Category Archives: Hydropower


Pico Energy Ltd Case Study 10 Site Name: Culbone
System type: Pelton Turbine Power output: 4.5 kW
Manufacturer: Pico Energy Ltd Typical Generation: 24 MWh p.a.
Client: Mr S Wyard Design Conditions: H = 50.00 m
Q = 0.016 m3/s
Location: Culbone, Exmoor, Devon Commissioned: December 2012
Culbone intake
Project description:

Pico Energy have commissioned a 4.5 kW scheme in the Exmoor National Park. The challenging site is located in a remote wooded valley on the North coast of Exmoor in the hamlet of Culbone which is famous for having the smallest church in England. The hydro power system works independently of the National Grid and provides power and heating for local residents.

Pico Energy have worked with the client from initial proposal to gain approval from the National Park and to ensure the scheme has minimal impact on the picturesque location. The building work was carried out by contractors under close supervision from Pico Energy. The ‘off-grid’ generator control panel has been connected to the existing inverter and battery bank, replacing an old diesel generator as the power source. In addition to providing AC power directly to the house, the hydro generator also maintains the battery charge. If the maximum electrical load temporarily exceeds the generator capacity, then the batteries supply the shortfall via the inverter. In this way a peak load of up to 8 kW can be accommodated for short periods.

The stainless steel Pelton turbine system used for this installation was designed, manufactured and installed by Pico Energy Ltd. In addition to providing supplying all loads with renewable electricity the client receives the Feed-in Tariff on all electricity consumed.

If you have a similar project in mind, then please get in touch for an informal discussion about how we may be able to assist with the scheme implementation:

Cwm Clydach

Hydromatch Consulting Case Study 8 Site Name: Cwm Clydach
System type: Pelton Turbine Power output: 55 kW
Manufacturer: Tepersac Typical Generation: 250 MWh p.a.
Client: Cwmclydach Communities First Design Conditions: H = 85.00 m
Q = 0.1 m3/s
Location: Clydach Vale, Clydach, Wales Commissioned: April 2011

Intake Clydach

Project description:

Cwm Clydach Communities First commissioned this project in a country park, developed on the site of a former colliery. Two lakes were created as amenity features during the landscaping of the park in the 1970’s.

The intake to the hydro scheme has been formed at the outflow of the upper lake and the water returned after passing through a Pelton turbine into the lower lake providing a pressure head of approximately 85 metres. The penstock pipe is about 1 mile long and buried under an existing footpath. The ‘coanda’ screen at the intake has been protected with a concrete cover to deter potential vandals. The electricity generated is exported directly to the national grid.

The project has been well received by the local community who have taken a keen interest particularly during the construction phase. Income from the scheme is being used to support further community initiatives. A further larger scheme is planned by Cwm Clydach Communities First lower down the valley which will make use of the fall available across an 800 metre length culvert and more abundant flow rates.

Longaller Mill

Hydromatch Consulting Case Study 7 Site Name: Longaller Mill
System type: Zuppinger Waterwheel Power output: 12 kW
Manufacturer: HydroWatt GmbH Typical Generation: 70 MWh p.a.
Client: Mr and Mrs Beaumont Design Conditions: H = 2.00 m
Q = 1.00 m3/s
Location: Near Taunton, Somerset Commissioned: August 2010
Longaller Intake
Project description:

The current owners had been planning a hydropower scheme at this former mill for 20 years before the system was finally installed in 2010. Previous feasibility studies had considered various low head turbine options but all were unsatisfactory from both a cost and a planning perspective. Plans to sympathetically update the mill with a new waterwheel system were proposed and permission was eventually granted to remove the existing listed wheel which was well beyond repair and unsuitable to adapt for electricity generation.

A layout was designed which enables as much of the historic infrastructure as possible to be preserved by positioning the new drive and generator on the opposite side of the wheel to where the old pit wheel is positioned. This now sits on a reinforced wall between the wheel pit and relief channel alongside.

The mill and surrounding area flood on occasion due to downstream flow restrictions. It is possible that future flood levels could reach the height of the wheel axle. With this in mind, the gearbox unit has been designed with labyrinth seals which prevent water ingress if temporarily submerged.

Under the guidance of Hydromatch Consulting, the scheme owners carried the site preparation and building work themselves. The scheme is accredited for FITs.

Algars Mill

Pico Energy Ltd Case Study 6 Site Name: Algars Mill
System type: Francis Turbine
(installed 1924)
Power output: 1.5 kW (single phase)
Manufacturer: Gilkes Typical Generation: 5 MWh p.a.
Client: Mr and Mrs Wright Design Conditions: H = 1.70 m
Q = 0.15 m3/s
Location: Iron Acton, Bristol Commissioned: October 2009


Algars Mill

Project description:

This former watermill was originally attached to the neighbouring manor house and originally adapted for electricity production to supply the house in 1924. The DC alternator had long since disappeared and well before the current owners who have lived there for the last 27 years. A resource assessment and appraisal of the remaining open flume turbine was carried out.

The most cost-effective hydropower option identified was to refurbish the existing turbine and install a new induction generator and control system. An actuation mechanism was also designed to allow the system to start and stop automatically and respond to varying flow rates. Refurbishment required complete removal of the turbine, replacement of the guide vane linkages, drive shaft and bearings, blasting and repainting. A G83 grid connection system was installed so that the modest amounts of power generated could be directly used by the household loads. The scheme is registered for the Feed in Tariff.