Tag Archives: Off-grid


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:  info@picoenergy.co.uk


Pico Energy Ltd Case Study 2 Site Name: Thima
System type: Pump as Turbine Power output: 2.2 kW
Manufacturer: Kirloskar Typical Generation: 19 MWh p.a.
Client: Thima CEA Design Conditions: H = 20.00 m
Q = 0.28 m3/s
Location: Kerugoya, Kenya Commissioned: January 2002
Penstock installation Kenya
Project description:

This scheme was installed as part of a program implemented by The Micro Hydro Centre at Nottingham Trent University to demonstrate Pico Hydro technology in Sub Saharan Africa. The project was financed by the beneficiaries with some additional help from external organisations. The small generator is driven by a pump working in reverse as a turbine. It produces a constant 2.2 kW of AC electricity which provides a reliable electricity service to more than 110 households. This project won the Ashden Award’s ‘Overseas Project for Light’ in 2004.

The scheme is owned and managed by the beneficiaries. The community elected a committee to manage the collection of funds and to mobilise labour for installation. The same committee now manages the scheme operation and repairs, and tariff collection.

There are approximately 160 houses within the vicinity of the generator, the furthest of which is 900 metres from the turbine house. The locations of the houses were mapped with a GPS unit which saved considerable time as no accurate maps of the area existed. The shortest route to connect all of the houses to the generator was then worked out to ensure that all the consumers were connected. This helped to keep the connection costs for the consumers as low as possible. Insulated cables were used for all elements of the distribution system to maximise safety. Only small diameter cables were required as each house draws a small current. In addition to electrical insulation particular care was taken with regard to load management, lighting protection and earth fault protection to maximise consumer safety.


Pico Energy Ltd Case Study 1 Site Name: Kathamba
System type: Pelton Turbine Power output: 1.2 kW
Manufacturer: NTU design / Local
Typical Generation: 10.5 MWh p.a.
Client: Kathamba CEA Design Conditions: H = 28.00 m
Q = 0.08 m3/s
Location: Kerugoya, Kenya Commissioned: November 2001

 Project description:

This scheme was installed as part of a program implemented by The Micro Hydro Centre at Nottingham Trent University to demonstrate Pico Hydro technology in Sub Saharan Africa. The cost of the penstock, turbine and generator equipment was met by the project funders (European Commission) and all other costs were contributed by the 65 households which the scheme now supplies with electricity.

The scheme makes use of a very small stream on farm land in a region of Kenya to demonstrate that very useful amounts of power can be reliably generated from small resources. Capital and installation costs were minimised by training local workshops how to manufacture the turbine units and work being undertaken to install the scheme by the local community who are also the beneficiaries.

An off-grid control system maintains the voltage and frequency of the system so that sensitive mains loads such as CFL lighting can be connected. All of the loads are carefully managed through load limiting circuits which prevent the generator from becoming overloaded and enable the power to be distributed in small current packages over a 600 metre radius. In this way, it has been possible to connect 60 houses to the 1.2 kW generator. In addition to lighting, radios, small TVs and a variety of battery powered products such as mobile phones and power tools are popular loads which can be connected.