Photos: Hybrids that give back to the grid

Plug-in hybrids are cousins of mass-market hybrids like Toyota's Prius, but on steroids. They have much larger batteries that owners can recharge overnight simply by plugging their cars into a wall outlet through a cord attached to the rear bumper. PG&E and CalCars brought three different plug-in hybrids to the Alternative Energy Solutions Summit at Advanced Micro Devices' headquarters in Sunnyvale.

The lithium-ion batteries for plug-in hybrids can store up to 9 kilowatt/hours of electricity in the trunk of a car. It takes about 5 or 6 hours to fully charge the battery from a common household wall outlet, which costs about the equivalent of 55 cents a gallon to fill up, according to PG&E.

Photo by Tom Krazit/CNET News.com