Energy from low head water sources.

The high cost of electrical power from fossil fuels in the developed countries, the lack of indigenous fuels in the developing countries, the world wide abundance of hydro sites with potential capacities in the region of 10 kW and recent UK legislation ensuring reasonable 'buy back' prices for surplus electricity from private generation, has led to a resurgence of interest in micro hydro sites. The authors describe a modular low head hydro device capable of efficient electrical power generation from available resource heads of as little as 1 metre. The device consists of a chamber which, by use of suitable valve action on the water flow, acts as a water to air gearbox and results in air being alternatively drawn into and expelled from the chamber. A Wells turbine located in the air ducting is directly coupled to an electrical generator, the type of which depends on user requirements. An analysis of a unit utilising a 10 kW resource with a head of 1 m is presented, as are indications of how production costs may be minimized by using locally available skills and materials. (A)