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British Hydro Association
Annual Conference 2008
Severn Trent Water’s Hydro Expansion
Martin Dent
Todays Presentation
• Company Profile: Severn Trent Water Ltd (STWL)
• Why Should STWL Invest In Renewables ?
• STWL Renewable Energy Activities & Plans
• Case Study 1 : Upper Derwent Valley
• Case Study 2 : Lake Vyrnwy
• The Future
Company Profile : Severn Trent Water Ltd
• 2nd Largest Water Utility in the UK.
• FSE 100 Listed Company
• We provide :
• 2 billion litres of drinking water each day, to
• 8 million customers
• We have a large asset base
• 5170 sites
• >1000 sewage treatment works,
• > 3000 sewage pumping stations.
• 40 large impounding reservoirs
STWL region 21,000 km2 across
Central England and Mid-Wales
Why Should STWL Invest In Renewables ?
From This …
…… To This
Gloucester (Summer 2007)
In 2007 it rained ...and rained ..and
Whatever actions are taken
over the coming years to
reduce emissions,
it is clear that climate change
already has serious
implications for our
operations and strategic
development.
We therefore need to
understand the impacts of
climate change on areas
such as water supply, water
usage, and sewerage, and to
develop adaptation
strategies.
Severn Trent’s Response to Energy Issues
NET ENERGY USE
KPI
Targeted reductions of electricity
imports
Energy Efficiency Plans
Renewable Energy Growth
Renewable Energy Activities
17%
In 2007/08
We generated 17% of our
electricity demand
30 %
Renewable Energy
Technologies
• Large Wind
• Hydro- Electric
2012/13
Renewable Energy
Target
• Biomass AD
• Sewage Sludge AD
• Energy From Waste
• Micro Renewables
Checkley
Wanlip
Minworth
Finham
Derby
Brancote
Ladybower
Alfreton
Newthorpe
Mansfield
Scunthorpe
Gainsborough
YADDLETHORPE
What’s Out There Now
} = 17%
Retford
GAINSBOROUGH
HYDRO
RETFORD
LADYBOWER
Rushmoor
CHP
MANSFIELD
Loughborough
Monkmoor
VYRNWY
MONKMOOR
Barnhurst
ALFRETON
NEWTHORPE
STOKE BARDOLPH
CHECKLEY
DERBY
STRONGFORD
TOTON
BRANCOTE
LOUGHBOROUGH
MELTON
RUSHMOOR
FOUR ASHES
WANLIP
Melton
BARNHURST
WIGSTON
HARTSHILL
MINWORTH
HINCKLEY
COALPORT
CLYWEDOG
BARSTON
ROUNDHILL
Clywedog
Toton
KIDDERMINSTER
RUGBY
Four Ashes
FINHAM
REDDITCH
WORCESTER
Vyrnwy
Wigston
HAYDEN
Stoke
Bardolph
NETHERIDGE
Hinckley
STROUD
Strongford
Roundhill
Kidderminster
Worcester
Redditch
Stroud
Netheridge
Hayden
Barston
Claymills
Rugby
7 Growth Areas
Renewables - 2005 to 2015
300
29.1%
30.6%
30.7%
30.0%
24.9%
250
25.0%
19.0%
16.0%
16.5%
20.0%
17.1%
150
15.0%
100
10.0%
50
5.0%
-
0.0%
2005/06
2006/07
2007/08
2008/09
2009/10
2010/11
Years
2011/12
2012/13
2013/14
2014/15
CHP - Excluding trade waste
Wind
Hydro
Energy Crop
CHP - Trade waste
Advanced Digestion
Energy From Waste
% Self Supply
% Self Supply
21.1%
200
GWh
30.7%
1.87%
Hydro Turbines
• Investigations in 4 areas:
– Impounding Reservoirs
– Flows in water distribution networks
– Sewage treatment outfalls to river
– Run of river (reservoir inlets)
2012/13
Hydro – Impounding Reservoirs
1.87%
• Desk study of 40
reservoirs
– Flow in
– Compensation flow
– Flow to treatment
• 550 kW at Upper
Derwent Valley.
• 135 kW at Vyrnwy
• Various sub 50kW
2012/13
Micro Hydro
Minworth 70kw
Strongford STW 7 kW ?
Vyrnwy
Run of River
Scheme ?
Case Studies
1. Upper Derwent Valley
2.Lake Vyrnwy
Case Study 1: Upper Derwent Valley
Howden Reservoir (1910)
Derwent Reservoir (1915)
Gravity Off Takes :• 100 ML/D To Bamford WTW
• 50 ML/D to Yorkshire Water
Ladybower Reservoir (1945)
• 57MLD Compensation flow to River Derwent
• 60MLD pumped to Bamford WTW
Bamford WTW supplies 160MLD to
the East Midlands via the DVA.
The DVA transports water to Leicester
7o miles way without any pumping
History Of HEP in UDV
•
HEP has existed in the UDV since 1945
•
2 turbine sets installed as part of the Ladybower reservoir project.
– Power needed to operate 3 pumps to lift water to Bamford WTW.
– Included a small generating unit to supply heat and lighting
– 1976 the equipment removed and sent to Glasgow Tramway museum.
•
Replaced with 2 direct drive Gilkes turbine pumps.
•
2000 Turbines were refurbished and drawoff pipework replaced.
•
2007 one of the turbine pumps was replaced with a turbine and
generator to enable HEP export to the grid
•
…… 2010 The Next Chapter
Upper Derwent Valley Catchment
Ave 75 MLD
TO RIVELIN LOWER
RESERVOIR & WTW
Ave 50 MLD
265.2m
Ave 73 MLD
YWS
INTAKE
50 MLD
HOWDEN AQUEDUCT
HOWDEN
236.0m
214.8m
213.6m
DERWENT
125 MLD
90 MLD
160-185 MLD
BAMFORD
WTW
203.0m
RIVER ASHOP
LADYBOWER
60 MLD
10 MLD
Ave 100 MLD
60 MLD
RIVER NOE
Ave 70 MLD
57 MLD (comp)
10 MLD
66 MLD (excess)
HydroSim Modelling By Jacobs
415,000
416,000
417,000
418,000
394,000
393,000
393,000
"
415,000
416,000
417,000
418,000
420,000
421,000
387,000
419,000
387,000
418,000
Howden HEP
rwe
De
qu
nt A
e du
Rivelin Tu
nnel
386,000
ct
Rivelin Tunnel Intake
"
386,000
Ladybower HEP
"
385,000
•
•
•
•
•
•
•
Characteristics of the 3 Reservoirs and
catchment diversions
Operation of raw water aqueducts
28 years of Historical Daily Flow Data
Reservoir Operating Rules
EA Licence Constraints (compensation)
Bamford WTW Water Supply Demands
Yorkshire Water Demands
Simulates hydropower generation
385,000
•
394,000
Inputs
418,000
419,000
420,000
421,000
Model Results (1)
• Howden Catchment yields 75 MLD (average daily),
peak of 120 MLD
• HEP at Howden 150kw at 100% capacity factor
• Option to install 300kw at 50% capacity factor.
• 1.5 GWH/yr
300kw
Model Results (2)
Utilising Howden Aqueduct
• Discharging Howden
flows into Ladybower
could provide 700kw at
50% capacity factor.
• Risks include
– pressurising aqueduct
– Reduced gravity storage
for Bamford WTW.
700kw
Model Results (3)
• HEP at Derwent Dam
discharging into Ladybower
• Combined catchment yield
in excess 200 ML/D
(average daily)
• HEP 900kw at 50%
Capacity Factor.
• Risks include
- Reduced gravity storage
for Bamford WTW.
900kw
Model Results (4)
• Existing HEP on
compensation flow (57MLD)
• Additional HEP at Ladybower
capturing spill flows
(>150MLD over 20% of time)
• Installing a second 250kw
turbine generator at
Ladybower would provide:– additional HEP capability
– Standby facility for the existing
turbine.
• 0.5 GWH p.a estimated add’l
generation
Summary
Additional 550kW by Jan 2010
TO RIVELIN
LOWER
RESERVOIR &
WTW
265.2m
HOWDEN
HOWDEN AQUEDUCT
300kW
236.0m
YWS
INTAKE
50 MLD
214.8m
213.6m
DERWENT
125 MLD
160-185 MLD
BAMFORD
WTW
203.0m
RIVER ASHOP
LADYBOWER
RIVER NOE
60 MLD
250kW
Additional
CAPEX £1.5 million
Payback <
Issues To Be Resolved
•
•
•
•
•
Grid Connection to Howden est.£500k.
Planning consent (PDNPA).
Generator Lead time
Access for Contruction
Achieving acceptable payback
– Howden scheme estimated £1,400k
– Ladybower scheme estimated £600k
Lake Vyrnwy
• Britain’s first large
masonry dam (1881-1890)
• At opening was largest
reservoir in Europe
• 2 Nr 30 kw turbines
generate on compensation
flow.
• Turbines are now > 60yrs
old,
• History of reliability issues.
• Intermittent fault on Control panel.
• Severe vibration could lead to imminent
failure.
Project Proposal
Replace 2 turbines with single larger turbine + new MCC.
• Larger unit is a turbine previously used at Ladybower, newly
refurbished it is an ideal match (efficiency curve) for the predicted
Vyrnwy flows.
Power Generation
• Yearly average 109kW (82% increase) calculated from historical
river flow data.
• Maximum production increased from 60kw to 135kw.
X Efficiency
X
X
Turbine
Data
Turbine : Design Outputs
Head
X
X
Max Flow
X
X
X
X
22.9 m
MLD
Power
kw
Effic %
65
150
88.9
99
84.8
49
74.2
(750l/s)
Standard
Compensation
Flow
(520l/s)
Low Flow
25
45
(290l/s)
Hydrological data* indicates flows will :
• exceed 65 MLD 33% of the time
• exceed 45 MLD 92% of the time
* Courtesy of National River Flow Archive
Project Scope and Timetable
Remove existing turbines
Replace :• Inlet pipework
• Equipment supports
• Lifting equipment
Install
• New control panel with remote monitoring
• Refurbished (2007) Ladybower turbine
• CAPEX £450k, payback in less than 5 years.
• Estimated completion April 2009
The Future ?
An Example Of How Energy Was Once Wasted
Acknowledgements:
Consultant :Jacobs
THANK YOU FOR LISTENING
Turbine Supplier :Gilkes
Contractor: Adroit Construction
email: [email protected]