An electric school bus can spend only a few hours each day doing what it was bought to do. The rest of the time, it sits. That idle period is becoming interesting to power companies. The battery that moves children around town in the morning can also store electricity for later use. In some places, utilities are already testing whether that stored energy can help during periods of high demand.
The idea is called vehicle-to-grid, or V2G. It allows electricity to move in both directions between a vehicle and the power system.
