> In my mind it's all a coordination problem.
But that's the point. It isn't. Electricity costs more in the evening than during the day and there is a technology that can profitably be used to arbitrage the difference. There is no coordination problem at all, people have the direct individual incentive to buy the technology, on credit if necessary, without any form of government subsidy or involvement whatsoever.
That cow is looking too spherical for my tastes. Credit is another thing which is highly intertwined with goverment involvement.