I was discussing solar with a mate last week.
This is in Oz so the sun does shine.
He was complaining that his input tariff was about to drop to 15c/KW.
(How much they pay him for the power from his panels)
Some power companies down here are starting to signal that soon they will CHARGE people to take the excess power from their panels.
His solution is not a Tesla battery but to replace their second car with an electric vehicle.
He claims that you get three times the storage of a fixed battery plus…a car.
Charge it all day for free, use it all night for the house.