Courtesy Photo / SustainX

Solar and wind power are intermittent, and if enough of them are powering the grid, some kind of storage will be necessary. And storage means batteries, right?

Not necessarily. In Seabrook New Hampshire, a start-up is doing it with compressed air.

It’s pretty easy to see how energy stored as compressed air works: When you let go of a full balloon, it flies all around the room because of the energy stored inside. So if you use electricity to run an air compressor, you basically just need to find a way to run that compressor backwards to get electricity again.