This could be a bigger business than electric cars, and could enable "smart grid" (and lower bill).
Quite appropriate for name (of Nikola) Tesla, and reputation of Elon Musk.
Elon Musk says Tesla will unveil a new kind of battery to power your home | The Verge:
"...Musk had laid out his ambition to make something that would live in consumers' homes, instead of their cars. "We are trying to figure out what would be a cool stationary (battery) pack," Musk said. "Some will be like the Model S pack: something flat, 5 inches off the wall, wall-mounted, with a beautiful cover, an integrated bi-directional inverter, and plug and play."
Tesla's Elon Musk: On Creating A 'Cool' Battery System For Home Energy Storage
"Tesla already is working with SolarCity, which bundles Tesla’s battery systems with solar panels and market them to consumers and businesses. Musk is SolarCity’s chairman and a cousin of the solar company’s two founders."
Elon Musk: Tesla Could Be Worth As Much As Apple Is By 2025 | CleanTechnica