The killer application for smart grid?

PHEVs: Killer app for smart grid?

What about plug-in electric cars and the smart grid? If millions of drivers started charging their cars in the early evening, it would require construction of more power plants and potentially be more polluting, according to some researchers.

This is where "smart charging" comes in. Instead of topping off a car's battery right before dinner time, a smart charging system will charge at off-peak times, taking advantage of available power generation capacity. Although this isn't yet done, the idea is that the car owner could get a slight discount on the electricity rate for charging at off-peak times. The system should be smart enough to know when to charge and still ensure a car is ready to go when a driver specifies. Here is a photo of a system designed by the Pacific Northwest National Laboratories for smart charging.

Utilities are looking at plug-in electric vehicles as more than an added load on their network, though. The cars' batteries can serve as a way to stabilize frequency on the grid and, years from now, feed stored energy back into the grid.