A huge battery made of air

Deep in a cavern in the Swiss Alps, an innovative system that stores electricity as compressed air is being developed in a pilot project that is a world first. The hope is that the system will give a boost to renewable energy, as well as reaffirm Switzerland’s role as Europe’s “battery”. Sun and wind energy have an irregular output. Often, lots of electricity is produced during times of low demand. So how can this situation be exploited? This is one of the main challenges to implementing renewable energy. Giw Zanganeh thinks he has the answer. The solution of the young engineering graduate of the federal technology institute ETH Zurich is based on compressed air – or more concretely, on the storage of this air in tunnels and spaces deep in the mountains. The principle is simple, said Zanganeh, who is in charge of the Alacaes project, which is supported by the energy ministry. “Excess electricity is used to power a compressor, which pumps air into the cavern. When ...