"Here's the problem: Solar and wind power are intermittent. Sometimes it's sunny, sometimes it's not, and it's the same for wind. But the grid needs constant and reliable sources of power."
"What's the answer? One solution, says Imre Gyuk, a researcher at the Department of Energy, is to store that energy. Gyuk and engineers at power companies have an idea for how to do that."
"'You put a large number of small batteries around a neighborhood,' Gyuk says, 'just like the neighborhood transformers - just a little green box that's innocuous.'"
