Hydro generation utilises the energy of falling water to generate electricity.

There is considerable potential for micro hydro electricity in the UK. Micro hydro refers to hydro power systems with a power rating of 100kW or less.

A proper install has no negative effects on the local water source, simply diverting a portion of available water from the stream to power the system before returning it unaltered. An initial analysis of your site may indicate if you should investigate a local water source's potential as a source of electricity.

In general, water power will produce between 10 and 100 times more power than solar or wind for similar capital investment. Since water flows day and night, a micro hydro system requires far less battery storage or grid connection than wind or PV, indeed it is often possible not to include batteries in the design at all. When your power requirements are the highest, in the winter, the water is usually flowing the fastest, and in summer the excess electricity can be utilised by immersion heaters or grain driers etc.

Generally, the larger the stream the more water available for a micro hydro development and the more power. However not all water can be diverted from a stream for energy production as water must remain in the stream for environmental reasons. The greatest fall over the shortest route is preferable when choosing a micro hydro site and more head is usually better, since power is the product of head and flow. Thus more flow is required at a lower head to generate similar amounts of power. Also, with a higher head the turbine is able to run at a higher speed.

Micro Hydro is a condensed version of traditional Hydro Electric Generation. Electricity is produced by channelling a body of water (such as a damned river, a flowing river, or a water body with a sufficient fall in height) into a turbine. This turbine then produces electricity and ejects the water back into the original source further downstream.

A correctly specified and designed system should not affect the local ecosystem or the water source.

Several different types of water turbines can be used in micro hydro installations, depending on the head of water, the volume of flow, and such factors as availability of local maintenance and transport of equipment to the site.

A Pelton Wheel, one of the many types of turbines used in Micro-Hydro.

Hydro costs are very site specific and are related to energy output and site and a proper technical survey will be needed for a quote. However, as a general guideline, costs may be in the region of £4,000 per kW installed, up to about 10kW and would drop per kW for larger schemes. For medium systems, there is a fixed cost of about £10,000 and then about £2,500 per kW up to around 10kW. A typical 5kW domestic scheme might cost £20-£25,000. Unit costs drop for larger schemes.

Feed in Tariff (FIT).

Micro Hydro systems are eligible for the Feed in Tariff. Eligible systems are paid the following rates for 20 years:

For more information on the FIT, see our Feed in Tariff FAQ, call 01293 821345 or contact us online.