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Hydro Power: Small-Scale

For thousands of years water has been used to power mills for grinding grains, for irrigation, and even to push conveyor-belts used in mines. People today use the technology in much the same way as our predecessors, except that mills and steady flows of water are now being utilized for creating electricity instead of for grinding grain. Hydro-power technology is such that any one person or group with a large enough body of stored or flowing water can make use of their resource: remote communities, large properties, farms, small industrial or commercial enterprises and even governments and schools can put hydroelectrical technology into action, through the use of a micro hydro turbine or related technologies.

Run Of The River Generation

In its more traditional incarnation hydroelectricity requires either a stored body or a steady and reliable flow of water. For small-scale schemes it is usually the latter that is utilized - streams, rivers and spillways are ideal for what is known as 'run-of-the-river' hydroelectricity. The run-of-the-river system, sometimes referred to as 'damless hydroelectricity', uses a penstock (a gate or sluice) to draw out a portion of a flowing body of water. The penstock channels the water rapidly downhill through a turbine or series of turbines, eventually returning the water back to the source further downstream.

The technology is favoured by environmentalists because it only takes a portion of the body of flowing water (not the entire river or stream) and because it eventually returns it to its source; the surrounding environment experiences minimal impact and locations further down-river do not suffer from a decrease in water supply.

Small Scale Dams

The other feasible option for a small-scale scheme is the use of a small dam or reservoir to hold back a body of water, allowing it to be released through a channel placed at the bottom of the reservoir wall. This technique makes use of the 'head', the force generated by the combination of the height and volume of the water pushing to get out of the release channel, to power a turbine.

Systems For Home And Business

Both of the hydroelectricity schemes mentioned above are suitable for use in microgeneration situations, and there are a number of suppliers and installation services in operation that can provide the parts necessary. Some companies offer pre-packaged 'water to wire' systems which can be installed quickly and easily. These systems tend to fall into the 'micro-hydro' and 'pico-hydro' classifications, that is generation of electricity that is less than 100kW and 5kW respectively. Larger systems that fall under the 'small-hydro' (generating less than 10MW) and 'mini-hydro' (less than 1000kW) definitions may need to be custom made and installed.

It is also worth noting that the British Department of Trade and Industry offers tax breaks to those who sell back excess electricity generated by a private hydroelectric system through the Low Carbon Buildings Programme (April 2006), making it financially beneficial to have your own system in place. To be sure that the system and the company you are thinking of using for installation are properly accredited and qualified it is worth getting in contact with the Department of Business, Enterprise and Regulatory Reform who operate the United Kingdom Microgeneration Certification Scheme. They keep a register of accredited stockists and tradespeople who work within the field of hydroelectricity.