Photos: Hybrids that give back to the grid

Pacific Gas & Electric's Vehicle-to-Grid project was demonstrated Monday in Sunnyvale, Calif., as an example of how future plug-in hybrid cars could transmit electricity in two ways: storing it conventionally to let the car get up to 100 miles per gallon, or redistributing it back to a home or the electrical grid to help curb energy demand--and perhaps make a profit.