Hydropower in general

Approximately 70% of the earth’s surface is covered with water, a resource that has always been central to human development. The use of hydropower has been characterised by continuous technical development, and it is currently the second most used renewable energy source in the world, just behind solid biomass. Hydro supplies the vast majority of renewable electricity, generating 16.6% of world supply and 92% of total renewable energy electricity (IEA, 2003).