Comment Do the math (Score 1) 296
Automotive grade lithium batteries are slowly falling in price but currently cost about $500 per kWh and can last perhaps 3000 charge-discharge cycles, so the cost to store and release one kWhr is about 16 cents, more than the total price of electricity in most of the US even at peak periods, but a good bit less than the retail price of electricity in Japan, about 32 cents. So in Japan it might actually make sense, depending of what the peak/off-peak differential is. But as suggested in the initial post, yes, is would make just as much sense to simply put some batteries in the basement and forget the cars. For that matter, you don't need lithium, lead batteries - cheaper but less durable - work out to about the same cost per kWh stored and released. But as lithium battery prices continue to fall, the day is not that far off when storing electricity from intermittent solar and wind sources in very large batteries will be economically feasible.