In case you didn't realize he is looking to store ALL of the summer generation into a battery and generate zero power in winter.. so rely entirely off of a battery during winter.. which is absolutely no feasible for a normal person and nobody would ever do.

I once did a related calculation on "How much of my garden do I need to dedicate to coppiced willow to heat my house for a week per year?"

I concluded that we're all going to need much bigger gardens.