Just about the time arrives for "affordable lithium" and the tree I am feeding grows ten feet, there will arrive new batteries. The chances of having twenty or thirty astonishing superior promising technologies prove fruitless is quite small in my estimation.
500 usable amp hours is not huge. A 1,800 square ft. home would need 50 times that to be basically outfitted. With induction stove and space heating it would have to be 500 times that A 40 ton A/C unit requires how many kWh over 24 hours, you say?