Small hydro power: technology and current status

Hydropower, large and small, remains by far the most important of the “renewables” for electrical power production worldwide, providing 19% of the planet’s electricity. Small-scale hydro is in most cases “run-of-river”, with no dam or water storage, and is one of the most cost-effective and environmentally benign energy technologies to be considered both for rural electrification in less developed countries and further hydro developments in Europe. The European Commission have a target to increase small hydro capacity by 4500MW (50%) by the year 2010. The UK has 100MW of existing small hydro capacity (under 5MW) operating from approximately 120 sites, and at least 400MW of unexploited potential. With positive environmental policies now being backed by favourable tariffs for ‘green’ electricity, the industry believes that small hydro will have a strong resurgence in Europe in the next 10 years, after 20 years of decline. This paper summarises the different small hydro technologies, new innovations being developed, and the barriers to further development.