Last month, at an event to show off Tesla's newest electric car, CEO Elon Musk proclaimed, "This is the year of the solar roof and Powerwall."

It's a sentiment that might seem out of a place at a car reveal party, but Tesla's energy collection and storage systems are inextricably tied to its vehicles. The Powerwall is Tesla's wall unit, which serves as a giant battery to supply electricity for a home or electric car; the solar roof is made up of small solar panel-tiles that turn sunlight into electricity and store that energy in the Powerwall.

Musk envisions an energy-conscious society generating its own power from the sun and then using it to charge electric vehicle batteries.  Read more...