Giant ‘water battery’ plant inaugurated in Switzerland

The Nant de Drance hydroelectric power plant has six giant turbines in a cavern hollowed out of a mountain. © Keystone / Laurent Gillieron

A Swiss pumped-storage power station, which can both produce electricity and store power from other sources, has been officially inaugurated.

The Nant de Drance hydroelectric plant in western Switzerland has been operational since July. Its turbines can generate 900 megawatts of electricity per hour by releasing water from an upper reservoir through dam sluice gates.

This is a similar amount of electricity production as the Gösgen nuclear power plant in Switzerland, making Nant de Drance one of the largest power producers in Europe.

The Nant de Drance facility can also store power by pumping the water back up to the reservoir ready for re-use when more electricity is needed. The storage capacity of the plant is equivalent to more than 400,000 car batteries.

It was built to cope with fluctuations in wind and solar-power supply and help stabilise electricity output Europe-wide.

It could, for example, store surplus energy from solar plants in Europe to be later released when the sun is not shining.

The Nant de Drance station is built in a remote region of canton Valais at an elevation of 2,225 metres above sea level next to the Vieux Emosson reservoir.