I think current estimates are something along those lines. For a residential off-grid installation they suggest 100% kwh/day of battery storage. Grid power has

I think current estimates are something along those lines. For a residential off-grid installation they suggest 100% kwh/day of battery storage. Grid power has backups and mitigation strategies that could reduce that significantly. I was mostly trying to be generous to grid battery installations. For the most part 1/3 is a bare minimum still requiring natural gas emergency peak plants.