Hydroelectric: Current UK Use
There are three main categories used to define the output from hydroelectric power:
- Large-scale capacity (systems producing more than 20 megawatts) in the UK is currently 907 megawatts.
- Small-scale capacity (systems producing less than 20 megawatts) in the UK is currently 503 megawatts.
- Micro-scale capacity (systems producing less than 50 kilowatts) in the UK is currently 46 megawatts.
Total hydroelectric capacity in the UK is approximately 4,244 megawatts (including 2,788 megawatts of pumped storage capacity).
Likely contribution of hydroelectric power to the renewables targets
The UK currently generates about 0.8 per cent of its electricity from hydroelectric schemes – most of which are large-scale schemes found in the Scottish Highlands. Hydroelectric is a proven and efficient technology. The most modern plants have energy conversion efficiencies of 90 per cent and above. Many smaller schemes already exist and more continue to be developed.
Future development
Opportunities to increase large-scale hydroelectric in the UK are limited as most commercially attractive and environmentally acceptable sites have by now been utilised. In the spring of 2005 construction began on a large 100-megawatt scheme at Glendoe. This scheme is due to commence generation towards the end of 2008. There are several new small-scale hydroelectric schemes in planning or development. A number of other smaller schemes have also been approved in Scotland over the past few years, such as the 3.5-megawatt development at Kingairloch in Lochaber and the 2.2-megawatt scheme at Braevallich in Argyll. These schemes will provide enough electricity to meet the demands of over 5,000 households.
Some old watermills are being refurbished and brought back into the energy supply network. If small-scale hydroelectric power from all of the streams and rivers in the UK could be tapped, it would be possible to produce 10,000 gigawatt hours (1 gigawatt hour = 1,000,000 kilowatt hours) per year – enough to meet just over 3 per cent of our total electricity needs and making a significant contribution to the Government’s renewables target of 10 per cent by 2010.