The future of clean energy will depend on scaling up technologies that can store massive amounts of both constant-running nuclear and intermittent renewable power. In his latest video, ClearPath Executive Director Rich Powell tours various ideas to develop this grid-scale storage, from the typical ion battery to “rock trains” and “fire bricks.” Each of these types of storage – chemical, gravity, pressure and heat – will need reliable federal investment to get to the finish line. But the potential return could radically transform the U.S. – and global – energy grid.