![This giant 'water battery' under the Alps could be a game-changer for renewable energy in Europe | CNN This giant 'water battery' under the Alps could be a game-changer for renewable energy in Europe | CNN](https://media.cnn.com/api/v1/images/stellar/prod/220728212554-1a-innovations-renewable-energy-storage.jpg?q=w_1110,c_fill)
This giant 'water battery' under the Alps could be a game-changer for renewable energy in Europe | CNN
![Bildnummer: 53869334 Datum: 19.03.2010 Copyright: imago/Xinhua (100320) -- VAUD, March 20, 2010 (Xinhua) -- Photo taken on March 19, 2010 shows a part of the solar-powered airplane Solar Impulse in a garage Bildnummer: 53869334 Datum: 19.03.2010 Copyright: imago/Xinhua (100320) -- VAUD, March 20, 2010 (Xinhua) -- Photo taken on March 19, 2010 shows a part of the solar-powered airplane Solar Impulse in a garage](https://c8.alamy.com/comp/2RK769B/bildnummer-53869334-datum-19032010-copyright-imagoxinhua-100320-vaud-march-20-2010-xinhua-photo-taken-on-march-19-2010-shows-a-part-of-the-solar-powered-airplane-solar-impulse-in-a-garage-of-an-airport-in-the-canton-of-vaud-switzerland-swiss-adventurers-bertrand-piccard-and-andre-borschberg-planned-to-fly-the-airplane-to-attend-the-world-expo-2010-shanghai-this-year-the-solar-impulse-has-a-long-wingspan-equivalent-to-that-of-an-airbus-a340-and-weighs-as-light-as-a-car-more-than-12000-solar-cells-are-mounted-onto-the-wing-supplying-energy-to-four-electric-motors-xi-2RK769B.jpg)
Bildnummer: 53869334 Datum: 19.03.2010 Copyright: imago/Xinhua (100320) -- VAUD, March 20, 2010 (Xinhua) -- Photo taken on March 19, 2010 shows a part of the solar-powered airplane Solar Impulse in a garage
![German test pilot Markus Scherdel takes off in the solar-powered prototype airplane "Solar Impulse" from the airbase in Payerne, Switzerland, on Wednesday, April 6, 2011 for the first test flight in 2011. Solar Impulse is ultimately aiming for the aviator's dream ... German test pilot Markus Scherdel takes off in the solar-powered prototype airplane "Solar Impulse" from the airbase in Payerne, Switzerland, on Wednesday, April 6, 2011 for the first test flight in 2011. Solar Impulse is ultimately aiming for the aviator's dream ...](https://l450v.alamy.com/450v/2p77rc9/german-test-pilot-markus-scherdel-takes-off-in-the-solar-powered-prototype-airplane-solar-impulse-from-the-airbase-in-payerne-switzerland-on-wednesday-april-6-2011-for-the-first-test-flight-in-2011-solar-impulse-is-ultimately-aiming-for-the-aviators-dream-of-perpetual-flight-and-to-prove-a-point-by-flying-through-the-night-the-propeller-plane-with-a-61-meter-200-foot-wingspan-is-powered-by-four-electric-motors-and-designed-to-fly-day-and-night-by-saving-surplus-energy-from-its-12000-solar-cells-in-high-performance-batteries-ap-photokeystone-dominic-favre-2p77rc9.jpg)