Stones that store heat, heat that generates steam, steam that expands in a machine that, in turn, generates electricity: this is an energy storage system that’s so simple it’s revolutionary – because instead of using “rare earth” minerals or raw materials that are only present in certain areas of the planet: it simply uses ordinary stones.

It’s called TES (Thermal Energy Storage) and it was inaugurated on November 4 at the combined cycle power plant in Santa Barbara in Cavriglia, in Tuscany. This area has a long history of mining and using coal, but today it’s shaping up to be a real energy innovation hub.