Hydro electric power in Cornwall

Alan BurgessEnergy ManagerSouth West water

What is hydropower

• Hydropower, or hydroelectricity, is a clean energy technology that uses moving water to produce electricity. In a hydroelectric system, water flows downstream through a hydraulic turbine that spins and in turn rotates adjacent generators to transform the rotational energy into electricity

In the beginning - Water Wheels

• Water wheels have been used for thousands of years for industrial power. Their main shortcoming is size, which limits the flow rate and head that can be harnessed.

• On average, the undershot wheel uses 22 percent of the energy in the flow of water, while an overshot wheel uses 63 percent (as calculated by English civil engineer John Smeaton in the 18th century)

• The migration from water wheels to modern turbines took about one hundred years.

Hydro – Some ‘traditional’ technologies

PELTON FRANCIS TURGO CROSSFLOW

PROPELLOR

Hydro – Some ‘new’ Technologies

Zeropex Difgen

Archimedes Screw KSB Pump

Generating capacity

• What does a good hydro scheme look like?

• Ideally - High flow, high head, high utilisation factor

• 1 m3 (1000 litres) of water falling 1m every second, would produce around 7kW

Hydro in Cornwall

• Overall - 18 hydro installations totalling 1.586MW• 7 Commercial (80kW – 300kW), 1.445MW• 11 Domestic (3kW – 30kW), 0.141MW

(SWW – none) source

REVision 2010 – June 2004

Potential sites identified from:•Terence O’Rourke/ETSU report•Cornwall RE studies •Regen SW’s

Constraints:•seasonality of water flows•financial viability of projects•willingness of landowners and •riparian rights owners to advance projects•the need for Environment Agency acceptance and permitting.

Overall target 9MW Hydro

REVision 2020 – June 2005

Opportunities – South West

“We have used the term ‘barrier’ to identify a site where there is sufficient height in river level to provide a hydropower opportunity. These sites are mostly weirs, but could be other man-made structures, or natural features such as a waterfall”.

Feed in Tariff – 1 April 2010

Hydropower – the EA position

• A sustainable hydropower scheme builds environmental protection into the siting and design of the scheme.

• Key features include:• A fish-friendly turbine, such as the Archimedes screw,

and/or adequate screening of the turbine. • Safe passage for fish where appropriate.

• Sufficient flow in any depleted reach to maintain the ecology and the fishery, including its amenity value.

• Design that avoids impairing flood management structures or adversely affecting land drainage so that flood risk in the area is not increased.

You probably need to apply for a licence.. • ..if you want to impound water or take

more than 20 cubic metres (4,000 gallons) of water per day from a:• river or stream • reservoir, lake or pond • canal • spring, or • an underground source

• Before you apply for a licence refer to the Catchment Abstraction Management Strategy (CAMS) for your area. These describe the availability of water for abstraction in each catchment:• Fal & St Austell Streams• North Cornwall• West Cornwall

Avon Reservoir 117 kWCrownhill WTW 425 kWLittlehempston 480 kWMary Tavy 2600 kWMeldon Res. 430 kWMorwellham 640 kWRoadford Res. 975 kW

Total Capacity 5.6MW(Devon – 26 schemes and 6.8MW)

South West Water hydro

• Constructed and filled 1990• Cost £75 million• Capacity 37,000 megalitres• Area 3 sq.km• Maximum release 148Ml/d• Max. Head 38m

• 3 x Francis turbines by Biwater• 730kW (shown in this photo)• 180kW• 40kW compensation m/c

Wheal Jewell Res.

170m head 3.2m pipe

Bennett’s Res’s.

70m head 0.8m pipe

Mary Tavy Generating Station

Catchment 125 sq. km1500-1800 mm rain/annum.Reservoir Area 0.026 sq.km

No.1 Pipeline

No.2 Pipeline

• Fed from Bennett's Reservoir• Commissioned December 1932• 3 x Francis turbines by Gilkes• 70m head• Each 220kW @ 410v

Mary Tavy Plant No.1

• Fed by Wheal Jewell Reservoir• Commissioned July 1942• 3 x Pelton Wheel turbines by Gilkes• 170m head• Each 650kW @ 410v

Mary Tavy Plant No.2

SWW’s renewable energy targets

• Currently generate ~17GWh • Plan to double this by 2015• Double again by 2020 – in line with Government

suggested WI target of 20% self supply• Particular focus on ‘on-site’ use.

• We shall consider all RE technologies:• Best for the site• Where most cost effective

• Starting with hydro…

What SWW are planning…

• Wimbleball 300kW• Pynes 260kW• Avon 245kW• Brokenbury (W) 225kW• Roborough 200kW• Colliford 100kW• Bratton Fleming 75kW• St Cleer 40kW• Hayle (W) 22kW• Drift ?• Others…

Conclusions

• Hydro is a proven technology• has it’s part to play• not necessarily the easy option• speak to the Environment Agency early on• Large volume, high head, high utilisation is good…• other renewable technologies should be considered

as well…

Thank you…

Some images and copy compliments Wikipedia..