Earlier quoted context omitted.
If you had a big enough battery, could you sell electricity back to the grid later? Get paid to charge the battery, get paid to discharge the battery? It seems silly, but actually... it's driving useful behavior I suppose. Then again, maybe a good government would notice this and just fast track grid storage rather than distribute that work to all the citizens.
Someone at the utility went through the same math you are and decided it isn't worth it at scale. It's probably not worth it at small scale.
Still, it would feel nice - after the initial cost- to have very cheap power (only charge when cheap).