 Tesla and Panasonic opened Giga Nevada, a battery factory in Nevada, in 2016, where they make a battery storage device called Powerwall that stores solar power for use as a battery backup.The device is sold to companies including SolarCity.SolarCity ran a 2015 pilot project in 500 California houses, using 10-kilowatt-hour battery packs, using the GridLogic software for Powerwalls as a grid backup resource.