Products - Hydro Technologies
Hydro Technologies
Micro Hydro Generation
Micro hydro is suitable for situations where there is a combination of sufficient water flow and 'head' (the height the water drops) to drive a turbine to generate electricity. The output from the system is a product of the two, with some efficiency factors to consider.
Not very much water is needed if the water drops more than 20metres (for example a mountain stream) or very large amounts are needed if the water only drops a few feet (a large river), not all the water in a stream may be taken for hydro purposes. Typically only up to 50% is allowed and it is necessary to obtain an abstraction license from the Environment Agency.
The system requires an intake for the water, a penstock through which the water is transported to the turbine. The turbine, generator and control gear need to be housed. Hydro can be used for off-grid or grid connected applications.
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 makes use of 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 should be made so as to 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, water usually flows at its fastest, and in summer the excess electricity can be used by immersion heaters or perhaps grain driers etc.
Generally, the larger the stream then the more water is available for a micro hydro development and also 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. Hydroelectric systems are totally site specific. You need a flow of water and a head of water to give you the latent power. Your turbine supplier will be able to calculate the potential in any location and advise you on its viability. Given the right location, hydro power is a renewable, low maintenance source of energy.
Given a suitable location, a run-of-river hydro scheme may be a practical and economic project that could provide power for a single residence or community. Recent technological advances in turbine efficiency mean that even locations with relatively small flows can generate electricity efficiently.
The British Hydropower Association has a useful guide to UK Mini Hydro Developments at www.british-hydro.org that you can download or view online.
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.
Financial Assistance
Some councils have been willing to offer small grants towards small-scale renewable energy projects in their area on an ad hoc basis. District and County Councils should be able to advise on the availability of such funds.
The VAT payable on hydroelectric plant has been reduced to 5% for domestic and other non-commercial developers for systems supplying buildings which are either residential or used for charitable purposes.
The DTI's Low Carbon Buildings Programme provides grants of up to £30,000 for small scale (up to 100kW) hydro projects for householders and community organisations.
Micro Hydro Schemes, Extraction License & Planning Permission
You will have to obtain an extraction license from the Environment Agency or the Scottish Environmental Protection Agency (SEPA) to divert water from a water course (even if the water is returned) and this will specify how much water may be diverted and when.
The Environment Agency are responsible for all water courses in England and Wales and will take into account the environmental impact particularly in times of low rainfall on fisheries. However they usually look favorably on renewable energy projects.
As well as this you will probably also require planning permission to erect a building to house the turbine especially if the project is in a National Park, AONB or Conservation Area.
Hydropower Facts
» Hydro produces 17% of the WORLD'S electricity
» It is, by far, the world's no.1 source of renewable electricity
» Hydro beats all other electricity generating technologies with a PAY BACK ratio of 300 (energy produced / energy to produce)
» There are NO CO2 emissions from hydro projects
» 40% of the UK's renewable energy generation is provided by hydropower
» Twenty five countries depend on hydropower for 90% of their electricity; twelve are 100% reliant on HYDRO
» 99.3% of the electricity generated in Norway comes from hydropower
» Vietnam has approximately 2500 'micro' hydro schemes producing electricity for 200,000 households
» Less than one third of the world's practical hydro capacity has been developed
» SMALL HYDRO schemes have minimal visual impact on their surrounding environment
» Hydropower, after 150 years as a generating source, is still one of the most inexpensive ways to generate power