On Thursday, California-based Tesla Motors announced plans to expand the applications of its car batteries and use them to power buildings. The wall-mounted units are integrated into the local power grid, but can harness their excess stored power to "give customers the flexibility to draw energy from their own reserve," according to the company. Businesses and residences could utilize the solar-charged, lithium-ion batteries as hedges against power outages by providing a back-up supply of electricity and to help with load shifting, which could reduce how much power needs to be purchased from a traditional utility and when that power is drawn from the grid. They will also connect to the Internet so customers can track their energy consumption, similar to other smart home products like Nest.

Powerwall, the residential version of the batteries, will cost $3,000 for 7 kilowatt-hours worth of energy and $3,500 for 10 kilowatt-hours worth, which equates to about a third of what the average U.S. household consumes daily. These prices do not include the cost of installation or a power inverter. Customers may reserve their Powerwall now for delivery beginning in the summer.

Tesla will also sell a larger suite of batteries for businesses and utilities called Powerpack, which could be used to generate power from solar panels, windmills, and other sources during off-peak hours to use during hours of peak demand. The price of the Powerpack has not yet been announced.