An enormous water battery, which can produce electricity equivalent to 400,000 electric car batteries, has commenced operation in Switzerland’s canton of Valais. The pumped storage power station took 14 years to build and cost €2 billion.
It's an ecological battery that uses the same water over and over, and with the ability to store and generate massive amounts of hydroelectric energy, the facility will be one of Europe's main renewable energy sources.
The battery is located nearly 2,000 feet (600m) underground in the Swiss Alps and will help stabilise European energy grids.
How does it work? A water battery consists of two large pools of water, located at different heights. When power production is high, excessive power is used to move water from the lower pool to the pool at a higher height, which is similar to charging a conventional battery. When power demand increases, the water at the higher level can be released, and as it heads to the lower pool, it passes through turbines that generate electricity.
The Swiss water battery has a storage capacity of 20 million kWh, the equivalent of 400,000 electric cars. The plant has six turbines that can generate 900 MW of power. At its peak, it can power 900,000 homes at a time.
The Swiss power plant, constructed by the company Nant de Drance, commenced operation on 1 July.