Thanks to its topography and high average levels of annual rainfall, Switzerland has ideal conditions for hydropower utilisation. Hydropower underwent an initial period of expansion towards the end of the nineteenth century, experiencing a boom between 1945 and 1970 when numerous new run-of-river power plants in the lowlands and the largest storage power plants were built.
Based on the estimated mean production level, hydropower still accounted for almost 90% of domestic electricity production at the beginning of the 1970s, but this figure fell to around 60% by 1985 following the entry into operation of Switzerland’s nuclear power plants, and now accounts for around 55%. Hydropower remains Switzerland’s most important domestic source of renewable energy.
Today there are 579 hydropower plants in Switzerland (power plants with a capacity of at least 300 kilowatts) which produce an average of around 35,913 gigawatt hours (GWh/y) a year. 47.4% of that is produced at run-of-river power plants, 48.2% at storage power plants and approximately 4.4% at pumped storage power plants. Two-thirds of this energy is produced in the mountain cantons of Uri, Graubünden, Ticino and Valais, while Aargau and Bern also generate significant quantities. Around 11% of Switzerland’s hydropower generation comes from facilities situated on bodies of water along the country’s borders. The hydropower market is worth around CHF 1.8 billion (basis = delivery from power plant at 5 centimes per kilowatt hour), and is therefore an important segment of Switzerland’s energy industry. (text informations: http://www.bfe.admin.ch/themen/00490/00491/index.html?lang=en