A May 2015 article in Forbes magazine calculated that using a Tesla Powerwall 1 model combined with solar panels in a home would cost 30 cents/kWh for electr…
A May 2015 article in Forbes magazine calculated that using a Tesla Powerwall 1 model combined with solar panels in a home would cost 30 cents/kWh for electricity if a home remains connected to the grid (the article acknowledges that the Tesla battery could make economic sense in applications that are entirely off-grid).
Event text from Wikipedia: “Tesla Powerwall” (linked citation above)