A revolutionary new form of energy storage is operating in Switzerland after 14 years of construction, and is changing the energy landscape - both literally and figuratively.
The massive engineering work for this $2 billion 'water battery' project, completed in July this year, has created a remarkable subterranean system that has a storage capacity of 20 million kilowatt hours, enough to store the excess energy from the country's wind, solar, nuclear or hydro and channel, on demand, it to nearly 1 million homes.
Located under the Emosson and Vieux Emosson in the Swiss Canton of Valais, the Nant de Drance 900 megawatt 'water battery' required 14 miles of tunnels under the Swiss alps in order to assemble vast turbines and pumps linked to two water reservoirs 1,800 feet underground.
This clever renewable energy storage system takes advantage of the fact that electricity can be “stored” by using it to move an object - in this case water.
Water from one large pool is pumped into another large pool (from excess clean energy generated elsewhere) in an underground chamber above. In this way electricity is “stored” in the sense that when power is needed, the water is then pumped through hydroelectric turbines to the chamber below with nothing other than the force of gravity. The electricity immediately generated from the kinetic energy of the falling water into the turbines is equivalent to plugging into a standard battery.
This pumped storage power plant is seen as an essential cog in the wheel for ensuring security of supply and grid stability in Switzerland and in the surrounding countries.
It's yet another ingenious solution to a modern problem.