Buy cheap overflow electricity to your own cars &amp; sell it back later automatically at higher demands. Interesting idea.,(reply>), @nightsage217 You're right but I don't know how much this would shorten the life span if a lot of cars would be used at low power for this (maybe it would pay of because of the cheaper tarrifs). I think a better option for demand-side management is in devices that have long thermal time constants like water heaters, just like they are doing in South Australia.,(reply>), @đeri662  Yes. no one wants the expensive battery overworked, reduced life span &amp; expired even if the car just being idle in the garage.,(reply>), Interesting idea but the effect on batteries should be evaluated before implementing a system like this.