In the Swiss Alps, located in a subterranean cavern in the Canton of Valais, lies Switzerland's new huge water battery. This pumped storage power plant can store as much electricity as 400 000 electric car batteries.
So what is this water battery? Basically it's a type of hydroelectric energy storage. Also known as a pumped storage power plant, it consists of two large pools of water located at different altitudes. According to Euronews.green the battery can store the surplus energy by pumping water from the lower pool up to the higher pool.
When the stored energy is needed, the battery releases the water back into the lower pool. When the water floods back, it rotates a turbine which generates hydroelectric power.
The battery features six pump turbines and has a total power output of 900 MW which is enough to power 900 000 homes. It’s located 600 meters underground and took 14 years to finish.
Large energy storage projects like this one are very useful when it comes to storing excess energy from infrequent energy sources just like solar and wind.