A 900 MW “water battery,” which cost Switzerland €2 billion and took 14 years to build, is now in use. The battery is situated nearly 2,000 feet (600 m) underground in the Swiss Alps.
The battery has been constructed between the reservoirs of Emosson and Vieux Emosson in Valais, a canton on the southwestern side of Switzerland. The massive engine room of the plant, which is nearly 2,000 feet (600 m) underground, is over 100 feet (32 m) wide and about 650 feet (200 m) long.
Scope of Switzerland’s water battery project
The engineers had to first carve tunnels through the Alps in order to transport the building materials to the site. The project’s tunnels have a total length of about 11 miles (18 km). After these tunnels were constructed, it took 14 years to move building supplies and prefabricated structures into the mountain.
By adding 65 feet to the height of the Vieux Emosson dam, more energy can be stored in the battery (20 m). The battery is now operational and, at its most efficient, is able to supply 900,000 homes with power at once.
How water battery works and the future of this technology
The water battery comprises 2 large pools of water situated at different heights. When power production is increased, excessive power is used to relocate water from the lower pool to the pool at a higher height. This is comparable to charging a conventional battery.
The water at the higher level can be released when there is an increase in power demand. As it flows into the lower pool, it passes through turbines that produce electricity that can be used to power the grid.
Although the idea may seem novel, Switzerland has been using it for centuries. China recently decided to build 270 GW of storage capacity by 2025. Additionally, the U.S. has also been using this method for almost a century.
The 20 million kWh water battery that recently started operating in Switzerland is equivalent to 400,000 electric cars. Thus, it will assist in stabilizing the energy grid in Switzerland and other connected grids in Europe. A total of 900 MW of power can be produced by the plant’s six turbines.