About Micro Hydro

Micro-hydro schemes extract energy from water flowing downhill, without the need for large dams. A range of turbines can be used, depending on the rate of flow and the head available (i.e. the height the water is falling). In addition to the turbine, civil works are required to divert water from a stream into the turbine, and return it to the stream afterwards.

The power from the turbine is delivered through a rotating shaft, which can be used to drive machinery directly, or can drive a generator to produce electricity. Micro-hydro schemes are often in off-grid areas, so any electricity produced is often used in a ‘mini grid’ for a village or town, selling power to households and businesses. The income is used to pay for operation and maintenance of the scheme, and sometimes to pay back a loan used to fund the construction. Micro-hydro is cheap to operate, but capital-intensive to install, so a subsidy is often required, unless loans are available of favourable terms.

Micro-hydro brings environmental benefits through avoiding the use of fossil fuels and by not using large dams, with their associated flooding of land. For an off-grid community, the benefits of a reliable electricity supply are significant, including refrigeration, communications, lighting, computers and the ability to run machinery. In many cases the availability of electricity allows new profitable businesses to be started, helping to pay for the micro-hydro scheme.

Micro-hydro schemes are popular in mountainous areas, with the Himalayas and Andes having large numbers of schemes, although they are also present in hilly areas in many countries. Micro-hydro schemes are also present in developed countries, where they are usually grid connected.