First, Randy Ross bought a Chevrolet Volt. Faced with the need to charge his car and eager to cut his utility bill, he installed solar panels on the roof of his Pleasanton, Calif., home.

Now Ross, 61, has taken the next big step toward energy independence: his own battery storage system, which gives him a source of backup power and could ultimately let him tap solar electricity whenever he needs it, not just when the sun is shining.

Battery-based energy storage – for homes, businesses and the electric grid – is a hot new industry in Silicon Valley, driven by advances in battery chemistry and state policies designed to support the emerging technology.

"It's pretty amazing how much growth there will be in energy storage," JB Straubel, chief technology officer for Tesla Motors Inc., said at a recent industry event. "We have to get to a 100 percent renewable grid, and storage becomes an absolute imperative to get there."

read full article via Energy storage seen as next step for 'green' power.