Switzerland launched a giant water battery with a capacity of 20 million kWh

Nant de Drance has launched a water-based energy storage device in the Swiss canton of Valais. Its construction took 14 years and cost 2 billion euros, because the workers had to lay 17 km of water supply in the mountains. The capacity of this giant structure is estimated at 20 million kWh, which, according to approximate calculations, should be enough to stabilize the energy system throughout Switzerland.

Structurally, the battery consists of two large reservoirs called Emosson and Old Emosson. They are located in such a way that the height difference between them reaches 700 m. This allows water to accelerate due to gravity when moving from the upper reservoir to the lower one. The moving water rotates the shafts of the generators and they generate electricity.

Six turbines are installed here, which can generate 900 MW of electricity. It will take at least 20 hours to completely empty the upper reservoir, but they plan to release the water little by little to compensate for the lack of energy in the network. And when it is in excess, pumps pump water back up and the process repeats.