Micro Hydro Generation

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. Hydro generation utilises the energy of falling water to generate electricity. A proper install has no negative effects on the local stream, simply diverting a portion of the available water and then returning that water back to the stream. An initial analysis of your site indicates you should investigate its 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 to design out batteries altogether. 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 perhaps 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.

Costs

Hydro costs are very site specific and are related to energy output and site. A proper technical survey will be needed for a quote, however as a general guideline, for low head systems (not including the civil works - so assuming there was an existing pond or weir), 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 heads, there is a fixed cost of about £10,000 and then about £2,500 per kW up to around 10kW - so a typical 5kW domestic scheme might cost £20-£25,000. Unit costs drop for larger schemes.

Grants

£5,000 Maximum.

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