Powerwall makes a whole bunch more sense for solar storage. If you're just using it for backup power off the grid, you have to convert AC -> DC -> AC again for

Powerwall makes a whole bunch more sense for solar storage. If you're just using it for backup power off the grid, you have to convert AC -> DC -> AC again for use. I don't know the all up efficiency of that system, but it's far from great. Probably <70%