final report - Hochschule Trier

Transcription

FINAL REPORT
Market Development
for Solar Thermal Applications in Thailand
(SolTherm Thailand)
Implemented by
The Joint Graduate School of Energy and Environment (JGSEE)
King Mongkut’s University of Technology Thonburi
International Institute for Energy Conservation (IIEC)
and
Institute for Solar Energy Systems (FRAUNHOFER ISE)
July 2007
A project co-financed by the EU-Thailand Small Projects Facility
ii
STAFF
The Joint Graduate School of Energy and Environment (JGSEE)
King Mongkut’s University of Technology Thonburi
Asst. Prof. Dr. Chumnong Sorapipatana
Project Director/ Solar Expert
Prof. Dr. –Ing. Christoph Menke
Project Leader/ Solar Expert
Prof. Dr. R.H.B. Excell
Solar Expert
Dr. Peter du Pont
Solar Expert
Asst. Prof. Dr. Sirichai Thepa
Solar Expert
Dr. Naris Pratinthong
Solar Expert
Dr. Surachai Sathitkunarat
Project Manager
Asst. Prof. Dr. Navadol Laosiripojana
Project Associate
Mr. Kofoworola , O.F.
Project Assistant
Ms. Kulakarn Suntornwat
Project Administative
Mrs. Kanyarat Nitheswitthayanukul
Ms. Montree Srilundai
Ms. Kanchana Augsonsom
Ms. Sirilak Ovarakul
International Institute for Energy Conservation (IIEC)
Mr. Sommai Phon-Amnuaisuk
Project Coordinator
Ms. Sirikul Prasitpianchai
Researcher
Ms. Kullakant Chertchutham
Research Assistant
Institute for Solar Energy Systems (FRAUNHOFER ISE)
Dr. Hans-Martin Henning
Project Coordinator
Dipl.-Phys. Edo Wiemken
Solar Thermal Expert
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EXCUTIVE SUMMARY
The Thai Solar Thermal Industry Outlook
Solar Thermal applications in Thailand is currently limited to water heating
application in the residential sector while the large market potential in the commercial
and the industrial sector remains untapped. Presently there are approximately 15 to
20 active Solar Thermal (ST) companies in the market, however, only few companies
have intensive experience and are capable of providing design and installation for
large solar systems. The outlook of the Thai solar thermal market over the past recent
years has been positive due to the recent fuel price escalation. It was estimated that
the sales of solar water heater was around 6,800 m2 in 2005 and 8,500 m2 in 2006.
The key local industry players estimate an average market growth of about 10% per
year.
The SolTherm Thailand Project
the Market Development Solar Thermal Applications in Thailand project (SolTherm
Thailand) is funded by the EU-Thailand Economic Cooperation Small Project Facility
(EU-SPF) and jointly implemented by the Joint Graduate School of Energy and
Environment (JGSEE), the International Institute for Energy Conservation (IIEC), and
the Fraunhofer Institute for Solar Energy Systems (ISE). The project aims at
identifying all related technical and non-technical barriers prohibiting the effective
development of the SWH market in Thailand through detailed situation analysis, and
developing a set of solutions, guidelines, measures and recommendations for related
government agencies and industry stakeholders. The project also aims to enhance a
mutual market access for existing European, Thai and EU-Thai joint-venture ST
companies as well as stimulate and facilitate more EU-Thai partnerships and
investments in ST technologies in Thailand.
The SolTherm Thailand project activities were successfully implemented during the
course of one-year project implementation, April 2006 – March 2007, and the project
activities can be classified into two broad categories:
1. Information research and verification activities conducted through questioners,
interview and site visits.
2. Information analysis and dissemination activities were organization of
meetings and seminars throughout the project implementation. The project
website (www.soltherm-thailand.net) has also been the key channel of
information dissemination.
To fulfill extensive information required, the project team comprehensively reviewed
past studies and demonstration as well as undertook numerous field trips to twenty
(20) commercial and industrial facilities in seven (7) larges provinces throughout the
country. Additional 6 meetings/workshops were also organized to solicit more
information and verify usefulness of the findings.
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Approaches Involved in the Project Activities
With the aim to remove barriers for SHW market development, the project has
conducted a through review of past studies and other project activities that have
implemented in the past 25 years history of solar hot water market development in
Thailand. The project team also further investigated and assessed technical barriers
through a series of site visit to exiting installations. Non-technical barriers which
involve policy measures and economical barriers were identified and analyzed when
the project team conducted interview with financial institutions, policy makers, solar
companies and customers. Research methodologies used in this project are listed
below:
x Review of past studies
x Questionnaire through phone interview
x Personal interview
x Survey of potential sites
x Visit to existing solar installations
Major Findings
The Thai Solar Water Heater Market and Industry
Development of SWH in commercial application in Thailand was initiated by the
government 25 years ago by installing SHW systems on public hospitals. The
campaign has somewhat triggered the market that several private hospitals and hotels
installed SWHs during that time. The equipments were mainly imported until 10 years
later, local fabrication of solar collectors became a cheaper option, though less
efficiency, to Thai customers. Origins of the solar collectors were mainly from
Australia until recently the imported SHW parts and collectors have shifted to China,
Germany and Israel. The CIF import values have been increasing over the past couple
of years in line with rising of crude oil price in world market.
The existing market of SHW in Thailand is relatively small and only limited number
of SHW suppliers is available. Moreover, SHW is not a core business for most
suppliers. A study by NEPO/DANCED reported that there were 12 companies involve
the SHW market in 1995. After the economic crisis in 1997, there were only 9
companies could remain active. Our recent market survey found that currently there
are approximately 20-25 companies operating in the market.
Technical and Non-Technical Barriers
- Technical barriers
System design and sizing: many solar companies are small and sometime
specialize in other area i.e. import. These companies often install solar systems
without knowledge of proper system design and sizing resulting poor
performance of the solar system that can not serve the actual hot water demand.
Quality and selection of materials: wrong selection of materials that when
soldering together cause corrosion and result in water leakages at joint and
seeming of tank and pipes. Cheap material used in the system could also
shorten the system life time.
v
Water quality: some areas of Thailand, well water are a major water supply for
even tourist cities like Chiang Mai and Phuket. Sediments from water have
been a major problem for solar hot water with open-loop configuration
installed in these areas.
Installation: small companies often hire installers which sometime do not have
knowledge in solar water heater or even plumbing. Wrong installation mostly
fails the solar system instantly in just days after first operation. In many cases,
owners who have no technical knowledge are not aware that their systems are
not operating.
-
Non-technical barriers
High investment cost and long pay-back period: due to limited size of market,
solar companies need to mark up cost at high price in order to cover for the
company’s expense. The cost of SHW in Thailand is relatively high as compare
to countries that have success solar hot water installations.
Lack of quality control scheme: Thailand does not have sufficient standards,
testing and certification or any other scheme that could control quality of solar
water heater in the market. Poor quality of systems and improper installations
lead to system failure and customers unsatisfactory and untrusting of the solar
thermal technology.
Lack of effective policy support from the government: the Thai government,
from time to time, supported solar hot water in forms of demonstration and
subsidies to limited number of systems. However, these financial supports did
not link with quality control and only resulted in more solar systems failure.
Other policies that can result in a more lasting and steady support to the market
such as tax incentives and awareness campaign have not been introduced.
Quality and Standard Issue
Europe experience
Quality of installation
In European countries, safety requirements are imposed on mechanical and
electrical components of solar thermal systems. As solar systems provide
service hot water, hygienic regulation requires that water has to be regularly
heat up to 60C to avoid Ella bacteria. Apart from training to designers,
installers, manufacturers, and users that regularly offered for quality design and
installation, some European countries e.g. Germany and Austria has specific
trainings for “certified solar planner” and “certified solar installer” which
extend regular planners and installers towards higher level of expertise in the
solar thermal systems. The certification program in Germany is voluntary,
however, the certified installers is required in France. Commercial simulation
programs e.g. TSOL and POLYSUN are widely applied in the planning phase
for the optimization of solar system.
Test standards
In the European countries, there are several independent institutes to perform
mechanical load tests and performances tests on solar thermal collectors in
accordance with national standards and European standards. Until 1994, a
harmonization of European standards was carried out based on existing
vi
standards and recommendation e.g. ISO 9806. Current standards practiced for
solar thermal collectors and systems are listed as follow:
EN 12975 – Solar Collectors
Part 1: General requirements; Part 2: Test methods.
EN 12976 – Factory Made Systems
TS 12977 – Custom Built Systems
Pat 1: General requirements; Part 2: Test methods; Pat 3: Storages
In some European countries, standards are tied to public funding scheme i.e.
only collectors tested according to the EN 12975 are approved for funding in
Germany.
Quality label and certification
In 2003, a uniform European quality label for solar thermal products, the Solar
Keymark, was established as a tool for customers to easily identify quality solar
thermal products. After the initiation, there are more than 100 Solar Keymark
licenses issued to qualified products, an indication of successful quality scheme.
Furthermore, Germany is considering connecting its public funding for solar
thermal to the quality label. More information on the Solar Keymark and
approved certification laboratories may be found at the website if the European
Solar Thermal Industry Federation (ESTIF) www.estif.org.
Thailand experience
The lack of training courses to system designers, installers, manufacturers, and
users in Thailand has resulted in slacked quality of installation. Our project
survey of existing systems installed in many hotels found that many systems are
wrongly configured i.e. most of the storage tanks are placed in horizontal
position instead of a vertical position that allow stratification. Open looped
configuration is often applied to minimize investment cost; however, poor
quality of water has caused corrosion in tanks. Most systems are also lack of
safety components such as air vent and weather protection for pumps. The
percentage of system failure shortly after installation in Thailand is remarkably
high. It is recommended that Thailand initiates a program for improving local
knowledge and capacity and raises the awareness of quality installation to
prevent more solar thermal systems failure in the future.
Equipment standards
In Thailand, there is a standard related to solar thermal collector issued by the
Thai Industrial Standard TIS 899-2532. However, it is clear, that the standard is
being applied to local and imported collectors available in the market.
Test standards
There are 4 test facilities for indoor and outdoor solar thermal collector the
following academic institutions.
1) Asian Institute of Technology (AIT)
2) King Mongkut’s University of Technology Thonburi (KMUTT)
3) School of Renewable Energy Technology (SERT), Phitsanulok
4) Chiang Mai University (CMU)
vii
The test facilities are not continuous in operation due to the low national
production level of collectors and commitments from manufacturers.
Quality label and certification
Presently, quality label and certification for solar thermal are not available in
Thailand.
Economic and Financial Feasibility
Economic of solar thermal system
Criteria for design and optimization of solar thermal systems which is crucial for
the economic viability of solar hot water are
Solar radiation: Thailand has an average solar radiation at 4.5-4.7 kWh/m2 per
day which is higher than the economic profitability figures for solar thermal
systems. Monsoon season cause seasonal variation of solar energy that should
be taken into account when designing a solar system
Load pattern and continuity of demand: applications that have demand during
daytime and operate all year round gain most economic benefit. Some
industrial applications fall in this criterion that could have return on
investment as soon as 3 years.
Working temperature and types of collectors: working temperature below 70C
can use low-efficiency collectors that are economically suitable for solar
systems. Three types of solar collectors available in Thailand are unglazed,
flat plate and evacuated tubes can be used at this working temperature.
Solar fraction: solar fraction is a percentage or portion of annual energy
demand meet by solar energy. It is recommended that solar systems are design
not higher than 60% of solar fraction for the most cost effective
implementation.
Pay back period
A market survey by the SolTherm-Thailand project team reported that average
system cost for domestic SHW is 29,000 baht/m2 and 23,000 baht/m2 for large
systems in commercial and industrial applications. The pay back periods for solar
systems are varied depends on types of fuel replaced and applications. Calculation
of pay back periods based on the survey system cost and the current fuel prices are
shown in the table below.
Table E.1 Pay back period for difference fuel types in 3 applications
Pay back periods (years)
Sectors
Electricity
LPG
Fuel Oil
Residential
5-6
Commercial
3-5
7-8
6-8
Industrial
4-8
Sensitivity analysis
There are several economic factors that have impacts to year-to-positive cash flow
or pay back time. Analysis of the impacts lead us to more understanding of how
pay back time can be shorten to an acceptable range among Thai investors and
what financial measures are needed to achieve the target. Three parameters are
viii
selected for the analysis: energy delivered from solar system, initial cost and
annual operating cost. Results from sensitivity analysis show that reduction of
initial cost has the most impact to pay back time. The only case that the solar
system can pay back within 4 years is replacing electric heater in hotel
applications. Other applications require more than 4 years for return on
investment. In order to achieve 5 years target pay back time, a reduction of system
cost are needed as 30% of residential and 50% of the present cost of commercial
and industrial systems.
Potential of Solar Water Heater in Thailand
Energy demand at low-medium temperature (60-150C) in 3 economic sectors in
Thailand is estimated around 1,200 ktoe/year, a 1.9% of the total final energy
consumption in Thailand in 2005. Assuming market penetration for solar water heater
are 20% in residential and commercial sectors and 10% in industrial sector, a potential
market size is estimated at 1.5 million square meter of collector area.
Table E.2 Technical and economical potential of solar thermal energy in Thailand
Sectors
Residential
Commercial
Industrial
Total
Energy
demand in
low-medium
temperature
(ktoe)
314
18.5
874
1,206.5
%
penetra
-tion
20
20
10
Potential
of solar
hot water
(ktoe)
Electricity
(GWh)
LPG (kg)
62.8
3.7
87.4
153.9
730.36
12.91
2,158,333
743.27
2,158,333
Fuel oil
(liter)
92,856,232
92,856,232
Collector
area (m2)
608,637
22,872
847,052
1,478,561
The economic potential of 1.5 million m2 of solar collector can save energy
approximately 153 ktoe and 500,000 tons of carbon emission can be avoided per year.
Solar Thermal Related Policies and Measures
Many energy and greenhouse gas reduction related policies are results of national and
international commitments to reduce energy and greenhouse gas to the target goal
such as a recent European Council meeting has announced a target to increase a share
of renewable energy to 20% of primary energy consumption in Europe by 2020. To
achieve the objectives, there are measures being implemented as follow:
x Financial incentives such as subsidies and grant are mostly needed to boost up
the market at the initial phase. A success case of growing solar market in
Greece has shown the influence of the subsidy measure.
x Tax incentives e.g. tax credit and import duty exemption can help bring the
cost down particularly for imported products. The classifications of solar
water heater components that are currently grouped together with other
electric equipments have made it difficult to exempt import duty. The Thai
Customs Department has recommended that solar water heater should have a
separate code; however, this would require changes at a global level.
Importers of solar products in Thailand pledge that should the import duty be
exempted, the cost of solar system can be lower as much as 20%.
ix
x
x
x
x
x
Regulations are often tied to building code such as mandatory installation of
solar water heater in new buildings. A sample of success implementation of
the measure is Israel where solar water heater is required for buildings higher
than 27 meters.
Quality assurance can ensure sustainable growth of solar thermal market.
Standards and testing requirements can be tied to government incentives to
assure that only quality systems will be installed. Success cases are Germany,
Austria and Israel.
Demonstration projects can effectively promote solar thermal systems in the
country or area that have low acceptance of the technology.
Research and development is available in many countries, mostly through
academic or research institutions to improve efficiency of solar collector and
innovative design that could ultimately lower the cost of the technology.
Awareness campaign in raising concern of the energy cost saving and
greenhouse gas reduction can bring attention from public and remove the
misconception of technology ineffectiveness.
Key Recommendations
To establish a sustainable solar thermal market in Thailand, the following policies are
recommended.
Policy measures
1. Quality assurance
2.Financial
incentives
3.Awareness
campaign
4. Demonstration
Addressed problems
- Substandard quality of materials
Measures / Schemes
-Training
for
manufacturers
- Improper design and sizing
-Training for system
designers
- Training for installers
- Training for users
- Subsidy for investment
cost.
- Quality of installation
- Lack of maintenance
- High investment cost
- Long pay back period
-Tax incentives i.e. credit
for income tax, corporate
tax
-Tax
exemption
i.e.
import duty, VAT
- Unaware of cost effective energy -Awareness
campaign
saving potential
through advertisements
– Misconception of the technology and other media.
- Unaware of technological - Demonstrations of solar
potential
hot water systems in
different applications
x
CONTENTS
CHAPTER
TITLE
STAFF
EXECUTIVE SUMMARY
CONTENTS
LIST OF FIGURES
LIST OF TABLES
Page
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iii
x
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1
PROJECT OVERVIEW
1.1 RATIONALE
1.2 PROJECT TASKS AND ACTIVITIES
1.3 FOLLOW-ON ACTIVITIES AFTER COMPLETION
1
1
1
3
2
THE THAI SOLAR WATER HEATER INDUSTRY
2.1 MARKET OVERVIEWS
2.2 SWH SYSTEM COMPONENT
2.3 MARKET CHARACTERISTICS AND SUPPLY CHAIN
4
4
13
17
3
BARRIERS
3.1 INTRODUCTION
3.2 MAIN TECHNICAL BARRIERS
3.3 OTHER TECHNICAL BARRIERS
3.4 NON-TECHNICAL BARRIERS
3.5 SUMMARY OF BARRIERS
20
20
23
25
26
26
4
QUALITY AND STANDARDS
4.1 QUALITY OF INSTALLATION
4.2 EQUIPMENT STANDARD
4.3 STANDARD TESTING
4.4 QUALITY LABEL AND CERTIFICATION
4.5 OPTIMIZATION OF STANDARD AND SOLAR THERMAL
TESTING CENTER IN THAILAND
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28
33
37
41
44
5
ECONOMIC AND FINANCIAL
5.1 ECONOMIC OF SOLAR THERMAL SYSTEM
5.2 PAY BACK PERIOD
5.3 SENSITIVITY ANALYSIS
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57
6
FINDINGS FROM SELECTED SITE VISITS
6.1 FACULTY OF NURSING, KHON KAEN UNIVERSITY
6.2 WHALE HOTEL
6.3 THAI-DENMARK DAIRY FACTORY
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CHAPTER
TITLE
6.4 PATONG MERLIN HOTEL
7
8
9
Page
72
POTENTIAL OF SOLAR WATER HEATER
7.1 POTENTIAL APPLICATIONS FOR SOLAR THERMAL
TECHNOLOGY
7.2 ENERGY SAVING POTENTIAL
7.3 MARKET POTENTIAL
7.4 CARBON EMISSION REDUCTION POTENTIAL
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POLICY AND FRAMEWORK
8.1 INTERNATIONAL POLICY
8.2 DIFFERENT POLICY ACCOMPANYING MEASURES HAVE
BEEN APPLIED SO FAR ON AN INTERNATIONAL LEVEL, TO
ACCELERATE THE MARKET GROWTH OF SOLAR THERMAL
APPLICATIONS
8.3 RECOMMENDED POLICY AND FRAMEWORK
87
87
94
100
CONCLUSION
103
APPENDIX
A. TRIP REPORTS
B. RECOMMENDED STANDARD FOR THAILAND
C. THAI INDUSTRIAL STANDARD FOR FLAT PLATE SOLAR
COLLECTOR (TIS 899-2532)
D. REMARKS ON ECONOMIC ASSESSMENT
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85
104
134
154
156
xii
LIST OF FIGURES
FIGURES
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
3.9
4.1
4.2
4.3
4.4
4.5
4.6
4.6a
TITLE
Non-Electric Heater Trade Flow for Thailand during 19901996
Non-Electric Heater Trade Flow for Thailand during 20012006
Glazed Flat Plate Collector
Evacuated Tube Collector
Storage Tank – Thermosyphon System
Different Storage Tank Designs in Force Circulation Systems
Storage Tanks in a Closed-Loop Force Circulation System
Service and Product Flow Diagram within the SWH Market
in Thailand
Picture of a neglected solar system In Thailand
Quality measures are required at different levels in the
installation of a solar thermal hot water system.
Example of solar thermal system layouts for large hot water
preparation systems with an additional reservoir in order to
have always a sufficient amount of domestic hot water free
of legion Ella by minimizing the demand on auxiliary heating
energy. The layouts were developed within the large German
demonstration programme ‘Slolarthermie2000plus’. Figures
extracted from ‘Grosse Solaranlagen zur
Trinkwassererwärmung’, German BINE information service,
Info III/2002
Typical layout of Thai large solar thermal systems for hot
water preparation, found during the site visits within the
SolTherm project
Left: air vents are a rare item in the visited installations. The
lack of air vents may cause serious maintenance and service
problems. Right: typically, the insulation of the ducts shows
signs of disintegration already in systems, installed a few
months ago only. Probably, under the Thai climatic
conditions, encasing the insulation with jackets is more
appropriate in order to avoid thermal losses
Internal corrosion of a flat-plate collector due to water
penetration. The corrosion is forced, if no ventilation holes in
the collector frame are existing and the wetted insulation
causes a permanent wet atmosphere in the collector. Photo
taken at a collector System of the River Hotel, Bangkok,
equipped with Chromagen collectors (Israel)
Broken control unit and wrong temperature control
installation
System control unit MES from the German company
PAGE
9
9
15
15
16
16
16
18
25
29
30
31
32
33
34
35
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FIGURES
4.6b
4.6c
4.6d
4.7
4.8a
4.8b
4.9
4.10 a
4.10 b
4.11
4.12
4.13
5.1
5.2
5.3
5.4
5.5
5.6
6.1
6.2
6.3
TITLE
Paradigma for large solar thermal plants. Also available:
remote control for the unit
Programmable system control unit UVR 1611 from the
German company TA
System control unit UVR 1611 from the German company
SOREL GmbH.
System control unit Thermius from the Danish company
AllSun A/S
Components of the TS 12977 – Custom Built Systems.
Figure from German BINE information service, Info II/2001.
Outdoor solar thermal collector test facility at Fraunhofer
ISE (part of the Test Centre for Solar Thermal Systems).
Left: tracking rig for computer controlled automated
collector tests; right: mechanical load test facility
Indoor solar thermal collector test facility at Fraunhofer ISE
(part of the Test Centre for Solar Thermal Systems) for
collectors with liquid heat transfer medium and for air
collectors.Between collector and lamp array, an artificial aircooled sky area is installed
Experimental test system
SERT experiment
CMU experiment
The European Solar Keymark quality label for solar thermal
products
Overview on the steps, necessary to obtain the European
Solar Keymark quality label for solar thermal products.
Described by the Solar Thermal Test Center at Fraunhofer
ISE, one of the certified test institutes in Germany
The success story of the European Solar Keymark. Since
October 2006, the number of keymark licenses has grown to
approx. 100 items
Solar radiation in Bangkok, Phuket, Chiang Mai and Khon
Kaen
Optimum collector area determination from the slope of the
Vs AC thermal performance curve
Solar fraction and number of solar collectors
A comparison of system efficiency and tank sizes
Load profile for typical hot water demand in Thai hotels
Effect of increasing the value of the parameter
Schematic diagram of SHWS at faculty of nursing, (1)
collector arrays, (2) the sediment deposited inside the
collector, (3) pipe connection, (4) auxiliary heater, (5) water
draining system, (6) insulation on pipes
Collector array and vertical storage tanks
Schematic diagram of SHWS installed at Whale hotel
PAGE
35
36
36
38
39
39
40
41
41
41
43
44
48
50
51
51
52
58
60
61
62
xiv
FIGURES
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
7.1
7.2
7.3
7.4a
7.4b
7.5
8.1
8.2
8.3
8.4
8.5
TITLE
The system components for the building B at Whale hotel,
upper left: collector array, a few of collectors show internal
corrosion. Upper right: storage tanks of which steel jacket
disintegrated. Lower left: the temperature gage seems to be
out of order as it indicated the temperature of water at 5 oC.
Lower right: the setting point for controlling the system is
not clear.
Three HFO-boilers (7 bar each) of the dairy factory. The
preheat oil tank is located between the boiler no.1 and no.2
Overview of processes of dairy products, pasteurized milk,
UHT milk drink and pasteurized fermented milk drink
Simplified sketch of the process heat supply system at the
Diary Farm One of the possibilities to apply solar heat for
fuel saving by pre-heating the condensate from 80°C to any
higher temperature is indicated (dotted).
Simplified sketch of the process heat supply system at the
Diary Farm One of the possibilities to apply solar heat for
fuel saving by pre-heating the fresh water from ambient
temperature to 70 oC (dotted)
Patong Merlin Solar water heater system diagram
Electric and water consumption in January 2006 at Patong
Merlin
T-Sol® analysis of solar system in building#2 of Patong
Merlin hotel
Trends of final energy consumption by economic sector
(DEDE 2005)
Energy consumption in manufacturing sub-sector in 2005
(DEDE 2005)
Daily peak demand of electricity in 2000 – 2004
Potential market of SHW
Current market share
SHW market growth scenarios
Solar Thermal market in europe: cumulated capacity in
operation (red line, right axis) and annual growth (white line,
left axis). in 2005, the cumulated capacity in operation was
approx. 11000 mwth, with a growth in 2005 of approx. 1500
mwth
Share of the annual growth in 2005 (approx. 1500 MWth) by
country
Share of the cumulated capacity in operation in 2005 by
country and per 1000 capita
The independent Test Centre plays a central role in the
quality chain of solar thermal installations
Self-perpetuationg positive and negative market development
PAGE
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70
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84
92
93
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xv
LIST OF TABLES
TABLE
TITLE
PAGE
2.1
Imported Product Items Covered by HS 8419.190.001 in
Thailand during the 1990-1996 period (Thousand Baht)
6
2.2
Imported Product Items Covered by HS 8419.190.001 in
6
2.3
2.4
2.5
2.6
2.7
2.8
4.1
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
6.1
6.2
6.3
6.4
6.5
7.1
7.2
7.3
7.4
Exported Product Items Covered by HS 8419.190.001 in
Exported Product Items Covered by HS 8419.190.001 in
Compilation of Solar Water Heater Suppliers in Thailand,
1985 – 2006, Sorted by Year involved in the Thai SWH
Mar
Generic Types of Solar Thermal Collectors
Choices of Piping in SHW Systems
Components and Accessories in a SWH System and
Availability of Domestic Supply
Comparison Test Condition between ASHRAE Australian
and Thai
Energy produced by 3 types of collectors for water at 60°C
Review of Existing Installation and proposed optimized
design
A Market Survey of Domestic solar hot water system cost
in 2007
A market survey for cost of Solar System in Commercial
application
Solar system cost breakdown in percentage of total cost in
commercial applications
Pay back periods of solar thermal system for each sector
Country comparison for pay back periods of DSHW
Sensitivity Analysis for Year-to-positive cash flow
Pay back periods for the reduction of initial cost
The SHWS of Whale hotel
Input parameters for calculating energy saving by
preheating fresh water (the possibility 4)
The simulation results obtaining from T-Sol program
Solar hot water systems in Patong Merlin hotel
Summary of Patong Merlin simulation results
Potential applications for solar thermal energy
Temperature of industrial heat processes
Fuel consumption of manufacturing sub-sector in 2005
(unit: ktoe)
Daily hot water demand in commercial sector
7
8
11
13
17
19
46
49
53
54
55
55
56
56
58
59
62
71
71
72
75
76
77
79
80
xvi
TABLE
7.5
7.6
7.7
7.8
8.1
8.2
TITLE
Energy demand in low-medium temperature
Potential of solar water heater
A comparison of investment cost and carbon emission
avoided
Potential of carbon emission reduction from using solar
thermal energy
Summary of policy measures for SHW implemented in
several countries.
Recommended policy measures for sustainable
development of solar thermal in Thailand
PAGE
81
82
85
86
94
102
1
1
PROJECT OVERVIEW
1.1 RATIONALE
Solar Thermal energy (ST) is the simplest and most efficient form of renewable energy
available today. When solar energy is used for on-site heat generation, the system efficiency
is much greater than converting solar energy into electricity and then delivering through the
power grid for the same end-use heating applications. Situated in a tropical zone, Thailand
has favorable conditions and significant potential for utilizing solar water heating (SWH)
compared with many other regions. Based on past studies, annual mean daily global solar
radiation in Thailand is between 4.5 kWh/m2/day in winter and 4.7 kWh/m2/day in summer.
Despite the significant potential, the overall SWH market size is still small and
underdeveloped due to different obstacles and Thailand has not been able to capitalize this
cost-efficient and reliable solar energy source, particularly in the commercial and industrial
sector.
In recognition of the existing market potential, the Market Development Solar Thermal
Applications in Thailand project (SolTherm Thailand) was initiated to identify all related
technical and non-technical barriers prohibiting the effective development of the SWH
market in Thailand through detailed situation analysis. SolTherm Thailand is funded by the
EU-Thailand Economic Cooperation Small Project Facility (EU-SPF) and jointly
implemented by the Joint Graduate School of Energy and Environment (JGSEE), the
International Institute for Energy Conservation (IIEC), and the Fraunhofer Institute for Solar
Energy Systems (ISE).
The project aims at developing a set of solutions, guidelines, measures and recommendations
for related government agencies and industry stakeholders. Moreover the project also
directly enhance a mutual market access for existing European, Thai and EU-Thai jointventure ST companies as well as stimulate and facilitate more EU-Thai partnerships and
investments in ST technologies in Thailand. Additional benefits resulting from the project
actions include establishment of appropriate supporting schemes for the Thai SWH market,
such as SWH Industry Association and National SWH standards for equipments, designs,
installations and services. All these project outputs will essentially and eventually facilitate
bi-lateral trades between EU and Thailand.
1.2 PROJECT TASKS AND ACTIVITIES
With the overall objective to remove informational and other unidentified barriers that are
inhibiting the effective development of solar thermal market in Thailand, the specific
objectives of the project actions are:
x To identify related technical and non-technical barriers to the development of the
industrial solar thermal technology market in Thailand and to illustrate potential
solutions to the barriers.
x To determine potential technical, economic and environmental gains from
commercial and industrial solar thermal technologies
x To analyze the technical and economical feasibility of solar energy in selected
commercial applications and in certain industrial processes
x To develop a list of possible demonstration sites for future activities
x To assess the market size of solar thermal technologies in the Thai industrial and
commercial sector
2
x
x
x
x
x
x
To learn from successful European experiences to introduce solar thermal systems in
the commercial and the industrial sector
To develop a set of solutions, guidelines, measures and recommendations for policymakers, regulators and businesses which would lead to future appropriate supporting
scheme, regulatory frameworks and standards for the Thai market
To facilitate an initial dialogue on problems and solutions among key stakeholders
To create awareness and introduce solar thermal energy to stakeholders through
workshops with potential customers and solar system providers (manufacturers) and
independent solar experts
To strengthen and reinforce ties between stakeholders in the solar thermal industry in
Thailand
To build a network between European and Thai Solar Thermal Industries
To meet the project overall and specific objectives, the project team implemented different
project tasks and activities in four phases within the proposed one-year implementation
timetable (April 2006 to March 2007) as follows:
1.2.1 Phase I: Seeking Stakeholder Support
The first phase aims to inform the existing market players about the project actions and to
assure that all project activities will be in a complementary manner to the overall
development of the new market segment of the domestic solar thermal industry. The project
task in this phase includes:
x
Task 1: Inception Meeting and Establishment of the Project Advisory Committee
Through this task, the project team has informed relevant government agencies and
industry stakeholders about the project actions, and established the project advisory
committee whose members will provide opinions and comments to improve project
methodologies and activities as necessary.
1.2.2 Phase II: Assessing Market Potential
The second phase provides an estimate of the size of the potential market for industrial and
commercial solar thermal technologies and will determine potential demonstration sites
where technical and economical aspects are feasible. The project tasks in this phase consist
on Task 2 and 3 as follows:
x
Task 2: Review of Existing Reports/Project activities and European Experience in
Developing Industrial Solar Thermal Market
The EU-Thai project team thoroughly reviewed existing reports produced by
government and private sector in promoting industrial and commercial solar thermal
applications in both Europe and Thailand. Experiences and lessons learned were
utilized by the project team throughout the project implementation period.
x
Task 3: Industry and Commercial Sub-Sector Review
Through semi-structured questionnaires, the project team conducted interviews
selected commercial and industrial end-users as well as government agencies to
assess the potential market size and future growth.
3
1.2.3 Phase III: Understanding Market Characteristics
The third phase will provide understanding of supply chain and decision-making process
which is important to policy makers and industry on how to enhance the industrial solar
thermal market. The project tasks in this phase consist on Task 4 and 5 as follows:
x
Task 4: Review of Supply Chain and Regulatory Frameworks
The project team utilized personal meeting, focus groups and round table meeting
technique to gather information on supply chain and regulatory frameworks. The
team organized such activities for two target groups: one for government agencies
and authorities, and one for the solar thermal industry.
x
Task 5: Market Survey and Site Visits
The project team performed site visits to twenty (20) commercial and industrial
facilities in 7 larges provinces throughout the country. Findings from the site visits
help verify outcomes of Task 2, 3 and 4 and essentially serve as the main inputs for
preparation of the final report.
1.2.4 Phase IV: Information Analysis and Dissemination
The final phase will utilize project findings to stimulate dialogue between key stakeholders
as well as encourage better industry and public-private coordination. The project tasks in this
phase are captured below:
x
Task 6: Detailed Analysis and Report Preparation
The outcomes and findings from the previous tasks were consolidated together for the
preparation phase of the final report.
x
Task 7: Information Outreach and Training
The project team regularly informs the related government agencies and industry
stakeholders the progress and outcomes of the project implementation. The outreach
activities have been undertaken through the Internet-based Solar Thermal Information
Clearinghouse for Thailand, www.soltherm-thailand.net as well as training and
information dissemination workshops and meetings. The project team organized a
total of 6 meetings/workshops during the one-year project implementation period.
1.3 FOLLOW-ON ACTIVITIES AFTER PROJECT COMPLETION
Following the completion of project activities in March 2007, the SWH suppliers in Thailand
agreed in principle to pursue the initiative on establishment of the Thai Solar Thermal
Association to continue the future SWH promotional activities and maintain the momentum
established by the project. In addition, the Department of Alternative Energy Development
and Efficiency, DEDE, under the Ministry of Energy, Thailand is planning to establish ten
(10) demonstration project to substantiate the technical and economic feasibility and to
stimulate replication of SWH applications in the hotel sector in Thailand.
4
2. THE THAI SOLAR WATER HEATER INDUSTRY
2.1 MARKET OVERVIEWS
2.1.1 Past and Present
The solar water heater market in Thailand was probably triggered by the government
initiative in 1982 when the Department of Alternative Energy Development and Efficiency
(DEDE), formerly known as the Department of Energy Development and Promotion
(DEDP), installed 352 square meters of flat plate collectors in 6 hospitals, 1 hotel and 1 small
1
industry . The initial phase ended in 1984 and ownership of those solar water heater systems
was transferred to respective entities responsible for management of those premises.
In the early 90s, the solar water heater market in Thailand picked up its momentum and more
than 10 solar water heater suppliers existed in the market. The solar water heater market in
Thailand in the 90s was dominated by imported products from Australia, Germany and
Israel. The local manufacturers were also available but unable to capture significant market
share. All suppliers of solar water heaters whether imported or domestically manufactured or
assembled provide installation and maintenance services to customers. The key end-use
sectors were limited to the upper-income residential sector and the commercial sector
(hotel and hospital).
DEDE also resumed its solar thermal promotion in 1994 with the focus on technical support
and capacity building for end-users particularly in the commercial sector, i.e. hotels and
hospitals. The study conducted in 1996 by DEDE estimated that the total installation of flat
plate collectors in Thailand until 1996 is about 50,000 m2. The study also cited that in 1996
alone, Solar Water Heater (SWH) systems of a total collector area of 4,150 m2 was installed
in Thailand, of which 2,740 m2 were installed in residential households and the rest 1,410 m2
was installed in hotels and hospitals.
In the late 90s, the solar water heater market in Thailand rapidly declined for two main
reasons, i.e. 1) the 1997 Asian economic crisis dramatically hampered new investment in the
commercial and residential sector, and 2) quality and durability of solar water heater systems
were tarnished by incorrect designs and poor workmanship during installation and
maintenance. In 1998, the Thai government introduced a financial incentive scheme to spur
the utilization of solar water heater in the residential sector. The scheme however was not
able to deliver significant impacts on the overall solar water heater market in Thailand and it
was discontinued 1999.
Following the initial 15-year of solar water heater market in Thailand, only a few suppliers
established in the early 90s were able to survive this roller coaster trend after the year 2000.
However, the total number of suppliers in the solar water heater market in Thailand has been
relatively constant as new importers and manufacturers have been established to respond to
the new demand emerged from new investments in the commercials sector, specifically in the
hotel industry. It is important to note that in addition to Australia and EU member countries,
1
Country Paper for Thailand, Amnuay Thongsathitya, Director Energy Research and Development Branch,
Financing and Commercialization of Solar Energy Activities in Southeast Asia, Kunming, Yunnan Province,
China, 26-30 August 1996.
5
specifically Germany and Israel, China has become one of main country of origin for solar
water heater products imported to Thailand by companies established after 2000.
Although the solar water heater technologies have been promoted in Thailand for almost 25
years, the overall market size is still relatively small and immature. Most solar water heater
companies in Thailand (importers and manufacturers) employed only traditional
direct-marketing strategy to sell their products. The government support in the solar thermal
industry is very minimal and considered to be in significant.
Key barriers that hamper new investments and large-scale replications of solar water heater
technologies in Thailand will be explored in this report and some pertaining to market
structures and supply chain will be highlighted in this chapter.
2.1.2 Trade Flow
In the 90s, solar water heater products in Thailand were dominated by imports from
2
Australia. Based on an assessment conducted by CEERD in 1998, about 9 companies
supplied systems of different make through import and local fabrication. Of which 4
companies supplies the Australian products capturing over 60% of the total market share.
After the Asian economic crisis, products imported from EU member countries, specifically
Germany and Israel, have gained their momentum due to stronger local presence. Chinese
made solar collectors have also been making their penetration to the Thai market with
competitive costs offered.
Similar to other countries adopting international harmonization code (HS), all solar water
heater systems and components import and export statistics in Thailand are covered by HS
3
8419. However the definition of the HS 8419 is quite broad , and, specifically, in Thailand,
solar water heaters together with other non-electric heater products are covered by
“8419.190.001- Other”. Table 2.1 to 2.4 presents import-export statistics in Baht
4
(CIF value ) during the period of 1990 – 1996 and 2001 - 2006 of HS Code
“8419.190.001- Other”. It should be noted that there is an ongoing effort to distinguish solar
water heaters from other non-electric products under the same HS heading so that appropriate
tariff for this renewable energy product can be proposed accordingly.
2
Assessment of Potential Use of Solar Thermal System in Thailand, Center for Energy-Environment Research
and Development (CEERD), Asian Institute of Technology (AIT)
3
Harmonization Code 8419.190.001 - Other: "Machinery, plant or laboratory equipment, whether or not
electrically heated (excluding furnaces, ovens and other equipment of heading 85.14) for the treatment of
materials by a process involving a change of temperature such as heating, cooking, roasting, distilling,
rectifying, sterilising, pasteurising, steaming, drying, evaporating, vaporising, condensing or cooling, other than
machinery or plant of a kind used for domestic purposes; instantaneous or storage water heaters, non-electric."
4
CIF = Cost Insurance and Freight
6
Table 2.1 Imported Product Items Covered by HS 8419.190.001 in Thailand during the
1990-1996 period (Thousand Baht)
Country
1990
1991
1992
1993
1994
1995
1996
Australia
6,976
1,186
3,305
2,750
6,396
5,234
1,835
Austria
0
0
0
0
0
0
218
Belgium
0
40,631
0
0
0
3,488
0
Canada
0
11
0
0
209
0
0
Denmark
9
0
207
262
0
1,050
773
France
38
32
1,041
0
0
48,169
151
Germany
1,832
329
3,514
224
3,089
2,900
2,096
Hungary
0
79
0
0
0
0
0
Iceland
0
0
0
0
0
1,146
0
India
0
12
0
20
514
2,532
0
Israel
436
720
0
0
633
697
0
Italy
0
0
0
0
340
1,443
3,158
Japan
6,473
3,583
2,049
9,502
2,280
13,327
2,201
Netherlands
0
0
0
28
0
0
0
Norway
0
0
0
0
62
0
0
Philippines
0
0
0
0
0
0
1,057
S. Korea
0
31
13
0
0
129
0
Singapore
0
43
0
7
0
9
0
Sweden
0
17
0
6,740
1,390
0
0
Switzerland
47
39
0
57
132
30
0
Taiwan
201
2,375
1,748
0
4,039
1,394
4,786
UK
384
0
0
0
2,815
5,108
4,626
Ukraine
0
0
0
0
128
0
0
USA
3,295
3,962
4,321
11,128
8,957
26,036
3,612
Total
19,691
53,049
16,198
30,717
30,985
112,692
24,513
Source: Assessment of Potential Use of Solar Thermal System in Thailand, Center for Energy-Environment
Research and Development, Asian Institute for Technology (AIT), 1998
Table 2.2 Imported Product Items Covered by HS 8419.190.001 in Thailand during the
2001-2006 period (Thousand Baht)
Country
Austria
Australia
Belgium
Brazil
Canada
China
Germany
Denmark
Spain
France
UK
Hong Kong
Hungary
Israel
India
Italy
Japan
2001
0
14,625.78
5,313.45
0
0
1,175.55
2,465.11
1,197.71
0
0
242.53
27.13
0
255.76
8,263.04
1,146.95
2,627.41
2002
0
471.45
0
0
0
689.91
4,010.98
0
0
0
337.12
102.52
0
105.14
85.99
797.99
4,952.31
2003
0.37
6,211.27
24,291.93
116.22
0
22,857.73
2,204.82
617.23
0.79
0
2.51
85.29
0
0
5,089.24
357.82
43,374.74
2004
0.61
2,436.92
0
10.76
3,230.93
1,830.18
1,036.11
0
0
165.06
1,324.98
87.47
0
0
4.11
238.07
19,238.40
2005
0
1,642.58
0
8.02
112.71
5,279.56
3,934.37
3,045.62
0
8,546.03
2.05
0
6.64
1,171.99
2,407.11
145.00
38,395.90
2006
670.36
59.56
0
0
0
12,356.94
6,944.19
0
57.40
297,984.39
1,031.53
172.70
0
6.63
940.32
1,895.95
32,519.59
7
Korea, DPR
0
Korea, R
443.10
Mexico
1,441.07
Malaysia
178.10
Norway
0
Netherlands
0
Sweden
972.99
New Zealand
19.42
Singapore
384.53
Slovakia
0
Sri Lanka
404.56
Switzerland
0
Taiwan
1,883.25
Turkey
0
UAE
0
USA
4,096.13
South Africa
0
Total
47,163.57
Source: http://www.customs.go.th
0
669.85
48.94
379.89
0
5,430.47
8.67
0
290.66
0
0
45.69
10,845.00
13.32
0
2,467.63
0
31,763.95
49,826.64
1,109.87
0
11,309.31
0
563.59
40.47
0
2,887.65
0
11.77
400.60
2,477.75
0
0
4,345.06
0
178,182.67
0
262.32
235.93
5,120.88
0
0
22.42
0
7,851.93
0
0
0
3,813.99
29.46
0
3,329.04
0
50,269.53
0
1,252.45
0
1,549.75
0
10,715.86
0
0
525.91
0
0
867.63
4,481.50
0
1.40
4,813.12
10.17
88,915.38
0
457.62
0
23.91
1,260.63
0
7.50
0
23,283.47
1,779.81
0
0
13,349.80
216.28
0
16,270.85
0
411,289.41
Table 2.3 Exported Product Items Covered by HS 8419.190.001 in Thailand during the 1990-1996 period
(Thousand Baht)
Country
1990
1991
1992
1993
1994
1995
1996
Australia
25
0
0
0
0
0
0
Barbados
29
0
0
0
0
0
0
Central Africa
0
2
0
14
0
0
0
China
0
0
0
800
0
93
0
Denmark
0
0
0
0
10
4
0
France
0
0
0
0
4
0
0
India
0
0
0
0
0
0
236
Indonesia
30
0
0
101
0
0
0
Japan
0
12
0
0
714
12
0
Laos
8
89
13
148
371
187
196
Malaysia
398
0
0
0
0
199
617
Myanmar
37
0
0
11
0
74
0
Cambodia
0
0
0
0
0
0
118
Pakistan
0
259
0
0
0
0
0
Philippines
9
0
0
0
0
0
0
Singapore
11
0
8
2,219
1,241
0
13
USA
0
0
1
0
0
534
0
Vietnam
0
917
85
0
83
413
0
Total
547
1,278
106
3,293
2,423
1,516
1,179
Source: Assessment of Potential Use of Solar Thermal System in Thailand, Center for Energy-Environment
Research and Development, Asian Institute for Technology (AIT), 1998
8
Table 2.4 Exported Product Items Covered by HS 8419.190.001 in Thailand during the 2001-2006 period
(Thousand Baht)
Country
2001
Australia
0
Bangladesh
107
Bhutan
0
Cambodia
22
China
43
Egypt
0
Hong Kong
15
India
261
Indonesia
107
Japan
580
Korea DPR
0
Korea R
0
Lao Republic
641
Malaysia
2
Maldives
0
Myanmar
1,798
Netherlands
18
New Zealand
0
Nigeria
0
Philippines
816
Singapore
0
Sri Lanka
0
Taiwan
0
UAE
0
UK
0
USA
3,079
Vietnam
359
Total
8,058
Source: http://www.customs.go.th
2002
1
0
0
192
50
0
0
90
138
642
0
0
76
0
6
495
181,580
0
603
0
234
0
0
8
0
7,762
63
193,023
2003
429
0
0
2
184
0
0
2
0
0
0
0
243
124
1
390
19,825
414
0
78
552
0
0
0
0
533
24,984
47,794
2004
0
139
0
241
1,219
201
48
1,774
623
0
0
0
2,193
43
25
300
0
0
0
0
3,083
0
150
0
0
180
4,004
14,326
2005
0
0
499
331
23
0
1,861
0
0
30
1,673
1,114
998
5,125
1
0
0
0
0
198
748
35
0
1,502
109
2
112
14,590
2006
0
2
0
2,971
283
0
0
0
0
307
0
2,978
990
10,583
0
564
0
130
0
841
1,258
59
54
152
198
84
1,518
23,067
The broad classification of non-electric instantaneous or storage water heater makes it
difficult to estimate trade figures of SWH for Thailand. The available statistical data given in
the above Tables, however, indicated that key SWH trading partners for Thailand are mainly
from Europe, North Asia, North America and Australia, as illustrated by trade flow in Figure
2.1 below. Based on the market development status in countries in those key trading partner
regions, it is very likely that imported SWH products in Thailand have their origins in
Australia, China, Japan, Germany, Israel and USA. The import statistics also indicate that
country of origins have been shifted from Australia and some European countries during
1990-1996 to specifically China, Germany and Israel during 2001-2006. It should also be
mentioned that CIF import values have been increasing over the past couple years in line
with rising of crude oil price in the world market.
9
Figure 2.1 Non-Electric Heater Trade Flow for Thailand during 1990-1996
Figure 2.2 Non-Electric Heater Trade Flow for Thailand during 2001-2006
10
2.1.3 Solar Water Heater Suppliers
The existing market of solar water heater is relatively small in Thailand and only limited
number of SWH suppliers (importers, assemblers and manufacturers) is available to serve
emerging demand majority in residential and commercial sector. It is important to note that
SWH is normally not the core business of these SWH suppliers in Thailand, and
classification of these SWH suppliers as importers, assemblers and manufacturers is made
based on how they supply solar collectors as other system components are either locally
made or purchased from other suppliers.
Most of SWH suppliers in Thailand are already in the business of providing either water
heating solutions or solar energy technologies for residential, commercial and industrial enduse, and SWH is an additional business line offering to their customers. There are also few
Thai companies set up with core business on SWH and most of these are small importers.
Given the limited SWH market size in Thailand, the existing SWH suppliers must offer onestop-service for their customers, meaning all designs, equipment sourcing and selections,
installations and maintenance. Unfortunately many suppliers do not have sufficient capacity
to provide such one-stop-service requirement and this, hence, has resulted in poor
performance and durability of relatively expensive SWH systems in Thailand.
The market assessment conducted for NEPO/DANCED reports that there were 12 companies
involved in the SWH market in 1995, but 3 importers were severely affected by the 1997
economic crisis and only 9 companies were left active in 1998. However, based on industry
interviews and market observations, more companies have become active in the Thai SWH
market after the year 2000 to respond to existing and emerging demand in the residential and
commercial sector due to rising crude oil price in the world market.
Table 7 shows a full compilation of companies involved in SHW in Thailand since 1985. As
the total SWH market size in Thailand is still limited, the market demand is therefore not
consistent. Most local SWH suppliers in Thailand need utilize their other business lines to
cover their operating expenses when SWH demand becomes diminished. This scenario
makes many importers with SWH as their core businesses went into deep trouble during the
1997 economic crisis and approximately 50% of all SWH suppliers were able to survive that
downfall. After 2000, the Thai SWH market began to experience a new wave of SWH
suppliers, both local manufacturers and importers from China and Germany, and most of
them are still active in the market.
As also shown in Table 7, most SWH importers in the Thai market in the 80s and 90s
imported their collectors from Australia and Germany where domestic SWH markets are
mature with a number of manufacturers. During the early development stage of the Thai
SHW market, imported solar collectors, mostly from Australia, were able to capture a large
market share, over 80%, and SWH was considered as the premium product for medium- to
high-income families due to their high investment cost. Imported SWH products from
European countries (mostly from Germany and Israel), and China have been able to
strengthen their market positions. In general, German SWH product importers have better
technical capacity and are able to serve both residential and commercial customers. For
Chinese SWH product importers, only the large ones have sufficient technical capability to
serve more technical intensive commercial sector demand. Most small Chinese product
importers have focused on the residential sector.
11
Table 2.5 Compilation of Solar Water Heater Suppliers in Thailand, 1985 – 2006, Sorted by Year involved in the Thai SWH Market
No.
Name
1
2
3
Boonyium & Associates Limited
Bermuda Thai Co. Ltd
Forbest Co., Ltd.
4
Pranee Tech Co. Ltd.
5
6
7
8
Intertech Sales and Service
Solarnet Co. Ltd.
Solar Trading Co. Ltd.
Water System and Service
Co., Ltd.
9
10
11
12
13
15
B.B. Business Pattaya Co., Ltd.
Poomipat Co. Ltd.
Scandinavian Pacific Co. Ltd.
Heritage Co. Ltd.
Grand Technology Co. Ltd.
J-7 Engineering Co., Ltd
16
17
18
Electricity Generation (EGAT)
Force Link Co., Ltd.
Infratech Engineering & Services
Co., Ltd.
Solason Solar Energy (Thailand)
Co., Ltd.
SMT Hitech Ltd., Part.
Solar Solutions Co., Ltd.
19
20
21
Type of
Supplier
SWH
Marketing
since
Brand
Country of
Origin
Status To
Date
(2006)
Inactive
Active
Active
Remark
I
M
I
1985
1985
Thailand
China
UK
I
1985
Bermuda Super
Everhot (China),
Heatrae Sadia (UK),
Rycroft (UK)
Solahart
Stiebel Eltron
Solar Lee
Australia
Germany
Canada
Active
Formerly
known as
Pranee Phan
Co., Ltd.
I
I
M
M
1988
1990
1990
1990
Sole Alpha
Edwards
Solar-mix
Solar Ultra
Australia
Thailand
Thailand
I
I
I
M
I
I, M
1992
1992
1992
1992
1993
1997
2000
2000
Australia
Australia
Australia
Thailand
Israel
Thailand
Australia
Thailand
China
Australia
Active
Inactive
Inactive
Active
Inactive
Active
M
I
I
Edwards
Solahart
Edwards
Heritage
Geysor
Ecotech (Thailand)
Rheem (Australia)
EGAT
Sunlink
Edwards
I
2000
Solar Plus
China
Active
M, A
I
2001
2002
Sun
Flexi-Line,
Thailand
Germany
Active
Active
Inactive
Inactive
Inactive
Active
Active
Active
Active
formerly
known as
Solar Ultra
Co. Ltd.
12
No.
M
M, A
24
Sunluck Solar Power Co., Ltd.
Chuchuay Trading Group Co.,
Ltd.
ENVIMA (Thailand) Co., Ltd.
SWH
Marketing
since
2002
2003
I
2003
ENVIMA Solar
Technology
25
26
BNB Inter Group Co., Ltd.
Leonics Co., Ltd.
M, A
I
2003
2003
Solar Bank
Apricus
27
28
NTP Techno Co., Ltd.
Siamsolar and Electronices Co.,
Ltd.
Thai Advance Save Energy Ltd.,
Part.
ARC Siam Solar Co., Ltd.
Century Sun Co., Ltd.
I
I
2004
1993
Rhein Series
Solarson
China
(Germany
design)
Thailand
China
(under
Australian
management)
China
China
I
2004
NEWGOT SOLAR
China
Active
I
I, A, M
2005
2005
Schueco
Century Sun
Germany
China
Thailand
Denmark
Active
Active
22
23
29
30
31
Name
Type of
Supplier
Brand
Suntech
Country of
Origin
Thailand
Thailand
Status To
Date
(2006)
Active
Active
Active
Active
Active
Active
Active
32
Forefront Foodtech Co., Ltd.
I
2006
Active
33
Sunpower Asia Co., Ltd.
I
2006
Sunpower
Active
34
Pro Solar Group Co., Ltd.
2007
Active
Note: I: Importer, M: Manufacturer, A: Assembler/Fabricator
Source: 1) Assessment of Potential Use of Solar Thermal System in Thailand, Center for Energy-Environment Research
and Development, Asian Institute for Technology (AIT), 1998
2) www.SolTherm-thailand.net
Remark
13
2.2 SWH SYSTEM COMPONENTS
Various types of solar thermal technologies and configuration designs are commercially
available to provide heat and hot water for residential, commercial and industrial end
uses. This section of the project report covers only the most widespread solar thermal
technologies and components which are equipped in the SWH systems commonly used in
Thailand including types of solar collectors, storage tanks, piping and system accessories
such as circulation pumps and temperature sensors.
Solar Collector
The component of solar water heating systems which absorbs the solar irradiance is called
collector. Collectors used in solar water heating system are available in different
configurations with different techniques to collect solar energy (see Table 2.1). However,
the most widespread solar collectors in Thailand include Unglazed Flat Plate Collector,
Glazed Flat Plate Collector and Evacuated Tube.
Table 2.6 Generic Types of Solar Thermal Collectors
Configuration
Picture
Collector
Solar Pond
N/A
Operating
Temp qC
30-70
Unglazed Flat
Plate
40-60
Glazed Flat Plate
60-120
Evacuated Tube
50-180
Fix Concentrated
100-150
14
Configuration
Picture
Collector
Parabolic Trough
Operating
Temp qC
150-350
Parabolic Dish
250-700
Central Receiver
500-3000
Unglazed Flat Plate Collector
Unglazed flat plate collectors consist simply of an absorber with flow passages and have
no covering glass (glazing), insulation, or expensive materials such as aluminum or
copper and can attain a temperature as high as 32 Cq above ambient. This type of
collectors is less efficient in retaining solar energy when outdoor temperatures are low,
but are quite efficient when outside temperatures are close to the temperature to which the
water is being heated. They are highly suitable for swimming pool heating and other uses
that require only a moderate increase in temperature and are most commonly used in
warmer areas. In warm climates, low temperature collectors are sometimes used in
hybrid systems that heat a pool in the winter and supplement domestic water-heating in
the summer, when pool heating is not needed.
Glazed Flat Plate Collector
Glazed flat plate collectors are most commonly used in the residential and commercial
sector in Thailand. The collector plates are coated with a non-reflective mat back
(or dark blue) paint and are always covered by a glass or plastic cover glazing to trap heat
waves. The working fluid absorbs the heat energy collected by the flat plates through
tube walls. They normally attain temperature as high as 120 qC. The special coatings on
the absorber maximize absorption of sunlight and minimize re-radiation of heat. Gaskets
and seals at the connections between the piping and the collector and around the glazing
ensure a water tight system.
15
Figure 2.3 Glazed Flat Plate Collector
For the residential sector, the natural circulation (Thermosyphon) system is commonly
used with the typical size of each collector about 2 m2 with 160 liters storage. The typical
size collectors can be connected into an array to serve large hot water demand in large
residential or even in commercial buildings, e.g. hotels and hospitals. An array of flat
plate collectors could be designed as a thermosyphon or force-circulation system
depending upon demand profiles and designers.
Evacuated Tube Collector
Evacuated glass tube collectors are used to house the absorber with sealed pipe
connection. These tubes have improved geometry and thermal insulation to achieve
higher temperature than in the case of flat plate collectors. Evacuated tube collectors can
be designed to attain higher operating temperature (50-180qC). They may use a variety of
configurations, but generally encase both absorber and tubes of working fluid in a
vacuum glass tube for high level of insulation. These are most efficient collector types
for cold climates with low level diffuse sunlight. They are often used in the commercial
and industrial sector where hot water at high temperature is essential. They can be
mounted either on a roof or on the ground, but they need to be protected from severe
environment or objects that may cause damages. This type of collectors is becoming
popular over the recent years even in the residential sector in Thailand given ability of
manufacturers to bring down the production cost.
Figure 2.4 Evacuated Tube Collector
Storage Tanks
Storage tank is one of the key components in SWH system as it enables hot water supply
when solar energy is not available. Storage tanks used in SWH systems in Thailand are
16
generally low pressure storage tanks. Tanks equipped with the natural circulation
(thermosyphon) systems are virtually 100% made of stainless steel and insulated with
polyurethane or fiberglass. Capacity of each storage tank in thermosyphon systems in
Thailand ranges from 160 liters to 1,000 liters depending upon hot water demand and
building structure. These thermosyphon storage tanks may be equipped with electric
water heaters to maintain water temperature at a required level.
Figure 2.5 Storage Tank – Thermosyphon System
Storage tanks in the force circulation system are generally much larger than those in
thermosyphon systems with capacity up to 10,000 liters depending upon hot water
demand. Designs of storage tanks in the force circulation system are more sophisticated
with three main configurations as shown in Figure 4.
Figure 2.6 Different Storage Tank Designs in Force Circulation Systems
Storage tanks in the force circulation system can be made of both stainless steel and
normal steel. Although virtually 100% of storage tanks fabricated and installed over the
past 15 years in Thailand are made of stainless steel, corrosions have been noticed in
many installations during site visit activities in this project. Auxiliary or back up heaters
typically equipped with storage tanks in the force circulation system are typically electric
water heaters, especially in the single storage tank design. In the two storage tanks
design, auxiliary heating systems are more flexible as LPG or heavy fuel boiler or even
waste heat recovery systems can be used to provide back-up.
Figure 2.7 Storage Tanks in a Closed-Loop Force Circulation System
17
Piping
Piping in solar water heating systems in Thailand can be divided into three major parts,
i.e.: 1) piping interconnected solar collectors within an collector array; 2) cold water
supply piping, and; 3) hot water supply piping. Piping choices which are available and
commonly used in Thailand for SWH systems include galvanized iron (GI), copper,
stainless steel and plastic. Summary of piping choices are shown in Table 2.7 below:
Table 2.7 Choices of Piping in SHW Systems
SWH System Section
Collector Interconnection
Cold Water Supply
Hot Water Supply
Available Choices of Piping
Copper, stainless steel, GI
Copper, stainless steel, GI, Plastic
Copper, stainless steel, GI
Normally choice of piping is typically pre-determined by designers and investment
budget. However, the most widely used piping for solar water heating systems,
particularly small thermosyphon systems, is copper tubing. Copper tubing is also the
primary choice for connection between collectors within an array. Piping that carries
potable water may be copper, galvanized iron, or stainless steel. Plastic piping, PVC or
PE, can also be found in cold water supply section of the systems.
Water Circulation Pumps
Water circulation pumps are required only in the case of forced circulation system where
gravity or natural convection is insufficient to provide the amount of water flow required.
Capacity of the pumps in the solar water heating system is chosen based on the head and
flow rate. The head of a pump is the pressure it has to overcome - both the vertical height
that the liquid must be pumped and the friction of the liquid against pipe walls. Frictional
head loss is no significant except in very large piping systems. Virtually 100% of water
circulation pumps used in SWH systems in Thailand are imported with variety of brands,
materials and specifications.
2.3 MARKET CHARACTERISTICS AND SUPPLY CHAIN
This section will review the overall characteristics of service and product flow within the
SWH market in Thailand which will enable thorough understanding on how market
works and different stakeholders involved in supply-side and demand-side. The overall
service and product flows within the SWH market in Thailand are respectively illustrated
with orange and blue lines in Figure 2.8 below. Each blueish green rectangular box
represents key stakeholder providing products or services. It should be noted that Figure
2.8 does not include government regulatory frameworks and standards related to SWH
products and systems as only voluntary product performance standards are available in
Thailand.
18
Figure 2.8 Service and Product Flow Diagram within the SWH Market in Thailand
Basically flows of service and product within the SWH market in Thailand are divided
into 3 phases; i.e. 1) Design phase; 2) Procurement and Installation phase, and; 3)
Maintenance phase. For any small capacity SWH systems, the design phase is normally
bypassed as standard sizes are already available for end-user selections, especially
thermosyphon systems. Larger SWH systems in the commercial sector normally
encompass all 3 phases in every market transaction.
2.3.1 Service Flow
Three (3) major stakeholders involve in the flow of services in the Thai SWH market are
engineering/consulting firms, SWH suppliers and end-users. The engineering/consulting
firm involvement in the residential sector is very limited as system design and sizing
services are normally provided by SWH suppliers themselves. In the commercial sector,
involvements of the engineering/consulting firms are depending upon end-users as well as
technical knowledge and know-how of SWH suppliers. In the industrial sector, end-users
may involve in the design and installation phase as most industrial end-users are able to
contribute their experience and direct involvement in production processes.
The service flow diagram above clearly depicts that, in Thailand, SWH suppliers are the
key to quality service delivery in each phase of market transactions. However, there is no
government agency or industry association to control quality of services in each phase.
Moreover, end-users are probably not fully aware of important of quality service to SWH
system performance and lifetime. The poor quality and intermittent service have been an
issue in the Thai SWH market and apparently one of the major causes of negative
perception by end-users in both residential and commercial sector.
2.3.2 Product Flow
SWH products and system components are mostly channeled through SWH suppliers
(importers and manufacturers). For Thai manufacturers of solar collectors, most system
19
components and accessories, except differential temperature sensors and special
requirement circulation pumps, can be locally purchased from major hardware stores
throughout the country or can be specifically ordered directly from local manufacturers
and fabricators. These components include tempered glass for glazed flat plate collectors,
various sizes of copper tube, GI or stainless steel piping, stainless steel storage tanks,
polyurethane or fiberglass insulation, etc. Solar collector importers, especially small
thermosyphon systems, would apparently require only domestic support in piping
installation. Table 8 lists components and accessories required by a SWH system and
availability of domestic suppliers and/or fabricators.
Table 2.8 Components and Accessories in a SWH System and Availability of Domestic Supply
SWH Components / Accessories
Solar Collector
Evacuated tubes
Tempered Glass (for solar collector)
Copper tubing/piping
GI piping
Plastic piping
Stainless Steel piping
Insulation
Small Storage Tanks (< 600 liters)
Large Storage Tanks (> 600 liters)
Circulation Pump
Differential Temperature Sensor,
electrical apparatus and other controllers
Valves and Gauges
Domestic
Manufacturers
Domestic
Fabricators
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Import
Yes
Yes
Yes
Yes
Yes
Yes
Although most SWH system components and accessories are locally available for SWH
suppliers, one of the key problems in Thailand is that product standards which are
appropriate for SWH applications have not yet been recognized by designers,
manufacturers, SWH suppliers and even end-users. In many cases sub-standard
components and accessories have been integrated into the system with high quality solar
collectors, and this incorrect combination has severely affected and shortened the SWH
system lifetime.
20
3
BARRIERS
3.1 INTRODUCTION
The listed barriers describe the problems encountered and perceived towards a
“self-sustaining steadily growing solar thermal market in Thailand”
The description of barriers is based on:
1. A review of implemented solar thermal systems in Thailand during the last two
decades
2. A review of past studies on this subject (mainly four in the last decade)
3. Several site visits to various solar sites during the EU SolTherm project
(see as well site visit reports in the annex)
Earlier studies and reviews on the solar thermal applications in Thailand resulted in the
following statements concerning barriers and problems encountered:
1. In 1997 the DEDE’s site visits revealed four main barriers to long-term
operational success.
a. Firstly, the systems had largely been designed and installed without
necessary technical expertise and knowledge of SWH systems.
b. The SWH products themselves were not standardized so that even if there
were communication between different SWH operators, no meaningful
comparisons could be made from which to effectively problem solve or
draw informative conclusions.
c. Also, no regular maintenance of the system seemed was scheduled to
ensure that problems were diagnosed and fixed effectively.
d. Lastly, in some areas of Thailand it is necessary to purify the water before
it is run through the SWH system and when needed this was sometimes
overlooked.
2. According to a study by Martin Vis in 2000, Thailand experienced a long period
of SWH system breakdowns because suppliers of the systems were unreliable in
repairing them.
3. Additionally, a KMUTT study suggested that lack of knowledge of the everyday
use of the systems inhibited their long-term success, and that there was simply no
staff to provide the systems’ required maintenance.
4. In 2000 ISE, Fraunhofer Institute, one of the partners in this EU project as well,
undertook another study on the solar thermal market in Thailand and found the
following main barriers:
21
Constraints for the Dissemination of Domestic Solar Water Heating Systems
The main constraints to the dissemination of domestic solar water heating systems are:
x The financial viability of domestic solar water heating systems is low.
x There is no structure of distributors and skilled installers available.
x Domestic solar water heating systems have a very low reputation in Thailand, due to
two facts:
- owners of solar water heating installations often do not have the habit to care about
the systems and, as result, collectors are covered with dust within a short time,
which brings system efficiency down,
- as a result of the lack of infrastructure with regard to distributors and skilled
installers, system service and maintenance often is not available.
x In contrast to electric water heating systems, solar water heating systems require a hot
water distribution system which normally cannot be installed in existing buildings,
consequently domestic solar water heating system are mainly installed in new
buildings.
x The heat generation from solar power is not reliable. A backup should therefore be
installed in order to guarantee the hot water supply even during periods of low solar
gains. However, most manufacturers realised this and install either an electrical
backup heater or use the waste heat of a chillers as backup heat source.
x There are no national standards for tests and, as result, no data to compare the
performance of different products are available.
Constraints for the Dissemination of non-residential Solar Water Heating Systems
The constraints for the dissemination of non-residential solar water heating systems are
more or less the same as those for domestic systems.
The lack of skilled designer and computer design tools, in particular, is a limiting factor
for the distribution of large scale water heating systems for non-residential applications.
Another observation made during the visits to several installations was that most of the
installed collectors were completely covered with dust, sometimes the glass panes were
broken and the collectors were corroded completely in some systems. In other words, the
owners do not care about the installations, most of them even do not notice that the
system does not work any more because non-residential systems have a compulsory backup system and hot water is available without solar assistance.
This might be a crucial point for the dissemination of non-residential solar water heating
systems. A promotion programme should therefore include conditions like those
described below to assure system service and maintenance.
The “Vicious Solar Thermal Circle” in Thailand
The general problem with the solar thermal market in Thailand was that it was in a
negative vicious circle:
1. Reputation and performance expectation of solar thermal application is low.
22
2. Therefore customers are not willing to spend a lot of money for planning,
installation, good quality of components, control and monitoring of the system.
3. Suppliers offered inferior components, sub-optimal designs, little warranty and
hardly any maintenance to meet the financial requirements/limits of the
customers.
4. Measurement equipment to prove energy saving was never installed.
5. Many customers did not even care about the system on their roof, so they did not
know if something went wrong, as the back-up system still was providing the
necessary hot water.
6. Customer had hardly any interest in regular maintenance of the system and if the
supplier were asked they did not to come to fix the problem, as warranty time was
expired, it was too short (6 months) anyway and additional service was not
factored into the investment costs and maintenance contract were not signed.
7. This situation lead to deteriorated, non-functioning installed solar systems often
working unsatisfactorily:
a. low performance of the system,
b. leakages in the piping and the collectors
c. and non-functioning of the control systems
d. clogged piping due to non-purified water etc.
were leading to unsatisfied customers in the long run.
8. The consequence was: The image of solar thermal systems was getting even
worse!
The general perception about solar thermal systems in Thailand is:
=> The investment cost is too expensive!
=> It is not economical!
=> It is not reliable!
=> It requires too much maintenance!
This image of solar thermal applications in Thailand is the consequence of the
negative development in the last 20 years!
How could it happen?
1. The early systems installed had inferior material and were not properly designed,
as once aimed to make it “cheap” and partly as solar thermal technologies were
not developed in the early days.
(In Europe technology was inferior as well at that time.)
2. Regular maintenance and warranty was not provided and customers did not
understand the system concept.
3. Monitoring and measurement of achieved system performance and achieved
energy saving was never done. If data were recorded they were not analyzed later.
4. Customers got disappointed as realized systems did not hold the promises given
before by the suppliers. That led to a disappointment.
5. Once a major component failed, like the controller, it was not replaced and the
whole system was dismantled or abandoned.
6. The consequence was another “solar ruin” on the roof, which made the image of
solar systems even worse.
7. The government undertook very limited activities to overcome this problem.
Hardly any awareness, training and research were initiated and supported.
23
8. The research intuitions “lost” interest in the subject in the late eighties
9. Companies in the sector dropped out as market size was reducing
10. Most systems still sold were according to the method: “sell it and forget the
customer”, like a consumer good.
11. The result is that the negative image of solar thermal applications spread out and
many institutions, companies lost their interest in that energy field.
12. The consequence is that the market for solar application is stagnating or even
shrinking, which leads to negative growth of the market.
13. Cost reduction for solar systems could not be achieved in such a market, as solar
systems were “made by demand”.
This kind of development of a solar thermal market happened the same way in Europe
and other countries as well. It was the “normal” development path for this energy
technology in the eighties and early nineties.
But the main point is: How to break this vicious circle and how to move it to a
positive circle, which leads in the long run to a self-sustaining growing solar thermal
market, as in many other countries in Europe or Israel. How could it happen, that
Germany has a steady growing market of more than 1 Mio. m²/a despite the fact, that
solar systems in Germany are expensive, the pay-back period is between 10 -15 years
and sunshine is half of that in Thailand? The answer is in chapter 8, where we deal
with adequate policy that makes the changes possible.
Before we come to this in the later chapters, we like to describe the various barriers
encountered here in Thailand, as they show what has to be done to improve the
situation and to come to a positive circle concerning solar thermal applications. The
main barriers had be mentioned already in early studies, cited above, but in the
following we try to look at it in a more systematic way to show what has to be done to
change the “vicious circle” to a “positive upward oriented circle”
3.2 MAIN TECHNICAL BARRIERS
The technical barriers can be defined along the planning, installation and operation
process of solar thermal systems:
1. The knowledge for correct planning, design, selection of appropriate components
and material as well as correct installation of solar systems is not available with the
suppliers/manufactures of solar thermal systems
- The sizing of the solar system is done based on “rules-of-thumb” and not based on
measurement of the actual hot water demand.
- The sizing of the components and the optimization of the system is not done by
using a dynamic simulation software.
- The final design of the system is done without “good practice engineering”, like
sizing of pipes, heat exchangers etc.
- Corrosion aspects are neglected by selecting wrong material and combining
material, that should not be used together.
- Used material and components are of inferior quality and do not perform on the long
run.
- Problems of sediment in pipes and solar collector resulting from poor water quality
were not considered in system design (open primary solar loop)
24
- The knowledge of correct installation process is missing.
- Basic rules for installation of systems are neglected or are not know
(vertical or horizontal storage, fixing point for back up system too low, etc.).
Example:
- See as well “Conditions of typical Thai large commercial solar hot water systems”
described in chapter 4.1 (Quality of installations)
- See as well chapter 6 case studies, where individual solar systems visited are
described
- See as well site visit reports in the annex, which give a detailed description of
individual solar systems visited.
Reason for this is:
- A lack of training and a lack formal education for the suppliers/manufacturer.
- Non- engineering companies have entered the solar thermal market and do not know
the standard practice of detail engineering for such systems.
- The suppliers are not willing to invest in the purchase of a simulation software
(less than 1000 US$).
- Some materials for installation and repair such as insulation or controllers are not
available in local hardware stores, so they do not get replaced.
- Lack of skilled technicians for proper installation, repair and maintenance.
- Solar thermal technology is considered a “simple” low technology, so the supplier
and the technician did not care too much about the technical requirements and
standards to be applied.
- Customers did not request “high” technology standards, as they were only interested
in a “low” investment costs. They did want to save energy, but even more they
wanted to save investment costs. They were not willing to spend more as they did
not trust the systems offered.
Consequences are:
- Inferior design, under- or over sizing of the components, which lead to
underperformance of the system.
- Investment costs are relative too high for the performance of the system
- The predicted pay-back period for the investment is not achieved.
- Low performance of the system and mal-functioning systems after a short time.
- Finally unsatisfied customers.
2. Neither many customers nor most of the suppliers cared for the solar systems
during operation in an adequate way.
3. No monitoring and measurement equipment is installed to monitor status and
document “saved” energy
4. High maintenance costs due to climate conditions and non appropriate technical
material. For instance, the degradation of rubber seal and water deposits were most
common in a solar water heating system. These problems caused water leaking and
damages in water pipe and water tank - particularly corrosion - and could happen
within 2-3 years of installation.
Reason:
- As indicated in earlier studies( see above) many collector arrays were covered
with thick dust as they were not cleaned, piping systems were leaking and not
repaired, non-functioning control systems were not replaced, etc.
- Inappropriate material and components used in the installation.
25
-
Not to install measurement equipment: To save investment costs and customer are
not willing to pay for this equipment as they were not convinced to need it!
Consequences are:
- Customers and suppliers do not know if the solar system is still operating and if is
still operating, what is the performance of it. So nobody can tell, if the predicted
pay back period for the investment is achieved or not. This gives room for
“feelings” like: I think I save energy or the system does not work and solar
thermal applications are too costly.
- As long as there is no systematic and consistent monitoring of performance
introduced in as many as possible solar systems, there is no chance to reverse this
perception and come up with concrete data and reliable figures, how much kWh of
fuel energy per m² of collector has saved in one year.
Figure 3.9 Picture of a neglected solar system In Thailand
3.3 OTHER TECHNICAL BARRIERS
1. In residential applications no central hot water system exists. Typical Thai houses
and buildings are not designed for hot water service (only cold water pipe and
single way water tap).
2. Low hot water demand in domestic sector and in low budget hotels. Therefore this
customers group is not suitable for solar thermal systems in Thailand
=> In this energy sector (existing residential houses and low budget hotels) solar
water systems can hardly be introduced.
3. Lack of Early Integration of SWH into Building Design.
As a solar water heater system requires a precise piping work, the system must be
brought in the early stage of the building construction so that necessary hot water
pipes could be properly designed and installed. It could be very complicated,
costly and thus not convinced to install the systems for existing buildings where
26
no hot water pipes are available (in houses) or hot water supply systems is not
centralized in the case of commercial buildings.
3.4 NON-TECHNICAL BARRIERS
1. Relative high investment costs for solar thermal systems compared to electrical
heater or LPG boilers, lead to pay-back periods, which are sometimes higher than
accepted by customers. (See as well chapter 5 economical and financial aspects)
2. Missing standards for collectors and systems performance lead to a nontransparent market. The performance of “cheap” components and of “expensive”
components can not be compared. The consequence is that the selling of the solar
systems is done mainly over the prize, regardless of their performance. This leads
to a decrease of quality of the components offered over the time.
(see as well chapter 4.2. equipment standards)
3. Testing of components and systems is hardly done, so the performance of the
different collector systems can not be measured and compared.
(see as well chapter 4.3. standard testing)
4. Quality labels and certification does not exist, so the quality of products can not
be recognized in the market (see as well chapter 4.4. Quality label and
certification)
5. Lack of financial incentives by government. In Thailand there is no financial
support for the installation of solar water heater (see as well chapter 8 policy and
framework)
6. Lack of awareness. There is hardly any awareness activities, demonstration
activities and promotion activities for solar thermal applications in Thailand.
Customers do not know the benefit of the systems or are wrongly informed by
perceptions or bad experience of old systems installed 20 years ago.
7. Lack of a long term policy to promote solar thermal applications. So far it does
not exist. There is hardly any interest in this renewable energy by the government
so far.
3.5 SUMMARY OF BARRIERS
To summarize the main barriers:
1. Lack of technical expertise by suppliers to design and install solar thermal systems
2. Lack of quality of installed material and components
3. Lack of maintenance during operation
4. Lack of monitoring and evaluation of system performance during operation
5. Lack of standards for components and systems
6. Lack of testing facilities for components and systems
7. Lack of quality labels and certification
8. Lack of awareness by customers for their installed solar systems
9. Lack of financial incentives
10. Absent of adequate government policy to support the development of a solar
thermal market in Thailand
27
To reverse the “vicious circle” to a “positive self-sustaining growing circle” it is
necessary to tackle as many as possible of the listed 10 barriers.
It is necessary to systematically deal with these identified barriers and to design an
adequate program and to promote the private sector companies currently in the market,
that want to improve the quality of their products offered and want to overcome the
negative image of solar thermal systems in Thailand.
This EU SolTherm project was a first step to identify the barriers and to revitalize the
solar thermal market in Thailand. The first response by the manufactures and suppliers is
very positive, but as this project lasted only for one year not all barriers could be tackled
and it is expected that the respected government agency DEDE will take up the points
identified in this project and develop it further in a systematic way.
28
4
QUALITY AND STANDARDS
4.1 QUALITY OF INSTALLATION
A certain quality level of the system components and of the system installation of a solar
hot water system is a pre-condition in order to guarantee an appropriate and optimized
function of the system. The optimized operation of a solar hot water system is essential to
the success of this technology, since the comparatively high first cost of a solar system
requires special attention to a maximized exploitation of the available solar radiation.
This holds especially for custom made large solar thermal plants with forced loop and
collector areas > 20 m².
Of course, national requirements on the performance and on the mechanical and electrical
safety of the system components and on the hygienic quality of the delivered product – in
this case in general hot water - have to be fulfilled as well.
Above these safety requirements, the quality of the solar thermal system begins with the
planning of the system and ends with the capability of the end-user, to assess the
energetic gains and the economic and environmental benefits. Thus, quality of the
installation addresses
-
the quality of the planning and installation process: here, an appropriate ‘solar’
training of planners and installers is required. The training should include beside
technical system aspects also design and sizing methods with respect to the given hot
water load profile. Beside, clear recommendations on maintenance and troubleshooting to the end-user should be given. Parts of the planning and installation quality
are also service availability and warranty on the installation.
-
the quality of the system components and of the system control. A special training of
the manufacturer may be helpful in order to increase the life time of the components
with respect to corrosion, leakages, etc. by applying appropriate materials. An
important measure to increase the exploitation of the solar energy is an advanced
system control, which may also include an eye-catching display of system
malfunctions as well as providing information on the system status and gains to the
end-user.
-
available national standards or adapted international standards, independent test
facilities and certification schemes in order to guarantee a defined quality level of the
components. The standardization procedure one the one hand defines a certain quality
level of the components, on the other hand the thermal performance of a specific the
collector is more comparable to other products due to the uniformed test procedures.
A further step may be including the production quality and certification of the
manufacturers according to a keymark scheme.
-
a certain awareness of the end-user or system operator in order to assess the benefits
and the reliability of the solar thermal system. This awareness may be achieved
through end-user information campaigns or the like.
The summarize of quality measures, necessary to for a successful working solar system is
shown in as below.
29
Planner
Installer
Quality of planning & design
Quality of service
TRAINING
Manufacturer
System
Quality of
components
Standards
Quality of
control
Quality of information
User / operator
Assessment of gains, benefits
and reliability
Figure 4.1 Quality measures are required at different levels in the installation of a solar thermal hot
water system.
In some European countries, e.g., Germany and Austria, training courses for ‘certified
solar planner’ and ‘certified solar installer’ are offered in order to extend the experience
of regular planners and installers toward solar thermal installations. A broad assistance is
given here by non-profit associations on renewable energies like the DGS (German
Society for Solar Energy) with approx. 3000 members in Germany and the AEE (Austrian
working group renewable energy) in Austria. Both organizations organize seminars,
workshops, publications, journals and planning/installation guidelines. The journals and
publications are also an important information source to raise the awareness of the enduser of the solar installations.
Although in Germany no extra solar qualification for installers is formal required, the
participation on training courses is high with positive effect to the installation quality. In
France, only installers qualified by training courses organized from ADEME, the French
Environment and Energy Management Agency, are allowed to install solar thermal
systems.
5
Commercial available simulation software, e.g., TSOL and POLYSUN is widely applied
in the planning phase to design and size the system with respect to the typical
meteorological site conditions, orientation of the collector array and to the typical hot
water consumption profile.
5
Typical commercial software for the design and sizing of solar thermal systems is presented in the 1st
SolTherm Thailand Newsletter (April-June 2006)
30
Solar
buffer
storage
reservoir
Auxiliary
heater
Source
Solar
buffer
storage
reservoir
Auxiliary
heater
Source
solar
pre-heating
storage
Figure 4.2 Example of solar thermal system layouts for large hot water preparation systems with an
additional reservoir in order to have always a sufficient amount of domestic hot water free of legion
Ella by minimizing the demand on auxiliary heating energy. The layouts were developed within the
large German demonstration programme ‘Slolarthermie2000plus’. Figures extracted from ‘Grosse
Solaranlagen zur Trinkwassererwärmung’, German BINE information service, Info III/2002,
Source: www.bine.info.
In central Europe, the market share of solar thermal systems with additional heating
support for building space heating increases slowly. Additionally, the hygienic
requirements on the domestic hot water quality demands for specific system designs, in
order to avoid an extended growth of legion Ella bacteria. For this reason, the water has to
be heated regularly up to at least 60°C. Consequently, the system design for large systems
turns a little more complex with the installation of an additional small reservoir storage,
which is heated by an auxiliary heater if necessary, allowing still using a maximized
stratification of the solar storage and thus a high exploitation of the solar thermal
collector. Figure 4.2 presents possible configurations for a large solar hot water system
(without space heating support), but other solutions are applicable as well.
31
During the site visits of Thai large commercial solar hot water systems (details of the site
visits are outlined in section 9.3), it was obvious that the quality in all above mentioned
steps and levels in a solar hot water system installation was not assured in most of the
systems. A typical layout of the systems is shown in Figure 4.3. The solar collector is
connected to a buffer storage by a forced loop. Typically, the buffer storage is fed by an
open feed storage, located at the highest roof level. An auxiliary heater, in general an
electrically driven heater, is connected to the buffer storage. In most installations, the
solar buffer storage is mounted horizontal instead of vertical, thus the stratification in the
storage is low and the solar collector yield is not optimized. Additionally, the auxiliary
heater is positioned often below the hot water entrance from the collector, which is
another source for a non-optimized collector operation.
Feed storage
Flat-plate
Collector
70 m²
Consumption
Electricity
heater
4 m³
Supply
Circulation
Figure 4.3 Typical layout of Thai large solar thermal systems for hot water preparation, found
during the site visits within the SolTherm project.
The concept of open loop systems leads on the one hand to lowest investment cost, on the
other hand, the danger of corrosion in the collector and solar hot water storage is high,
depending on the local quality of the supply water. Alternatively, the collector and the
solar storage may be designed as closed system and connected via a heat exchanger to the
second storage, which contains the auxiliary heater and is connected to the supply grid.
The closed solar loop may then operate at higher temperatures as well. Other topics
related with the hot water distribution system in the building: installation of mixing taps,
in order to allow in general higher temperature levels than approx. 40°C to 50°C (and to
avoid rising problems with bacteria, e.g., legion Ella).
Furthermore, the planners and installers should be trained for more awareness on the
quality of the installation, such as safe system operation (air vents, weather protection for
pumps) and for an optimised energy yield from the system (complete insulation, jackets,
advanced control with meters, proper position of temperature sensors, etc.).
32
Figure 4.4 Left: air vents are a rare item in the visited installations. The lack of air vents may cause
serious maintenance and service problems. Right: typically, the insulation of the ducts shows signs of
disintegration already in systems, installed a few months ago only. Probably, under the Thai climatic
conditions, encasing the insulation with jackets is more appropriate in order to avoid thermal losses.
The service and maintenance for solar hot water systems may be subject to
improvements. This includes extended warranty periods for the delivered system as well
as clear instructions for maintenance or regularly maintenance by the
manufacturer/installer for at least 5 years. In the commissioning, the energy yield of the
system should be monitored within a few days (with mobile monitoring equipment) in
order to assess the performance and reliability of the system. A list of providers for spare
part of both, hydraulic equipment and control equipment, may be handed over to the
operator. Alternatively, special companies may rise up, working mainly in the field of
commissioning, service and maintenance of solar hot water systems, independent from
the life time of the installing companies.
Training is also recommended to the operating personnel of the large solar thermal plants:
the operating personnel has to be provided with more information on the surveillance of
the solar system, e.g., to estimate the solar heat contribution to the overall heat demand, to
check the reliability of the components on a regular basis, to obtain knowledge on
information sources on solar hot water systems, etc.
In general, the operators and managers of hotels, hospitals etc. should be more aware on
the achieved economic and environmental benefits of the existing solar hot water
application. These figures are not really available yet, but important to stimulate
improvements in the reliability of the system on the one hand, and to assess the potential
of solar hot water preparation in the commercial sector on the other hand, thus
contributing to a positive image of solar thermal systems in Thailand.
33
4.2 EQUIPMENT STANDARD
The central component in a solar hot water system is the solar thermal collector. In the
past, most of the collectors in the Thai systems are imported from Australia, Israel, and
China and to a minor degree from European countries. Collectors, produced in Thailand,
have a small market share. Nowadays even the solar collector has still imported but the
local made solar collector shares the market of 60 percent. The collectors, imported from
Australia and Israel often are produced and tested according to their national Standards or
according to the European Standards EN 12975,1/2. For collectors imported from China,
the Standard is not documented. The collectors imported from China are mainly vacuum
tube collectors; systems equipped with these collector types have not been among the
visited systems.
In Thailand, for solar thermal flat plate collectors the Thai Industrial Standard TIS
899-2532 exist, but it is not clear, if the national produced and imported collector types
have been evaluated, whether they fulfill the TIS requirements or not.
The quality level of the collectors in the visited plants covers a wide range.
In installations more than 10 years old or more, the glass cover was separated into two
sections, which has caused tightness problems and forces water penetration into the
collector. The old collectors often consist of a steel frame and steel absorbers were used
as well. Consequently, corrosion of the absorber and of the frame was often detected. In
the national products, tempered glass seems to be not often applied; old collectors with
broken glass covers contain dangerous sharp-edged glass fragments.
Figure 4.5 Internal corrosion of a flat-plate collector due to water penetration. The corrosion is
forced, if no ventilation holes in the collector frame are existing and the wetted insulation causes a
permanent wet atmosphere in the collector. Photo taken at a collector System of the River Hotel,
Bangkok, equipped with Chromagen collectors (Israel).
As a general problem appears the improperly preparation of most collectors for water
penetration, caused either through internal leakages or due to untight sealings: the
insulation in the collector, mainly consisting of mineral wool, turns wet without a chance
regeneration and thus degrades, causing increasing thermal losses of the collector. If
34
water penetration cannot be avoided by sure, the preparation of the collector frame with
ventilation holes and with water-resistant insulation material (e.g., closed-pored) may be
an appropriate measure for use at humid sites like in Thailand.
The general appearance of newly installed collectors is more favorable. The collector
frame is made preferably of aluminium, the absorber is produced from aluminum as well
or made of copper. Imported products are mainly equipped with safety glass cover
(tempered) or even with low absorption solar glass.
The solar buffer storages are often not designed for an optimized exploitation of the
collector system, stratified storages are not common in Thailand. The current design of
the horizontal positioned storages in large solar thermal plants seems to be deduced from
the small solar thermal syphon hot water systems. The development of adequate solar
thermal storages and a properly integrated auxiliary heater can contribute to an increase
of the overall efficiency of the system.
Beside the collector and buffer storage, a well designed system control is essential for the
overall operation of the system. In most of the systems, the control is an unattended
component in the installation. At the visited plants, the original temperature control
device of the pump control often was broken and due to missing spare parts, a timer
controlled pump operation was installed. There is nearly no information on the achieved
solar thermal gains and on the electricity input.
Figure 4.6 Broken control unit and wrong temperature control installation.
For large commercial operated solar thermal systems, advanced control units should be
applied, providing information to the system operator with respect to
-
monitoring of achieved solar thermal gains
-
monitoring of auxiliary energy input (e.g., electricity demand for heater element)
-
monitoring of set temperatures and operation temperatures
-
fault diagnostics
Several micro-controller based control units are on the market available, a small arbitrary
excerpt is shown in Figure 4.6. Control units of this standard are supposed to be not
available on the Thai market yet, but advanced control units, combined with an
appropriate training of the installer and operator may be a pre-requisite for the further
success of solar thermal systems in Thailand.
35
Figure 4.6a System control unit MES from the German company Paradigma for large solar thermal
plants. Also available: remote control for the unit.
Figure 4.6b Programmable system control unit UVR 1611 from the German company TA.
36
Figure 4.6c System control unit UVR 1611 from the German company SOREL GmbH.
Figure 4.6d System control unit Thermius from the Danish company AllSun A/S.
37
4.3 STANDARD TESTING
In the European countries, several independent institutes exist to perform mechanical load
tests and performance tests on solar thermal collectors according to national Standards
and European Standards. The foundation of test centers was driven by the awareness that
missing standards
-
increases the differences in the comparability of the component performance and thus
complicates the estimation of system yields, especially in the planning phase
-
complicates the export of the collectors
-
does not increase the confidence of the potential customers into solar thermal
components.
Consequently, the missing of comparable Standards lead in the past to a lack of reliance
on solar thermal systems, caused time-consuming procedures to estimate the performance
and thus did not contribute to the cost-effectiveness of the systems.
The situation improved, when in 1994 a harmonization of European Standards by the
European Committee for Standardization CEN was carried out. As a result, European
wide Standards and Test procedures for solar thermal collectors and systems have been
established since then. They were developed on base of existing national and international
Standards and Test recommendations, e.g., ISO 9806 (which still is a worldwide valid
Standard) and have been extended to dynamic test methods and additional criteria for
reliability and durability. It is essential that the European Standards are maintained in
regular intervals of at least five years according to further improvements in the
technology.
The following Standards concerning solar thermal collectors and systems currently exist:
EN 12975 – Solar Collectors
EN 12976 – Factory Made Systems
TS 12977 – Custom Built Systems
Part 1: General requirements; Part 2: Test methods; Part 3: Storages
The latter one is currently in the status of a technical specification (preliminary Standard,
former: prEN, ENV).
The Standards have been widely accepted in between in many European countries. In
Germany, only collectors tested according to the EN 12975 are approved for public
funding schemes. The situation is similar in France, where the French Environment and
Energy Management Agency ADEME is responsible for the approval of solar thermal
components. Only collectors, tested according the European Standard in combination
with additional national requirements, are accepted for installation.
Currently, the collector Standard EN 12975 is the most important Standard considering
large scale solar thermal systems. Whereas part one of the Standard outlines general
requirements on the materials, design, durability and reliability of solar thermal collectors
with reference to the required test methods of part two, test criteria and test methods are
described more in detail in part two (Test Methods). The main tests required in part two
are:
38
-
Reliability testing
Internal pressure test for absorber
High temperature resistance test
Exposure test
Thermal shock test (external and internal)
Rain penetration test (glazed collectors only)
Mechanical load test
Freeze resistance test
Stagnation temperature test
Final inspection
optional: impact resistance test (e.g., due to hailstones)
-
Thermal performance testing (collectors with liquid heat transfer medium)
Glazed / unglazed collectors under steady state conditions
Glazed / unglazed collectors under quasi-dynamic conditions
-
Annex
Schemes for durability and reliability tests
Report sheets
Moreover, the preliminary Standard TS 12977 may become important in the near future,
since this Standard combines the component testing with system simulation approaches
(CTSS method) for an overall performance prediction of the system. The Standard is
flexible for the application to different system configurations, such as solar combi
systems (domestic hot water preparation and heating support). The central part of the
Standard is thus
-
CTSS method (Component Testing – System Simulation)
Separate testing of collector (according to EN12975),
storage and control unit (TS 12977)
Total system performance prediction with parameters derived from the
component tests and using an appropriate simulation tool
(e.g., with TRNSYS)
The main components of TS 12977 is shown in Figure 4.7.
Collector
EN 12975-1
EN 12975-2
hot water
Aux.
heater
controller
Storage
TS 12977-3
Controller
TS 12977-2
annex B
supply water
Figure 4.7 Components of the TS 12977 – Custom Built Systems. Figure from German BINE
information service, Info II/2001.
39
Various test facilities, operated by independent organizations, exist throughout Europe.
One of the German test facilities for example, certified by the German DIN CERTCO
certification body, is the Test Centre for Solar Thermal Systems, operated at Fraunhofer
ISE. Figure 4.8 shows some of the equipment for testing collectors at this centre.
Figure 4.8a Outdoor solar thermal collector test facility at Fraunhofer ISE (part of the Test Centre
for Solar Thermal Systems). Left: tracking rig for computer controlled automated collector tests;
right: mechanical load test facility.
Figure 4.8b Indoor solar thermal collector test facility at Fraunhofer ISE (part of the Test Centre for
Solar Thermal Systems) for collectors with liquid heat transfer medium and for air collectors.
Between collector and lamp array, an artificial air-cooled sky area is installed.
In Thailand, test facilities for indoor and outdoor solar thermal collector tests have been
developed at Asian Institute of Technology (AIT), King Mongkut’s University of
Technology Thonburi (KMUTT), School of Renewable Energy Technology (SERT) in
Phitsanulok province and Chiang Mai University (CMU). The test facilities are not
continuous in operation due to the low national production level of collectors and due to
40
missing commitments for manufacturers, to apply performance and reliability tests at
national certified test institutes.
An interesting outdoor collector test method was developed and described by Prof.
Supachart Chungpaibulpatana at AIT, Bangkok in 1988. He developed a dynamic test
method, especially adapted to the prevailing meteorological conditions in Thailand called
a transient test method. In contradiction to the standard collector performance tests with
tracked systems, requiring periods with continuous high radiation level for days, his
method requires a more simple fixed test rig and focuses on a special evaluation
algorithm, allowing performance tests during periods including overcastted sky as well. A
simple one-node heat capacitance model is used to characterize the collector thermal
performance. In the experiment, the collector inlet and outlet are connected in a closed
circuit by a tube equipped with a circulating pump and the fluid inside the whole system
is circulated at a very high flow rate. Figure 4.9 shows a sketch of his test facility.
For the establishment of certified national solar thermal test centers it would be of interest
to activate the dynamic test method and to evaluate the test results with tests on existing
equipment for stationary thermal performance tests. For this reason, a solar collector
sample may be circulated to the different test facilities, and the test results are to be
compared finally in order to assess the precision of the test methods and to increase the
performance test quality.
Figure 4.9 Experimental test system
Source: Supachart Dissertation, Asian Institute of Technology, Bangkok, Thailand Chungpaibulpatana
(1998), Non-Steady State Method for Testing Flat-Plate Liquid-Type Solar Collector Performance, PhD
There are many experiments by using the Solar Simulator and Outdoor Test in KMUTT
such as “Development of Testing Method for Domestic Solar Water Heating System” by
Ms. Sawitri Chuntranulak and Prof. Prida Wibulswas. The researchers from SERT
studied entitled “A Study of Suitable Meteorological Condition for Solar Collector
Performance Testing for Thailand” as the Figure 4.10 a. In addition, CMU researchers
have studied on the performance of solar collector in the north region of Thailand as
shown in the Figure 4.10 b.
41
Figure 4.10 a. SERT experiment b. CMU experiment
4.4 QUALITY LABEL AND CERTIFICATION
In the following, the European approach on a quality label and corresponding certification
process for solar thermal products is outlined.
In 2003, a uniform European quality label for solar thermal products, the Solar Keymark,
was established as a further measure to market solar thermal products more easy
throughout Europe with one European quality mark.
For this reason, a new European harmonized certification scheme has bee drawn up for
solar thermal collectors and solar thermal system components. This certification scheme
is based on the above described product standards EN 12975 and EN 12976. As soon as
TS 12977 has moved from the preliminary status into an obligatory EN 12977, this
standard will be integrated into the solar keymark as well.
Figure 4.11 The European Solar Keymark quality label for solar thermal products.
Briefly outlined, the procedure to obtain the solar keymark is as follows:
-
the manufacturer is committed to establish a quality system, comparable to the level
of EN-ISO 9002;
-
a sample of the component to be labeled (e.g., collector or factory made system) is
selected by an approved organization from the manufacturers running production
charge and is tested according to the valid Standards (EN 12975, EN 12976). This is
done once;
-
the production process and production line is inspected regularly in annual intervals;
-
the labeled product is physically inspected in intervals of two years.
42
Only those solar thermal products are certified with the keymark, which were
successfully tested by a testing laboratory, approved by the CEN Certification Board and
6
by DIN CERTCO (Germany) , CERTIF(Portugal), ELOT (Greece), etc.
Approved European test institutes, which can perform the keymark lablleling for
collectors on behalf of the certification bodies are for example (non-complete):
Austria: Österreichisches Forschungs- und Prüfzentrum Arsenal Ges. mbH, Vienna
Switzerland: Institut für Solartechnik SPF, Hochschule für Technik, Rapperswil
Spain: CENER-CIEMAT, Centro Nacional de Energías Renovables, Sarriguren
Greece: NCSR Demokritos, Solar & other Energy Systems Laboratory, Attikis
Italy: ENEA, Italian Agency for New Technology, Energy and Environment, Research
Centre TRISAIA, Rotondella
Portugal: INETI, Instituto Nacional de Engenharia,Tecnologia e Inovacao, Lisboa
France: CSTB, Centre Scientifique et Technique du Batiment, Sophia-Antipolis
In Germany, test institutes which can perform the keymark labelling on behalf of DIN
CERTCO are
Universität Stuttgart, Institut für Thermodynamik und Wärmetechnik, Stuttgart,
[email protected]
TÜV Immissionsschutz und Energiesysteme GmbH,Testzentrum Energietechnik,
Cologne, [email protected]
ISFH – Institut für Solarenergieforschung GmbH, Hameln, [email protected]
Fraunhofer Institut für Solar Energiesysteme (ISE), Freiburg, [email protected]
IZES Institut für ZukunftsEnergieSysteme, Hochschule für Technik und Wirtschaft,
Saarbrücken, [email protected]
6
DIN CERTCO is the German certification organisation of TÜV Rheinland Group and of DIN, the
German Institute for Standardisation.
43
Figure 4.12. Overview on the steps, necessary to obtain the European Solar Keymark quality label for
solar thermal products. Described by the Solar Thermal Test Center at Fraunhofer ISE, one of the
certified test institutes in Germany.
Source: www.kollektortest.de.
Actual information on the Solar Keymark and approved certification laboratories may be
found at the web site of the European Solar Thermal Industry Federation ESTIF
(www.estif.org).
The strong increase of solar keymark licenses (Figure 4.13) indicates the success of the
labeling. Until October 2006, about 100 licenses have been distributed. The number does
not correspond to the number of companies, since one company can apply more than one
keymark to different products.
Another expression of the success of the keymark is the intention in Germany, to connect
in the near future the public funding for solar thermal collectors with the solar keymark
instead of the EN Standards only.
44
Figure 4.13. The success story of the European Solar Keymark. Since October 2006, the number of
keymark licenses has grown to approx. 100 items.
Source: ESTIF.
4.5 OPTIMIZATION OF STANDARD AND SOLAR THERMAL TESTING CENTER IN THAILAND
Site surrey of solar water heating system in Thailand found that main problems of water
heating system are originated from:
Maintenance technicians lack of knowledge and understand in operating the solar
water heating system
Misconception that where hot water is available, the system still operates
No consideration of depreciated equipment including its efficiency in producing
hot water
Therefore, a lack knowledge and understand in solar water heating system results in
problems as follow:
1. Hot water temperature is not satisfied as a result of:
Incorrect direction and tilt angle of the solar collector
The solar collector is shaded by other objects such as a bill board
The solar collector is deteriorated , e.g. the peel off of the black color at the
absorber plate , the broken transparent cover plate , and a formation of dirt at the
transparent
Leakage of pipe in the solar collector
Solar collector area small
Hot power pipe should be insulated ( It was found that there was no insulation for
pipe and joint )
A flow of hot water is obstructed by rust and dregs.
Water pressure is insufficient
Cold water is left over during the night time.
There is a problem with water pumping system.
This is because of insufficient pumping pressure, non – stop operation and a
malfunctioned installation.
45
2.
3.
4.
5.
The insulator of the hot water storage tank is not in good condition and the size of
the size of storage tank is not suitable to the application.
Failed installation of temperature controller , low temperature control and leakage
Hot water is not available during the day time because:
There is cold water left over in the pipe during the night time.
Piping insulator is deteriorated.
Additional heater is out order or the controlled temperature is too low.
Insulator of hot water storage tank is degenerated
Noise from solar water heating system:
Vibration of water piping due to blockage inside the pipe.
Pipe was not well-installed. Joints were lose
No lubrication for “bullet” of the pump
Water leakage due to:
Joints, valves or leakage of the pipe.
Leakage was often found at the joints of solar collector and hot water pipes due to
the pipe expansion.
High demand of electrical load due to:
A problem is occurred from the storage tank situated at the lower level than it
should be or there is a reverse flow of cold water in the solar collector to the
storage tank.
An additional heater works at all time.
The temperature is much higher than the temperature required
Problem found from surveys hospitals and hotel such as :
1. In satisfied operating temperature
2. Damaged solar collector
3. Rusty storage tank
4. Damage joints
5. Damage insulation
6. Malfunctioned additional heater
7. Obstruction from dregs
8. Too much dust
9. Motor of the hot water pump
From problems because at produce equipments have not the quality
testing to solar collector industrial product standard (TIS 899-2532) 1989 and
solar water heater for domestic uses (TIS 1507 – 2541) at 1998.
46
Table 4.1 Comparison Test Condition between ASHRAE Australian and Thai
Detail
1. Solar Radiation
(W/m2)
2. Ambient
temperature (ºC)
3. Wind velocity
(m/s)
4. Pressure
Differential
between water in
and out collector
(kPa)
5. Equation of
efficiency of solar
collector
ASHRAE
More than 790 ± 32
Australian
More than 790 ± 32
less than 30
less than 30
Thai
More than
600
less than 30
2.0-4.5 ± 0.5
2.0-4.5 ± 0.5
2 ± 0.5
3.5
3.5
-
K )5 ¬ªWD H 8 / 7L 7D º¼ K K 8 7 L 7H , W K )5 ª¬WD H 8 / 7L 7D ¼º
47
5
ECONOMIC AND FINANCIAL
5.1 ECONOMIC OF SOLAR THERMAL SYSTEM
Economic viability is crucial to development of solar thermal market. Above all barriers
that have hindered the market growth, high cost of solar systems has been a major cause
that shun potential users from its environmental benefits and energy cost saving. While
there is no general guideline or proven records of how solar thermal systems save energy
available to public, leave the customers only information source to suppliers who
sometime are new to the technology as well. In this chapter, we will outline some of the
criteria that make the solar thermal systems’ economic feasible.
Solar thermal systems generally have high first cost and low operating cost. The initial
cost of solar system can be minimized by proper sizing system’s main components which
are collectors and tanks to the optimum size that delivers energy at the average demand.
A system that design at full load may be oversize for applications that have seasonal
demand. For example, hotels have low hot water demand during low tourist season. A
system that design to serve full load would be too large when the hotel has only half of
the occupancy rate in low season. It is recommended that users measure their hot water
consumption for at least one year in order to understand their actual demand for proper
sizing for solar thermal systems.
Solar thermal system performance associates with quality of installation, solar radiation,
type of collector, and maintenance. A good installation can greatly increase the system
efficiency which means more energy produced and more positive cash flow that shorten
the pay back period. Regular maintenance can extend the system lifetime and increase life
cycle cost saving.
Below outline some of the criteria for design and optimization of solar thermal systems.
5.1.1 Solar radiation
Thermal performance of solar system is determined by solar radiation, ambient
temperature, and heat losses from collectors, storage tanks and pipes. As heat losses can
be prevented by good insulation, system performance is primarily influenced by solar
radiation. Thailand has an average global solar radiation at 4.5-4.7 kWh/m2 per day with
seasonal fluctuation within ±20% of the average value.
Although annual solar gain is higher than the economic profitability figure as compare to
countries in higher latitudes, Thailand solar radiation is affected by tropical monsoon.
Applications which demand occurs during monsoon season are less suitable for solar
thermal systems. For example, manufacturing of canned agricultural products, large
quantity of hot water is needed to make syrup and containers washing. However, as some
fruit and vegetable are harvested during this time of the year, solar system can not
economically providing heat source in this agro sector. As shown in Figure 5.1, Phuket
daily global radiation is highest during the first quarter of the year and lowest during the
monsoon months in the second half of the year. Chiang Mai and Khon Kaen, although
peak radiation is lower, the solar radiation is relatively constant throughout the year. In
understanding seasonal variation of the energy source, solar thermal system can be design
to properly serve heat demand throughout the year with least investment cost.
48
MJ/m 2-hr
Bangkok hourly global radiation
Bangkok Daily global radiation
2
MJ/m
20.00
3.00
2.50
19.00
2.00
18.00
1.50
17.00
1.00
0.50
16.00
0.00
6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00
15.00
Jan
Feb Mar
Apr
May
Jun
Jul
Aug Sep Oct
Nov
Dec
hour
(a) Bangkok hourly global radiation
2
MJ/m -hr
(b) Bangkok daily global radiation
Phuket hourly global radiation
3.00
2
MJ/m
Phuket daily global radiation
21.00
2.50
20.00
2.00
19.00
1.50
1.00
18.00
0.50
17.00
0.00
16.00
Jan
6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00
Feb Mar
Apr May Jun
Jul
Aug Sep Oct Nov Dec
Hour
(c) Phuket hourly global radiation
MJ/m 2-hr
Chiang Mai hourly global radiation
(d) Phuket daily global radiation
2
MJ/m
Chiang Mai daily global radiation
20.00
3.00
2.50
15.00
2.00
1.50
10.00
1.00
5.00
0.50
0.00
6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00
hour
(e) Chiang Mai global radiation
MJ/m 2-hr
Khon Kaen hourly global radiation
0.00
Jan
Jul
Aug Sep Oct
Nov Dec
(f) Chiang Mai daily global radiation
2
MJ/m
3.00
25.00
2.50
20.00
2.00
Feb Mar Apr May Jun
Khon Kaen Daily global radiation
15.00
1.50
1.00
10.00
0.50
5.00
0.00
6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00
0.00
Jan
Feb Mar Apr May Jun
Jul
Aug Sep Oct
Nov Dec
hour
(g) Khon Kaen hourly global radiation
(h) Khon Kaen daily global radiation
Figure 5.1 Solar radiation in Bangkok, Phuket, Chiang Mai and Khon Kaen
5.1.2 Load pattern and continuity of demand
The most suitable application for solar thermal is when the demand occurs during
daytime and operation is continuous all year round. Residential and commercial
applications have hot water demand in the morning and evening hours, thus require
storage tank that increase the system cost. Some applications in industrial sector can
integrate solar thermal system directly into the existing process.
49
5.1.3
Working temperature and types of collector
With weather condition in Thailand, applications that require temperature below 70°C can
use low cost, non-concentrated or lower efficiency collectors. Typical temperature
required for hot water demand in residential and commercial applications and water feed
to boilers in industrial application is around 50-60°C, this temperature level can be served
by flat plate or evacuated tubes collectors typically sold in Thailand. Table 5.1 shows a
comparison of energy produced from 3 types of collectors; unglazed, flat plate and
evacuated tubes using simulation from a software tool, T-Sol®, to simulate performance
of solar collectors under weather conditions in 4 major cities representing 4 regions in
Thailand (central, north, northeast, and south). The energy produced is in the range of
1,000-1,300 kWh/m2 for water temperature demand at 60°C which shows that at low
temperature, efficiency of collector is not a key factor. Users should select the most cost
effective collectors according to demand temperatures.
Table 5.1: Energy produced by 3 types of collectors for water at 60°C
Weather data
Bangkok
Chiang Mai
Khon Kaen
Phuket
5.1.4
Unglazed
1,134
1,052
1,078
1,057
kWh/m2
Flat plate
1,237
1,218
1,193
1,173
Evacuated
1,312
1,308
1,264
1,243
Solar fraction
Solar fraction is a percentage or portion of annual energy demand meet by solar energy. A
hundred percent solar fraction means that all of the energy demand is supplied by solar
system. However, larger size of solar system requires higher investment cost. Proper solar
fraction that uses least investment cost while gives highest performance is the key to
economic viability for large solar thermal systems.
F-chart method is generally used for the analysis for an optimum size of solar collector
and tank. From Duffie and Beckman (1991), the optimum collector area can be
determined by plotting the solar fraction to the annual thermal performance. The optimum
area is where the slope of thermal performance is P2CA/P1CF1L.
wf
wAC
P2 C A
P1C F 1 L
Equation 5-1
Where
g = fraction of solar energy to annual heat load
Ac = collector area
P1 = ratio of the life cycle fuel cost savings to the first year fuel cost savings
P2 = ration of the life cycle expenditures incurred because of the additional capital
investment to the initial investment
CF1 = first year fuel cost without a solar system
50
Figure 5.2 Optimum collector area determination from the slope of the g Vs AC thermal performance
curve. From Duffie and Beckman (1991).
The analysis use life cycle cost method which takes into account all future expenses. The
method provides a means of comparison of future costs with today’s costs by discounting
all anticipated costs to present worth value. Detail of the analysis involves complicated
mathematic equations. Alternately, we use software tools that can perform the economic
analysis. Two simulation software tools are used in this study, Retscreen£, developed by
Retscreen International Clean Energy Support Center, Natural Resource Canada and TSol£, developed by Dr. Valentin EnergieSoftware GmbH. Both of the software gives
similar results when simulate with the same parameters. Only T-Sol£ gives more
graphical results in technical analysis while Retscreen£ accommodates more in the
economic details.
Using T-Sol£, results of simulation for a hotel (100 guestrooms, double occupancy) are
shown in Figure 5.3 and Figure 5.4. Storage tank size 1000, 3000, and 5000 liters are
compared for the least solar collectors required to achieve solar fraction at 60%.
51
Figure 5.3 Solar fraction and number of solar collectors
The simulation shows that at 60% solar fraction, 3,000-liter and 5,000- liter systems
require only 50 solar collectors while 1,000 liter tank system needs nearly 70 collectors to
achieve the same solar fraction. As larger number of collectors gain higher solar fraction,
however, the incremental of heat gain is not linear. After 70% of solar fraction, the
system yield only 20% more with double the number of collectors. Therefore, the solar
fraction at 60% is mostly recommended for cost effectively implementation of solar
thermal systems.
Since system cost is largely determined by the size of solar collector and storage tank. A
small tank may cost lower but the system would require larger number of collectors while
a larger tank may cost more but require less collectors. Designers should be cautious in
cost comparison for the optimum size of tank and collectors. Design results of the 3 tank
sizes are compared in Figure 5.4. Systems with 3,000 and 5,000-liter tanks yield similar
system efficiency and number of collectors. Selection of system sizes is to be decided by
cost comparison between the 2 systems
Figure 5.4 A comparison of system efficiency and tank sizes
Based on our survey to existing solar hot water systems in hotels, most of the systems
were design at 90-100% solar fraction. System installed in hotels during 1986-1988 cost
approximately 8,000 – 10,000 Baht/m2 of collector area. More recent installations during
1990’s cost were between 17,000 – 18,000 Baht/m2.
52
Table 5.2 shows economic analysis for 3 solar hot water systems. Two systems installed
in 1987 and 1988, and another system installed in 2003. Since there is no record of actual
hot water consumptions, the economic analysis shown here is based on simulations with
typical load profile for hotels in Thailand.
1) Hot water demand is 100 liters/room/day for double occupancy.
2) Room occupancy rate is 70%.
3) Hotel annual hot water demand is based on Thai tourist season as shown in Figure 5.5.
(a) Daily load profile
(b) Annual load profile
Figure 5.5 Load profile for typical hot water demand in Thai hotels
Simulation results show that all of the three systems have solar fraction nearly 100%
resulting in the high investment cost and pay back periods nearly 10 years.
When simulate system performance for solar fraction at 60% and assume system costs
were proportion to the number of collectors, pay back period for the optimized design
could be minimized to 5 years for replacing electricity and 8 years for LPG.
It should be noted that hotel 1 and 2 installed solar systems nearly 20 years ago. The costs
of systems and price of electricity were of those during that time.
53
Table 5.2 Review of Existing Installation and proposed optimized design
System
Location
Year of Installation
Annual solar irradiation
Collector type
Collector efficiency
Collector annual Solar gain
Number of collectors
Storage volume
Hot water demand
Type of fuel
Annual fuel saving
Solar fraction
Fuel price
Investment cost
Net present value
Pay back period
Hotel 1
Hotel 2
Hotel
South
1988
1,711.76 kWh/m2
Flat plate
70%
499 kWh/m2
60
8,000 liter
4,000 liter/day
Electricity
51,298 kWh
98.9 %
1.7 Baht/kWh
(in 1988)
escalation 3%/year
960,000 Baht
2,210,473Baht
10 years
Northeast
1987
1,895.71 kWh/m2
Flat Plate
70%
988 kWh/m2
45
8,000 liter
3,500 liter/day
Electricity
55,518 KWh
97.8%
1.7 Baht/kWh
(in 1987)
escalation 3%/year
800,000 Baht
1,545,988 Baht
8 years
North
2003
1,970.49 kWh/m2
Flat Plate
75.5%
1,176 kWh/m2
48
10,000 liter
6,500 liter/day
LPG
8,760 kg
94.6 %
16.5 Baht/kg
1,680,000 Baht
2,473,157 Baht
10 years
Proposed size of solar system for optimum investment
Solar fraction
Number of solar collectors
Investment cost
Pay back period
60.1%
18
256,000 Baht
5 years
58.8%
14
248,888 Baht
5 years
62%
24
840,000 baht
8 years
54
5.2 PAY BACK PERIOD
For commercial and industrial applications, solar water heater is considered as an
auxiliary heat source to conventional heating system. Businesses invest in the solar
system anticipate to the future conventional fuel cost saving. While least cost analysis
should be performed for the optimum investment to the energy deliver, conventional fuel
cost savings indicate return on investment of the solar system.
The initial investment cost is mostly associated with cost of the solar system to meet with
the annual loads in supplemental to conventional fuel. Operating cost, fuel cost and
system maintenance is considered negative cash flow and the energy produced from the
solar system is accounted for revenue generated.
The initial cost of solar water system in Thailand is relatively high as compare to other
countries. Low annual turnover of the solar companies due to low sell volume has driven
solar companies to mark up high price on the products in order to cover for company
expenses.
Domestic hot water system cost approximately 29,000 baht/m2. Locally produced flat
plate collectors system cost lower than imported products and Chinese evacuated tubes
collectors cost similar to local flat plate collectors. The solar systems sold during the year
2000 cost around 35,000 Baht for the same specification, a nearly 10% increase of the
domestic system price.
Table 5.3 A market survey of domestic solar hot water system cost in 2007
Domestic
SHW
Collector
Tank
Cost (Baht)
Installation
VAT 7%
Total
Cost/m2
Local 1
2.16 m2
160 liters
49,000
8,000
3,990
60,990
28,236
Local 2
2.0 m2
200 liters
53,000
3,710
56,710
28,355
Flat plate
Local 3
2.02 m2
200 liters
57,500
57,500
28,750
Import 1
1.9 m2
160 liters
57,300
4,000
61,300
32,263
Import 2
2.3 m2
150 liters
96,000
96,000
41,739
Evacuated tube
Import 3
Import 4
15 tubes
20 tubes
200 liters
165 liters
48,000
39,000
5,000
5,000
3,710
3,080
56,710
47,080
28,355
23,540
The cost of solar system for commercial applications is slightly lower than those in the
domestic application. Size of installation is varied from 10 – 100 m2 and the system cost
is in a range of 17,500 – 27,500 Baht/m2. The variation of the prices among different
solar companies does not seem to have a pattern whether it is based on the size of system
or the quality of materials. Although local products tend to have lower prices, the price
quotes are rather arbitrary as customers can not easily compare the price for large
systems. The average and more consistent cost is 23,000 Baht/m2. With reference cost of
system in the year 2000, locally produced system cost increase on average of 6% over the
last 6 years.
55
Table 5.4 A market survey for cost of Solar System in Commercial application in baht/m2
Year
Local 1
Local 2
Local 3
Import 1
Import 2
2000
2007
14,000
17,500
27,500
23,400
22,936
32,000
A cost breakdown for commercial solar systems in the table below shows that solar
collectors make up for approximately 60% of the total cost.
Table 5.5 Solar system cost breakdown in percentage of total cost in commercial applications
Item
1. Collectors
2. Tanks
(size 3,000 – 5,000 liters)
3. Balance of System
(pump, control, pipe etc)
and installation
Cost
13,000 – 15,000 Baht/m2
150,000 - 300,000 Baht
(depends on material and tank size)
Estimated at 20-30% of the materials
cost
%
50 – 60%
20 – 30%
20 – 30%
Most of Thai solar hot water buyers make cash payment. Tax incentives and financing
scheme for solar system are not yet available. Return on investment can be relatively
straightforward calculated based on the initial cost and fuel saving with the fuel price
escalation over the lifetime of the system.
Pay back period, the time needed for the cumulative savings to equal the initial
investment, is the term that is most common used and comprehensible among Thai solar
customers and general public. Economic factors such as inflation and fuel escalation are
taken into consideration for the calculation of pay back periods. With initial cost of solar
system at 29,000 Baht/m2 for domestic and 23,000 Baht/m2 for commercial and industrial
applications and with the economic parameters below, the pay back periods are
calculated as shown in Table 5.6.
Key economic indicators
7
- GDP 5% (average over the year 2000-2006 )
-
8
Inflation 3.5% (average over the year 2003-2006 )
Fuel cost
2000
2007
Average % increase/year
7
8
Electricity
(Baht/kWh)
2.5
3.9
8%
www.bot.or.th
Inflation Report 2006, Bank of Thailand
LPG
(Baht/kg)
9
16.7
10%
Fuel Oil
(Baht/liter)
8.5
17.5
10%
56
Table 5.6 Pay back periods of solar thermal system for each sector
Sectors
Residential
Commercial
Industrial
Pay back periods (years)
Remark
Electricity
LPG
Fuel Oil
5-6
3-5
7-8
6-8
4-8
Depends on types of collectors and
hot water demand.
Pay back period at 4 years is
calculated based on unglazed
collector’s pre-heat feed water to
boilers.
For optimized design variables, pay back periods for solar thermal system are in the
range of 3-8 years. Thailand cost of solar system is relatively high while electricity cost is
relatively low as compare to other countries that have success installation of solar water
heater. Prices and typical size of domestic solar water heater in Table 5.7 are summarized
from the Sun in Action II report of ESTIF, Thailand data came from our market survey.
There are several factors contributed to the pay back periods. The next section in
Sensitivity Analysis will discuss of factors that have impact to the pay back periods of the
solar systems.
Table 5.7 Country comparison for pay back periods of DSHW
Country
Baht/m2
Japan
Thailand
Spain
Italy
Israel
Greece
China
25,450
29,000
25,000
17,500
11,800
14,750
7,150
Typical size
Collector-tank
2x2 m2 - 200 liter
2 m2 - 160 liter
2 m2 - 200 liter
4 m2 - 200 liter
2.5 m2 - 150 liter
2.4 m2 - 150 liter
2 m2 - 180 liter
Total
(Baht)
101,800
58,000
50,000
70,000
29,500
35,400
14,300
Electricity
(Baht/unit)
7.3
3.9
11.5
10
4.85
3.8
1.8 - 5
Pay Back
Period
8
6.2
3.5
3.5
3.5
3.6
2.5 - 6
57
5.3 SENSITIVITY ANALYSIS
There are several economic factors that have impact to year-to-positive cash flow or pay
back time. Analysis of the impacts lead us to more understanding of how pay back time
can be shorten to an acceptable range among Thai investors and what sort of financial
measures are needed to achieve the target. There are 3 parameters selected for sensitivity
analysis: the amount of energy produced from solar system, the initial costs and the
annual operating costs. All are analyst within 40% sensitivity range using Retscreen®.
Parameters for simulation
Application: Hotel
Load: Hot water for 180 Rooms, 70% occupancy rate
Fuel replaced: Electricity 3.9 Baht/kWh escalation at 8%/year
Collector: 22 collectors, Glazed, efficiency 78%
Tank: 5,000 liter
Solar fraction: 58%
Simulation results
- RE delivered 27.24 MWh
- Initial cost 1,006,940 Baht
- Annual cost 1,520 Baht (pump running cost)
- With the electricity cost at 3.9 Baht/kWh, pay back period is 3.4 years.
Using a typical hotel application for the sensitivity analysis, the results are shown in the
next page. With the same fuel cost at 3.9 baht/kWh, reducing initial cost 20% from its
original cost resulted in pay back time at 2.8 years. Further reduction to 40%, the pay
back period can be greater decrease to 2.1 years. While increasing RE energy delivered
which can be done by using higher efficiency collectors or higher number of collectors
can decrease the pay back time to only 2.5 years. This shows that initial cost is the key
parameter to reducing the pay back time.
58
Table 5.8 Sensitivity Analysis for Year-to-positive cash flow
Electricity
RE delivered
(MWh)
16.34
21.79
27.24
32.68
38.13
Initial costs
(THB)
604,164
805,552
1,006,940
1,208,328
1,409,716
Annual costs
(THB)
912
1,216
1,520
1,824
2,128
789%
-40%
-20%
0%
20%
40%
7.9
-40%
-20%
0%
20%
40%
7.9
-40%
-20%
0%
20%
40%
2.3400
-40%
7.9
6.3
5.3
4.5
4.0
Avoided cost of heating energy (THB/kWh)
3.9000
3.1200
4.6800
-20%
0%
20%
6.3
5.3
4.5
5.0
4.1
3.5
4.1
3.4
2.9
3.5
2.9
2.4
3.1
2.5
2.1
5.4600
40%
4.0
3.1
2.5
2.1
1.8
2.3400
-40%
3.4
4.4
5.3
6.1
6.9
3.9000
3.1200
4.6800
-20%
0%
20%
2.6
2.1
1.8
3.4
2.8
2.4
3.4
4.1
2.9
4.8
4.0
3.4
5.5
4.5
3.9
5.4600
40%
1.6
2.0
2.5
3.0
3.4
2.3400
-40%
4.1
4.1
4.1
4.1
4.1
3.9000
3.1200
4.6800
-20%
0%
20%
3.7
3.4
3.1
3.7
3.4
3.1
3.4
3.7
3.1
3.7
3.4
3.1
3.7
3.4
3.1
5.4600
40%
2.9
2.9
2.9
2.9
2.9
Impact on Year-to-positive cash flow
Initial costs
RE delivered
Annual costs
-0.800
-0.600
-0.400
-0.200
0.000
0.200
0.400
0.600
0.800
Effect of increasing the value of the parameter
Figure 5.6 Effect of increasing the value of the parameter
Sorted by the impact
Avoided cost of heating energy
59
Although replacing electric water heater with solar water heater in residential application
has a long pay back period of 6.2 years, the same fuel replacement in commercial
application require only 3.4 years. This is partly due to lower cost of collectors in larger
systems and higher hot water demand in commercial application.
As compare to countries where solar thermal technology is successfully implemented,
Thailand pay back time for DSHW is relatively long because the initial cost is high while
fuel price particularly electricity is low. Since change of fuel price will have impact to the
country economic, left the initial cost of solar system the only option that we can
interfere.
Table 5.9 compares variation for the percentages of initial cost reduction.
For the current domestic solar system cost at 29,000 Baht/m2 (or 58,000 Baht for a
system), pay back period is 6.2 years for replacing electricity. In order to make solar
systems more appealing to customers, pay back time should not be longer than 5 years.
Hence a 30% reduction of initial cost is needed for the economic feasibility in domestic
hot water heater.
For commercial applications, replacing electric water heater in hotel/hospital can already
be feasible within 5 years. The case shown here is calculated for replacing LPG where
pay back time is still up to 8.2 years. The industrial application is based on a solar system
that would require a storage tank and glazed collectors in a case of replacing fuel oil.
With the initial cost of 23,000 Baht/m2, solar systems for commercial and industrial
applications need more than 6 years to pay back the investment. In order to reduce the
pay back period to less than 5 years, a 50% initial cost reduction is needed, which is
higher percentage than the residential application required due to low price of fuel even
they are escalated at 10%/year. The potential of future increase of LPG price due to
ceasing of government subsidy on the fuel may make the pay back period shorter than the
current price. There are financial incentives can make this initial cost reduction possible
such as tax privilege, tax incentives, tax credit, subsidy or other policies. Reviews of
international policy in success countries and recommendations for Thailand will be
illustrated in Chapter 8.
Table 5.9 Pay back periods for the reduction of initial cost
Current
Sectors
Residential1
Commercial2
Industrial3
Pay
back
time
6.2
8.2
7.7
Percentage of initial cost reduction
Initial cost
(Baht/m2)
50%
40%
30%
20%
10%
29,000
23,000
23,000
3.5
4.9
4.5
4.1
5.6
5.3
4.7
6.3
5.9
5.2
7
6.6
5.7
7.6
7.2
Note
1. Residential solar system replacing electricity
2. Commercial solar system replacing LPG
3. Industrial solar system replacing fuel oil
60
6
FINDINGS FROM SELECTED SITE VISITS
This chapter outlines findings from potential and existing SWH applications in four
facilities where the project team visited during the project implementation. Detailed
analysis of data gathered during the site visits is also included in each case study. Brief
description of each facility and findings are captured in the following sections:
6.1 FACULTY OF NURSING, KHON KAEN UNIVERSITY
Faculty of Nursing, Khon Kaen University is located in the northeast of Thailand, 450 km
away from Bangkok. The SWH system was installed by DEDE in 1986 on the overhang
for car parking facing to the south, as shown in figure 6.2.
Existing solar hot water system
The schematic diagram of the system is shown in figure 6.1. The solar collector was
made in Thailand, and the collector array consists of 20 collectors, 2 m2 each, arranged as
2 banks in series of 10 collectors each in parallels. The system was also equipped with air
vent, pressure and temperature gage. It included two vertical storage tanks and an electric
heater backup. The purpose of using hot water was for shower with a daily consumption
of 1.5 – 2 m3. The system produced hot water at 50 oC. In 1991, hot water produced by
the system was piped to use in another building, 50 m away.
Figure 6.1 Schematic diagram of SHWS at faculty of nursing, (1) collector arrays, (2) the sediment
deposited inside the collector, (3) pipe connection, (4) auxiliary heater, (5) water draining system, (6)
insulation on pipes
61
Figure 6.2 Left: collector arrays installed over the car park. Right: two vertical storage tanks
Status, overall appearance and problem occurred
The SWH system has been abandoned for 2 years. The system failed two years ago and
the administrative unit of faculty decided not to retrofit this 20-year-olds system basically
due to high retrofitting cost with the new SWH system. Hot water demand in the nursery
today is met by electric water heaters.
Overall appearance and problems found are as follows:
1. Severe corrosion found on the piping system
2. The insulation on pipes came off
3. The insulation at the back of collector panel failed
Summary
The system by record was installed and in operation for over 20 years, and it was not
operated for two year due to the system failure. At that time, there was not available data
analysis result, thus the manager of faculty believed that renovating the SWH system to
produce hot water was not worth in comparison with electric heaters. He then decided to
install electric heaters instead. To promote SWH again for the faculty of nursing, the
data analysis result regarding economic comparative assessment of the systems must be
presented to the manager. The following scenarios should be done.
1. Renovate the existing SWH system and hybrid with the existing electric heaters
2. Install a new SWH system
6.2 WHALE HOTEL
Whale hotel, a three-star hotel, is located in Nakorn Prathom province, 60 kilometers
West of Bangkok. The hotel consists of 4 buildings (A, B, C and D). Solar hot water
systems were installed in building A, B and D and the installation was done in 1992,
1989 and 1993, respectively. Among three buildings, building D contains the largest
62
number of rooms. The size of collector array in each building varies according to the
number of rooms. The demand period of hot water is usually in the early morning (6:008:00) and in the evening (19:00-20:00) but consumption data of hot water are not
available to the project team during the site visit.
Solar collectors
The collectors are of flat plate type with a panel size of 2 m2. The brands of collector are
LORDAN and CHROMAC from Israel. For LORDAN, the cover is made of glass
having low reflection losses. The collector frame and absorber were probably aluminium
and the insulation was supposed to be mineral wool. There was no ventilation hole. The
collector was faced south with an approximate tilt angle of 20 degree. There was no
serious shading on solar collectors.
For the building B, the system contains two storage units mounted in horizontal position.
The circulation of water between the solar collector and the storage tank no.1 (collector
loop) was performed using an electric pump. The hot water from the upper of storage
tank no.1 will discharge through pipe to the bottom of the storage tank no. 2 where the
immersion electric heater was installed to serve as an auxiliary heat source, as shown in
figure 6.3. The storage tanks were equipped with insulation and metal jacket. The total
volume of storage tanks was around 12 m3. The temperature different controller was used
in controlling the system, but the setting point for triggering the pump was not clear. The
system data were summarized and presented in table 6.1
Solar Collector
RETURN
SUPPLY -HW
Storage
tank 1
Electric
heater
Feed water
Figure 6.3 Schematic diagram of SHWS installed at Whale hotel
Table 6.1 The SHWS of Whale hotel
1. No. of rooms
2. Average occupation rate
3. Daily water consumption
4. Year of installation
5. Period of using hot water
Building A
128
60 %
N/A
1992
Building B
89
60 %
N/A
1989
6:00-8:00
Building D
179
30 %
N/A
1993
63
6. Hot water temperature desired
7. Solar collector size / panel
8. No. of collector panels
9. Collector brand
7. Orientation
8. Inclination of collector array
9. Capacity/type of storage tank
10. Backup system
N/A
44
CHROMAC
(Israel)
South
20 degree
2 horizontal
tanks
8 and 4 m3
Immersion
electric heater
19:00-20:00
N/A
2 m2
32
LORDAN
(Israel)
South
20 degree
2 horizontal
tanks
6 and 4 m3
Immersion
electric heater
N/A
48
N/A
South
20 degree
2 horizontal
tanks
8 and 4 m3
Electric heater
100 W
Since the temperature sensors do not function properly and the setting point temperature
was not clear, the collector loop of the building B was obviously in stagnation during
inspecting the system.
The insulation of storage tank was completely degraded through heavy corrosion of the
steel jacket and disintegration of the foam insulation to a large extent (figure 6.4). In the
other systems, the storage jacket was made of stainless steel. As two storage tanks were
installed in horizontal position, the temperature gradient especially on the top and the
bottom of the tank was probably low. There was no available data on temperature
distribution in the tanks.
For reasons of accessibility of the roofs at first visit, only the collectors of the first
systems (Building B) were inspected (consisting of 32 collectors). The appearance of
most of the collectors is comparatively good with little signs of corrosion. A few
collectors show clearly internal corrosion of the absorber plate, caused by contents of
humidity which could not be removed from the collector.
The foam insulation of the collector pipes is likewise disintegrated, as they are not
protected by a jacket. Some water had apparently leak from the pipes.
The pumps are, likewise to other inspected systems, mounted below the collector area
without any further protection against weather impact.
The control board is equipped with an electricity meter for the auxiliary electrical heaters,
but no readings have been applied. The control of the systems is ‘decentralised’, e.g., in
one of the systems, the auxiliary heater was replaced or supported by 2 additional
electricity heaters, either started manually or by their own internal control. These
additional heaters are designed for domestic inside use, but were installed outside close to
the storage without any weather protection.
The inspection of the systems by the technicians is done by checking for sufficient hot
water output temperature of the systems, without tracing the origin of the heat (solar or
electrically produced).
64
In inspecting the system at second visit, the SHWS for the building A still worked but the
system efficiency by calculation was quite low, approximately 10-15 %. The problem of
low water temperature obtaining from SHWS significantly effects on hotel customers,
especially in the winter.
The system still worked for the building D but functioned not well. Even the numbers of
customers in this building were less than those of other buildings; the electric heaters
were installed additionally. For reasons of difficulty of access to the roof, the systems
were roughly inspected.
There are no available data on system cost and annual electricity cost for the systems.
Figure 6.4 The system components for the building B at Whale hotel, upper left: collector array, a
few of collectors show internal corrosion. Upper right: storage tanks of which steel jacket
disintegrated. Lower left: the temperature gage seems to be out of order as it indicated the
temperature of water at 5 oC. Lower right: the setting point for controlling the system is not clear.
Summary
The hotel manager realized on energy saving, but she did not know how to take care and
evaluate the system. The Watt-hour meter was installed to measure energy consumption
65
of auxiliary electric heater but no reading has been applied. The inspection of the system
by the technicians was done by checking only for sufficient hot water output temperature,
without tracing the origin of the heat (solar or electrically produced).
The experience made at the Whale hotel is of special interest, since the solar systems
were installed nearly 20 years ago and are still in operation. Part of the collectors show
corrosion, but the array at a whole may still contribute to the hot water supply.
The problems in the systems are addressed mainly to all system controls. It would be
worth to apply a retrofit to the system, focusing on:
- Exchange of control units of all systems by advanced control units with
electrical meters.
- Exchange and improvement of pipe insulation
- Exchange of degraded/damage parts by the new ones
- Training of technicians in order to detect the system operation efficiently
- Rising the awareness of hotel management to hot water and electricity
consumption figures to assess the benefits of the solar hot water systems
6.3 THAI-DENMARK DAIRY FACTORY
Thai-Denmark factory is located in Saraburi province, around108 km North of Bangkok.
At the factory, about 170 tons of raw milk is prepared for dairy products such as
pasteurized milk, fermented milk, UHT flavored milk, yoghurt etc., Monthly
consumption of water, and heavy fuel oil and electricity are 16,520 m3, 57,700 liters and
314 MWh respectively.
Steam production and processes
To produce the dairy products, the steam is needed in the processes. Steam is produced
using three HFO boilers (7 bar each) as shown in figure 6.5. They were alternately
operated. Normally, the boiler no.1 and no.2 are operated simultaneously with a total
steam production of 4.2 tons/hr, while the boiler no.3 usually operated at 3.3 tons/hr is
reserved.
The steam is basically used in the two production steps as shown in figure 6.6
- Pasteurising process, the milk is heated to a temperature level 80 °C for 22 sec.
Subsequently, the finished milk so-called ‘pasteurized milk’ is packaged and cooled
down to 5°C, using electrically driven compression chillers. Likewise the pasteurized
milk, the pasteurized fermented milk drink is produced at temperature level 85 oC for
15 min, and cooled down to 4-8 oC.
-
Sterilizing process of producing Ultra high treatment (UHT), the milk is heated to a
temperature level 138 oC for 3 second. It is subsequently stored at 25°C.
In addition to these processes, the steam and condensate are used for the cleaning purpose
e.g. cleaning vessels and machines when the models of products are changed, cleaning
milk containers on trucks, cleaning floor after work and preheating HFO. After using
66
additionally of condensate in the processes, the condensate is finally returned at a
temperature level of 80 oC to the boiler. It was mentioned that make-up fresh water a day
for producing steam is approx. 27-30 m3.
1
Preheat
HFO
tank
2
3
Figure 6.5 Three HFO-boilers (7 bar each) of the dairy factory. The preheat oil tank
is located between the boiler no.1 and no.2
67
Figure 6.6 Overview of processes of dairy products, pasteurized milk, UHT milk drink and
pasteurized fermented milk drink
System analysis
As a large amount of steam is needed in the processes of producing diary products, the
energy saving should be realized. Integration of solar hot water system in the steam
production is one of strategies to save energy. The possibilities to include solar energy for
fuel saving are as follows:
1. Direct steam generation at the requested system pressure in concentrating solar
thermal collectors, e.g., parabolic trough collectors with one-axis tracking. Under the
68
prevailing meteorological conditions, this would probably lead to considerably large
collector installations with additionally required steam storage to smooth power
fluctuations
2. Pre-heating of the condensate from 80°C towards 100°C (or more) in a highefficiency collector system, using pressurised water as heat medium. As collector
type, vacuum tube collectors may be use, but high-efficiency flat plate collectors
(e.g., double-glazed with non-reflective coating) can be considered as well.
3. Pre-heating of the fuel oil from ambient temperature (30°C) to any temperature until
100 °C. Thus, the condensate from the steam supply system will be less used for fuel
pre-heating and returns into the boiler with a temperature above 80°C, thereby saving
fuel for steam generation. This requires a well designed collector system as well, but
not necessarily vacuum tube collectors. The heat could be used for cleaning purpose
as well. Due to the daily delivery rate of fuel, this solution would probably lead to the
smallest solar thermal installation and thus smallest investment cost, but consequently
to the smallest potential for fuel saving as well. Figure 6.7 shows a possible solar
thermal application for pre-heating the condensate.
4. Since the steam and condensate lost from the system is replaced with approx.27-20
m3 of fresh water, it is possible to preheat a large amount of fresh water from ambient
temperature to 70 oC using simple SHWs before entering the boiler. The schematic
diagram of simple preheat water is shown in figure 6.8
The possibility 1) will be not really suggested here, since a concentrating solar process
heat supply system should be first subject to a pilot plant, before applying this technology
to a commercial process.
The possibilities 2), 3) and 4) should be subject to a feasibility study, considering
different collector technologies, collector system sizes and storage volumes, in order to
find an optimised system configuration with respect to the exploitation of the solar
system, to the saved primary energy and to the investment costs and payback time.
A preliminary calculation on preheating water by SHWS (possibility no.4) was carried
out using T-Sol simulation program. The analysis was done based on the following
economic factors: an average cost of package deal for construction work, life span of the
system of 20 yr, interest rate of 5 %/yr and price increasing rate-running cost of 3 %/yr.
There is no any additional cost in installation when using the existing water storage tank.
The technical input parameters including with cost had been tabulated in table 6.2. The
simulation results showed that daily preheating 30 m3 of fresh water from ambient
temperature to 70 oC with 250 m2 of solar collectors yielded a 3 yrs payback period. The
annual fuel saving is about 44 m3 of HFO. The summarized outputs are shown in table
6.3.
69
Figure 6.7 Simplified sketch of the process heat supply system at the Diary Farm One of the
possibilities to apply solar heat for fuel saving by pre-heating the condensate from 80°C to any higher
temperature is indicated (dotted).
70
Pasteurizing,
Sterilizing
Cleaning, etc
Process
Fuel
(100 oC)
Boiler 3
Boiler 3
Steam
(7 bar)
Boiler 3
Condensate
(100 oC)
Storage
Fuel (30 oC)
Hot water
(70 oC)
Storage
Feed fresh water
Collector array
Figure 6.8 Simplified sketch of the process heat supply system at the Diary Farm One of the
possibilities to apply solar heat for fuel saving by pre-heating the fresh water from ambient
temperature to 70 oC (dotted)
71
Table 6.2 Input parameters for calculating energy saving by preheating fresh water (the possibility 4)
Input parameter
i) Preheat fresh water
30 m3
-Average diary consumption:
-Desire temperature:
-Load profile:
-Cold water temperature
70 oC
Constant (6:00-19:00)
24 oC winter
29 oC summer
ii)System components
- Collector loop
-Type:
European standard panel
2
(FR(UL) 3.74 W/m .K, FR(ĲĮ) 78.7 %)
-DHW Standby Tank
-Total surface area:
250 m2
-Inclination (avoid dust deposition on col):
25 o
-Azimuth:
0o
-TSol Database Volume:
2 x 5 m3
-Length for inside of building:
0m
-Length for outside of building:
50 m
-Heat loss/per meter
0.3 W/m.k
-Pump and Piping:
-Power of pump
iii) Costs and economic
factor
- Investment cost
Solar collector:
6,000 baht/m2
(whole sale package for a large system, some parts of collector cost are included
in the installation cost)
Installation:
329,000 baht
Storage tank (existing one):
0 baht
Interest rate:
5 %/yr
Subsidy:
0 baht
Life span:
20 yr
- Operation and energy cost
Price increase rate – running cost: 3%
LPG:
15 baht/kg
Heavy oil C:
15 baht/L
Electricity:
4 baht/kWh
200 W
Table 6.3 The simulation results obtaining from T-Sol program
Simulation Results
DHW Solar fraction
System efficiency
Solar contribution to DHW (annual)
Heavy Fuel Oil
44 %
49 %
243 MWh
Annual Fuel Savings
44 m3
Amortization period
3 years
Summary
The plant manager of the dairy factory is really interested and enthusiastic in applying a
solar thermal system for fuel saving. A payback period of three years is highly
appreciated in his opinion, but five years would be still acceptable.
Since the solar collector system is expected to be a large one and operates at temperature
levels up to 100°C, monitoring and accompanying research of this system is mandatory
for at least three years. Manufacturers, planner and installer should give sufficient
72
warranties and support and may participate from the project results and experiences in
order to raise their interest in a successful running project.
6.4 PATONG MERLIN HOTEL
Patong Merlin Hotel is one of the 4 hotels in the Merlin Group comprisingof 3 hotels in
Phuket and 1 hotel in Khaolak, Pang-nga, owned by a Thai family. Patong Merlin is a 34 star hotel of 386 rooms in 6 low-rise buildings. The hotel was first built in 1986, started
with one building and completed its 6th building in 1992. Upon requirement of the hotel
owner, the solar water heaters were incorporated during the architectural design of the
hotel providing sufficient flat space on the south facing roof and easy access for
maintenance. A summary of the solar hot water systems for each building are shown
below in table 6.4.
Table 6.4 Solar hot water systems in Patong Merlin hotel
Building
1
2
3
4
5
6
Year
1986
1988
1990
1990
1991
1992
No. of rooms
80
56
72
56
32
93
Other function
Kitchen, laundry
Staff kitchen
Kitchen
No. of collector
65
60
72
42
18
60
Due to availability of the data, only building#2 which have sufficient information is
reviewed in this section.
Solar Collector:
Manufacturer: Lordan
Country:
Israel
Type:
Flat plate
Efficiency:
67%
Aperture area: 1.8 m2 / collector
Year of Mfg: 1988
System Configuration
73
Figure 6.9 Patong Merlin Solar water heater system diagram
Control system
- Solar collector: circulation of water in the collector array is control by differential
controller which set to start the circulation pump when temperature between hot and cold
sensor is more than 9°C and stop when temperature difference is lower than 4°C.
- Auxiliary electric heater: a temperature sensor is placed at half water level inside the
storage tank. When water temperature drops below 50°C, the thermostat triggers the
magnetic contactor to turn on the electric heater.
- Circulation pump: the circulation pump is controlled by a thermostat which turns on the
pump when water temperature in return pipe from the building is lower than 35°C.
All of the solar collectors are in pretty good condition for an 18 year-old system, no glass
cover broken although some collectors show sign of slightly corrosion. There are a few
spot of water leakages from 2-3 pipe connections between collectors and pipe from tank
to collector array. Pipe insulation (Aeroflex 1” wall x 1 1/8” diameter) is mostly still
intact although condition of the insulation is pretty much degraded from years of heated
under the tropical sun. Hot water pipes (between collectors and outlet pipe from collector
to tank) are copper and cold water pipes are PVC. The overall condition of the system is
serviceable and serving hot water all year round.
Patong Merlin has a relatively good recording system for its water and energy
consumption. Technicians take daily reading for water and electric meter of the solar
system and recording of weather condition of the day. Below is plot of water measured at
hot water storage tank outlet and electric consumption (pumps and auxiliary electric
heater in solar system) in January 2006.
74
Electric and water consumption in January 2006
100
80
60
Water (m3)
40
Electric (kWh)
20
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
Day of month
Figure 6.10 Electric and water consumption in January 2006 at Patong Merlin
In figure 6.10, the weather conditions were recorded as cloudy during the days where the
electric consumption is high (day 1-5, 6-13 and 23-25). On cloudy days, the electric
demand for water heating was approximately 2-5 kWh per one cubic meter of water. On
sunny days, electric consumption was average at 1-2 kWh per m3. This pattern of
electric/water and weather provide us a primary assumption that the solar fraction of the
system was approximately 80-90%.
System analysis
In order to analyze the solar system cost effectiveness, we use T-Sol software to simulate
system performance using Phuket weather data. The annual simulation result in shown
figure 6.11.
Figure 6.11 T-Sol® analysis of solar system in building#2 of Patong Merlin hotel
Results from simulation shows that the solar fraction is approximately 86% of hot water
demand. Although during rainy season, solar water heater is less efficient but the hot
75
water demand also reduced from lower occupancy during those months resulting in
relatively constant requirement for electric heater back up all year round.
A summary of the simulation results is shown in table 2. The solar system had save
electricity around 89,710 kWh/year and paid back its investment in the 6th year. Over 18
years of system operation, solar hot water has saved 1,195 Ton of CO2 emission.
Table 6.5 Summary of Patong Merlin simulation results
Results of annual simulation
System yield
Annual electricity consumption – pump
Annual electricity saving
Solar fraction
System efficiency
Economic analysis
Investment cost
Net present value
Pay back period
Cost of solar energy
Environmental benefit
GHG emission saving
76,254 kWh / year
6,867 kWh / year
89,710 kWh / year
85.9 %
37.0 %
960,000 Baht
2,337,545 Baht
6 years
0.9 Baht/kWh
66.37 Ton CO2 / year
Summary
The solar hot water system at Patong Merlin is an outstanding case of good installation
and maintenance that keep the system in operation for over 18 years. The system has
been a main supply for hot water demand for the hotel and paid back its investment in
just 6 years.
76
7
POTENTIAL OF SOLAR WATER HEATER
7.1 POTENTIAL APPLICATIONS FOR SOLAR THERMAL TECHNOLOGY
Since the Climax, the early generation of solar water heater, was patented and
commercialized in 1891 by Clarance Kemp in the US, solar thermal technology has been
improved by innovative design and development over the past 100 years. Nowadays,
solar thermal systems are not only producing hot water for home usages, newer
technology has allow solar thermal for variety of applications from simply hot shower to
industrial steam generation and absorption cooling . Many hot water demand applications
require temperature between 60-150°C which can be well served by reliable and cost
effective solar thermal technology available at present days.
Nowadays, there are more than 500 brands available worldwide, there are at least 15 solar
companies in Thailand operating with either imported or locally made collectors. While
imported collectors with a more advanced design and technology may have higher
efficiency, costs of the collectors are higher as well. Type of solar collector should be
selected in accordance with the desired working temperature and the climatic condition.
Table 7.1 Potential applications for solar thermal energy
Sectors
Residential
Commercial
Applications
50 - 60
Kitchen
50 - 60
Laundry
60 - 70
Shower, bathing
50 – 60
Kitchen
50 - 80
Laundry and steam iron
Industry
Temperature level (°c)
Shower, bathing
120
Food
60 – 150
Paper
90 – 180
Textile
< 90
Automobile
35 – 220
Since its first commercial application for home water heating in the past century, solar
water heater is still typically perceived as the technology for residential applications.
Most energy policy makers, industry and end-users, particularly in Small and Medium
Enterprises (SMEs) are not well aware of the potential of the solar thermal technologies
particularly in the industrial sector. Industrial processes such as washing, drying and
pre-heat feed water employ temperature at low-medium level. Industrial processes and
their temperature level which are applicable for solar technology are shown in Table 7.2.
77
Table 7.2 Temperature of industrial heat processes
Industry
Brewing and Malting
Milk industry
Food preservation
Processes
Temperature level (°C)
Wert boiling
100
Bottle washing
60
Cooling
90
Drying
60
Pasteurization
62 – 85
Sterilization
130 – 150
Sterilization
110 – 125
Pasteurization
< 80
Cooking
70 – 98
Scalding
95 – 100
Breaching
< 90
Beverage
Bottle washing
< 90
Textile industry
Washing, bleaching and dying
< 90
Automobile industry
Degreasing
Paper industry
35 – 55
Paint drying
160 - 220
Paper pulp: cooking
170 – 180
Boiler feed water
Bleaching
Drying
Source: Solar Heat for Industrial Processes, POSHIP
< 90
130 – 150
130 - 160
7.2 ENERGY SAVING POTENTIAL
Solar Water Heater technology can cover a significant fraction of energy consumption in
form of heat and electricity demand for hot water generation in residential, commercial
and industrial sectors. These 3 sectors represented 56.8% of the TFEC (Total Final
9
Energy Consumption) in 2005 . Trend of energy consumption in Figure 7.1 shows
slightly increase in the manufacturing sector over the year 2001-2005, while energy
consumption in residential and commercial sector remain relatively constant. As Thailand
is moving toward industrialization, energy consumption will unavoidably heighten in this
sector. While energy conservation measures as well as technologies such as high
efficiency machinery and cogeneration are being implemented for energy cost saving in
the industry, solar thermal technology can potentially further lower fuel cost in heat
generation.
9
Thailand Energy Situation 2005, Department of Alternative Energy Development and Efficiency
78
70,000
60,000
ktoe
50,000
Transportation
40,000
Commercial
Residential
30,000
20,000
Manufacturing
10,000
Agriculture
0
2001
2002
2003
2004
2005
Figure 7.1 Trends of final energy consumption by economic sector (DEDE 2005)
7.2.1 Energy Demand for Heat Generation in Low-Medium Temperature
Industrial Sector
Thailand classifies energy consumption in industry into 9 sub-sectors. The sub-sectors
that are identified as having potential for solar thermal applications are Food and
Beverage, Textile, Paper, and Chemical. These 4 sub-sectors constitute 48% (10,964
ktoe) of the total energy consumption in industrial sector (22,641 ktoe) in 2005.
ktoe
8000
7000
6000
5000
4000
3000
2000
1000
0
F
d
oo
d
an
ge
ra
e
v
Be
les
xti
e
T
d
oo
W
d
an
re
tu
ni
r
fu
r
pe
Pa
i ca
em
h
C
ic
al
al
al
et
et
et
m
M
m
d
te
s ic
nBa
ic a
No
r
b
Fa
l
rs
he
ot
Figure 7.2 Energy consumption in manufacturing sub-sector in 2005 (DEDE 2005)
In order to capture the potential of solar thermal in the industrial sector, it is necessary to
quantify the amount of heat demand in the processes. However, this is rather a
complicated analysis. Energy demand for each industrial sub-sector is determined
primarily by machinery equipment used for steam production, process heating, hour of
operation, and annual production. Unfortunately, Thailand has not had a detail statistic of
such valuable data that could be used to estimate potential energy saving in the industrial
79
heat process. This study conservatively estimated heat demand in the industry using only
the data of petroleum products consumed in each sub-sector.
Table 7.3 Fuel consumption of manufacturing sub-sector in 2005 (unit: ktoe)
Sub-sector
Food and
beverage
Textiles
Paper
Chemical
Wood and
Furniture
Non-metallic
Basic metal
Fabricated
metal
Others
Coal &
ITS
products
Petroleum
products
Natural
gas
Electricit
y
Total
New &
Renew
Energy
Grand
Total
28
43
444
809
728
344
195
481
84
8
469
794
655
176
790
1,634
1,050
815
2,549
4,719
197
6,353
1,050
815
2,746
5,173
162
46
267
339
1,089
-
128
596
548
174
7,125
1,049
18
448
-
192
7,573
1,049
96
6,755
156
1223
3,779
327
1,977
1,017
44
4,748
1,500
1,363
17,259
5,382
1,500
1,363
22,641
Among the 4 sub-sectors, food and beverage consumed highest amount of petroleum
products which is also accounted for 44% of its non-renewable fuel consumption. Total
petroleum products used in 4 sub-sectors is 1,748 ktoe. From DEDE data, the petroleum
products cover LPG, gasoline, jet fuel, kerosene, diesel, and fuel oil. Fuel oil is most
common used in the industrial hot water and steam generation.
Recent studies in several countries show a general tendency that about 50% of the
10
industrial heat demand is located in the temperature range 60-250°C . Assuming 50% of
fuel oil is used in generating heat at low-medium temperature, heat demand for the 4
industrial sub-sectors is estimated at 874 ktoe at this temperature level.
Commercial Sector
Potential uses of solar water heater in commercial sector are services requiring hot water
such as hotels, hospitals, apartments, condominiums, restaurants, laundry services,
schools, nurseries, sport clubs etc. Although, these sub-sectors are applicable for
utilization of solar energy, only hotels and hospitals are identified as having the most
potential for their continuous and large amount of hot water requiring for daily operation.
The ownership of solar systems and energy bill responsibility are also a key factor to
installing solar water heater. While hotels and hospitals responsible for their energy cost,
most of apartments and condominiums in Thailand have individual electric meter for
residences that are responsible for their electric bills. Therefore owner of these
10
Solar Heat for Industrial Processes, POSHIP
80
commercial buildings have less incentive in energy cost saving and installing of solar
water heater.
For hotels, the energy cost is estimated around 10-30% of the operating cost. The cost for
hot water generation is estimated at 5-10% of the energy cost for the hotels using LPG
boiler and 10-15% for hotels using electric heater. In 2004, there are 2,152 hotels in 9
most touristy provinces in Thailand. The average occupancy rate for these totaling
11
168,690 rooms is 52% .
Hospital hot water demand is similar to hotels, with hot water in patient rooms, laundry
and kitchen. In addition, hospitals may use hot water for sterilization of medical
equipments. In 2002, there are 1,293 hospitals in Thailand with a total of 134,453 patient
beds and 72% occupancy rate.
Table 7.4 Daily hot water demand in commercial sector
Commercial
sub-sector
Hotel
Hospital
Number
Rooms
% Occupancy
2,152
1,293
168,690
134,453
52
72
No. of room in
use
Total
87,719
96,806
184,525
Hot water
demand
(liter/day)
4,385,940
4,840,308
9,226,248
Table 7.4 shows a summary of room number of hotels and hospital and the estimated hot
water demand in these two commercial sub-sectors at 9,226,248 liters/day. The annual
energy demand for hot water generation is approximately 18.5 ktoe.
Residential Sector
Although the SolTherm-Thailand project mainly studied solar thermal market
development for commercial and industrial sectors, we acknowledged that the main
market of this technology in Thailand is still in the residential sector. Through our
interviews with solar companies, the residential sector shares approximately 50-60% of
their annual sales.
Most of hot water usage in residential sector is produced by electric water heater.
Although hot water is not a necessity for Thai households and mostly used by higher
income families, the low price of the products has led market expansion in this comfort
goods with annual sale at around 200,000 units in recent years. Many countries have
noted that electric water heaters contribute to energy demand in certain times of the day.
Some countries have initiated Demand Side Management (DSM) programs for electric
water heaters. Figure 7.3 shows daily electricity peak demand in Thailand during
2000-2004. Electricity demand rise up in the morning and drop during lunch hours before
peaking at around 14:00PM when air conditioners work at their full capacity to fight off
the afternoon heat. The second peaks of the day are observed during 19:00-20:00PM
11
Thailand in Figures 11th Edition 2005-2006, Alpha Research Co., Ltd.
81
which are mostly demand from residential sector. Although other appliances such as
televisions possibly had a role in this energy consumption, the electric water heaters
which consume much higher wattage should be responsible for this second peak demand
during early evening hours.
Figure 7.3 Daily peak demand of electricity in 2000 – 2004
With annual sale at 200,000 electric heaters, there are approximately 1.5 millions of these
heaters being used all over the country. Thailand has an average number of inhabitants at
3.4 per dwelling. Assuming each water heater is 4,500 Watt and operates 1.5 hour/day.
The electric consumption is 3,695 GWh/year (314 ktoe). In 2005, total electric
12
consumption in residential sector was 25,613 GWh . Energy conservation programs in
Thailand are mostly focus on air-conditioners and refrigerators. There should be an
energy conservation program for electric water heater which estimated consumption is up
to 14% of the total electricity in the residential sector and is a possible source of evening
peak demand.
Table 7.5 Energy demand in low-medium temperature
Energy demand in low-medium
temperature (ktoe)
Sectors
Residential
314
Commercial
18.5
Industrial
874
Total
1206.5
Table 7.5 Energy demand in low-medium temperature summarizes energy demand for
heat generation in residential, commercial and industrial sectors. The total demand of the
12
Electric Power in Thailand 2005, DEDE
82
3 sectors is estimated at 1,206 ktoe per year, a 1.9% of the total final energy consumption
in Thailand in 2005.
7.2.2 Potential of Solar Thermal Systems
Although solar thermal can technically be used for heat generation at low-medium
temperature, not all the heat demand can be replaced by solar energy. For example, solar
thermal systems require a sufficient space for installation of solar collectors. There are
also certain criteria for utilization of solar energy economically as described in chapter 5.
Economic is the major factor for the penetration of solar water heater to this fossil fuel
heat source application. The project’s market survey shows that a typical Thermosyphon
(2 m2 collector and a 160 liter tank) cost is approximately 50,000 Baht including
installation. Without financial incentive, return on investment of solar systems in
Thailand is varying between 3-8 years depending on type of fuel replacement and other
factors such as continuity of use. In general, return on investment is faster for replacing
electricity.
-
Residential sector: 5-6 years for replacing electric heater
Commercial sector: 3-5 years for replacing electric heater and
7-8 years for substituting LPG
Industrial sector:
4-8 years for substituting fuel oil
Pay back period influence customers’ decision in investing in the solar technology. In
general, residential customers are deterred by the high first cost and not fully aware of the
pay back time. Decision making for investing solar systems in commercial and industrial
sectors is more complicated and may need consultations and authorization from several
departments in the organizations. With longer pay back time and the complication
mentioned, market penetration for industrial sector is assumed only 10%.
Table 7.6 shows potential of energy saving in 3 sectors in replacing 3 sources of fuel.
With our visits to hotels and hospitals, we estimated that 30% are using electric water
heater and the rest of hotels and hospitals use LPG boilers.
Assuming market penetration of solar water heater are 20% for residential, 20% for
commercial and 10% for industrial sector, potential energy saving is 153.9 ktoe per year
in replacing 743 GWh of electricity, 2.1 million kg of LPG and 92,856 liter of fuel oil
which would require around 1,500,000 m2 of collector area.
Table 7.6 Potential of solar water heater
Sectors
Residential
Commercial
Industrial
Total
Energy
demand in
low-medium
temperature
(ktoe)
314
18.5
874
1206.5
%
penetrat
ion
20
20
10
Potential
of solar
hot water
(ktoe)
Electric
ity
(GWh)
LPG (kg)
62.8
3.7
87.4
153.9
730.36
12.91
2,158,333
743.27
2,158,333
Fuel oil
(liter)
92,856,232
92,856,232
Collector
area (m2)
608,637
22,872
847,052
1,478,561
83
7.3 MARKET POTENTIAL
7.3.1 Current market
The current market of solar water heater in Thailand is still considered a niche market.
Customers are mostly in the high income families, well educated and having energy and
environmental concern. Although there is a huge market potential in the industrial sector,
current market is still in the residential. Presently there are approximately 15-20 solar
companies, increased from 3-5 companies during the economic crisis in 1997. However,
less than 5 of the current active companies have enough experience and capable of
designing and installing large solar systems. This limitation has made many solar
companies aim their marketing to only residential sector while huge market in the
industrial sector remains untapped.
Residential
Residential
Commercial
Commercial
Industrial
Industrial
(a)
(b)
Figure 7.4 a. Potential market of SHW and b. Current market share
The SolTherm-Thailand project had made a survey for annual sales from 5 solar
companies whose make up majority of the market. The annual sell reportedly shows a
25% increase during the year 2005-2006. Extrapolating the annual sale to all of the active
companies, we estimated that the selling of solar water heater was around 6,800 m2 in
2005 and 8,500 m2 in 2006. It should be noted that some of the companies are newly
established and have just enter the market in 2006.
7.3.2 Market Growth
Thailand has no direct financial incentive for solar water heaters. Recent fuel price
escalation is the key factor to last year’s market growth. Energy and environment concern
alone can not drive the market to a substantiate level, economic soundness and policy
measures are required for market expansion.
The selling of solar water heater is not only depends on oil price, it is also tied to the
economic situation of the country. Although, solar water heater has a prospective of
energy cost saving, pay back period is not attractive enough particularly during the
economic downturn. Presently, Thailand is facing instability politic and economic
situation. Many businesses started using conservative measures for any investment during
this year. Selling of solar water heater in 2007 may not anticipate a 25% increase as in the
year 2006. We estimate an averaged solar thermal market growth at 10% per year.
84
There are several policies support to stimulate the solar thermal market being
implemented in many countries such as financial incentives, subsidy, grant for
demonstration, regulation, and awareness campaign. Solar thermal market in Thailand,
like some other countries, has suffered from bad reputation of the early installations.
Many potential customers are not aware of the newer technology or do not have enough
knowledge and information. The awareness campaign is the policy that requires less
amount of government budget and has a widespread impact on the market while financial
incentive policy can bring down the pay back period and make solar thermal system
attractive to potential users. If we set a target of solar thermal installation at 1,500,000 m2
within 10 years, this would require a 40% growth rate of the market. Figure 7.5 shows
market growth scenarios of solar thermal market for the current situation comparing with
growth under policy support.
1) Current growth (no policy support), 10%
2) Awareness campaign, 20%
3) Financial incentives + Awareness Campaign, 35%
4) Target, 40%
m2
Market Growth
20
06
20
07
20
08
20
09
20
10
20
11
20
12
20
13
20
14
20
15
20
16
2,000,000
1,800,000
1,600,000
1,400,000
1,200,000
1,000,000
800,000
600,000
400,000
200,000
0
Current 10%
AC 20%
AC+FI 35%
Target 40%
year
Figure 7.5 SHW market growth scenarios
If Thailand implements an awareness campaign policy continuously, solar thermal
market would reach 400,000 m2 in the next 10 years. However, in order to achieve the
target at 1,500,000 m2, a stronger policy support such as financial incentive in
combination of awareness campaign is needed.
85
7.4 CARBON EMISSION REDUCTION POTENTIAL
While solar thermal can potentially displace the need for other heating fuels and
contribute to the global climate protection, the technology is often overlook for its
simplicity and considered as low technology. These have underlying its benefit for local
economic in developing countries. Solar thermal collectors can be manufactured without
highly sophisticated or expensive manufacturing technology and use materials that are
locally available in many developing countries.
Today, while millions of dollars are being spent in research and development of
sophisticated alternative energy technologies globally, solar water heater – one of the
simplest and oldest renewable technology has just being acknowledge for its cost
effectively carbon emission reduction. The European Union, in realize of this huge
potential, has succeed its target of installing 15 million m2 of solar collector in 2003 and
13
is now setting a new target to complete 100 million m2 by 2010 .
In comparison to solar photovoltaic technology which has recently receiving promotion
from the Thai government, solar thermal technology investment cost is much lower for
the equivalent production of energy. For a typical home used SWH, a Thermosyphon
with 2 m2 of solar collector and 160 liter water storage tank, SHW produced
approximately 1.44 MWh per year. To produce the same amount of energy, it would
require a Photovoltaic system at a size of 790 Watt. Assuming both systems lifetime are
25 years, investment cost for reducing 1 ton of carbon emission for SHW is 6,882 Baht
while the PV system would require 22,735 Baht. Thus SHW can effectively reduce
carbon emission at a cost 3 times lower than PV technology.
Table 7.7 A comparison of investment cost and carbon emission avoided
Technology
System Size
Solar thermal
Solar PV
2 m2 - 160
liter
790 W
Annual
Energy
production
(MWh)
CO2
(ton/year)
CO2
(tonlifetime)
First cost
(Baht)
1.44
1.44
0.31968
0.31968
7.992
7.992
58,000
181,700
Baht/ton
7,257
22,735
The carbon emission avoided depends on the type of fuel source that would be used in
heating water. For residential sector, electricity is the most common use for water
heating. Thailand electricity has considerably lower emission as compare to countries
where electricity is produced by oil and coal. In 2005, 72.3% of electricity in Thailand is
produced by natural gas. However, in industrial sector where steam boilers are using
heavy fuel oil, the carbon emission can significantly be diminished by replacing fuel oil
with solar thermal energy. With the economical potential of 153.9 ktoe in replacing
electricity, LPG and fuel oil, Thailand can avoid 458,772 ton of CO2 per year, a 0.25% of
total carbon emission of the country in 2005.
13
Sun in Action II – A Solar Thermal Strategy for Europe, ESTIF
86
Table 7.8 Potential of carbon emission reduction from using solar thermal energy
Sectors
Residential
Commercial
Industrial
Total
Potential of
solar hot
water (ktoe)
62.8
3.7
87.4
153.9
Electricity
(GWh)
LPG (kg)
730.36
12.91
2,158,333
743.27
2,158,333
Fuel oil (liter)
92,856,232
92,856,232
CO2 emission
avoided
(Ton/year)
162,141
9,705
286,926
458,772
Carbon trading has become a promising financial opportunity for many renewable energy
projects. Although, Thailand has not yet adopted the Clean Development Mechanism
(CDM), this mechanism may be come eligible in the near future that will potentially
increase system affordability. At the present price of 5 dollars per ton of CO2, the solar
hot water would generate CER revenue approximately 80 million baht per year.
87
8
POLICY AND FRAMEWORK
8.1 INTERNATIONAL EXPERIENCES
The policy in the European countries is forced by the common European goals in saving
primary energy and thus on the development of renewable energies. One of the goals of
the European Commission, expressed in the ‘White Paper’ 10 years ago, is to reach 100
million m² of installed solar thermal collectors by 2010.
The European goals have directly influenced the past and current European Framework
programmes for funding of research and demonstration projects in the field of renewable
energy application.
Other driving sources for national policies are to meet the obligations of the Kyotoprotocol or of the results from the recent European Council meeting, to increase the share
of renewable energies in primary energy consumption in the European countries to 20%
until 202014.
To achieve the objectives, it is essential, to develop mechanisms for a broad market
dissemination of solar thermal systems. Mainly, this is done by implementing funding
schemes or implementing building codes with the obligation, using renewable energy
sources, or a combination of both.
The transmission of the targets into the policy of the member countries is done with
different instruments and with different intensity, thus leading to different growth rates of
e.g. solar thermal installations. The success of the measures, expressed in installed
capacity and on the national shares on the installed capacities, is visualized in the
Figures 8.1 to 8.3, all extracted from the ESTIF15 home.
ESTIF has also promoted a Solar Thermal Action Plan for Europe, outlining different
targets and measures for the growth of solar thermal applications in Europe until 202016.
Examples of strategies in European countries17
I Greece
Still, Greece shows one of the strongest market developments of solar thermal
systems. Nearly all installed systems are simple thermo-syphon systems (average
size: 2.4 m² collector area and 150 l storage size). In between, approx. 25% of the
households dispose of a solar hot water system, thus covering 80% to 90% of the
hot water demand by solar energy.
14
Press release of the German Federal Ministry for the Environment, Nature Conservation and Nuclear
Safety of March 09,2007, www.bmu.de/english/aktuell/4152.php
15
16
17
ESTIF: European Solar Thermal Industry Federation, www.estif.org
Solar Thermal Action Plan for Europe, www.estif.org/281.0.html
Details of funding policies in European countries are taken e.g. from the study ‘Internationale
Erfahrungen mit der Förderung von Solarkollektoren zur Warmwasserbereitung auf Haushaltsebene’,
prepared on behalf of German Society for technical co-operation (GTZ), June 2006. Download from
www.gtz.de/de/praxis/12538.htm
88
One of the most important measures, which led to the impressive market growth,
were tax reduction programmes for an indirect subsidy for private households in
case of the implementation of a solar hot water system. The effective funding of the
system due to this measure was estimated in the range of 30% to 40% of the system
investment cost. These tax incentives started in 1978 and lasted – with an
interruption of a few years – until the end of 2002. The transaction of the
programme was simple, although the disadvantage was that the households had first
to pre-finance the systems by 100%, before the reimbursement was effective.
The programme was accompanied by an intensive information campaign, organised
by the Greek solar industry, including also the dissemination of TV spots. For a
more effective marketing, also a co-operation with a large utility was started.
In between, national quality standards have been established and most of the
products seem to correspond to the standards, although they have more the
character of recommendations. Due to an originally lack of qualified installation
personnel, large solar thermal companies have established own installation and
maintenance services.
Although after the ends of the tax incentive programme no further public funding is
currently available, the growth seems to have stabilized (annual growth in 2004:
still 34%). In this context, the Greek market may be described in between as selfsupporting.
II Germany
One of the German goals in environmental policy is the increase of the share of
renewable energies on the total primary energy demand to 4.2% by 2010 (50% by
2050).
Dominating solar thermal technology in Germany are closed forced loop solar
thermal systems with 4 to 6 m² collector area and a buffer storage of 300 l, but more
complex designed systems allowing space heating support have a rising market
share. Although the utilization of solar thermal installations started after 1973,
regular funding schemes have been established first in 1995.
The main important instrument currently is a market stimulation programme, which
awards direct investment grants for small private solar thermal systems. The
funding directives have been modified for several times, causing casually a strong
fluctuation in the number of requested funds.
Since 2007, the new conditions (with decreased funding rates) for funding of
systems with a collector area < 40 m² are as follows:
- the apply for funds has to be done after the installation of the system; the readyto-operate status has to be proved (apply for funds at least 6 month after the
installation);
- for systems with domestic hot water preparation, the investment grant is 40 ¼ per
m² gross collector area;
89
- for systems with additional heating support, for process heat or for solar thermal
cooling application, the investment grant is 70 ¼ per m² gross collector area;
- new solar thermal collectors, being tested and approved in 2007, have to be
labeled with the Solar Keymark, to be accepted for funding. Other collectors have
to be certified according to EN12975 Standard.
For systems with collector areas > 40 m², or for innovative systems applying new
components or concepts, increased subsidies are possible and generally awarded in
terms of a perceptual grant to the solar system investment cost (e.g., 30%).
Furthermore, investment grants may be given for large pilot and demonstration
plants within the funding programme SolarThermie2000plus for systems with
collector areas above 100 m² and for specified applications (solar heating support,
process heat, district heat support, solar cooling). The financial support is given
here in a range between 30% and 50% of the solar system investment cost.
Beside the requirements on the quality of the collector (according to EN 12975 or
Solar Keymark), no further requirements on the planning and installation exist.
Nevertheless, the system quality is high in between due to in general well trained
installers.
Beside some ‘normal’ information activities (information at the web sites of the
funding agencies, ministries, etc.), the information on the funding possibilities is
mainly spread by the installation and planning companies. The successes of the
participation on the funding programmes are moreover due to a comparatively high
public awareness on the use of environmentally friendly technologies. Additionally,
existing strong non-governmental organisations play an important role in the
dissemination of funding possibilities.
The system standard in Germany is high for different reasons: danger of freezing,
anti-legion Ella regulations required high system efficiency and large systems due
to comparatively low radiation amounts, etc. This leads in the sum to comparatively
high system cost of still approx. 700 ¼ per m² collector area, although the costs are
slowly decreasing. For this reason, the market in Germany is not as self-supporting
as the Greek market is still sensitive to funding programmes.
III France
Renewable energy (with the exception of hydro power) was for long years an
unattended energy source in France. A reason for this fact is the still very strong
nuclear power industry in France. The situation changed some years ago with the
installation of national funding schemes, which includes also mechanisms for
funding of solar thermal systems.
The most important funding mechanism is the ‘Plan Soleil’, which started in 2000
and runs until at least 2008. The plan comprises funding for private solar thermal
domestic hot water preparation and for large solar thermal installations at apartment
buildings, hospitals, hotels, etc. The intention is to increase the annual growth rate
to 200,000 m² by 2010, leading to a cumulated collector area of 1,000,000 m² by
90
2010. The funding programme is co-coordinated by ADEME, the French
Environment and Energy Management Agency.
The funding scheme of Plan Soleil was modified in the last years. In the first years
of the Plan, a flat rate of total 900 ¼ was given for solar domestic hot water systems.
Since 2003, the funding was connected to the size of the systems: a flat rate of
690 ¼ for systems up to 3 m² collector size, 920 ¼ for systems between 3 m² and
5 m², and 1150 ¼ for systems between 5 m² and 7 m² collector area. Since 2005, the
subsidy was modified from direct grants to indirect subsidies in terms of tax
reduction.
The funding scheme is mainly oriented on the funding of systems for private
households, but Plan Soleil also includes funding measures for public and
commercial applications (with reduced subsidies).
Information campaigns to disseminate the programme were mainly organized by
ADEME in terms of advertisement activities in papers and TV, but also national
manufacturers share in the campaigns.
In comparison to the programmes in other European countries, a remarkable focus
in France was directed to quality assurance measures. The funded systems are
allowed to be installed by installers only, who participated a special solar thermal
qualification programme ‘Qualisol’, a central component of the ADEME
dissemination strategy. It is reported that by the end of 2005, more than 9000
installers were already qualified.
Additionally, only collectors certified by the national test institute CSTB (Scientific
and Technical Centre for Building), are accepted for funding. The certification is
done on base of the European Standards and on additional national requirements.
Although the share of the French solar thermal market on the total European market
is currently small, the growth rate is very high (more than 100% annually) and the
market development is promising since the introduction of the funding schemes.
The average system size of a solar domestic hot water system is approx. 4.5 m²
collector area with a storage size of 250 l, normally installed as closed forced systems.
The experience with the qualification measures seems to be very positive as well
and broad frustration due to low-quality installations could be avoided. Consequently, the French approach may be exemplary for countries with low general
planning and installation experience in solar thermal systems.
IV Spain
Until the year 2000, solar thermal systems were nearly not installed in Spain.
National goals, formulated in 2000, to have at least 12% of the total consumed
energy by 2010 provided by renewable energies, has brought considerable
movement in the development of all kinds of renewable energy sources. Concerning
solar thermal energy, the national target is to achieve in 2010 a cumulated solar
thermal collector area of 4,900,000 m².
91
Of large importance in the development of the solar thermal market were municipal
policy laws and obligations for the construction of new buildings, to install solar
thermal systems for domestic hot water preparation with a defined coverage rate of
the hot water. Those installation obligations were created first in Barcelona (in force
since 2000) as a first obligation of this type in Europe.
In Barcelona, the target is to have with this measure 90,000 m² of solar thermal
collector area installed by 2010. The energy demand for domestic hot water
preparation in new buildings has to be covered to at least 60% by solar thermal (for
buildings with a daily hot water consumption above 2000 l, thus apartment
buildings, etc.). Additional obligations exist for commercial buildings and other
applications (e.g., heat demand for swimming pools has to be covered to 100% by
solar thermal). As a consequence, approx. 40% of new buildings are equipped with
a solar hot water system.
The applied collectors have to be certified, installers have to prove their installer
qualification.
Due to the obligation, the installed collector area in Barcelona increased from
1.1 m² per 1000 capita in 2000 to 16.4 m² per 1000 capita in 2004.
The Barcelona model was copied by other cities, like Madrid and Sevilla. Since the
end of 2006, the new Technical Building Code CTE includes similar obligations on
the installation of solar thermal systems at new buildings, now valid on a national
level for whole Spain. The solar thermal obligations in the new CTE require
coverage of domestic hot water demand by solar thermal hot water production in
the range between 30%-70%, depending on the hot water demand and on the
position of the building18.
It is interesting that the regional and national obligations for solar thermal in Spain
are not connected to any funding scheme.
In between, the neighbour country Portugal has brought a new building code with
similar solar thermal obligations into force as well.
The set-up of solar thermal obligations in countries with only little existing infrastructure in manufactures, knowledge distribution to the users, solar system
knowledge of planners and installers, and only small solar thermal organizations,
active in the promotion of solar thermal application, may conflict with the quality of
the installed systems. Many of the building owners never had the intention before,
to install a solar thermal system, but now they are obliged, without being convinced
on the benefits of a solar thermal system. Consequently, the impulse to install
lowest-cost systems only is high. If an obligation programme does not include well
balanced quality assurance measures, improvements in the system quality are small
and not necessarily connected to the increased number of systems. Thus, a certain
risk of broad frustration with solar thermal systems exists. The near future will
show the experience with the Spanish model. However, a long-term positive effect
18
More details on the CTE in Spain may be found ant www.estif.org/262.0.html
92
of solar thermal obligations is observed in Israel, where a solar obligation is in force
since 1980, accompanied with strong quality assurance measures. In between, this
policy has brought Israel to the world leader in solar thermal usage. Although the
saturation is theoretically nearly reached, the market is still high due to retrofitting
and replacement of old systems.
Figure 8.1 Solar thermal market in Europe: Cumulated capacity in operation (red line, right axis)
and annual growth (white line, left axis). In 2005, the cumulated capacity in operation was approx.
11000 MWth, with a growth in 2005 of approx. 1500 MWth.
Source: ESTIF.
93
Figure 8.2 Share of the annual growth in 2005 (approx. 1500 MWth) by country.
Source: ESTIF.
Figure 8.3 Share of the cumulated capacity in operation in 2005 by country and per 1000 capita.
Source: ESTIF.
94
Israel
Greece
Austria
Germany
China
Spain
Italy
France
Belgium
England
Finland
Thailand
Note: I = Industrial
R = Residential
x
x (I)
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x (R)
X (R)
x
x
x
x
x
x
x
x
x
x
Awareness
Campaign
R&D
Regulation
Quality Assurance
Financial Incentive
Subsidy
Grant
demonstration
Collector area/
head
2
(m / 1000 capita)
Country
Table 8.1 Summary of policy measures for SHW implemented in several countries.
x
x
x
x
x
x
x
8.2 POLICY MEASURES TO ACCELERATE THE MARKET GROWTH OF SOLAR THERMAL
APPLICATIONS
Like many other renewable energy technologies, solar thermal is still not widely adopted
that make the cost of technology relatively high as compare to conventional technology.
In order to stimulate the market growth, commitments are needed at the national or to the
global level. The Kyoto Protocol is one example of the global commitment for
greenhouse gas reduction that has triggered renewable energy policy in many countries.
Commitments should be set as a practical target goal that can be achieved within a certain
time frame. The European Commission’s target of 15 million m2 installed by 2003 has
been reached with its Campaign for Take-Off. The new target is now set at an ambitious
goal of 100 million m2 installed by 2010.
With the economic potential of solar thermal applications in Thailand as analyzed in
chapter 7, a target at 1.5 m2 million within 10 years will require 40% of the market
growth. This target may be ambitious, however, achievable based on the European
experience that the market volume was doubled by the results of strong political support
and continuous effort of the industry.
95
The policy measures that have been effectively utilized to stimulate solar thermal market
in European countries and worldwide are given below:
Policy measures
Description
Financial incentives can be
Financial
- Subsidy
incentives
- Rebate program
- Tax incentives (i.e. tax credit, tax exemption)
- Soft loan
These schemes can help bring down the high investment cost that has
been the major barrier. Among these incentives, subsidy scheme tends
to have most impact on customers’ decision. Greece’s success
installation of solar thermal exemplifies the influence of subsidy in
bringing renewable technology to public acceptance. Tax incentives
require more paper work and time from customers. In the US, the
states of Oregon and California have tax credit and tax rebate
programs for solar thermal systems. The programs have helped
increase the market volume, however, not as high as the subsidy.
Laws or regulation that require or enforce installation of solar thermal
Regulations
systems, from international experiences, are only applied to residential
sector. Israel’s building code requires that residential building higher
than 27 meter have solar thermal for its hot water supply. Some other
countries and cities may require solar thermal for new buildings. This
mandatory measure can effectively increase the installation, however,
may not applicable for Thailand.
Quality assurance can be tied to financial incentives and other
Quality
measures to prevent feud in subsidy scheme and help market growth
assurance
with assurance that systems will function and perform through their
life time. Quality assurance can be voluntary and mandatory.
- Capacity training and qualification of manufacturers, planners
and installers;
- Service and warranty on component and installation level;
- Evaluation of monitored systems, evaluation of funding
programmes
- Agreement on Standards of solar thermal components;
- Establishment of approved national test centers for the
certification of solar thermal system components;
- Responsibility of a national certification body for the approval of
national test centers;
Demonstration programs are mostly used for technologies that are
Demonstration
new or not well known in the market. The measure often provide grant
to demonstrate use of the technology.
R&D is available in many countries through national research grant.
Research and
Most research in solar thermal technology aims at improving quality
Development
and efficiency of products.
(R&D)
Awareness campaigns mainly addressed to the end-user. Beside all
Awareness
96
campaigns
other measures of awareness campaign, clear contacts should be
established (hot lines, web pages, etc.) to provide actual information
on funding schemes, conditions, and quality measures.
Below outline some experiences in Thailand and other countries for each policy measure.
8.2.1 National commitments
As a backbone for any national effort to increase the solar thermal market, national
compulsory targets on the use of renewable energies should be defined. Department of
Alternative Energy Development and Efficiency (DEDE) has responsibility for energy
efficiency promotion, energy conservation regulation, energy sources provision,
alternative development of integrated energy uses, energy technology dissemination in
systematic and continuous proceeding to adequately respond the demand from every
sector at optimal costs beneficial to the country development and the people better living
standard. For the renewable energy DEDE supports solar energy, wind energy, Biomass
energy, water energy, and hydrogen energy. Unfortunately they focused on the solar PV
which refers to DEDE solar energy system 8 projects are the solar PV. In many European
countries, such compulsory targets have turned out as a driving source to install funding
schemes for renewable energy applications, independent of the fact that some of the
targets seem to be too ambitious from the traditional energy sectors point of view.
8.2.2 Quality assurance
Before launching broad funding schemes for the market stimulation of solar thermal
systems, quality assurance measures have to be elaborated. Different levels are
addressed:
-
Standards and certification
Here, the ‘players’ are to be identified (national certification body, test institutes) and
national test standards for collectors and systems have to be defined. National
manufacturers should be involved into this identification process. It is essential for a
reliable operation of a test center that a more continuous flow of component testing can
be expected. This enables the test center, to recognize and to assess the quality of the
products, applied in the installed systems and available on the market. Imported
components should fulfill the defined Standards as well. To elaborate test centers and
Standards, a broad understanding of the involved partners on the required Standards and
on the number and distribution of test centers is required. The role of an approved test
center is briefly shown in Figure 8.4.
97
End-user
End-user
Nat ional f unding
programmes,
law s, ...
Accept ed f or
applicat ion
cert if icat ion
& labelling
Solar
SolarThermal
Thermal
Indust
Industry
ry
inspect ion
product
Independent
Independent
Test
Test Cent
Centre
re
Nat
National
ional
Cert
Certifificat
ication
ion
Body
Body
St andards and
Test Condit ions
Figure 8.4 The independent Test Centre plays a central role in the quality chain of solar thermal
installations.
- Quality conditions of a funding scheme
A funding scheme should be connected with quality measures. Usually, grants are given
to systems where certified collectors according to the national valid Standards are
applied.
Additionally, as in the French funding schemes, it seems necessary to link grants only to
systems, installed by special certified installers. Thus, a further pre-condition for
launching a funding programme is the definition and execution of training courses for
installers. These trainings may be defined and executed by the standardization and
certification group and the involved local manufacturers.
Generic system schemes should be elaborated for the funded systems in order to obtain a
minimum level of system quality. This may be also a task of the established test centers
or of the connected research facilities in close collaboration with the manufacturers.
A funding programme should additionally include evaluation measures, applied after a
defined running period. A certain set of parameters, allowing the assessment of the
success of such a programme, may be determined. These measures range from simple
energy demand assessments (water and electricity or auxiliary energy bills before the
installation and in the first years after the installation) to inspection and service reports,
assessment on the users satisfaction with the system, to more advanced energy supply
assessments carried out in a number of selected monitored systems (equipped with energy
meters, etc.).
98
-
Installers of solar thermal systems should be obliged to give warranty and to offer
service contracts. Moreover, a clear operation handbook should be provided to the
user / operator.
For large systems, a commissioning phase should be launched after the installation of
the system. The contract should contain guaranteed yields for the system, depending
on the annual radiation sum only.
8.2.3 Financial incentives
National funding programmes seem to be an adequate measure, to combine both, market
growth and a certain quality level of the installation together with accompanying quality
assurance measures.
Which funding scheme is preferred, depends strongly on national customs. For small
private solar home systems, a funding scheme according to the former French model of a
flat rate, i.e., a fixed investment grant per system may be an adequate simple model,
which avoids the barrier of a pre-financing of the system for low-income users. For larger
systems, funding schemes related to the type or size may be more appropriate, either
given as specific direct investment grant or as indirect grants through tax reduction. It is
also conceivable, to connect the funding with a certain support of local manufacturers,
such as small, well-balanced higher grants for national products.
Moreover, funding schemes should be connected with some kind of evaluation of the
funding programme after some years, in order to assess the achieved quality of the
installations, the environmental benefits, the market development and the market position
of local manufacturers. According to the results of the evaluation, the funding scheme
may be extended for another period and / or modified, to direct the outcome of the
programme towards the originally defined goals.
Funding scheme periods should not be defined too short. A funding programme running
only for two or three years will not really mobilize the manufacturers to do strategic
investments on solar thermal. Moreover, the confidence of the user into such a
programme is smaller, as it appears with a short running time not as an important policy
measure. An appropriate running period of a funding programme may be e.g. approx. five
years, with the option of extension after a positive evaluation.
Recommendations on funding schemes:
-
Small sized thermo-syphon systems, using system components, certified by the
national test facilities. An investment grant is given as a flat rate. Programme
duration: 5 years, followed by an evaluation process and with the possibility of
programmed extension. At least 5000 systems should be funded within the first five
years.
-
Medium sized forced solar hot water systems (< 20 m² collector area) for apartment
buildings, etc. An investment grant is given as a flat rate for two different sizes of the
system. Programme duration: 5 years, followed by an evaluation process and with the
possibility of programme extension. At least 500 systems should be funded within the
first five years.
99
-
Large size forced solar hot water systems (> 20 m² collector area) for apartment
buildings and for commercial applications. Investment grants are related to the size of
the system, either as direct grant or indirect through tax reductions. Programme
duration: 5 years, followed by an evaluation process and with the possibility of
programme extension. At least 100 systems should be funded within the first five
years.
8.2.4 Regulations
This instrument has to be considered with care. In the context with the general
installation quality of solar thermal plants as observed during the site visits, a compulsory
installation of solar thermal systems at new buildings may be too early with respect to the
limited knowledge distribution in Thailand. The risk of a large scale distribution of nonoptimized systems, or, even more critical, of not properly working systems is high.
Thus, if desired, obligations on solar thermal system installations may be restricted to
certain types of new or renewed buildings, such as hospitals or public buildings.
8.2.5 Awareness campaign
It is important, to accompany the programs with awareness campaigns, mainly addressed
to the end-user. At least, they have to obtain a certain level of understanding and of the
benefits of a solar hot water system. Central information sources are to be established,
such as well-maintained web pages, providing actual details on solar system technology
and on funding possibilities. A hot line or similar contact possibility should be accessible
to users, in case their system installer is no longer on the market available.
Additionally, general information and training units may be established for architects,
consultancies, planners and installers, but also for policy makers, focusing on the
potential of solar thermal systems, general applications and technology.
8.2.6 Demonstration programmes
A separate demonstration programme is valuable, to assist the market development of
solar thermal systems. More focusing on large scale systems, different technical
approaches may be demonstrated here, such as large commercial hot water preparation
for hotels and hospitals, or solar thermal process heat supply for industrial applications.
Other technologies may be demonstrated as well, such as solar cooling, etc. The systems
should be implemented into a running commercial application in order to demonstrate
their full applicability. Latest system technology should be applied here with focus on
optimized system control for high solar energy gains and on high system reliability. A
transfer of the system results to industry and target user groups should be mandatory.
Again, a central web page for the dissemination of the programme status and of the
results is important.
Recommendations on funding schemes:
100
Within programme duration of five years, 25 high quality systems should be installed to
demonstrate the solar thermal use in the different application sectors.
8.2.7 R&D
Parallel R&D activities should be funded on base of qualified proposals. The objective is
to encourage Thai research groups and companies to share on the development and
improvement of solar thermal concepts, system components and control equipment.
Components and strategies developed here may be demonstrated within the
demonstration programme.
The above mentioned measures are necessary, to reach a critical mass in the solar thermal
market for a self-perpetuating growth, as it is shown in Figure 8.5, again extracted from
ESTIF’s Solar Thermal Action Plan for Europe.
Figure 8.5 Self-perpetuationg positive and negative market development.
Source: ESTIF.
8.3 RECOMMENDED POLICY AND FRAMEWORK
Based on international experiences and current situation of solar thermal in Thailand, 4
policy measures are recommended to stimulate the market growth: quality assurance,
financial incentives, awareness campaign and demonstration. These measures should be
implemented simultaneously particularly the quality assurance measure that should be
implemented along with other measures.
101
Quality assurance addresses to the most important and urgent issue of solar thermal in
Thailand. It is the starting point to build a firm foundation for a sustainable market
growth. National standards and test center may require a high level of commitment from
the government. Measures that can have immediate and direct respond to the needs of the
industry are capacity training and qualification of manufacturers, planners and installers.
Therefore, capacity building is recommended for Thailand’s first step to quality
assurance. However, this also requires a monitoring and evaluation scheme to verify the
effectiveness of measures. Trainees are needed to be tested before they can become
certified planners or installers and the solar systems that are design and installed by the
certified installers should be monitored and checked.
Financial incentives such as subsidy and tax credit can stimulate the market growth
particularly during the early stage. Thailand has some form of subsidy in the past,
however, only to a limited number of systems and in a short period of time. Without
national awareness campaign, the subsidy program had only a small impact on solar
thermal market in Thailand. This incentives measure is recommended for Thailand only
in combination with quality assurance to ensure that only quality systems are installed.
Awareness campaign and demonstration programs are measure that address barriers from
the customer side. Based on our interview, many of potential customers are not aware of
the technology. Some can not differentiate the two solar technologies; solar Photovoltaic
and solar thermal. Awareness campaign is recommended not only to raise the awareness
of technological potential; it can address the quality issue by providing customers with
un-bias guidelines for a selection of quality suppliers.
102
Table 8.2 Recommended policy measures for sustainable development of solar thermal in Thailand
Policy measures
1. Quality assurance
2. Financial
incentives
Barriers
Technical
Nontechnical
3. Awareness
campaign
Nontechnical
4. Demonstration
Nontechnical
Addressed problems
- Substandard quality of
materials
Measures / Schemes
- Training for manufacturers
- Improper design and sizing
- Lack of maintenance
- Training for system designers
- Training for installers
- Training for users
- High investment cost
- Long pay back period
- Subsidy for investment cost.
- Unaware of cost effective
energy saving potential
– Misconception of the
technology
- Unaware of technological
potential
- Tax incentives i.e. credit for
income tax, corporate tax
- Tax exemption i.e. import
duty, VAT
- Awareness campaign through
advertisements and other
media.
- Demonstrations of solar hot
water systems in different
applications
Monitoring and evaluation
- National standards and
testing for system
components
- Certified system planner
- Certified installers
- Monitoring of system
performance
- Monitoring of market
growth rate
growth rate
growth rate
- Poll and questionnaire
- Poll and questionnaire
103
9
CONCLUSION
The SolTherm-Thailand project with objectives to analyze and to understand the current
situation of the solar water heater market in Thailand and factors that curtail large scale
replications of Solar Water Heating (SWH) applications particularly in the commercial
and industrial sector was successfully implemented by JGSEE, IIEC and ISE from April
2006 to March 2007. Reviews and assessments undertaken by the project activities
during the course of project implementation produce valuable findings and results
necessary to development of the Solar Thermal market in Thailand.
Although each section of the report as well as the Executive Summary already outline
findings and results of the project activities, this conclusion section provide an additional
summary of key findings and recommendations necessary to improve the situation for the
application of solar water heaters in Thailand and to lead to a steadily sustainable future
growth. The following main conclusions are drawn and listed based on priority of
implementation to overcome the current market situation:
1. Quality improvement in planning, installation and maintenance for solar water
systems are urgently required to improve image, reliability and economics of the
systems.
2. Introduction of standards and their application needs to be made mandatory to
ensure quality of the systems installed.
3. Public awareness campaigns are necessary to inform public about benefits
4. Selected demonstration activities that verify savings and usefulness of solar
thermal systems need to be carried out to improve image and confirm pay back
periods.
5. A long term financial support scheme, either through tax credits, investment
subsidies or other tools shall be introduced to accelerate the market growth and to
support a decreasing specific installation costs that are currently hampering the
wider application of solar thermal systems in Thailand.
6. Finally a political signal of long term commitment to support and to develop the
solar thermal market is necessary to encourage more companies to enter into the
market.
104
APPENDIX
A. TRIP REPORTS
SITE VISIT SUMMARY IN CHIANG MAI DURING 31/08/06 - 01/09/06
CHAING MAI GATE HOTEL
http://www.chiangmai-online.com/cmgate/
Specification of the SHWs
- Collector brand: no brand
- No of collectors: 54 panels
- Auxiliary heat: electric heater
- Energy consumption monitoring: watt-hour meter (Fig.8)
- For washing or other purpose: they used LPG (Figs.13 and14)
Problems found
- The sheet metal of storage tank corroded.
- Installation the system was not correct.
- The insulation on pipes and storage tanks came off.
- The pipes rusted.
- Condensation on the inner cover of the collector as a result of leakage of water
into the collector.
- No exact record data of energy consumption on producinghot water even if there
is a watt-hour meter
- No expertise technician in charge of the SHWs
TARIN HOTEL
http://www.asiatravel.com/thailand/tarin/index.html
Specification of the SHWs
- Collector brand : Solahart
- Auxiliary heat: LPG-boiler
- No. of collectors: 54 panels
Problems found
- The cover glasses of some panels broke.
- The insulation wrapped up the pipes came off.
- The inlet water pipe of collector was bended.
- Hot water was leaking from the fittings.
- No expertise technician in charge of the SHWs
CHAING MAI UNIVERSITY
Dr. Pitchaya kindly informed to SolTherm team about the possibility of using SHWs in
food process and the market of solar collector in Chaing Mai as follows.
In food science, hot water is used in the parboiling process (65-80 oC) in order to restrain
the enzyme. In addition to use of hot water in drying process (60-70 oC), it is also used in
producing of cider (100 oC). Canned food industry should have a good potential to use
SHWs.
105
In Chaing Mai, evacuated tube solar collector made in China is now sold in the
supermarket. The price per set for 20 tubes with a capacity of 165 liter is 39,000 baht (vat
included) and for 24 tubes with a capacity of 200 liter is 49,000 baht.
Prof. Dr. Tanongkiat Kiatsiriroat presented his research works on the solar thermal
systems to SolTherm team. There is a test rig of testing the performance of solar collector
at his laboratory. The test is performed according to ASHRAE standard.
VISIT SUPPLIER: SUNPOWER-ASIA COMPANY
http://www.sunpower-asia.com
Mr. Eithan Frankental the company owner expressed his kindness in welcoming
SolTherm team. The company specializes in selling and marketing in SHWs. Almost all
the components are imported from Israel. Sunpower designs the system according to
customer demand using monogram in couple with the product manual.
From his experience, he comments on the problems of market development of SHWs as
follows.
- Some users do not understand how the SHWs works
- Some manufacturers in Thailand lack of knowledge in installing the system
- After service is necessary for this business.
- Image of SHWs in the last decade was bad because the system failed.
- Tax between SHWs and PV is different.
SITE VISIT SUMMARY IN BANGKOK NAKORN PRATHOM NAKORN RATCHASIMA AND
SARA BURI DURING 02/10/06 - 04/02/06
MONDAY, 2 OCTOBER
x
Dusit Thani Hotel, Bangkok
Visit: SWH system
x
Saint Louis Hospital
Visit: SWH system
TUESDAY, 3 OCTOBER
x
River Hotel, Nakorn Prathom
SWH system
x
Whale Hotel, Nakorn Prathom
SWH system
WEDNESDAY, 4 OCTOBER
x
University Nakorn Ratchasima
Visit: SWH system
x
NEP, Nakorn Ratchasima; Jute Factory
Visit: SWH system
x
Thai Danish Dairy Farm and Training Centre, Muak Lek, Sara Buri
Discussion on solar thermal process heat support
106
SOLAR WATER HEATING SYSTEM AT DUSIT THANI HOTEL, BANGKOK
In operation
Since May 2006
Purpose of hot water preparation

Supply of hot water to 240 hotel rooms (showers, taps). The average occupation of the
rooms is approx. 80%

Water consumption related to a temperature level of 60°C was estimated in the
planning phase to 12000 liter/day
Collector system

Flat-Plate; type: HTU-SA from ARCON Solvarme, Denmark (imported)

Glass cover (structurised for reflection supressing)

150 m² collector gross area, divided into 12 large area modules, arranged in four rows

Specifications:
- Aluminium absorber with selective coating / copper pipes
- Rear side insulation: 75 mm mineral wool
- Collector dimensions: 2.27 x 5.96 x 0.14 m per unit (12.5 m²)

Ventilation hole

South oriented with a tilt angle estimated to 25°

No serious shading
System configuration

Primary collector circuit designed as closed loop; heat is transferred via a heat
exchanger to the storage circuit

The collector circuit is equipped with a heat sink loop to avoid stagnation temperature
(ventilation unit with heat rejection to ambient air). Currently, the heat sink is in
operation if the storage temperature exceeds 60°C and solar heat is still available

Two hot water storages of 5 m³ volume each connected in series in a horizontal
position, of which the first one is charged by solar thermal energy, and the second
storage may be charged additionally by an auxiliary boiler. This auxiliary heater is
operated with Heavy Fuel Oil (HFO).
Control

Central system control unit with temperature difference control for the collector
system;
single speed collector pump

The storage temperature is limited to approx. 60°C by the system control
107
Planning and sizing
The system was planned and sized by the company Consultants of Technology Co., Ltd.
(COT), Bangkok. For sizing, the solar thermal simulation software tool POLYSUN was
used. With the given size (limited due to financial reasons), it was estimated to save
28,000 liter HFO/a of the total required 300,000 liter HFO/a. Thus, a solar coverage of
the overall heat demand of ca. 9% is expected, corresponding to fuel savings in terms of
460,000 Baht/a.
A warranty of 5 years is given to the collector, and one year for the system. In the first
year of operation, the system is controlled for malfunction via the web-based monitoring
system installed by COT, which at least records the provided heat from the collector
(primary collector loop) and the heat delivered from the heat exchanger to the storage.
Overall appearance, problems occurred
Since the system is newly installed, up to now no corrosion or degradation problems can
be detected. The overall appearance is good: the installation is professional; the insulation
of pipes and of the (new) solar storage is sufficient and additionally protected by a
complete metal jacket.
It was reported that during clear sky days the heat sink is approximately for one hour per
day in operation. This situation should normally not arise in a system with 9% solar
coverage. It is recommended, to adjust the control settings in a way to avoid this function
as far as possible. It might be checked to allow storage temperatures higher than 60°C.
During the first months of operation, a leakage was detected and repaired in the collector
array
System cost
The overall system cost amount to 3.9 million Baht, but a grant of 1.6 million Baht was
given by the Danish DANIDA. The resulting investment thus finally was 2.3 million
Baht. Under the condition of the above mentioned savings, the static pay-back time is
approx. 5-6 years, maintenance not considered.
Summary of Dust Thani Solar Hot Water system
Compared to other visited system, some effort was put into the planning and sizing of the
system. A hydraulic sketch of the system is available, calculations on fuel saving and on
dimensioning of the system have been made before installing. The installation could be
therefore seen as a ‘reference’ for further system plannings.
Through the ongoing monitoring, valuable data of the plant operation may be achieved to
determine the real savings and long periods of non-properly working due to system
trouble can be avoided.
The operation data may contribute to a real performance data base of commercial solar
hot water system applications in Thailand.
A scheme of the system is shown in Figure 1.
108
Flat-plate
Collector
150 m²
Consumption
Heat
exchanger
2
1
5 m³
Heat sink
Supply grid
5 m³
Heat input
from oil
boiler
Circulation
Figure A1 Simplified scheme of the Dusit Thani solar hot water system. Hot water from the solar
thermal system is stored in storage no. 1, whereas auxiliary heat from the oil boiler serves storage 2 at
low storage temperatures. Extracted from the hydraulic plant scheme of COT.
SOLAR WATER HEATING SYSTEM AT SAINT LOUIS HOSPITAL, BANGKOK
In operation
Installed approximately 20 years ago, no longer in operation since 15 years

Hot water preparation in the Physical Treatment Department for patients, but the
treatment was stopped after a few years of system operation. Since then, the system is
no longer used

No consumption figures available
Collector system

Flat-Plate, glass cover, import from Israel

6 Collectors, total area approximately 12 m²

Two vertical positioned storages, total volume ca. 1 m³

Forced system
Overall appearance
The entire system shows heavily degradation through corrosion. The original idea of the
hospital staff to move the system for newly utilisation to another building of the hospital,
seems to be not efficient
109
Energy concept chilled water and hot water preparation of the St. Louis Hospital
In the course of the discussion of the energy concept some unfavourable current operation
of the chilled water system and of the heat pump system turned visible.
The chilled water system consists of four electrically driven compression chillers,
providing chilled water at a temperature level of 10°C or below. The chilling capacity of
each unit is 150 refrigeration tons (520 kW); 90% of the time is one unit in operation, for
10% of the time are two units running, with the other two units in reserve.
Additionally, two electrically driven heat pumps serve for hot water of approx. 58°C, fed
into a storage of 25 m³ volume. The driving source of the heat pump is cold water,
extracted from the chilled water distribution circuit, thereby operating the heat pump with
a broad temperature difference between condenser and evaporator of close to 50 K.
The electricity costs of the hospital amount to approx. 3 Mio. Baht per month.
It may be of advantage in terms of electricity and primary energy saving, to re-design the
hot water generation by e.g. using the temperature level of the heat-rejection of the chiller
(approx. at 35°C) as driving temperature source for the heat pumps, as from a theoretical
point of view the efficiency of a heat pump increases with increasing temperature level of
the driving source. In case of switched-off chillers, still ambient air may be used as heat
source. Through this modification, the temperature difference between the heat sink and
heat source temperature of the heat pump can be decreased to approx. 25 or 30 K. In
general, this decrease in temperature difference leads to a higher performance of the heat
pump. An example for this tendency is shown in figure 2.
Figure A2 Example: COP of a heat pump as function of the temperature difference 'T between
condenser and evaporator (COP = Coefficient of Performance = heat capacity / electricity input).
Figure extracted from the training unit ‘Siemens Building Technologies’. For a specific given type of
heat pump, the numbers of the COP may differ from the shown curve.
It could not be decided jet, which modifications will be necessary to the heat pump, when
operated with other heat source temperature levels. The benefit of such a modification
will be less electricity demand for the heat rejection system as well as less electricity
demand for the heat pump. Before modification of the system, a yield calculation to
determine the energetic benefit should be executed.
A sketch of the current configuration is given in the upper part of figure 3; the lower
sketch visualises the possible re-design with the following options of operation:
110
-
no operation of heat pump, but operation of chiller: cooling water is re-cooled via the
cooling tower (like current operation)
-
chiller and heat pump in operation: depending on the actual capacities, cooling water
from the chillers is complete or in part used as heat source for the heat pump via a
heat exchanger
-
heat pump is in operation only: ambient air may be used as driving source.
In case the hot water generation after this re-design is still not sufficient, further measures
like an additionally solar thermal hot water system may be discussed.
Heat rejection
Compression chiller
(520 kW/unit)
35°C
8°C
Cold
11°C
Heat pump
58°C
25 m³
electricity
Heat
Distribution
electricity
Heat rejection
Compression chiller
(520 kW/unit)
35°C
8°C
Cold
11°C
Heat pump
58°C
25 m³
Heat
Ambient
air
electricity
electricity
Distribution
Figure A3 Simplified scheme of the chilled water and heat supply system at Saint Louis Hospital,
Bangkok (upper figure). In the lower figure, a possible re-design of the system is shown.
The modification concerns the driving heat source, to which the heat pump is connected (dotted area
in the upper figure). The heat pump may be connected to the heat rejection circuit of the chiller or to
the ambient temperature level instead.
111
Summary of the heat supply system at Saint Louis Hospital
The re-activation of the existing solar hot water system is not really recommended, as the
system is in a high corroded state. Additionally, the supporting power of the small solar
plant would be vanishing in contrast to the capacity of the installed heat pumps.
It is recommended, to analyse the present configuration of the heat supply and chilled
water system with the existing heat pumps and chillers and to apply a performance
calculation in order to find an optimised system configuration which show benefits in
electricity and primary energy savings. The installation of a large solar heating system
could be than an additional measure.
SOLAR WATER HEATING SYSTEM AT RIVER HOTEL, NAKORN PRATHOM
In operation
System I:
installed more than 15 years ago
System II:

installed in 2006, ½ year in operation
The systems provide hot water for approx. 80 hotel rooms per system (two hotel
buildings). All rooms are equipped with shower and hot water tap. The average
occupation of the hotel is 60%

The desired hot water temperature for both systems is below 50°C

No hot water consumption data are available
Collector system I:
Flat-Plate; type: CHROMAGEN, Israel (imported)

Glass cover; quality not known

80 - 90 m² collector gross area

No specifications; collector frame and absorber probably aluminium

No ventilation hole

No serious shading

Configuration of system I
Open loop forced system; hot water for use is pumped through collector and storage

Two storage units mounted in horizontal position, total volume estimated to approx.
5 m³; storages are equipped with insulation and metal jacket

Arrangement of storages: storage 1 is charged by the solar system, storage 2 contains
the electric auxiliary heater (similar to storage interconnection shown in figure 1).
112

Control of system I
The collector pump is actually controlled by a timer, since the original temperature
difference control is out of function (no spare parts available). Hourly or two-hourly
start of the solar pump for a certain period during day

The electric heater operates through the control settings in a small band-gap between
39°C and 41°C.

Planning and sizing system I
No data
Overall appearance, problems occurred at system I
A few collectors are corroded inside, probably caused by penetration of humidity. Since
the collectors do not dispose of ventilation holes, humidity might have been accumulated
in the mineral wool insulation of the collector, thus leading to corrosion in a long term.
The majority of collectors were free of serious corrosion (as appears from outside
inspection).
The foam insulation of the collector pipes is degraded to large extent, as the insulation
was not protected by a metal jacket. Short collector connection parts have not been
insulated.
Several strings of the collector array show leakages at the interconnection part of the
collectors (internal leakages) and thus were shut off and not in operation. Roughly
estimated, up to 50% of the collector array was not in operation.
The pumps are direct placed on the roof area and not protected against weather
conditions.
After the break-down of the solar controller, the solar pump is operated by a timer. This is
supposed to be far away from an optimised system control.
Collector system II:
Flat-Plate; type: HERITAGE, model HS 200L
(not clear, whether imported or manufactured in Thailand)

4 mm glass cover; solar glass quality

70 m² collector gross area

Frame: aluminium; absorber: black copper

No ventilation hole

No serious shading
113

Configuration of system II

No air vent in the collector system

One storage unit mounted in horizontal position, volume estimated to approx. 4 m³;
storage is equipped with insulation and metal jacket

The storage contains an electric auxiliary heater

Control of system II
The collector pump is controlled by absolute temperature levels: the pump is activated
at a collector temperature > 48°C, and is switched off at temperature below 45°C

The electric heater is controlled in order to keep the storage temperature at 42°C.

Planning and sizing system II
No data; son of hotel manager decided to install the system
Overall appearance, problems occurred at system II
The system is in operation since 6 months up to now, thus the appearance of the
collectors is quite well. The collectors do not dispose of ventilation holes; in case of
humidity penetration internal corrosion may not be excluded in a long term (insulation
supposed to be mineral wool).
The collector pipes are covered with a thin foam insulation, not protected by a metal
jacket. Consequently, the foam already shows first marks of degradation.
The temperature sensor in the collector array is not properly positioned to monitor the real
collector output temperature.
The pumps are direct placed on the roof area and little protected against weather impact
only by the collector array.
No reports on serious system problems. No data available on expected or achieved
electricity savings; the system is checked mainly ‘optically’ (function check of control
board).
Service and maintenance of system II
Service by Heritage Co. is given for two times in intervals of two months after the
installation. From Heritage, some suggestions on the operation of the system were
provided, but no information on maintenance. No warrenty data available.
System cost
No data available on system cost and annual electricity cost for both systems.
114
Summary of River Hotel Solar Hot Water systems
Although most of the collectors in the first system (Chromagen) appear in a functioning
state, a considerable part of the collector array is shut off due to internal leakages,
pointing to a critical construction detail. Once water and humidity has entered the
collector through sealing problems, removal of the water is difficult and danger of
corrosion is high. This is valid for the new Heritage collector systems as well, although
there is yet no experience with the collector sealing.
The duct insulation of both collector arrays seems to be not sufficient. In the climatic
conditions of Thailand, a metal jacket protection of the insulated pipes may be
recommended in order to avoid early degradation of the insulation and the accordingly
heat losses.
Both systems do not dispose of air vents in the collector array. This complicates the
proper operation of pumps and lowers the collector efficiency, if air has entered the
collector circuit.
As a major problem appears to be the availability of spare parts in the system control,
such as temperature difference controllers. This is a barrier to an optimised energy gain
from the collector.
Possible improvements in both systems:
-
envelope for pipe insulation to increase the life time of the insulation and thus to
reduce heat losses
-
air vent in the collector array to simplify maintenance
-
improvement of collector control by implementation or re-activation of a temperature
difference control unit, using collector output temperature and lower storage
temperature
-
installation of electricity meter to monitor the electrical heater energy demand
-
regularly recording of electricity demand and hot water demand by the technician;
development of a guide for maintenance and system inspection
A scheme of the system is shown in Figure 4.
Feed storage
Flat-plate
Collector
70 m²
Consumption
Electricity
heater
4 m³
Supply
Circulation
Figure A4 Simplified scheme of the Heritage solar hot water system (solar system II) at the River
Hotel, Nakorn Prathom.
115
SOLAR WATER HEATING SYSTEM AT WHALE HOTEL, NAKORN PRATHOM
In operation
The hotel disposes of four different solar water heating systems, distributed at the roofs of
four different hotel buildings. The systems have been installed around 1987.

Each system provides hot water for the hotel rooms of the according building.
Example: system I with 32 collectors supplies hot water to 90 hotel rooms

Collectors:
Flat-Plate; type: LORDAN LSC-D, Israel (imported)

Glass cover; structures for low reflection losses; glass quality not known

Collector area varies between 70 m² and 95 m² for the four systems

No specifications; collector frame and absorber probably aluminium; insulation is
supposed to made of mineral wool

No ventilation hole

No serious shading

Configuration of the systems

Each system provides of two storage units mounted in horizontal position, total
volume per system is estimated to approx. 3-5 m³; storages are equipped with
insulation and metal jacket

Arrangement of the two storages per system: storage 1 is charged by the solar system,
storage 2 contains the electric auxiliary heater (similar to storage interconnection
shown in figure 1)

Air vent in the collector system

Control of the system
Functionality and settings of the control is not really clear

Planning and sizing
No data
116
Overall appearance, problems occurred at the systems
In the first of the visited systems, the storage insulation is completely degraded through
heavily corrosion of the steel jacket and disintegration of the foam insulation to a large
extent. In the other systems, the storage jacket was made of stainless steel.
For reasons of accessibility of the roofs, only the collectors of the first systems were
inspected (consisting of 32 collectors). The appearance of most of the collectors is
comparatively good with little signs of corrosion. A few collectors show clearly internal
corrosion of the absorber plate, caused by contents of humidity which could not be
removed from the collector.
The foam insulation of the collector pipes is part wise disintegrated, as they are not
protected by a jacket.
The pumps are likewise to other inspected systems mounted below the collector area
without any further protection against weather impact.
During the inspection, the collector was obviously in stagnation.
The control board is equipped with an electricity meter for the auxiliary electrical heaters,
but no readings have been applied. The control of the systems is ‘decentralised’, e.g., in
one of the systems, the auxiliary heater was replaced or supported by 2 additional
electricity heaters, either started manually or by their own internal control. These
additional heaters are designed for domestic inside use, but were installed outside close to
the storage without any weather protection.
The inspection of the systems by the technicians is done by checking for sufficient hot
water output temperature of the systems, without tracing the origin of the heat
(solar or electrically produced).
System cost
No data available on system cost and annual electricity cost for both systems.
Summary of Whale Hotel Solar Hot Water systems
The experience made at the Whale hotel is of special interest, since the solar systems
were installed nearly 20 years ago and are still in operation. Part of the collectors show
corrosion, but the array at a whole may still contribute to the hot water supply.
The problems in the systems are addressed mainly to the system control in all of the
systems and to the heat storages in one of the systems. It could be worth, to apply a
retrofit to the systems, focussing on:
-
exchange of storages in one of the systems
exchange of controls of all systems by advanced control units with
electricity meters
removal of domestic electrically heaters at one of the systems for safety
reasons
exchange and improvement of pipe insulation (jackets)
training of technicians in order to detect insufficient collector operation
rising the awareness of hotel management to hot water and electricity
consumption figures to assess the benefits of the solar hot water systems
117
SOLAR WATER HEATING SYSTEM AT THE RAJABHAT NAKORNRAJASRIMA UNIVERSITY
In operation
The system was installed in 1992 and in operation for two years only. The system was
installed in the frame of a solar hot water promotion programme.

Providing hot water to 40 rooms of the Guest House of the University; all rooms are
equipped with showers and hot water tap. After several electricity blackout problems
12 years ago, the system operation was stopped (problems to lift water to the system,
air in pipe ducts, not air vents to remove air). All hotel rooms were equipped with
decentralised eletricity water heaters
Collector:
Flat-Plate, Thai product
Glass cover; no tempered glass, no solar quality
Collector area approx. 35 m² (18 collectors)
No specifications; collector frame and absorber made of steel
No serious shading

Configuration of the system
Thermosiphon system, three collectors are connected to one elevated storage. All
storages of the collectors are connected to an additional storage (approx. < 1 m³),
equipped with an electrically auxiliary heater
No air vent in the system
Overall appearance, problems occurred at the system
Jacket of the thermosiphon storages completely corroded (steel). The collectors show part
wise corrosion of the absorber and of the frames. One collector glass cover is broken.
Coating of the collector absorbers is no more black. Due to the arrangement of the
storages, it is not clear whether the system ever has achieved its full capacity during
operation.
Summary of the Solar Hot Water system at RAJABHAT NAKORN RATCHASIMA
University
It is not really recommended, to make efforts in order to re-activate the existing solar hot
water system due to the advanced state of corrosion and degradation.
On the other hand, the building size with 40 rooms is attractive for the installation of a
new well-monitored and maintained medium-sized solar thermal hot water system,
planned and installed according to the present knowledge. This system type should be a
forced one, and with the background of the University infrastructure it could be used as a
demonstration plant to show the contribution of solar hot water systems to the heat
demand in dependency of demand profile, solar radiation and applied system quality and
technology. The system could be also used for training purpose of installers and system
operators with respect to quality aspects, system control and maintenance.
118
SOLAR WATER HEATING SYSTEM AT NEP JUTE FACTORY AT NAKORN RAJASRIMA
In operation
The system was installed in 1984 and was not in operation the last 10 years
During operation, the system has provided process heat at approx. 45°C temperature for
chemical treatment of jute coating material to increase the stability of the jute brin.
Due to some bad experience with the operation of the solar system (water quality,
maintenance), the operation was stopped and the heat is provided by electrical heaters.
Moreover, the company slowly replaces jute raw material by plastic fibres, thus the low
temperature hot water demand decreases. It is therefore not planned, to apply efforts in
the installation of a new solar hot water system.
Collector:
Flat-Plate, Thai product
Glass cover; no tempered glass, no solar quality
Collector area approx. 70 m²
No specifications; collector frame made of steel;
absorber from cooling equipment heat exchanger, made of aluminium

Configuration of the system
Forced system with two vertical storages, approx. 4 m³.
Overall appearance, problems occurred at the system
The overall appearance is rather poor: the solar system is completely ruined by corrosion
and broken glass covers.
Summary of the Solar Hot Water system at NEP Jute Factory
The origin for the problems with the solar systems, leading to the decision for a stop of
the system, is not really clear. One source for problems might be seen in the type of
applied absorber in combination with the water quality, leading to corrosion in the
collector.
Due to the slow decrease of jute fabrication (still very large), there is no intention of the
management to invest in solar thermal systems again. For the manufacturing of the plastic
made products, heat at 200°C is required in some constructional elements in the
fabrication, generated by local electricity heaters.
119
SOLAR PROCESS HEAT AT A DIARY FARM (MILK FACTORY)
Products and load profile
At the Diary Farm, 170 to 180 tons milk are prepared daily for ready-for-sale milk
products, e.g., mainly milk and yoghurt.
The heat, necessary for the treatment of the products, is generated by two HFO-boilers
with the capacities 1.0 and 3.2 tons of steam generation per hour at 7 bars; a third boiler
of 3.3 tons steam per hour capacity is installed as reserve. The steam generation is
continuously for 24 hours per day, amounting for a fuel demand of approx. 2000 Liter
HFO per day.
The steam is basically used in two production steps:
-
Pasteurising. The milk is heated to a level between 67°C and 85°C for a period of a
few minutes. Subsequently, the milk is cooled down to 5°C, using electrically driven
compression chillers.
-
Ultra high treatment (UHT). The milk is heated to > 138°C and subsequently stored at
25°C.
To a minor degree, steam is used for cleaning of storages, vessels and other production
facilities. The returned condensate of the steam is additionally used in a heat exchanger to
pre-heat the oil to a temperature of approx. 100°C, before entering the combustion
chamber. The condensate is thus finally returned at a temperature level of 80°C to the
boiler.
It was mentioned that due to leakages (steam losses) 27 m³ water per day have to be
replaced.
The management of the Diary Farm is interested and motivated, to apply a solar thermal
system for fuel saving; a payback time of three years is highly appreciated, but five years
would be still o.k.
In general, different possibilities exist, to include solar energy for fuel saving:
Direct steam generation at the requested system pressure in concentrating solar thermal
collectors, e.g., parabolic trough collectors with one-axis tracking. Under the prevailing
meteorological conditions, this would probably lead to considerably large collector
installations with additionally required steam storage to smooth power fluctuations
Pre-heating of the condensate from 80°C towards 100°C (or more) in a high-efficiency
collector system, using pressurised water as heat medium. As collector type, vacuum tube
collectors may be use, but high-efficiency flat plate collectors (e.g., double-glazed with
non-reflective coating) can be considered as well.
Preheating of the fuel oil from ambient temperature (30°C) to any temperature until 100°.
Thus, the condensate from the steam supply system will be less used for fuel pre-heating
and returns into the boiler with a temperature above 80°C, thereby saving fuel for steam
generation. This requires a well designed collector system as well, but not necessarily
vacuum tube collectors. The heat could be used for cleaning purpose as well. Due to the
daily delivery rate of fuel, this solution would probably lead to the smallest solar thermal
installation and thus smallest investment cost, but consequently to the smallest potential
for fuel saving as well.
120
The possibility 1) will be not really suggested here, since a concentrating solar process
heat supply system should be first subject to a pilot plant, before applying this technology
to a commercial process.
The possibilities 2) and 3) should be subject to a feasibility study, considering different
collector technologies, collector system sizes and storage volumes, in order to find an
optimised system configuration with respect to the exploitation of the solar system, to the
saved primary energy and to the investment costs and payback time.
Since the solar collector system is expected to be a large one and operates at temperature
levels up to 100°C, monitoring and accompanying research of this system is mandatory
for at least three years. Manufacturers, planner and installer should give sufficient
warranties and support and may participate from the project results and experiences in
order to raise their interest in a successful running project.
Figure 5 shows a possible solar thermal application for pre-heating the condensate.
Figure A5 Simplified sketch of the process heat supply system at the Diary Farm One of the
possibilities to apply solar heat for fuel saving by pre-heating the condensate from 80°C to any higher
temperature is indicated (dotted).
121
Suggestions
The problems encountered during the site visits are manyfold. The following areas may
be addressed, to increase the quality, reliability and performance of the plants:
- Training
- Service and maintenance, supply of spare parts
- Quality of components
- Quality of concepts
- Awareness of economic and environmental benefits
Training is necessary on different levels: the operating personnel has to be provided with
more information on the surveillance of the solar system, e.g., to estimate the solar heat
contribution to the overall heat demand, to check the reliability of the components on a
regular basis, to obtain knowledge on information sources on solar hot water systems, etc.
The planners and installers should be trained for more awareness on the quality of the
installation, such as safe system operation (air vents, weather protection for pumps) and
for an optimised energy yield from the system (complete insulation, jackets, advanced
control with meters, proper position of temperature sensors).
The service and maintenance for solar hot water systems may be subject to
improvements. This includes extended warranty times for the delivered system as well as
clear instructions for maintenance or regularly maintenance by the manufacturer/installer
for at least 5 years. In the commissioning, the energy yield of the system should be
monitored within a few days (with mobile monitoring equipment) in order to assess the
performance and reliability of the system. A list of providers for spare part of both,
hydraulic equipment and control equipment, may be handed over to the operator.
Alternatively, special companies may rise up, working mainly in the field of
commissioning, service and maintenance of solar hot water systems, independent from
the life time of the installing companies.
The quality of components mainly covers the quality of collectors and of the control unit.
The increase of the quality of collectors may be discussed separately with Standards and
Tests for solar collectors. This includes the choice of proper materials for glass cover,
frame, absorber, and insulation as well as construction details, such as the avoidance of
spitted glass covers, ventilation holes and the like. The quality of the control is connected
to reliable temperature control units, advanced displays with more information on the
actual system operation, electricity meters etc.
The quality of concepts addresses the basic system configuration, found in most of the
visited systems. The concept of open loop systems leads on the one hand to lowest
investment cost, on the other hand, the danger of corrosion in the collector and solar hot
water storage is high, depending on the local quality of the supply water. Alternatively,
the collector and the solar storage may be designed as closed system and connected via a
heat exchanger to the second storage, which contains the auxiliary heater and is connected
to the supply grid. The closed solar loop may then operate at higher temperatures as well.
Other topics related with the quality of concepts are using a vertical position of the
storages in order to use stratification effects, but also the hot water distribution system in
the building: installation of mixing taps, in order to allow in general higher temperature
122
levels than approx. 40°C to 50°C (and to avoid rising problems with bacteria, e.g., legion
Ella).
In general, the operators and managers of hotels, hospitals etc. should be more aware on
the achieved economic and environmental benefits of the existing solar hot water
application. These figures are not really available yet, but important to stimulate
improvements and the reliability of the system on the one hand, and to assess the potential
of solar hot water preparation in the commercial sector on the other hand, thus
contributing to a positive image on the use of solar thermal systems in Thailand.
123
SITE VISIT SUMMARY IN PHUKET DURING 12/02/07 - 14/02/07
This trip report is a part of the Market Survey and Site visit activity in the “Market
Development for Solar Thermal Applications in Thailand” project (2006-2007) co-funded
by the EU Small Project facility (SPF) program. The project team has been visiting
hotels, hospitals, and factories for inspection of the existing solar water heaters and
interviewing with key facility staff including owners, managers, and chief engineers.
Earlier visits had covered the North, Northeast, Bangkok and suburban area:
The Phuket trip during 12 – 14 February 2007 purpose is to evaluate solar water heater
market in the southern area particularly in the tourism Phuket city. Details of meetings are
listed in the schedule below.
12 Feb 2007
13 Feb 2007
Afternoon
Morning
Afternoon
14 Feb 2007
Morning
Afternoon
Patong Merlin
Seaview Patong
Swissotel
Novotel Phuket Resort
Meeting with owner of the Merlin Group
Choochuay Trading Group Co., Ltd.
Merlin Beach
Evason Phuket
Site Visit
The team had visited 6 hotels during the trip. Most of the hotels except Merlin Beach
have solar water heaterswith installation ranging from 5 to 20 years. In general, SWH
systems are indirect, forced circulation to storage tank size 5,000-9,000 liters with LPG or
electric auxiliary back up heater. Smaller hotels such as the Swissotel and others
(20-40 rooms) along Patong beach use 2-5 Thermosiphon systems connected in parallel.
During visiting to hotels, the team made visual inspection and interviewed with hotel
owner and technicians. Typical to hotel business in Phuket, the staff turn over is relatively
frequent. Should the hotels have systematic documentation, contracts of services or
manuals of equipments such as solar water heater would have remained in the hotel
administration. However, such a case is only applied to some hotels. Most of the cases,
documents such as manuals and maintenance instruction are not passed on to new staffs.
Some of the hotels were taken over recently and documents are lost during a transition of
the ownership. The Tsunami was not only tragedy took away life and property from the
beach front, some hotels reported that most of their documents including solar system
were lost during the disaster.
Some hotels particularly the Merlin group has a systematic recording of their hot water
consumption that is useful for detail analysis and primary assumptions of the stage of
functionality of their solar systems. Following are a brief summary of the solar hot water
systems in each hotel we visited. With courtesy from Patong Merlin, Evason, and Merlin
Beach who have provided data from their records, we are able to review the hot water
systems in detail for these 3 hotels.
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Seaview Patong
Seaview Patong hotel had unfortunately decided to dismantle its solar hot water system
during the hotel renovation after the Tsunami in 2003. The current chief engineer has
started his work only 2 years ago and has no knowledge of the solar system that was
dismantled. He was told that the system was removed for the reason that it was difficult
for maintenance. Currently for the 2 buildings on its premise, the hotel use individual
electric heater in guest rooms in one building and another use central electric heater.
The Swissotel
The Swissotel has recently just opened for 3 months. The Patong beach front, 38-rooms
hotel was brought over and redecorated into the Swiss chain hotel. The hotel has 5 sets of
300-liter-thermosiphon solar thermal system connected in parallel. Total capacity of
1,500 liter water storage tank could provide enough hot water if occupancy rate is 50%.
The technician reported a couple of guest complaints that it took several minutes for
water to become hot in the shower. This could be that hot water storage tank is too small.
When the hotel full up during high season, simultaneous showers could drain all hot
water in the tank and it would requires sometime for cold water refilling the tank to be
heated up by the electric heater. The solar system was newly installed in August 2006,
just a couple of months before the Swissotel took over the hotel. The solar collectors are
brand new and look functioning fine however pipes are not insulated. Heat loss from
pipes lessens system efficiency and could be one of the causes the guest complaint of cold
water. During a transition of the ownership, solar system documents i.e. contract,
guarantee, or manual were lost. Since the system is still in the 1-year guarantee period, we
suggested that the technician contact the company directly for the system check up which
is covered in the first-year- free-service and also to obtain system manual. The hotel
should also insulate the pipes; either requests the solar company to perform the task or
could easily insulate pipes by themselves.
The Novotel Phuket
The Novotel Phuket, a hotel in the Accor chain hotel, comprises of 215 rooms on Karim
beach close to Patong. The solar hot water system is connected to the hot water storage
hybrid with LPG boilers. There are 2 sets of collector array on 2 buildings; both of the
system comprises of 24 collectors. The current stage of collectors is quite degraded with
water condensate under glass cover. Both of the systems lack of temperature/pressure
relief valves which must be installed to prevent high pressure built up from high
temperature when water gets too hot. The lack of relief valves has caused collector
materials particularly the insulation to deteriorate quickly. The number of solar collectors
is not sufficient for all hot water demand for 215 rooms and other purpose such as laundry
and kitchen. Although, there is no monitoring for hot water from the solar system, we
presume that main fuel for hot water generation is from LPG boilers.
The Accor group has a guideline for energy consumption in its chain hotels. Thus chief
engineers/technicians keep well record of their electric consumption. The Accor –
Environment Guide 98 (Annex 4.2) provide a guideline of energy consumption for its
chain hotels; Sofitel, Novotel, Ibis, Etap and Formule 1. According to interviewing with
the chief engineer, the Novotel Phuket has an energy benchmark at 150 kWh/room/night.
From recording, the average electric consumption of the hotel is 62 kWh/room/night.
Although this has not included gas consumption into account, the figure is still well
below the benchmark for its hotel group.
125
Choochuay Trading Group Co., Ltd.
Choochuay Trading Group is a Phuket local entrepreneur manufacturing solar hot water
for Phuket and Pa-ngan islands for 6 years. Majority of its customers are in residential
sector and a small numbers of apartments. Phuket is not only a tourist destination for
foreigners, the island has also developing properties for vacation homes and long term
resident for retirement. With relatively high population of foreigners dwell in Phuket,
about half of Choochuay’s customers come from this segment.
Choochuay main business in air conditioning has been a channel for contacting with
potential customers. The regular services for A/C also help the company easily
performing maintenance service for solar hot water system at the same time with A/C
service. Choochuay offer a 3 and 5 years (depends on models) guarantee period for solar
collector and water tank and 1 year guarantee for other parts in the system i.e. pumps,
control, backup electric heater. The company provides free maintenance and check up of
system for 1 year, afterwards the service is charged at the rate similar to A/C maintenance
service at 500 Baht/service.
Choochuay fabricates solar collectors and water tanks in its own shop with most of
materials available locally; however some parts i.e. absorber, controller are only available
from companies in Bangkok which import these parts from other countries. Choochuay
reported that water quality on islands has been a problem for storage tank. Particularly, on
Pa-ngan Island where water has high acidity that the company recommend only higher
grade of aluminum tank for the island.
Patong Merlin Hotel General Description
Patong Merlin Hotel is one of the 4 hotels in the Merlin Group comprises of 3 hotels in
Phuket and 1 hotel in Khaolak, Pang-nga, owned by a Thai family. Patong Merlin is a 3-4
star hotel of 386 rooms in 6 low-rise buildings. The hotel was first built in 1986, started
with one building and completed its 6th building in 1992. Upon requirement of the hotel
owner, the solar water heaters were incorporated during the architectural design of the
hotel providing sufficient flat space on the south facing roof and easy access for
maintenance. A summary of the solar hot water systems for each building are shown
below in table1.
Table A1 Solar hot water systems in Patong Merlin hotel
Building
1
2
3
4
5
6
Year
1986
1988
1990
1990
1991
1992
No. of rooms
80
56
72
56
32
93
Other function
Kitchen, laundry
Staff kitchen
Kitchen
No. of collectors
65
60
72
42
18
60
Solar Water Heating System
Due to availability of the data, only building#2 which have sufficient information is
reviewed in this section.
126
Solar Collector
Manufacturer: Lordan
Country:
Israel
Type:
Flat plate
Efficiency:
67%
Aperture area: 1.8 m2 / collector
Year of Mfg: 1988
System Configuration
Figure A6 Patong Merlin Solar water heater system diagram
Control system
- Solar collector: circulation of water in the collector array is control by differential
controller which set to start the circulation pump when temperature between hot and cold
sensor is more than 9°C and stop when temperature difference is lower than 4°C.
- Auxiliary electric heater: a temperature sensor is placed at half water level inside the
storage tank. When water temperature drops below 50°C, the thermostat triggers the
magnetic contactor to turn on the electric heater.
- Circulation pump: the circulation pump is controlled by a thermostat which turns on the
pump when water temperature in return pipe from the building is lower than 35°C.
Visual Inspection
All of the solar collectors are in pretty good condition for an 18 year-old system, no glass
cover broken although some collectors show sign of slightly corrosion. There are a few
spot of water leakages from 2-3 pipe connections between collectors and pipe from tank
to collector array. Pipe insulation (Aeroflex 1” wall x 1 1/8” diameter) is mostly still
intact although condition of the insulation is pretty much degraded from years of heated
under the tropical sun. Hot water pipes (between collectors and outlet pipe from collector
to tank) are copper and cold water pipes are PVC. The overall condition of the system is
serviceable and serving hot water all year round.
System Analysis
Patong Merlin has a relatively good recording system for its water and energy
consumption. Technicians take daily reading for water and electric meter of the solar
127
system and recording of weather condition of the day. Below is plot of water measured at
hot water storage tank outlet and electric consumption (pumps and auxiliary electric
heater in solar system) in January 2006.
Electric and water consumption in January 2006
100
80
60
Water (m3)
40
Electric (kWh)
20
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
Day of month
Figure A7 Electric and water consumption in January 2006 at Patong Merlin
In figure 1, the weather conditions were recorded as cloudy during the days where the
electric consumption is high (day 1-5, 6-13 and 23-25). On cloudy days, the electric
demand for water heating was approximately 2-5 kWh per one cubic meter of water. On
sunny days, electric consumption was average at 1-2 kWh per m3. This pattern of
electric/water and weather provide us a primary assumption that the solar fraction of the
system was approximately 80-90%.
A system analysis using T-Sol® software
In order to analyze the solar system cost effectiveness, we use T-Sol software to simulate
system performance using Phuket weather data. The annual simulation result in shown in
figure 2.
Figure A8 T-Sol® analysis of solar system in building#2 of Patong Merlin hotel
Results from simulation shows that the solar fraction is approximately 86% of hot water
demand. Although during rainy season, solar water heater is less efficient but the hot
128
water demand also reduced from lower occupancy during those months resulting in
relatively constant requirement for electric heater back up all year round.
A summary of the simulation results is shown in table 2. The solar system had save
electricity around 89,710 kWh/year and paid back its investment in the 6th year. Over 18
years of system operation, solar hot water has saved 1,195 Ton of CO2 emission.
Table A2 Summary of Patong Merlin simulation results
Results of annual simulation
System yield
Annual electricity consumption – pump
Annual electricity saving
Solar fraction
System efficiency
Economic analysis
Investment cost
Net present value
Pay back period
Cost of solar energy
Environmental benefit
GHG emission saving
76,254 kWh / year
6,867 kWh / year
89,710 kWh / year
85.9 %
37.0 %
960,000 Baht
2,337,545 Baht
6 years
0.9 Baht/kWh
66.37 Ton CO2 / year
Summary
The solar hot water system at Patong Merlin is an outstanding case of good installation
and maintenance that keep the system in operation for over 18 years. The system has been
a main supply for hot water demand for the hotel and paid back its investment in just 6
years.
129
Evason Phuket & Six Senses Spa
General Description
The Evason Phuket & Six Sense Spa is located at Rawai Beach on the south eastern side
of Phuket Island. The luxury 5-star resort hotel is a part of the Six Sense BVI Company
which has 12 locations in Thailand, Maldives, Oman and Vietnam. The Evason Phuket
has 3 swimming pools and among the 260 guestrooms in 5 low-rise buildings, 28 suite
rooms provide private pools. The hotel efforts for responsible tourism such as water
treatment and reuse of water have contributed toward its awards in the environmental
tourism.
Solar Water Heating System
The solar water heater system was installed before the Evason took over the Phuket Island
hotel 6 years ago. During our visit, we could not obtain solar related documents; this may
be because the documents may have lost during the changeover of the ownership. In
general, there are 2 sets of solar collectors, the array on the lower roof has 36 of Solarhart
collectors and the upper area has 33 of Solasaver collectors. The collectors connect to hot
water storage tank through heat exchanger in a 2-tank system configuration. The main
tank is supported with LPG boilers.
Solar Collector
Array 1:
Manufacturer: Solarhart
Country:
Australia
Type:
Flat plate
Efficiency:
N/A
Aperture area: N/A
Year of Mfg: 1987
Array 2:
Manufacturer: Solasaver
Country:
Thailand
Type:
Flat plate
Efficiency:
N/A
Aperture area: N/A
Year of Mfg: N/A
Visual Inspection
The solar collectors seem fine on the exterior; frames are still intact and no broken glass
covers on any collector. Collectors and support structure show no sign of heavy
corrosion. However, most of glazing is deteriorated from high temperature. The system
piping is improper design and installed. There is no drainage nor pressure relief valves in
the system. The lack of draindown valve shows that no regular service has been
performed to prevent scale build up inside pipes. The pressure/temperature or air vent
valves are usually required to install at high point of the collector array in the solar hot
water systems. The valves automatically discharge steam when water temperature gets
too high to prevent high pressure inside pipes and collectors. From visual inspection, the
solar system seems not functioning. A through inspection is recommended to verify this
assumption and to evaluate whether the solar system can be refurbished.
130
System Analysis
The hotel does not have a water meter dedicated to hot water. Without hot water
consumption data, evaluation of solar water heater whether it is functioning or
functioning at what level can not be perform. However, with LPG gas data available, we
tried to estimate hot water generation from LPG consumption in order to have some
guideline for our system analysis. The kilogram of LPG is converted to liter of hot water
assuming boilers heat up water from 25°C to 80°C.
Assumptions
- LPG heat capacity, Cp = 50.226 kJ/kg
- 25°C water enthalpy, hin = 104.829 kJ/kg
- 80°C water enthalpy, hout = 335.012 kJ/kg
Calculation
From a heat transfer equation Q = m*(hout – hin)
The amount of hot water generated from LPG boilers is shown below as an average liter
per guest.
Hot Water Generation
Liter/guest
80
60
40
20
Ju
l
Au
g
Se
p
O
ct
No
v
Se
c
Ja
n
Fe
b
M
ar
Ap
r
M
ay
Ju
ne
0
Year 2006
Figure A9 Amount of hot water generation from LPG/guest in 2006
The hot water consumption per guest is in the range of 40-70 liter/guest which is within
an average range for hotels. Although, this estimation can not be realistically represent
the hotel hot water demand, in which this could be all of the hot water demand or the
demand could be higher and supplemented by the solar water heater. However, this
average 57 liter/guest from LPG conveying that nearly or possibly all of the hot water
generation is fueling with LPG reaffirm our primary assumption that solar water heater
may not be functioning.
Summary
The current hot water generation using LPG is cleaner than using fuel oil. However,
further CO2 emission can be avoid if the hotel use solar water heater or other hot water
generation technology that can produce hot water more efficiently and less emission. It is
recommended that the hotel may consider a through inspection of the solar system to
estimate whether it can be restored. Hot water could also be measured by installing a
water meter at the hot water tank outlet and also at other facilities i.e. kitchen, laundry to
monitor energy and water usage. The data would be valuable for efficient water and
energy
management
and
planning
for
the
hotel.
131
MERLIN BEACH RESORT
General Description
The Merlin Beach Resort is located on Tri-tang beach on the south eastern side of the
Phuket Island. The 4-star hotel is managing by the Merlin Group like Patong Merlin.
Heat Pump Water Heating System
All of hot water demand for 414 guestrooms, kitchen and laundry is served by five 45 kW
heat pumps. Cool exhaust air is currently exhausted to outdoor. The heat pump is an
American brand, installed by a local distributor. According to the specification, the 45
kW heat pumps can deliver hot water at 60-65°C from inlet cold water at 20-25°C with
heating capacity at 25 kW and cooling capacity at 20 kW.
Visual Inspection
The heat pump hot water system is newly installed in less than 3 years. The system seems
working in a good condition. There is sufficient air space around the heat pump. Noise
and vibration is minimal and in an acceptable range. Pipes are well insulated and in good
condition. There are a few spots of water dripping around seeming of water storage tanks.
The rust on tank seeming may have occurred from the welding process. The chief
engineer reported that the hotel is considering several options for tanks overhaul.
System Analysis
The Merlin Beach Resort has hot water consumption around 65-75 liter per guest which is
within an average range for a 4-star hotel. The electric requirement for generating hot
water is average at 1.46 kWh per 1 cubic meter of water for the year 2006 as shown in
figure 5.
Electric Consumption per 1 cu meter of Hot Water Generation
2.50
kWh/m3
2.00
1.50
1.00
0.50
0.00
Jan Feb Mar Apr May Jun
Jul
Aug Sep Oct Nov Dec
year 2006
Figure A10. Electric consumption per 1 cubic meter of hot water generation
Summary
Heat pump water heater is 2-3 times more efficient than electric water heater. This
innovative technology has less efficient in cold climate however works well in hot
climate and could well be an option for efficient hot water generation in Thailand.
132
CONCLUSION
Throughout our visit to hotels on Phuket Island, we have inspected solar water heaters
and other water heating systems for hotels for the analysis of barriers of solar hot water in
the southern climate. In general, there are technical barriers and non-technical barriers.
Technical barriers involve quality in manufacturing, improper installation, and the lack of
maintenance. Most of hotels do not have a systematic recording of water and energy
consumption which could help monitoring their energy usage and could be an indicator
when there are problems in the system such as water leakage that water meter would be
anomaly higher than usual.
Non-technical barrier involve the misconception that Phuket is in a tropical monsoon
climate where rainy season prolong for 6 months per year from May to October and this
would not be a good condition for solar hot water. However, Phuket tourism in rainy
season is lower as well and has contributed to less hot water demand. The concurrent
relation of solar radiation and tourist season shows that solar hot water system can
suitably provide hot water for hotels in the South of Thailand.
133
ANNEXES AND REFERENCES
List of Contacts
No.
Site
1
Patong Merlin hotel
2
Seaview Patong
3
Patong Swissototel
4
Novotel Phuket Resort
Hotel
Phuket Merlin Hotel
5
6
7
Choochuay Trading
Group Co., Ltd.
Merlin beach hotel
8
EVASON Phuket
Contact Person
Mr. Piroj Hararak
Chief Engineer
Mr. Visit Chootong
Chief Engineer
Mr. Teerachai Wongsukitja
Mr. Sompong Patburi
Mr. Somchai Chirayus
Deputy Manageing Director
Mr. Sutham Choochuay
Managing Director
Mr. Sathian Visuthsiri
Chief Engineer
Mr. Pornchai Jatupuchaporn
Chief Engineer
Mr. Arnfinn Oines
Environment Coordinator
Tel
Tel.: 076 340037
Fax.: 076 340394
Tel.:
Fax.:
Tel.:1502-5
Fax.:340933
Tel.: Fax.:
Tel: 076 212866-70
Fax: 076 234930
Tel: 076 321562
Fax: 076 321562
Tel: 076 294300
Fax: 076294310
Tel.:
Fax.:8
134
B. RECOMMENDED STANDARDS FOR THAILAND
STANDARDS FOR SOLAR THERMAL COLLECTORS
SUGGESTIONS FOR THE ADAPTATION AND MODIFICATION OF CURRENT STANDARDS FOR
THE APPLICATION IN THAILAND
The following recommendations are made on base of the European Standard for Solar
Thermal collectors EN 12975, mainly part 1 (general requirements) and part 2 (test
methods), as well as on base of the Australian / New Zealand Standard AS/NZS
2712:2002.
Requirements on material (chapter 1), stagnation temperature (chapter 2) and on
performance tests (chapter 3) have been combined within one part. Subsequently, in
chapter 4, a template is provided as example for the durability and reliability test report
sheets.
The thermal performance test procedure is not described here, since this procedure may
be defined and included by the involved Thai institutes with respect to the prevailing
meteorological conditions and existing test facilities (e.g., dynamic test procedure).
Main focus of the recommendations is solar thermal flat plate collectors with a fluid as
heat transfer medium. Parts of the recommendations are in general valid for all types of
collectors (vacuum tubes, air-collectors, etc.).
MATERIAL
The operational ability and long lifetime of solar collectors depend on the correct choice
of appropriate materials.The materials of collector components should be selected and
constructed so, that they can withstand the maximum temperature which may occur at
stagnation conditions and the thermal shocks they may be exposed to during periods with
high temperatures and high solar irradiance. Therefore the use of non-combustible
materials should be preferred. Furthermore, the material should be resistant to exposure to
ultraviolet radiation and in cases where materials selected are not so, they should be
protected against incident and reflected ultraviolet radiation.
The construction of the collector should ensure that no undue stress is built up in the
cover, even at the maximum stagnation temperature of the collector.The components and
the materials of the collector should be able to withstand the mechanical loads resulting
from the heating up and cooling down of the collector. They should also be resistant to
environmental stress from outdoor climate caused by factors such as rain, wind, high
humidity and air pollutants.
The collector box should be water-tight to prevent penetration of rain water. It should be
constructed in such a way, that condensed water does not accumulate in the collector, as
this might impair its functional capability and durability. For that purpose the collector
should be properly designed to enable ventilation of air through the collector box.
The collector shall as well provide for safe installation and mounting. Sharp edges, loose
connections and other potentially dangerous features shall be avoided.
135
If the weight of the empty collector exceeds 60 kg, an anchorage for a lifting device shall
be included, except for the collectors that are assembled on the roof. Ducts leading
through the box should be constructed so, that no leakage can occur caused by thermal
expansion. The collector box bushings should withstand any damage, if they have to be
soldered for assembly. The design of the collector should be such, that heat bridges
between the collector box and the absorber are avoided.
In case other than pure water is applied as heat transfer fluid, the heat transfer fluid used
should not be toxic, seriously irritant to the human skin or eyes, or water polluting and it
should be fully biodegradable. Collectors filled with a heat transfer fluid irritant to human
skin or eyes, or toxic shall carry a warning label.
It is helpful to label the collector with a visible and durable label bonded onto the casing.
The following data may be used:

Name of manufacturer
Type
Serial number
Year of production
Gross area of collector
Dimensions of collector maximum operation pressure
Stagnation temperature at 1000 W/m2 incident radiation and 35 ºC ambient air
temperature
Volume of heat transfer fluid
Material and quality of cover (e.g., Solar glass, tempered glass, 4 mm)
Weight of empty collector
Made in ...
It is also helpful to accompany solar collectors by an installer instruction manual, if
traded as stand-alone components. When they are part of a complete system, the system
installation manual can cover the complete system. In that case no separate manual for
the collector shall be required.
The instruction manual shall at least contain the following information:
dimensions and weight of the collector; instructions about the transport and
handling of the collector;
description of the mounting procedure;
recommendations about lightning protection;
instructions about the coupling of the collectors to one another and the connection
of the collector field to the heat transfer circuit;
if water is used as heat transfer fluid: recommendations on the quality and purity of
the water in order to avoid blocking of the fluid through the absorber;
in case other than pure water is applied as heat transfer fluid: recommendations
about the heat transfer media which may be used (also with respect to corrosion)
and precautions to be taken during filling, operation and service;
the maximum operation pressure; the pressure drop and the maximum and
minimum tilt angle;
permissible wind load
maintenance requirements.
136
ABSORBER
Absorbers should be made from suitable materials to cope with mechanical and thermal
requirements of the application. The compatibility of the absorber material shall also be
guaranteed within the collector unit so that accelerated chemical degradation does not
take place. The application of absorbers made of steel should be avoided. The effect of
the manufacturing processes like cutting, brazing, soldering etc., on the properties of the
absorber should be considered. Where fabricated from copper alloy, the absorber shall be
resistant to the effects of dezincification and stress corrosion cracking.
The absorber ducts which guide the flow of the heat transfer fluid, including the
connection lines, should be designed and constructed in such a way that venting can be
effected in the installed condition, thus ensuring the functional capability of the collector.
Absorbers should be dimensioned on the basis of a calculation pressure corresponding to
the permissible working overpressure specified by the manufacturer taking into
consideration a safety factor of 1.5. The properties of the heat transfer medium should be
considered as well.
The material used should have a surface having the property of high absorptance to solar
radiation. A low thermal emittance may also be desirable and may be achieved by a
selective surface treatment.The effect of the maximum temperature (stagnation
temperature) of the absorber should be considered in the selection of material. In the case
of materials with strength characteristics, which vary appreciably with the temperature
and/or ultraviolet exposure, the evaluation criteria should be determined individually in
each case.The inside of the absorber ducts should withstand corrosion under normal
operating conditions and taking into account the admixture of possible additives to the
heat transfer fluid. (Swimming pool collectors connected directly to swimming pool water
shall be resistant to the additives used for the treatment of the swimming pool water.)
Absorber coatings should retain their optical properties under stagnation temperature,
high humidity and condensate
TUBING
For solar water heaters where the fluid ways of the absorber are formed from tubing, as
opposed to being formed integrally with the absorber plate, the tubing shall be one of the
following:
(a) copper tubing of appropriate material standard
(b) stainless steel tubing of appropriate material standard
(c) tubing of other materials provided that such tubing is not inferior with regard to
corrosion, pressure rating and durability, under the conditions of use, to that specified
in items (a) and (b) above.
Where solar water heaters are intended to be suitable for use with water having a high
chloride concentration, special attention should be given to the materials used.
Where the fluid ways of the absorber are formed from tubing as opposed to being formed
integrally with the absorber plate, the tubing shall be permanently and firmly bonded to
the absorber plate. The junction between the tubing and the absorber plate, either welded
or soldered, shall be capable to withstand the stagnation temperature of the absorber
without any degradation.
137
THERMAL INSULATION
Thermal insulation materials shall be such that it will not deteriorate in service or become
compressed and leave uninsulated voids during transportation or installation. Insulation
materials should withstand the local temperature reached by the absorber under maximum
stagnation conditions. At this temperature no melting, shrinkage or outgassing of the
insulation with consequent condensation inside the collector cover, or absorber
performance reduction or corrosion of metallic surfaces should occur to the extent of
seriously reducing the collector performance. The insulation shall be placed and
contained so that its efficiency is maintained, contact with wiring terminations or
temperature controls has to be prevented and attack by vermin has to be deterred.Where
the design of the collector unit is such that insulating material will be exposed to sunlight
under operating conditions, it shall not be adversely degraded by ultraviolet radiation.
Transparent insulation materials or Teflon layers used should not deteriorate appreciably,
both mechanically and optically, during the service life of the collector due to ultraviolet
radiation, as well as due to high temperature and humidity.
Water or humidity absorption by the insulation material may shortly or permanently
reduce the insulation performance of the material and supports corrosion of the absorber.
If compatible with respect to the stagnation temperature achieved in the collector,
insulation material with low water absorption properties may be preferred (closed pores).
Thermal expansion of the material used in the collector due to the wide range of
temperatures should also be taken into consideration because of different thermal
expansion coefficients. For the collector insulation no materials should be used which
have been manufactured under the use of CFCs or which contain CFCs.
DIFFUSION BARRIERS
Diffusion barriers are materials used between absorbers and insulation material to prevent
diffusion into or out of the insulation material. They should be able to withstand the
absorber high temperatures and the incident ultraviolet radiation without shrinking and
the high humidity or condensate accumulated remaining tight.
COLLECTOR CASING
The collector casing and mountings shall be fabricated from either
(a) metal or other material having durability properties under the conditions of use not
inferior to those of hot-dip zinc-coated steel sheet; or
(b) any material suitable for the purpose, which is a material used as external cladding
or roof covering of buildings.
The connecting material between collector glazing and casing shall be leak-proof.
Nevertheless, due to the heavy monsoon rain and generally high air humidity, it is
recommended to locate an adequate number of drain holes at the lowest point of the
collector casing, so that ingress of water can be avoided. Thereby the invaded water and
humidity can escape more easily.
REMARK Definitely, materials should be suitable for climatic conditions in Thailand.
Collector casings made of aluminium or stainless steel is recommended, but which
material composition is most preferable, has to be discussed with respective industry
or research groups in material. An Austrian collector manufacturer equips collectors
138
with a wooden frame with positive experience in all climates, but consequently the
rear side of the collector has to cover more mechanical load.
COLLECTOR GLAZING
Solar collectors are generally covered with glass or transparent plastic glazing made of
polymers. The transparency of the covers should not deteriorate appreciably during the
collector’s service life. The covers should be resistant to ultraviolet radiation, air
pollution, high humidity and condensate as well as to high temperatures depending on the
collector design. The durability of glass and tempered glass (toughened glass) under the
service conditions found in solar collectors is good, but the resistance of plastics and glass
treated with a special coating to the combined effects of UV-radiation and temperature
may be poor. There may be significant degradation with time, and in the case of a reduced
transmission in the solar wavelengths, this will finally lead to degradation in the collector
performance.
A reduction in the tensile strength or impact strength of a cover material may lead to a
failure of the collector cover. Therefore, for a glazed collector the glazing material shall
be securely fastened and sealed to make provision for thermal expansion and contraction
of the glazing material and the collector. It has to be considered that broken glass should
not be a safety hazard. Glass should either break into small pieces, as with tempered
glass, or be safely retained, preferably within the collector area. For the application on
facades, appropriate safety standards for building construction, especially for facade
elements, are to be met by the collector. Solar glass for a higher transmission in the
visible spectral range increases the performance and cost, but does not contribute to more
safety. For higher temperature applications than domestic hot water production, solar
glass is recommended. In general, split glass covers have to be avoided. The usual
thickness of glass used for glazed collectors shall be between 3.5 and 4 millimetres.
REFLECTORS
Reflectors, either diffuse or specular, are reflecting surfaces used to increase the incident
radiation on the absorber. Outside the collector box reflectors should resist mechanical
loads through wind and hail, and the reflecting surface should be resistant to
environmental influences such as air pollution and to corrosion through humidity or rain,
whereas inside reflectors should withstand high temperatures.
STAGNATION TEMPERATURE
All solar water heater systems shall be designed to resist damage due to stagnation.
The typical high stagnation temperatures occur during periods of no useful heat removal
from the collector, with high solar radiation (total radiation on the plane of the collector t
1000 W/m²) and high ambient temperatures (ambient air temperature t 35°C), when the
collector is
empty during installation,
empty during its service life or
filled with fluid but not being used in peak summer conditions
139
Having passed the stagnation temperature conditions,
there shall be no evidence of catastrophic or partial structural failure of the
collector, or of the collector cover without magnification when visually examined
(other than using normal eyeglasses);
there shall be no failure likely to impair the serviceability or durability of the
collector;
there shall be no evidence of any burning, scorching or heat shrinkage of any part
of the collector and
there shall be no degradation in the thermal performance of the collector.
140
PERFORMANCE TESTS
Test methods for validating the durability, reliability and safety requirements for liquid
heating collectors are specified below.
As a result of these methods there shall be no:
absorber leakage or such deformation that permanent contact between absorber and
cover is established;
breaking or permanent deformation of cover or cover fixing;
breaking or permanent deformation of collector fixing points or collector box;
vacuum loss;
accumulation of humidity in form of condensate on the inside of the transparent
cover of the collector exceeding 20% of the aperture area.
The results of the inspection of the collectors shall be reported.
INTERNAL PRESSURE OF THE ABSORBER
The absorber shall be pressure-tested to assess the extent to which it can withstand the
pressures which it might meet in service.
Inorganic absorbers shall be pressure-tested at ambient air temperature within the range of
20°C to 40°C.
The test pressure shall be 1.5 times the maximum collector operating pressure specified
by the manufacturer.
The test pressure shall be maintained for 15 min.
Meanwhile the collector shall be inspected for leakage, swelling and distortion.
EXPOSURE TEST
The exposure test provides a low-cost reliability test sequence, indicating operating
conditions which are likely to occur during real service and which also allows the
collector to "settle", such that subsequent qualification tests are more likely to give
repeatable results.
The collector shall be mounted outdoors, but not filled with fluid. All except one of the
fluid pipes shall be sealed to prevent cooling by natural circulation of air. One shall be
left open to permit free expansion of air in the absorber.
Corresponding climate parameter values are:
30 hours of global solar irradiance on collector plane, G > 850 W/m2
(in sequences with a minimum of 30 minutes or longer)
at least 30 days with a global daily irradiation on collector plane, H > 14 MJ/m2
(interruptions allowed)
surrounding air temperature, ta > 15 °C
141
The collector shall be inspected for damage or degradation.
HIGH TEMPERATURE RESISTANCE TEST
This test is intended to assess rapidly whether a collector can withstand high irradiance
levels without failures, such as glass breakage, collapse of plastic cover, melting of plastic
absorber, or significant deposits on the collector cover from outgassing of collector
material. The collector shall be mounted outdoors or in a solar simulator, and shall not be
filled with fluid. All of the fluid pipes except for one shall be sealed to prevent cooling by
natural circulation of air.
A temperature sensor shall be attached to the absorber to monitor its temperature during
the test. The sensor shall be positioned at two-thirds of the absorber height and half the
absorber width. It shall be fixed firmly in a position to ensure good thermal contact with
the absorber. Furthermore the sensor shall be shielded from solar radiation. (When testing
collectors, such as evacuated tubular collectors, the temperature sensor should be placed
at a suitable location in the collector, and this location should be clearly described with
the test results.)
Corresponding climate parameter values are:
global solar irradiance on collector plane, G t 1000 W/m2
surrounding air temperature, ta 20 – 40 °C
surrounding air speed < 1 m/s
The test shall be performed for a minimum of 1 h after steady-state conditions have been
established, and the collector shall be subsequently inspected for signs of damage such as
degradation, shrinkage, outgassing or distortion.
EXTERNAL THERMAL SHOCK
Collectors may be exposed to sudden rainstorms on hot sunny days, especially in months
of monsoon, causing a severe external thermal shock. This test is intended to assess the
capability of a collector to withstand such thermal shocks without a failure. The collector
shall be mounted either outdoors or in a solar simulator, but shall not be filled with fluid.
All except one of the fluid pipes shall be sealed to prevent cooling by natural circulation
of air. One shall be left open to permit free expansion of air in the absorber.
A temperature sensor may be optionally attached to the absorber to monitor its
temperature during the test. An array of water jets shall be arranged to provide a uniform
spray of water over the collector. The collector shall be maintained under a high level of
solar irradiance for a period of 1 h before the water spray is turned on. It is then cooled by
the water spray for 15 minutes before being inspected.
The collector shall be subjected to two external thermal shocks.
The corresponding solar irradiation level is:
global solar irradiance on collector plane, G > 850 W/m2
The water spray shall have a temperature of less than 25 °C and a flow rate in the range of
0.03 kg/s to 0.05 kg/s per square metre of collector aperture.
142
If the temperature of the water which first cools the collector is likely to be greater than
25 °C (for example if the water has been sitting in a pipe in the sun for some time), then
the water shall be diverted until it has reached a temperature of less than 25 °C before
being directed over the collector.
The collector shall be inspected for any cracking, distortion, condensation, water
penetration or loss of vacuum.
INTERNAL THERMAL SHOCK
Collectors may from time to time be exposed to a sudden intake of cold heat transfer fluid
on hot sunny days, causing a severe internal thermal shock, for example, after a period of
shutdown, when the installation is brought back into operation while the collector is at its
stagnation temperature. This test is intended to assess the capability of a collector to
withstand such thermal shocks without failure.
The collector shall be mounted either outdoors or in a solar simulator, but shall not be
filled with fluid. One of its fluid pipes shall be connected via a shutoff valve to the heat
transfer fluid source and the other shall be left open initially to permit the free expansion
of air in the absorber and also to permit the heat transfer fluid to leave the absorber. If the
collector has more than two fluid pipes, the remaining openings shall be sealed in a way
that ensures the designed flow pattern within the collector.
A temperature sensor may be optionally attached to the absorber to monitor its
temperature during the test. The collector shall be maintained under a high level of solar
irradiance for a period of 1 hour before it is cooled by supplying it with heat transfer fluid
for at least 5 minutes or until the absorber temperature drops below 50 °C.
The collector shall be subjected to two internal thermal shocks.
The corresponding solar irradiation level is:
global solar irradiance on collector plane, G > 850 W/m2
The heat transfer fluid shall have a temperature of less than 25 °C. The recommended
fluid flow rate is at least 0.02 kg/s per square metre of collector aperture (unless otherwise
specified by the manufacturer).
The collector shall be inspected for any cracking, distortion, deformation, water
penetration or loss of vacuum.
RAIN PENETRATION TEST
This test is applicable only for glazed collectors and is intended to assess the extent to
which glazed collectors are substantially resistant to rain penetration. They shall normally
not permit the entry of either free-falling rain or driving rain. Collectors may have
ventilation holes and drain holes, but these shall not permit the entry of driving rain. The
collector shall have its fluid inlet and outlet pipes sealed (unless hot water is circulated
through the absorber), and be placed in a test rig at the shallowest angle to the horizontal
recommended by the manufacturer. If this angle is not specified, then the collector shall
be placed at a tilt of 20° to the horizontal. Collectors designed to be integrated into a roof
structure shall be mounted in a simulated roof and have their underside protected. Other
collectors shall be mounted in a conventional manner on an open frame or a simulated
roof.
The collector shall be sprayed on exposed sides, using spray nozzles or showers.
143
The collector shall be mounted and sprayed while the absorber in the collector is kept
warm (minimum 50 °C). This can be done either by circulating hot water at about 50 °C
through the absorber or by exposing the collector to solar radiation. The heating up of the
collector should be started before the spraying of the water in order to ensure that the
collector box is dry before testing. In cases of collectors having wood in the backs (or
other special cases), the laboratory must take all necessary measures during the
conduction of the test so that the final result will not be influenced or altered by the
special construction of the collector. The collector shall be sprayed with water at a
temperature lower than 30 °C and with a flow rate of more than 0.05 kg/s per square
metre of sprayed area. The duration of the test shall be 4 hours. The water pressure shall
be 300 kPa. The collector shall be inspected for water penetration. The results of the
inspection, i.e. the extension of water penetration and the places where water penetrated
shall be reported.
The penetration of water into the collector shall be determined by inspection (looking for
water droplets, condensation on the glass cover or other visible signs) and by one of the
following methods:
weighing the collector before and after the test: the determined water quantity shall
be less than 50 gr/m² collector area;
measuring the humidity inside the collector (standard uncertainty better than 5%)
or
measuring the condensation level, which shall be less than 20 % of the transparent
cover and the quantity of the water that come out of the collector when tipping it
shall be less than 50 gr/m² collector area.
Due to the heavy monsoon rain and generally high air humidity, it is recommended to
locate an adequate number of drain holes at the lowest point of the collector casing, so
that ingress of water can be avoided. Thereby the invaded water and humidity can escape
more easily.
MECHANICAL LOAD TEST
Positive pressure test
This test is intended to assess the extent to which the transparent cover of the collector
and the collector box are able to resist the positive pressure load due to the effect of wind.
The collector shall be placed horizontally on an even ground. On the collector a foil shall
be laid and on the collector frame a wooden or metallic frame shall be placed, high
enough to contain the required amount of gravel or similar material. The gravel,
preferably type 2-32 mm, shall be weighed in portions and distributed in the frame so that
everywhere the same load is created (pay attention to the bending of the glass), until the
wanted height is reached. The test can also be carried out loading the cover using other
suitable means
(e.g. water), or a uniformly distributed set of suction cups. As a
further alternative, the necessary load may be created by applying an air pressure on the
collector cover.
144
The test pressure shall be increased at maximum steps of 250 Pa until a failure occurs or
up to the value specified by the manufacturer. The test pressure shall be at least 3200 Pa.
REMARK The value 3200 Pa corresponds to requirements in areas with high danger
of occurrency of tropical cyclones, e.g., like in Caribbean areas. In Europe,
recommended values are between 1000 and 2400 Pa.
A failure can be the destruction of the cover and also the permanent deformation of the
collector box or the fixings.
The pressure at which any failure of the collector cover or the box or fixings occurs shall
be reported together with details of the failure. If no failure occurs, then the maximum
pressure which the collector sustained shall be reported. The maximum positive pressure
is the pressure reached before a failure occurs. The permissible positive pressure is the
maximum pressure divided by the safety factor (SFpositive = 1.5).
When the test is done with an on-roof mounting system the test results is also valid for the
roof integrated mounting system.
Negative pressure test
This test is intended to assess the extent to which the fixings between the collector cover
and collector box are able to resist uplift forces caused by the wind.
The collector shall be installed horizontally on a stiff frame by means of its mounting
fixtures. The frame which secures the cover to the collector box shall not be restricted in
any way. A lifting force which is equivalent to the specified negative pressure load shall
be applied evenly over the cover. The load shall be increased in steps up to the final test
pressure. If the cover has not been loosened at the final pressure, then the pressure may be
stepped up until a failure occurs.
The time between each pressure step shall be the time needed for the pressure to stabilise.
Either of two alternative methods may be used to apply pressure to the cover:
Method 1
The load may be applied to the collector cover by means of a uniformly distributed set
of suction cups.
Method 2
For collectors which have an almost airtight collector box, the following procedure
may be used to create a negative pressure on the cover. Two holes are made through
the collector box into the air gap between the collector cover and absorber, and an air
source and pressure gauge are connected to the collector air gap through these holes.
A negative pressure on the cover is created by pressurising the collector box.
For safety reasons the collector shall be encased in a transparent box to protect
personnel in the event of failure during this test.
During the test, the collector shall be visually inspected and any deformations of the
cover and its fixings reported. The collector shall be examined at the end of the test to
see if there are any permanent deformations.
The test pressure shall be increased in steps of 250 Pa until a failure occurs or up the
value specified by the manufacturer. The test pressure shall be at least 2400 Pa. A
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failure can be the destruction of the cover and also the permanent deformation of the
collector box or the fixings.
A permanent deformation is to be assigned to a load value, while it is completely
relieved after every load increment of 250 Pa and the distortion is measured compared
to the beginning of the test sequence. The value of an inadmissible permanent
deformation amounts to max. 0.5 %. (Example: 10 mm distortions at 2 m length of
collector frame)
The pressure at which any failure of the collector cover or the box or fixings occurs
shall be reported together with details of the failure. If no failure occurs, then the
maximum pressure which the collector sustained shall be reported.
The maximum negative pressure is the pressure reached before a failure occurs. The
permissible negative pressure is the maximum pressure divided by the safety factor
(SFnegative = 2).
IMPACT RESISTANCE TEST
Collectors shall sustain no significant damage, cracking, breakage or puncture of any
glazing, or the absorber in an unglazed collector, when affected by hail.
This test is intended to assess the extent to which a collector can withstand the effects of
heavy impacts caused by hailstones. Where hail guards are provided, it is recommended
that they are located not less than 50 mm from the surface of the glazing of glazed
collectors, or the absorber surface for unglazed collectors.
The collector shall be mounted either vertically or horizontally on a support. The support
may be stiff enough so that there is negligible distortion or deflection at the time of
impact. Steel balls (diameter: 25.4 mm) shall be used to simulate a heavy impact. If the
collector is mounted horizontally then the steel balls are dropped vertically, or if it is
mounted vertically then the impacts are directed horizontally by means of a pendulum. In
both cases, the height of the fall is the vertical distance between the point of release and
the horizontal plane containing the point of impact.
The point of impact shall be no more than 5 cm from the edge of the collector cover, and
no more than 15 cm from the corner of the collector cover, but it shall be moved by
several millimetres each time the steel ball is dropped.
A steel ball shall be dropped onto the collector 10 times from the first test height (0.2 m),
10 times from the second test height (0.4 m), etc. until the maximum test height (2.0 m) is
reached. The test has to be stopped when the collector sustains some damage or when the
collector has survived the impact of 10 steel balls at the maximum test height.
The collector shall be inspected for damage. The results of the inspection shall be
reported, together with the height from which the steel ball was dropped and the number
of impacts which caused the damage.
REMARK The occurrence of hail in the Thai region and thus the importance of this
performance test has to be assessed.
FINAL TEST
When the full test sequence has been completed, the collector shall be dismantled and
inspected. All abnormalities shall be reported and accompanied by a photograph.
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DURABILITY AND RELIABILITY TEST REPORT SHEETS
COLLECTOR IDENTIFICATION
Collector Reference Number:
Manufacturer:
Brand Name:
Serial Number:
Year of Production:
Collector Type:
Unglazed
Glazed
Evacuated
Collector Surface Area: ……… m² (Gross); ……… m² (Absorber); ……… m²
(Aperture)
Material of glazing and thickness:
Material of absorber and type of coating (selective or not):
Material of absorber ducts:
Material of casing:
Material of insulation:
No. and position of drain holes:
Schematic Drawing:
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SUMMARY
All significant damage to the collector, including rain penetration, should be summarised
in Table C1.
Full details should be given in the individual test result sheets.
Table B1 All significant damage to the collector, including rain penetration
Test
Date
Start
Main Results
End
Internal Pressure Absorber
High Temperature Resistance
Exposure
External Thermal First
Shock
Second
Internal Thermal First
Shock
Second
Rain Penetration
Mechanical Load
Impact Resistance
Final Inspection
Remarks:
…………….……………….………………………………………………………………
INTERNAL PRESSURE TEST FOR INORGANIC ABSORBERS
Collector Type:
Glazed
Unglazed
Maximum collector operating pressure specified by manufacturer: ............................kPa
Test conditions:
Test temperature: ...................................................................................................... °C
Test pressure: ........................................................................................................... kPa
Test duration: .......................................................................................................... min
Test results:
148
(Details of any observed or measured leakage, swelling or distortion.)
………………………………………………………………………………………………
HIGH TEMPERATURE RESISTANCE TEST
Method used to heat collector:
Outdoor Testing
In Solar Irradiance Simulator
Test Conditions:
Collector tilt angle (degrees from horizontal): ............................................................... °
Average irradiance during test: ............................................................................. W/m2
Average surrounding air temperature: ........................................................................ °C
Average surrounding air speed: …………………………………………………….……
m/s
Average absorber temperature: .................................................................................. °C
Duration of test: ...................................................................................................... min
Additional Information:
(Especially for evacuated tubular collectors, the temperature of the collector was
measured at the location shown in the drawing below.)
Test results:
(Details of any observed or measured degradation, distortion, shrinkage or outgassing.)
………………………………………………………………………………………………
EXPOSURE TEST
Test Conditions:
Collector tilt angle (degrees from horizontal): ………………………….…………………
°
In Tables B2 and B3 full details should be given of the climatic conditions for all days
during the test, including:
daily global irradiation, H (MJ/m2);
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periods when the global irradiance G and the surrounding air temperature (ta) have
values greater than those specified in the corresponding climate parameter values;
surrounding air temperature, ta (°C);
rain (mm).
Table B2 Detail of of the climatic conditions
Date
H
MJ/m²
Ta
°C
Total:
Rain
mm
…………… days in which H > …… MJ/m²
Table B3 Detail of of the climatic conditions
Date
G
W/m²
Ta
°C
Total:
Time Periods
min
……….……. min in which G > 850 W/m²
Test Results:
……………………………………………………………………………………………
EXTERNAL THERMAL SHOCK TEST
Test performed:
Outdoors
Test Conditions:
Average irradiance during test: ............................................................................. W/m2
Minimum irradiance during test: ........................................................................... W/m2
Average surrounding air temperature: ........................................................................ °C
Minimum surrounding air temperature: ..................................................................... °C
Period during which the required operating conditions were maintained
prior to external thermal shock: ................................................................................ min
Flow rate of water spray: ................................................................................ kg/(s*m2)
Temperature of water spray: ...................................................................................... °C
Duration of water spray: .......................................................................................... min
Absorber temperature immediately prior to water spray: ............................................ °C
Additional information:
150
Test Results:
(Details of any cracking, distortion, condensation, water penetration or loss of vacuum.)
……………………………………………………………………………………………
INTERNAL THERMAL SHOCK TEST
Test performed:
Outdoors
Test Conditions:
Collector tilt angle (degrees from horizontal): ................................................................°
Average irradiance during test: ..............................................................................W/m2
Minimum irradiance during test: ............................................................................W/m2
Average surrounding air temperature during test: ...................................................... °C
Minimum surrounding air temperature: ..................................................................... °C
Period during which the required operating conditions were maintained
prior to internal thermal shock: .................................................................................min
Flow rate of heat transfer fluid: ....................................................................... kg/(s*m2)
Temperature of heat transfer fluid: ............................................................................ °C
Duration of heat transfer fluid flow: ..........................................................................min
Absorber temperature immediately prior to heat transfer fluid flow: ........................... °C
Additional information:
Test Results:
(Details of any cracking, distortion, condensation, water penetration or loss of vacuum.)
………………………………………………………………………………………………
151
RAIN PENETRATION TEST
Collector mounted on:
Open frame
Simulated roof
Test Conditions:
Method used to keep absorber warm:
Hot water circulation
Exposure of collector to solar radiation
Water spray flow rate:
…………………………………………….………………..g/(s*m2)
Duration of water spray:
………………………………………….………………………..h
Test Results:
Area with visible sign of water penetration
(expressed as a percentage of aperture area): …..………………………………………%
Give details of water penetration, reporting the places where water penetrated and the
time the sign of rain penetration took to vanish.
……………………………………………………………………………………………
MECHANICAL LOAD TEST
Positive pressure test of the collector cover
Method used to apply pressure:
Loading with gravel or similar material
Loading with water
Suction cups
Pressurisation of collector cover
Test Conditions:
maximum pressure load:
………………………………………………………….Pa
152
Test Results:
(Details of any damage to the collector cover after the test, reporting the value of
pressure load which caused the damage.)
……………………………………………………………………………………
NEGATIVE PRESSURE TEST OF FIXINGS BETWEEN THE COVER AND THE
COLLECTOR BOX
Method used to apply pressure:
Suction cups
Pressurisation of collector box
Test Conditions:
maximum pressure load:
………………………………………………………….Pa
Test Results:
(Details of any damage to the collector cover or cover fixings after the test,
reporting the value of pressure load which caused the damage.)
………………………………………………………………………………………
IMPACT RESISTANCE TEST
Test performed using:
Vertical impact (dropping ball)
Horizontal impact (pendulum)
Test Conditions:
Diameter of ball:
…………………………………………………………………………..mm
Mass of ball:
…………………………………………………………………………………..g
Test Procedure:
Drop Height
m
0.4
0.6
0.8
1.0
Number of Drops
153
1.2
1.4
1.6
1.8
2.0
Test Results:
(Details of any damage.)
………………………………………………………………………………………………
FINAL INSPECTION
Date of inspection: ………………………...
Table B4 Final Inspection
Collector Component
Collector Casing and
Fasteners
Potential Problem
Cracking/ Warping/
Corrosion/ Rain penetration
Mountings/
Structure
Strength/ Safety
Seals/ Gaskets
Cracking/ Adhesion/ Elasticity
Cover/ Reflector
Cracking/ Crazing/ Buckling/
Delamination/
Warping/ Outgassing
Cracking/ Crazing/ Blistering
Absorber Coating
Absorber Tubes and Headers
Absorber Mountings
Insulation
Deformation/ Corrosion/
Leakage/ Loss of bonding
Deformation/ Corrosion
Water Retention/ Outgassing/
Degradation
Evaluation
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C. THAI INDUSTRIAL STANDARD FOR FLAT PLATE SOLAR COLLECTOR (TIS 899-2532)
This Thai Industrial Standard specifies types, components, required characteristics, label,
samplingand judging criteria, and testing of solar collector with exposure area larger than
0.5 m2.
1. Types
Solar collector can be divided into 4 categories according to the production
processes of absorbing plates.
Type 1: The solar collector consists of an absorber plate which is produced by
electroplating technique.
chemical process.
painting technique.
other techniques.
2. Components
Generally, the solar collector consists of frame, transparent plate, absorber plate,
tubes located inside the solar collector, insulator, and container and backing plate
3. Required characteristics
3.1 Solar collector performance
3.1.1 Leakage
3.1.2 Tolerance of temperature change
3.2 Materials for solar collector
3.2.1 Transparent plate
3.2.1.1 Glass used as a transparent plate should be complied with
TIS 54 or tempered glass
3.2.2 Absorber plate
3.2.2.1 Optical property
Solar absorptance and emittancemust be complied with the
label.
3.2.2.2 Tolerance to the weather
There must be visible crack or flake at the surface of the
absorber plate no more than 1% of the whole surface.
3.2.2.3 Adhesion
The surface of the absorber plate that is peeled off with the
glue strip should be no more than 5 mm2.
3.2.3.4 Tolerance to corrosion
There must be no corrosion or swelling at the surface of
the absorber plate and there no rust should be found at
the metal base.
3.2.3 Container and backing plate
3.2.3.1 Tolerance to the weather
There must be no visible crack or flake at the surface of the
container and the backing plate.
3.2.3.2 Tolerance to corrosion
There must be no visible corrosion or swelling at the weld.
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3.2.4 Insulator
Changes of mass and dimensions of the insulator must not be larger
5%.
4. Signs and labels
There must be, at least, numbers, letters or signs indicated on the solar collector plates
visibly and permanently as follows:
1) wording “Flat Plate Solar Collector”
2) Types
3) Dimensions, total area and exposure area
4) Mass of solar collector in kg
5) Maximum working pressure in kPa
6) Minimum absortance and maximum and emittance
7) Plots of thermal efficiency
8) lot number
9) Name of manufacturer or registered trade mark
10) Country of manufacturing
5. Sampling and judging criteria
Sampling and judging criteria can be done for one particular lot with no more than 300
plates, and with the same type, materials, production process, and trading period.
5.1 Sampling and acceptance for performance testing of the solar collector
5.1.1 Random Sampling from the same lot for 1 plate.
5.1.2 The sample must be identical to item 3.1. Therefore, solar collectors in
that lot can be qualified. If any of the sample does not follow item 3.1,
another plate should be sampled for double-check.
5.2 Sampling and acceptance of the testing of absorber plate, container and backing
plate, and insulator
5.2.1 A sample of the absorber plate, container and backing plate, and insulator
are cut off from the solar collector that has been passed the performance
test and absorber plate testing.
5.2.2 The sample must be complied with the material standard for solar
collector.
5.3 Judging criteria
Samples must be complied with the sampling criteria and the standard of
material, which can be chosen as the material for a solar collector. If the
samples are qualified, that lot of solar collectors can be regarded as the solar
collectors approved by the TIS.
156
D. REMARKS ON ECONOMIC ASSESSMENT
This is just an example for a possible economic assessment of a given solar application;
other approaches may be applied as well.
Simple economic assessment by annuity method
A
Solar supported system
x
Investment cost, sum of
- collector
- collector support
- storage
- hydraulics
- auxiliary system
- installation
- control
- planning
- …..
x
Subsidy
- Calculation of annuity factor from final total investment cost (Investment cost –
Subsidy)
- Calculation of annual cost
=
total final investment cost * annuity factor
+ annual fuel & electricity cost
+ annual cost for maintenance, inspection
B
Reference system (non-solar conventional system)
Repeating the annual cost calculation for the reference system
Application:
Comparison of specific costs, e.g. heat generation costs (annual cost / annually produced
heat) between solar assisted system and reference system
Difference in annual cost may be related to annual primary energy savings, CO2 savings,
etc. See following example:
157
eingesparte Primärenergie
30%
25%
500
650
800
950
1100
1250
1400
20%
15%
10%
5%
0%
0
20
40
60
80
100
120
140
160
Speichervolumen, l/m2
Kosten eingesparte PE, ¼/kWh
0,25
0,20
500
650
800
950
1100
1250
1400
0,15
0,10
0,05
0,00
0
50
100
Speichervolumen, l/m
150
200
2
Example:
Upper figure: annually saved primary energy (difference in percent between primary
energy consumption of reference system and solar assisted system) as a function of the
storage volume (horizontal axis; liter per m² collector area) and of the collector size
(different curves; size in m²). Excerpt from a calculation of a large solar cooling system.
Figure below: specific costs of saved primary energy of the system as a function of the storage
volume (horizontal axis) and of the collector size, given in m² (different curves).
The specific costs are calculated from the difference in annual cost (solar system – reference
system) and divided by the annual saved primary energy [¼/kWhsavedPE ]. A flat cost minimum
appears in this application of large solar cooling system at collector areas > 1000 m², leading to
annually primary energy savings of > 20% in the range of an optimised storage size.
Static payback time
(Investment cost (solar assisted system) – Investment cost (reference system))
/ (annual O&M (reference) – annual O&M (solar))
In the example above, a payback time is not given, since the system (unfortunately often
the case in solar cooling systems) is under the applied cost figures not economic
beneficial