The simple scheme for large scale power storage entails the use of a hybrid, solar, wind, hydroelectric, system. A closed loop system would pump water into a reservoir with excess power produced by wind and solar and run this through turbines in times of low power production. Such a system would be expensive and complex and I'm not certain how efficient it could be made to be. Of course, it's mandatory to keep enough water available for LV fountains and golf greens! GD
