"It’s already cheaper to build a new solar or wind farm than a coal plant. But when the sun isn’t shining and the wind isn’t blowing, renewable electricity can still be fairly expensive to store–even though the cost of batteries is dropping. If the world shifted to 100% renewable electricity right now, we might pay more on electric bills. A new solution that uses basic physics could cut the cost of storage in half, or by as much as 80% over the total life of the system. It makes it possible for renewable power to be cheaper than fossil fuels all day, every day of the year, everywhere. “Our solution, for the first time, will enable the world to achieve this,” says Robert Piconi, CEO and cofounder of Energy Vault, the startup that developed the new system. Tata Power, the giant Indian electric utility, will be the first customer."