Switzerland’s Massive Water Battery Will Stabilize European Electricity Grids

The construction of a 900 MW “water battery,” which cost Switzerland two billion euros and took 14 years to complete, is finally operational. It went online on July 1, 2022. The battery is located in the Swiss Alps, almost 2,000 feet (600 meters) underground, and can store 400,000 electric vehicle batteries’ worth of energy. That’s enough juice to power 900,000 households at once!

Why Does This Water Battery Matter?

Solar and wind power

Renewable energy sources will become increasingly popular as the world works toward becoming more sustainable. However, these technologies provide intermittent power because they rely on the weather (wind) or time of day (solar). This means we must also find a way to store the electricity it generates for the times it can’t generate enough.

Dense battery packs offer a solution to this issue. Still, they need minerals like cobalt, nickel, and lithium, which must be mined – a practice that is unfavorable to the environment and sustainability efforts. The water battery doesn’t require the consumption of any materials and will never need to be replaced.

Alain Sauthier, the Nant de Drance pumped-storage hydroelectric plant director and engineer, said:

“It is an ecological battery that uses the same water over and over. The output is more than 80%: for every kilowatt hour of electricity used to pump the water upstream, 0.8 is fed into the grid. In less than ten minutes, we can reverse the direction of rotation of the turbines and switch from electricity production to storage.

Such flexibility is key in order to react promptly to the needs of the electricity grid and adapt electricity generation and consumption. Otherwise, you risk a collapse of the grid and blackout, as happened in Texas at the beginning of the year. In the future, it will be increasingly necessary to store large amounts of electricity, as renewable sources gradually replace nuclear and fossil energy.”

The 20 million kWh water battery is expected to help stabilize Switzerland’s and Europe’s energy systems. Moreover, it’s so massive that it can store more energy than Switzerland needs, hence why it can also serve other countries in Europe.

Sauthier continued:

“It can play a role in stabilizing the grid at the European level. We are geographically at the heart of the continent, and energy flows pass through Switzerland. If there is an overproduction of wind power in Germany, we can use the surplus electricity to pump and store water.”

For example, during peak demand, such as a heatwave, the battery can minimize grid overload.

What is a Water Battery?

A water battery, also known as a pumped storage power plant, is a form of hydroelectric energy storage system. The battery is comprised of two enormous pools of water that are spaced at varying heights from one another.

By pumping water up from the lower pool to the higher pool, the battery “charges,” storing extra power generated by renewable energy sources. The flow of water is reversed to “discharge,” or use the stored electricity.

How Does a Water Battery Generate Electricity?

Like other forms of hydroelectric power, electricity is generated by the movement of water via a turbine. In the case of Switzerland’s water battery, there are nine giant turbines between the two pools. As water flows from one pool to the other, it goes through the turbines, and they generate electricity.

Why Did It Take 14 Years to Complete the Water Battery?

Switzerland's Massive Water Battery will Stabilize European Electricity Grids
(Credit: Nant de Drance)

The battery was constructed between Valais, Switzerland’s Vieux Emosson and Emosson reservoirs. The plant’s vast 650-foot-long (200 meters) and 100-foot-wide (32 meters) engine room lies 2,000 feet (600 meters) underground. That’s a space big enough to fit the leaning tower of Pisa.

Thus, engineers had to dig tunnels through the Alps to transport building materials. These tunnels are approximately 11 miles long (18 kilometers)! Only after the tunnels were built could building materials and prefabricated structures are carried into the mountain to make the battery.

In addition, the Vieux Emosson dam was raised 65 feet (20 meters) to boost the battery’s energy storage capacity.

The Potential for a Water Battery Revolution

According to Australian National University’s Matthew Stocks, there are 616,000 places throughout the world where closed-circuit hydro-pumping facilities could be developed. Stocks is a researcher who based his judgment only on geographical factors. He says installing just 1% of these would be sufficient to eliminate all difficulties associated with intermittent energy sources.

Pumped-storage hydropower is a well-established technique. Enthusiastic about its potential, Switzerland, together with 11 other nations, is participating in an international event to revive the development of pumped hydro storage in power markets.