Comment by philjohn
If you just want to come out cost neutral, the battery required is far smaller when paired with a large enough array, and a time-of-use tariff.
With 3 EV's in the house, and a 12.8kWp array, with a 10kWh battery, charging overnight in the winter on the cheap EV tariff (7p per kWh vs 27p per kWh) and exporting during the spring, summer and autumn at 15p per kWh I'm seeing an electricity bill of below 0.
Of course, with a shift in energy production to renewables, all of that maths may get upended, but for now, I'm going to break even far before my original estimates.
> Of course, with a shift in energy production to renewables
clearly, you're not in the US as renewables are considered the problem here and not part of the solution. i'm waiting for the administration to come out with clawback plans for all of the subsidies for home solar and even the EV subsidies. gotta pay for those tax cuts some how