Production

Storage lakes are a reserve of energy available on demand. While nuclear power plants and run-of-river hydroelectric power plants produce ribbon power, 24 hours a day, storage power plants make it possible to generate what is known as peak and regulating energy that is available as quickly as possible and can flexibly compensate for fluctuations in electricity demand. Particularly with the development of new renewable energies, such as solar and wind power, whose production is intermittent and random, and the gradual decentralisation of power generation to many smaller units, storage power plants help to provide the right amount of electricity around the clock.

The facility has 3 production plants with a total power output of 2000 MW (Fionnay in the Bagnes valley, Nendaz and Bieudron on the banks of the river Rhône at Riddes). After fulfilling their mission and driving the turbines, the waters are returned to the river Rhône. The energy produced by the complex represents a fifth of the electricity stored in Switzerland.