If you are asked to draw the look of a battery you will probably be quick to draw an AA dry cell or car wet battery. But the definition of a battery is not limited to these two most frequently used types of batteries. In Switzerland, for example, a "water battery" finally started operations on July 1 after undergoing a 14 -year construction process at a cost of € 2 billion (~ RM 9.4 billion).
The water battery consists of the Vieux Emosson dam and the Emosson reservoir pool located 300 meters lower in Valais. Between these two water reservoirs the Nant de Drance power station is placed 600 meters underground. When it is not peak time, water from the water reservoir pond is pumped up to a higher dam. When needed, water from the dam is released and it will drive a turbine in an underground power station.
It is capable of generating 900 MW of power to supply electricity to 900,000 homes in the surrounding area. Due to its large water capacity, it is capable of storing up to 20 GWh which is expected to also supply power to the European energy grid when needed during peak hours.
The construction of this battery took 14 years due to the need to build a 14 km long underground tunnel connecting the two dams. The higher Vieux Emosson Dam was also added 20 meters in height to allow more water to be stored.