Why reservoirs are becoming increasingly important

Dusseldorf The Nant de Drance pumped storage power plant is located high in the Swiss Alps between two reservoirs. On sunny days, the huge expanses of water, a good 2000 and 2200 meters high, shine crystal blue in the middle of the peaks.

But the technology of the pumped storage power plant can play to its strengths when there is no sun shining to make the water glow. If renewable energies such as photovoltaics or wind power produce too little electricity, Nant de Drance steps in. Water then flows down from the upper reservoir through a turbine – and generates electricity. If there is too much electricity, the power plant pumps the water back up until it is needed.

For Pascal Radue, buildings like Nant de Drance are crucial for the energy transition. The hydropower boss of the US technology group General Electric Renewable Energy says: “With pumped storage power plants, existing wind power plants or photovoltaic parks can be better utilized.” Radue expects an era of expansion.