Accounting for 20% (around 3,400 TWh) of global electricity production – even though its contribution to gross final energy consumption is only about 2% – hydropower plays a vital role. This is largely due to the fact that it can be readily regulated to meet fluctuations in demand and substantial reserves can be stored in reservoirs. Hydropower supplies around 56% of Switzerland's electricity needs. Worldwide, there are at least 47,655 large dams and an estimated 800,000 smaller ones.1,2 Since 2000, investments in hydropower pro-jects have risen once again. The World Bank and the World Commission on Dams expect to see further strong growth in this sector3. The key figures for Switzerland are as follows:
- 576 large plants (>300 kW capacity), plus around 700 microhydropower plants (<300 kW).
- About 1,400 withdrawal sites4 and 102 reservoirs >0.1 km2 5
- Total electricity production (2010): 66.3 TWh/year; hydropower 37.5 TWh/year (56% share)6
- A notable feature of hydropower in Switzerland is the high proportion (57%) of production to meet peak demand from Alpine reservoirs; 43% comes from run-of-the-river plants.
- Storage pump consumption (2010): 2.5 TWh/year