This is what loans and installment plans are for, the payments for which come out of the savings on the utility bill.
> It's beneficial for society here if the government redistributes wealth for the benefit of all.
Which has nothing to do with batteries. If you want to do that then provide them with a refundable tax credit that allows for a negative tax rate in cases where that's deemed desirable.
And even that doesn't apply to the majority of people who are currently paying a non-negative amount of tax. Why attach strings to the money going to a middle class homeowner who should have just been allowed to keep that portion of their own salary?
Neither loans nor subsidies are dirty words IMHO.
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.