They are re-using batteries that have gone past their useful lifespan in cars as excess grid storage in California. Should be doing it everywhere.

I also think the power grid issue is overblown. As prices go down and once V2L and V2G gets introduced to more cars, I actually think EV's may HELP the power grid by being able to power houses during times of high usage. If you can imagine, in the summer, you're car charges to 80% overnight, you drive it back and forth to work, plug it back in to your V2G charger at home around 50%, and then if the grid gets stressed due to high usage, your house can move over to being powered by your car, and then once the grid demand wanes, your house switches back to the grid and your battery gets charged back to 80% for the next day.