market; we are expanding our product range, so we
will run on profits.
2.
How long has been DWL in this business?
2009. We started in 2009 but it was a green field; so actually in 2009 there were just 6 people here, and
they made some water, they filled the bottles, they dropped them at the customers themselves, only in
Mtwapa. I think the real turnaround came in 2011. We started growing.
3.
What are the main activities and products of DWL?
I do the 10 liter jerry cans and I do bulk, so 1,000, 2,000, 4,000, 6,000 liters which we drive to schools.
4.
How much does the water you produce costs?
When we sell in bulk is 5 shillings per liter, including transport and everything, and we clean the tanks, we
maintain also the tanks.
With the jerry cans it depends on the area where you are. In Mtwapa people pay 60 (shillings per the 10
liter jerry can), outside people pay 70, if you go a little bit further way is 80 schillings. It depends on the
transport.
The expense of the bottles, the jerry cans, is a deposit system. The first time you have to pay the jag, for
which we charge 150 schillings, so the first time you buy, for instance here at Mtwapa, the shop keeper
pays 150 for the jag and 60 for the water, so 210 schillings. The next time you exchange, you only pay for
the water.
5.
Shops, retailers. Although our model is business to consumer, I deliver at the shops. I don't do the last part.
The shops are the ones in charge of the distribution. In the market the water is not sold in 60 schillings. The
customer will pay 70 or 80 schillings, and the shop make 10 or 20 schillings per jerry can.
6.
What is your current situation?
The profit margin is non-existent. It is very seasonal. Your season runs from November, so it just started,
up to April. The rest of the year we are running in lost. It is rainy season and people don’t buy that much.
They use rain water.
7.
Now you're running at break-even. Do you think that if you increase the price a little bit it the water
won't be sold?
Yes. Competition is already 10 schillings under our price. There is enough competition. We started this; the
whole jerry can idea is from DWL. It didn't exist. We introduced this system. People had no idea. At the
moment in the Mombasa market only there are 56 competitors, doing exactly the same. Stealing my jerry
cans, filling them, putting a sticker with a different brand, because we are buying the jags in bulk and they
can't afford that price.
Appendix
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All these competitors started in the last 2 years, and we are still the bigger one. They compete with us, we
don't compete with them. We set the market. That's also the only way we can survive. If I would come here
now and I want to enter the water market, I wouldn't even try. I would move to a different county. Mombasa
coast? No chance. If you want to introduce a new brand now? No chance. The market is set. Even if you go
to an area where there is not a lot. The moment it peaks and people get used to it all of the big brands will
push you out. Immediately. If you don't go down by the cheating and everybody stealing the bigger brands
will do it. I would do the same. I can go into the market and just flood it. I have the capacity. I can just keep
pushing.
8.
I was going to ask you if you can recognize different marker segments, but basically your market
are the shops...
This is my market. The people that set this up, one of them, thought that at 60 schilling we would reach the
bottom of the pyramid. No, forget it. The lowest 36% of the community we do not reach, even with these
prices. They buy 20 liters for 10 shillings or 20 schillings, they add a bit of water guard to it, a chemical, and
they have drinking water, compared to 10 liters for 60 shillings. They used to drink from brackish water,
so what would they pay more now? The lower end of the middle class is my market. As soon as they go up
a bit they start buying expensive bottled water.
You won't reach the bottom of the pyramid. You won't be able to compete with well water or water they
get from a tap for free, somewhere.
9.
How do you find your customers? You go to the shops and propose your product?
For the shops is all about the money. They are only interesting in making money, so they don't care which
brand, if it's healthy or not, as long as they can make the most money with it. Kenyans are not interested in
quality. Kenyans go for price. Water is a null interest product, is not even low interest, it is a null interest.
People think "water is water", and even we know is not true, water is water for them. If it’s packed, it looks
nice, is probably OK. So there are people here filling tap water, government tap water, and selling it
containerized almost at the same prices we do, and people buy it, and like it.
10. But most of the hotels that I have interviewed so far are saying that they have to treat the water
because they are aware that the water they're getting from the KIMAWASCO pipes is not good
Yes, but nobody drinks that water. Why hotels are interested? Hatenboer Water has tried to sell them
machines, straight up, even not sell them but lease them out, you don't have to pay anything, and you pay
for litter. The hotel business is gone. There is no business. Hotels are not the market. There are 70 hotels
on sale around the coast. Then hotels are interested in money, revenue, so what they're doing is selling
bottles to customers. How can you compete with that? Why would they buy your water? They are not
interested on it, they don't make money out of it, and you can't sell it to a customer in the room. For cooking
they boil, so borehole water is good enough. What is your water for? Why would the hotels need your
water? Yes, they like the idea, until they have to pay for it. We have the conversations everywhere, and is
not a market. If you can offer them very cheap, bottles, with their logo on it, that you can sell to the
customers for a lot of money, yes, they're interested. They'll take it to the room. Otherwise, why? The
customer doesn't want to see it being pour from a big jerry. They want so see the bottle being opened,
nicely. So the hotels are no market. The hotels are a market for water because they use it. White Sands Hotel
here has a big installation as we have. Why? For their washing machines. The water is purified but is not
drinking water quality. They take the chalk, the limestone, out of the water.
11. I talked yesterday to a big hotel in Kilifi, the Mnarani club, probably the bigger in the area, and they
do have their own desalination plant.
Yes, and they use it mainly for cooking and for the washing machines. Most of the times not even for the
shower. So for this water, unless you start packaging like I told you before, on which you cannot compete
to the big ones because you need a production line or a big investment, it is no market. People here like to
talk until they have to pay, and then nothing happens.
Appendix
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12. Can you tell me a little bit more of the process to get the water to your customers?
From the plant to the trucks, from the trucks to the depots, and from the depots to the customers. It is a
two-step delivery system.
13. Is there any feedback you get from the people that is consuming your water?
I ask you to go to any shop and ask them what the best water is. They start with Keringet*, the most
expensive one. If you ask what’s the best water in 10 liter containers they will tell you DWL: "Is a bit more
expensive but that's the best". Branding.
Trust is a big issue in Kenya, in Africa in general, and we have been around for a long time. People trust us,
they know us. We were the first; we will also be there next year. They know that we are not a Somali filling
bottles in the back of his house and putting in a very nice looking sticker. That happens. Out of the 56
competitors I mentioned you before 45 are doing it at the back of the house filling bottles with tap water.
Maybe, if you're lucky, using a carbon filter. Or somebody buys a small Chinese machine, after 6 months the
filters are polluted, and they just keep running it. For the first six months it’s nice and after that the water
is rubbish. We see a lot of brands coming into the market and fading out again, and a new brand comes in.
Trust is an issue. We survive on branding. We built the brand because were the first. We had a monopoly
at the beginning, so we could wrap the market. Now we have the market and we just have to maintain
ourselves.
14. How has this surge of all this new competition affected you then?
Here in Mtwapa we lost 30% of market share. Of course it hurts us, but still the question is how long will
they be around? Now we're expanding our operation area.
15. Reaching the customers and communicating with them has been a problem for you? How has your
business plan changed?
We started like that. Small scale it will work, but big scale won't. At the moment you look at this as a
business and not a hobby, you won't be able to do it door to door. Is just not possible, you won’t reach the
volume, you don’t have time for that. I don’t have time to drop one here and drop one two stories up. I go
to the shops, tuk-tuks**, 10 here, 20 there, 50 here... you don’t have time, you don't reach scale and water
is scale. We started like that, but we had to change that business model. You also cannot compete. We run
on business hours, meaning that we are open between 7:00 and 4:30 at the factory, and between 8:00 and
5:30 outside. People here are used to go to the shop at 9:00 pm. We are closed; the competition is there, so
we cannot do it ourselves. We need the shops, because they have other opening hours. The availability of
your water is very important. Now we still have our own depots and we go with tuk-tuks to the customers
and now we are testing the usage of distributors. Why distributors? It takes over our depot, we just drop a
full truck of water and we disappear for discounted price. The distributor will go to the shops and make
some money out of it. Why is that interesting for us? Again, we close at 5:30, while their business starts at
7:00 in the morning and runs until 10:00 in the evening. I can't compete with that, so it is better to have a
distributor that is willing to do that and make his own money. I have my labor laws, and I can't ask my staff
to work 12 hours a day. A distributor does that. Selling water is a huge organization to get it up and running
(bills, certificates), especially in Africa, in a country like Kenya, which is very corrupt. If you miss one, they
find you millions. I have had supervisors spending a weekend in jail because a form was not there. They
(the authorities) go on Friday afternoon at 4:00 because they know everything is closed, so if you get locked
up you get locked up for the whole weekend. People can't get you out anymore, so that's what they do in
purpose. "You go to jail now unless you pay". We have a no corruption policy so we don't pay, so this poor
guy sat on jail for two nights, from Friday until Monday, and then we went with the form and he was
immediately released. They only do that to get cash. They find an opportunity to make some money. You
have to stay out of trouble. As a tourist is OK, but you will not be a working as a tourist.
Appendix
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16. Is DWL developing a new product?
Yes, we have to, we are running just at break even with the jerry cans. It’s not a sustainable business model.
We have no margin, so we're introducing 20 liter bottles for the upper market and we're currently looking
at small volume packaging. That's all I can say about it.
17. In your experience here, what would you think are the main barriers and drivers for the business
of affordable water in Kenya?
Water used to be a very high margin product, especially mineral water, but that has changed. When we
came in with the 10 liter jerry cans we changed the market, actually we did, the whole business model. We
made a brand, and that's carrying us.
If you can reach high volumes, well organized, and have your distribution in order you can survive and also
make some money, but is a huge challenge. You can't trust your staff, people don't see is stealing but as an
opportunity they took. Government is corrupt to the bone. You got to mistrust your staff, People here cheat
their brothers and sisters, people cheat their own father. Is opportunity, is normal. Everybody wants
something. Short-term vision. Plain. Just long-term vision and good organization can survive. In this
country the money is in government contracts, trades, real estate. Kenya doesn't produce anything.
Now we have the counties government. They followed the American model, in which Mombasa is a county,
Malindi is a county. What's happening is that now I'm paying, from one day to the other they setup a toll
booth and every truck going into Mombasa, passing the bridge, has to pay 4,500 shillings, every truck.
That's 12-16 trucks per day, just like that. You can't prepare for that. They don't give you any preparation.
It’s illegal by the way. We negotiated and it finally came down to 1,000 schilling per truck, and that's it. We
are still paying 12,000 - 16,000 every day. Gone. It can happen like that. Every county has their own
government, their own parliament. They are different small countries and they are all grabbing. If I go with
my truck to Mombasa I pay 1,000 schilling. If I go to Kilifi and I pass the Tuskys there the truck also pays.
Whichever way I move I have to pay. I pay the national government and` now the counties come in as well,
and you have to be prepared for that. If you miss one thing they will fine you, or you pay and they let you
go, and once you pay for the first time they will find you every day.
18. Is there any other actor selling affordable water in the region?
The 56 competitors I mentioned before. There are also some good ones. There is one company here in
Mtwapa coming up, Ahmed water, is good. There is also honest competition, and there is no problem with
that. The problem is that the majority of them are dishonest. And even the honest competition steals your
jerry cans. They take them, they scratch the logo, they put a sticker on, and I can go on.
19. Is there any regulation or law that is affecting your product in the market?
There are a lot. Kenya is based on the English law. Quality laws, distribution law, is all there. Don't think
that you're coming to Kenya and that is easy. No. You have to comply with the same laws you would have
in England. The problem here is that they don't understand their own laws, and if you miss one, they will
get you. In first world countries if you make a mistake or a tax thing they give you a chance to correct it.
Here they see opportunity. You make a mistake: "You owe me". There is no way to correct. That margin is
not there. Either you comply or you don't, and if you don’t, they have an opportunity to get cash. "I fine you
2,000,000 or you can give me 200,000 now".
20. Do you receive any funding for running this?
We started up with funding, some big investors. They put all these buildings last year. It’s an investment,
real funding. We have a foundation, we deliver to public schools bulk water, about 250,000 - 280,000 liters
per month, and that's donated by a Dutch Foundation, but we deliver at cost price. Nothing enters, that's
our social side.
Appendix
183
21. Those your activities have been affected by the political situation in the country?
Yes, every day. Tomorrow can be completely different. This changes very fast. I told you this tax system,
that even though is illegal it is still there. People in Nairobi say its legal, but then in the court they said it
was illegal. But I don't want that position that I oppose the county because it will cost me far more that
what I'm paying now.
22. How does your product affect the customers?
In Mtwapa health improved significantly since DWL is here. We try to think that in part is due to us. That's
it. For the rest we're just sending good water.
23. What is the environmental impact of your product?
Why do you think we work with reusable jerry cans, which actually gets me a headache? Mainly because,
you see around, plastic bags everywhere, this country is polluted from top to bottom, so we choose not to
have a negative impact. It’s a very conscious choice.
24. Is the maintenance of the plan done by employees of DWL or a third party?
Employees
25. Do they get some sort of training?
Yes, in-house training. These things are high maintenance. Whatever they say, is high maintenance.
26. Do you find in the area all the tools and material required for the maintenance activities?
No, some things have to be imported, especially when you have a Hatenboer Water installation, which is
metric and here everything is in inches. I have to order all our piping from outside.
Most of the things you can get locally and we are able to find it, but some parts not, and they have to be
imported.
27. Are your employees people from the local community that you trained in the facilities to run the
plant?
No. We have, for example, a qualified nutritionist which is schooled and is though how these things work.
You can't teach just someone. It won't work. It will definitely cost you a lot of money. You need somebody
with the skill who is very qualified.
28. How much does a jerry can cost you?
They cost me what I put them out for, so if I buy them from a supplier is 150 schillings, and that is also the
money asked for it.
29. Buy them from the suppliers? You don't make them?
Yes, now we are making them with a molding machine.
30. How much does this molding machine costs?
Yes, I do. It’s a big investment. Only the material for the first run is a 100,000 euros, and I'm not even talking
about the machines. Let's have a walk around.
* Keringet: A local bottled water brand
* Tuk-tuk: Swahili expression for motorcycle
Appendix
184
Group #5 - Municipality water provider
Introduction
During the interviews with different people the name of KIMAWASCO was very often mentioned, as most
of the people from Kilifi depend on this organization to get their water; however, some complains about its
reliability and the quality of the water it provides were also heard,
An interview was held on site with KIMAWASCO with the goal of finding out more about the organization,
their products, customers, and what has to be done by any organization that wants to start water-related
projects in the area.
Interview
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
How long has your organization been providing clean water?
What are the main activities/products offered by your organization?
How much do they cost? What is your profit margin?
How are they divided (market segments)? How do they behave?
How do you get your products to your customers?
Do you get any feedback from your customers? How?
Has it been positive? Are your customers (in general terms) satisfied with you product?
Do you experience reaching and communicating with your customers as a problem? Why?
Has your business plan changed? How?
Is your organization developing a new product or strategy? Is there any change you are adapting
to?
What do you consider are the largest barriers and drivers for the business of affordable water in
Kilifi?
How big is the population of Kilifi and how many of them use your product?
Has this number been increasing or decreasing drastically in the last few years? If yes, what do you
think is the reason for this?
How many water providers are, besides KIMAWASCO, in the area? Is it possible to have some data
about them? (name, product, amount of customers)
Do you know about any other water related projects in the area?
What do the organizations have to do in order to start distributing water in Kilifi?
Do you consider the inhabitants from Kilifi accept new products easily?
Appendix
185
Interview 14: Cornelious K. Mutai (KIMAWASCO)
Interviewee: Cornelious K. Mutai
Organization: KIMAWASCO
Position: Area Manager - Kilifi
1.
KIMAWASCO is Kilifi Mariakani Water and Sewerage Company, and our main goal is to supply water from
Kilifi to Mariakani.
2.
How long has been your organization operating in the area?
We started this company in the year 2006.
3.
What are the main activities and products that your company offers?
I will summarize it, because there are quite a lot of activities. We do operation and maintenance of water
supply systems. At the moment we're supposed to be giving out sanitation and sewerage but we have yet
not started with that. That's why you find the name itself Kilifi Mariakani Water and Sewerage Company,
but the sewerage side hasn't started yet, so basically we’re dealing with water supply.
4.
How much does the water costs?
In terms of cost of selling that water? The tariff?
5.
Yes, exactly
We operate a tariff which we do in blocks system. We bill our people according to their consumption. We
own our connections and meters, so is a fully metered water supply. We have domestic rates, commercial
rates, institutional rates, and we also have kiosks rates.
For the kiosks you give the water at a certain price, a flat rate of 35 schillings per cubic meter and then they
charge 2 shillings per 20 litters.
The domestic rates are broken into blocks: if the consumption goes from 0 to 6 we charge 300 schillings,
constant, because is a bracket that is serving mainly the poor people. Then, from 7 to 20, we charge 75
schillings per unit, by cubic meter. Then from 21 to 50 we charge 97.5 schillings per unit and then from 51
to 100 we charge 120 schillings per unit. Then it continues like that. The more you consume the more you
pay.
6.
Our customers are various. We have institutions, we have industries, we have schools, we have
communities, and individual consumers.
7.
They come here by themselves, and then they do the applications. We offer our product and then they come
here, we give them application forms, they process them, and eventually we give them the connections.
8.
Do you get any feedback from your customers?
Of course. We communicate with our customers frequently. We normally post our messages through their
bills. We sometimes give them questionnaires and they answer them. Our company also have a website and
hotlines. And we don't deny our contacts, so they can call us anytime they want.
Appendix
9.
186
Has that feedback been positive?
Very positive, especially in terms of complains, we do handle them in a very short period of time. We are
very prompt. People are in general terms satisfied with our service. We can't say 100%, but the reception
is good.
10. Reaching and communicating with your customers has not been a problem?
It is not a big problem, because even though there are challenges we normally can reach them through their
local leaders, through the radio. We have different stations, communicating in their local language. Also
most of our employees come from the area, so they know the people and the language.
11. Has the business plan of the company change drastically in the last few years?
Yes, indeed it changed, because as I told you we started in the year 2006 to operate as a basically a semiprivate company recently. Even though we use the policy of the government we operate as a company.
Initially it used to be the government operating the water systems in the area, but when it changed, and we
started operating as a company, obviously many things changed, including the tariffs, the cost of water,
because we needed to cover other costs. The prices went up. We also started becoming very strict in our
revenue collection because we don’t get any subsidy from the government. Whatever we get we use it to
pay our salaries, to operate, for the maintenance, everything. That's from 2006, and before that it was the
government and the National Water Conservation.
12. Is KIMAWASCO the most important authority?
Years ago the water sector was divided in Boards. Here the Coast Water Service Board (CWSB), which is
Government entity, is the most important agent, as they own all the infrastructure on the coast. Any project
or development has to go through them.
13. What do you consider are the largest barriers and drivers for the business of affordable water in
Kilifi?
The bulk number of water users is, of course, the community, and meeting the bills for a lot of them is quite
a big challenge. That's why we are so strict now, and this could affect any new project.
14. How big is the population of Kilifi and how many of them use your product?
As in 2014 we have 826,180 customers, but that goes from Mariakani to Kilifi. It is not possible for me to
give you a number of Kilifi, but I can estimate that around 200,000 of those are in Kilifi.
15. Has this number been increasing or decreasing drastically in the last few years?
The number of clients increases every day. All this pile (showing me a pile of documents in his desk) is new
application forms.
16. What do you think is the reason for this?
There are no other fresh water services. Customers rely on the tap water we're sending to them.
17. How many water providers are, besides KIMAWASCO, in the area? Are there any other water
related projects in the area?
There is nobody else. There are some organizations such as World Vision and Plan, and some proposals
from the communities, but at the end everything has to go through us and the CWSB.
There also private donors, the CDF (local parliament fund) and the County Council Goverment pushing for
projects, but is the same case.
Appendix
187
18. What do the organizations have to do in order to start distributing water in Kilifi?
The organizations that want to start water projects in the area will own the structure, but they need to
communicate with KIMAWASCO, as they are the ones distributing the water, which is already flowing.
Communities will form committees with their own regulations and laws, but they need to pay the bills to
KIMAWASCO, who will regulate the prices.
19. And if there is no usage of the pipe water?
Is different. With boreholes for example, they manage their water resource, but still apply by the rules.
They need to apply to KIMAWASCO and pay certain fees. It is possible, but it might be an expensive process.
Desalination with this water is also possible.
20. Do you consider the inhabitants from Kilifi accept new products easily?
I would say is 50-50. If you prepare the new proposal and explain to them who are you, what are you trying
to do, the monetary issues, and the benefits for them it should be OK. It is very important to communicate
with the leaders.
21. How do you evaluate the environmental impact of your activities?
The water comes from the Sabaki River, but it not extracted directly. We use boreholes next to the river,
and before pumping the water through the pipes we filter it and add chemicals to make sure the water is
safe and can be consumed.
Appendix
188
A.3 REVERSE OSMOSIS ARRAY PI&D AND LAYOUT
Appendix
191
A.4 FEED WATER TEST RESULTS
Appendix
192
Appendix
193
A.5 PLANT LOCATION IN KILIFI
Appendix
194
Appendix
195
Appendix
196
A.6 WIND TURBINE ROTORS PERFORMANCE CURVES
Appendix
197
Appendix
198
A.7 CURVED PLATES WITH CHORD AT 25% EMPIRICAL
DATA
Appendix
α
-8.005
-6.005
-5
-4
-3.005
-2
-1.005
0
1.005
1.995
2.995
3.995
5.995
6.995
7.995
9
9.995
11
12.503
14.995
199
Cl
-0.32
-0.381
-0.413
-0.41
-0.342
-0.165
0.181
0.322
0.435
0.536
0.642
0.745
1.1
1.157
1.207
1.253
1.287
1.302
1.312
1.14
Cd
0.104
0.094
0.087
0.082
0.078
0.069
0.61
0.063
0.066
0.072
0.068
0.071
0.074
0.077
0.08
0.088
0.1
0.113
0.147
0.276
Cl/Cd
-3.1
-4.1
-4.7
-5.0
-4.4
-2.4
0.3
5.1
6.6
7.4
9.4
10.5
14.9
15.0
15.1
14.2
12.9
11.5
8.9
4.1
α
17.5
19.995
22.505
24.995
27.495
30
32.495
34.995
37.505
40
42.5
45
48.005
49.995
55
60
69.995
79.995
84.995
89
Cl
1.073
1.064
1.076
1.193
1.269
1.33
1.31
1.366
1.358
1.337
1.316
1.217
1.251
1.223
1.119
0.977
0.662
0.341
0.176
0.037
Cd
0.339
0.389
0.448
0.55
0.649
0.757
0.816
0.945
1.027
1.104
1.191
1.193
1.367
1.422
1.567
1.662
1.804
1.884
1.935
1.919
Cl/Cd
3.2
2.7
2.4
2.2
2.0
1.8
1.6
1.4
1.3
1.2
1.1
1.0
0.9
0.9
0.7
0.6
0.4
0.2
0.1
0.0
Appendix
200
A.8 ORIGINAL DESIGN BLADE SHAPE
Design tip speed ratio
Number of blades
1
24
Design aerodynamic conditions (curved plates)
Design lift coefficient
1.2
[degrees]
Design angle of attack
8
[degrees]
0.14
[radians]
Blade
section
r/R
0.05
0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
dr = 0.45 [m]
Local
radius
r
[m]
0.225
0.675
1.125
1.575
2.025
2.475
2.925
3.375
3.825
4.275
Local tip
speed
ratio
Inverse
λr
1/λr
0.05
0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
20.00
6.67
4.00
2.86
2.22
1.82
1.54
1.33
1.18
1.05
Local
angle of
relative
wind
φr
[rad]
1.01
0.95
0.88
0.82
0.77
0.71
0.66
0.62
0.58
0.54
Local
angle of
relative
wind
φr
[degrees]
58.1
54.3
50.6
47.1
43.8
40.8
38.0
35.4
33.1
31.0
Radius
Air density
4.5
1.225
[m]
[kg/m3]
Pitch angle at the tip
0
0
[degrees]
[radians]
Cosinus
cos(φr)
0.53
0.58
0.63
0.68
0.72
0.76
0.79
0.81
0.84
0.86
Local
chord
Local
pitch
angle
Local
pitch
angle
Local
twist
angle
Local
twist
angle
Cr
[m]
0.09
0.25
0.36
0.44
0.49
0.52
0.54
0.55
0.54
0.53
θp,r
[rad]
0.87
0.81
0.74
0.68
0.63
0.57
0.52
0.48
0.44
0.40
θp,r
[degrees]
50.1
46.3
42.6
39.1
35.8
32.8
30.0
27.4
25.1
23.0
θt,r
[rad]
0.87
0.81
0.74
0.68
0.63
0.57
0.52
0.48
0.44
0.40
θt,r
[degrees]
50.1
46.3
42.6
39.1
35.8
32.8
30.0
27.4
25.1
23.0
Chord
distribution
Cr/R
0.0206
0.0545
0.0798
0.0977
0.1095
0.1166
0.1202
0.1211
0.1203
0.1183
Appendix
202
A.9 THE BEM METHOD
Appendix
203
The BEM method
The blade element momentum (BEM) theory is a combination of momentum theory and blade element
theory. Momentum theory refers to a control volume analysis of the forces at the blade based on the
conservation of angular and linear momentum, while blade element theory refers to an analysis of forces
at a section of the blade.
Momentum theory
A wind turbine extracts kinetic energy from the wind. The presence of the turbine rotor causes the
approaching wind to slow down. The mass flow rate is the same everywhere along the stream tube. To
compensate for the slowed down air the stream tube must expand. The axial induction factor or inflow
angle a is the fractional decrease in wind velocity between the free stream and the disc plane. The pressure
difference across the actuator disc causes a change of momentum equal to the overall change of velocity
times the mass flow rate. From the conservation of linear momentum to the control volume of radius r and
thickness dr the following expression for the differential contribution of the thrust can be obtained.
𝑑𝑇 = 𝜌𝑈 2 4𝑎(1 − 𝑎)𝜋𝑑𝑟
Similarly, from the conservation of angular momentum the differential torque imparted to the blades can
be determined with the next equation.
𝑑𝑄 = 4𝑎′(1 − 𝑎)𝜌𝑈𝜋𝑟 3 𝛺𝑑𝑟
In this equation a’ is the angular induction factor and is defined as a’ =ω/2Ω. The momentum theory results
thus in two equations that are a function of the axial and angular induction factors. One defines the thrust
and the other the torque on an annular section of the rotor [59].
Blade element theory
Blade element theory refers to an analysis of forces at a section of the blade. The angle of relative wind ϕ
and the relative velocity itself can be calculated by means of the following equations.
𝑡𝑎𝑛𝛷 =
𝑈𝑟𝑒𝑙 =
𝑈(1 − 𝑎)
𝛺𝑟(1 + 𝑎′ )
𝑈(1 − 𝑎)
𝑠𝑖𝑛𝛷
In these equations a and a’ are the axial and angular induction factors, respectively. The angle of attack for
each element is a function of the local pitch angle and the local angle of relative wind. The local pitch angle
is the sum of the local twist angle and the pitch angle at the hub. These parameters are fixed after the blade
shape selection. With the angle of attack the local lift and drag coefficients can be found. With these
coefficients and the relative velocity the local lift and drag forces can be calculated using the next equations.
𝑑𝐹𝐿 =
1
𝐶 𝜌(𝑈𝑟𝑒𝑙 )2 𝑐𝑑𝑟
2 𝑙
1
𝑑𝐹𝐷 = 𝐶𝑑 𝜌(𝑈𝑟𝑒𝑙 )2 𝑐𝑑𝑟
2
With these equations and the angle of relative wind the local normal and tangential force can be obtained.
If the rotor has B blades the total normal force on the section at a distance r from the center can be
calculated by means of the next equation.
1
𝑑𝐹𝑁 = 𝐵𝜌(𝑈𝑟𝑒𝑙 )2 (𝐶𝑙 𝑐𝑜𝑠𝛷 + 𝐶𝑑 𝑠𝑖𝑛𝛷)𝑐𝑑𝑟
2
Appendix
204
The differential torque due to the tangential force is given by the following equation.
𝑑𝑄 = 𝐵𝑟𝑑𝐹𝑇 =
1
𝐵𝜌(𝑈𝑟𝑒𝑙 )2 (𝐶𝑙 𝑐𝑜𝑠𝛷 + 𝐶𝑑 𝑠𝑖𝑛𝛷)𝑐𝑟𝑑𝑟
2
Just as for the momentum theory the blade element theory also results in two equations that define the
normal force (thrust) and the tangential force (torque) on the annular rotor section. For the blade element
theory the equations are a function of the flow angles at the blades and airfoil characteristics. For the
momentum theory the equations are a function of the axial and angular induction factors.
Appendix
205
A.10 PROPCODE RESULTS ORIGINAL DESIGN WITH
ADJUSTED CHORD
Appendix
TSR
0.00
0.01
0.02
0.05
0.09
0.10
0.11
0.12
0.13
0.14
0.16
0.18
0.19
0.20
0.22
0.24
0.26
0.28
0.30
0.31
0.33
0.35
0.39
0.40
0.42
0.43
0.46
0.47
0.48
0.49
0.50
0.51
0.52
0.53
0.54
0.55
0.57
0.58
0.59
0.60
0.61
0.62
0.63
0.64
0.65
0.66
0.67
0.68
0.69
0.70
0.71
0.72
0.73
0.74
0.75
0.76
0.77
206
CT
0.642
0.643
0.643
0.643
0.643
0.643
0.644
0.644
0.644
0.643
0.644
0.644
0.643
0.642
0.641
0.642
0.647
0.653
0.654
0.655
0.656
0.658
0.661
0.662
0.662
0.660
0.659
0.658
0.659
0.661
0.663
0.664
0.666
0.668
0.668
0.667
0.666
0.666
0.665
0.664
0.664
0.663
0.662
0.661
0.660
0.660
0.659
0.658
0.657
0.656
0.655
0.653
0.652
0.651
0.651
0.650
0.650
CP
0.224
0.224
0.224
0.225
0.225
0.225
0.225
0.225
0.225
0.225
0.225
0.224
0.224
0.224
0.223
0.224
0.225
0.227
0.228
0.228
0.229
0.230
0.230
0.231
0.231
0.231
0.230
0.231
0.231
0.231
0.232
0.232
0.233
0.233
0.233
0.233
0.233
0.232
0.232
0.232
0.232
0.231
0.231
0.230
0.230
0.229
0.229
0.228
0.227
0.227
0.226
0.225
0.225
0.224
0.224
0.224
0.223
CQ
0.001
0.002
0.005
0.011
0.021
0.023
0.024
0.027
0.029
0.032
0.035
0.040
0.042
0.045
0.049
0.053
0.058
0.064
0.069
0.072
0.075
0.081
0.089
0.093
0.098
0.100
0.106
0.109
0.111
0.114
0.117
0.119
0.122
0.124
0.127
0.129
0.132
0.135
0.137
0.140
0.141
0.144
0.145
0.148
0.150
0.152
0.153
0.156
0.157
0.159
0.160
0.163
0.165
0.166
0.168
0.170
0.172
TSR
0.78
0.79
0.80
0.81
0.82
0.83
0.84
0.86
0.87
0.88
0.89
0.91
0.92
0.94
0.95
0.96
0.98
1.00
1.01
1.03
1.05
1.06
1.07
1.09
1.11
1.13
1.15
1.17
1.18
1.19
1.22
1.24
1.27
1.29
1.32
1.35
1.38
1.41
1.45
1.48
1.52
1.56
1.60
1.64
1.69
1.74
1.77
1.79
1.84
1.88
1.90
1.96
2.03
2.10
2.12
2.17
2.25
CT
0.651
0.651
0.652
0.653
0.656
0.659
0.662
0.666
0.676
0.682
0.686
0.693
0.710
0.720
0.731
0.737
0.749
0.754
0.758
0.768
0.772
0.774
0.775
0.780
0.786
0.788
0.790
0.792
0.794
0.794
0.794
0.791
0.788
0.784
0.781
0.775
0.769
0.762
0.756
0.749
0.740
0.735
0.724
0.714
0.706
0.693
0.686
0.681
0.668
0.656
0.652
0.634
0.615
0.593
0.586
0.570
0.544
CP
0.224
0.224
0.224
0.225
0.226
0.227
0.229
0.232
0.243
0.247
0.249
0.253
0.273
0.279
0.293
0.295
0.308
0.308
0.309
0.317
0.315
0.315
0.314
0.315
0.316
0.313
0.311
0.309
0.310
0.309
0.305
0.300
0.295
0.289
0.285
0.279
0.272
0.265
0.257
0.250
0.241
0.234
0.224
0.215
0.206
0.196
0.190
0.186
0.176
0.168
0.165
0.150
0.125
0.091
0.079
0.051
0.004
CQ
0.174
0.176
0.179
0.181
0.185
0.189
0.194
0.198
0.211
0.218
0.223
0.229
0.252
0.263
0.278
0.285
0.302
0.307
0.312
0.326
0.331
0.334
0.335
0.342
0.350
0.354
0.357
0.361
0.365
0.368
0.371
0.372
0.373
0.374
0.376
0.377
0.376
0.374
0.373
0.370
0.367
0.364
0.359
0.353
0.348
0.340
0.336
0.333
0.324
0.316
0.313
0.294
0.254
0.192
0.167
0.110
0.009
Appendix
207
A.11 PROPCODE RESULTS FINAL DESIGN
Appendix
TSR
0.00
0.01
0.02
0.05
0.09
0.10
0.11
0.12
0.13
0.14
0.16
0.18
0.19
0.20
0.22
0.24
0.26
0.28
0.30
0.31
0.33
0.35
0.38
0.39
0.40
0.42
0.43
0.47
208
CT
0.594
0.594
0.594
0.595
0.597
0.597
0.597
0.598
0.599
0.599
0.600
0.601
0.600
0.601
0.601
0.602
0.603
0.603
0.601
0.601
0.601
0.607
0.614
0.616
0.617
0.619
0.620
0.624
CP
0.180
0.180
0.181
0.181
0.182
0.182
0.182
0.183
0.183
0.183
0.183
0.184
0.184
0.184
0.184
0.184
0.184
0.184
0.183
0.183
0.183
0.185
0.187
0.187
0.188
0.189
0.189
0.191
CQ
0.001
0.002
0.003
0.009
0.017
0.018
0.020
0.022
0.023
0.026
0.029
0.032
0.035
0.037
0.040
0.043
0.047
0.052
0.055
0.058
0.060
0.065
0.071
0.072
0.076
0.080
0.082
0.090
TSR
0.50
0.51
0.53
0.54
0.57
0.59
0.61
0.63
0.64
0.65
0.71
0.77
0.79
0.81
0.85
0.88
0.94
1.01
1.06
1.13
1.18
1.21
1.41
1.70
1.77
1.88
2.12
2.36
CT
0.628
0.629
0.630
0.629
0.627
0.626
0.627
0.632
0.635
0.637
0.639
0.636
0.636
0.634
0.631
0.628
0.631
0.645
0.672
0.725
0.748
0.762
0.796
0.758
0.746
0.725
0.678
0.624
CP
0.191
0.192
0.192
0.192
0.192
0.192
0.193
0.194
0.195
0.195
0.195
0.194
0.194
0.193
0.191
0.189
0.190
0.195
0.215
0.258
0.271
0.279
0.270
0.223
0.210
0.189
0.152
0.106
CQ
0.097
0.099
0.102
0.104
0.109
0.113
0.117
0.122
0.125
0.127
0.138
0.150
0.152
0.156
0.162
0.167
0.179
0.197
0.228
0.292
0.320
0.338
0.381
0.378
0.372
0.357
0.322
0.249
209

Wind Power to Clean Water, the Kenya case

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