holy_calamity writes "Researchers in Delaware are working with electricity grid giant PJM on a scheme to use the batteries of electric vehicles to backup the grid while parked. Cars typically spend 23 hours a day off the road. During that time electric or plug-in hybrid vehicles can soak up excess generated power or trickle juice into the grid to smooth out mis-matches between supply and demand. Just 100 electric vehicles running the vehicle-to-grid software like their current prototype can provide 1MW of storage. City officials in Austin, Texas are keen to try the idea."