Switzerland builds the world’s largest water battery to store surplus renewable energy
Nant de Drance represents something genuinely exciting: proof that we can store renewable energy at a scale that changes how entire continents manage their grids. Tucked 2,000 feet inside the Swiss Alps, the plant holds 20 million kWh by moving water between two mountain reservoirs — absorbing surplus solar and wind, then releasing it as hydropower within minutes when demand spikes. It can supply roughly 900,000 homes and acts as a rapid-response buffer for Switzerland and neighboring European countries. Projects like this show that the hardest engineering problems in the clean energy transition are solvable.









