US electric carmaker Tesla Motors has unveiled batteries that can power homes and businesses as it attempts to expand beyond its vehicle business.
Chief executive Elon Musk announced the firm would build batteries that store solar energy and serve as a back-up system for consumers during blackouts.
The device would allow consumers to get off a power grid or bring energy to remote areas that are not on a grid.
Tesla plans to start shipping the units to installers in the US by this summer.
In a highly anticipated event near Los Angeles, Mr Musk said the move could help change the “entire energy infrastructure of the world”.
“Tesla Energy is a critical step in this mission to enable zero emission power generation,” the company said in a statement.
The rechargeable lithium-ion battery unit would be built using the same batteries Tesla produces for its electric vehicles, analysts said.
The system is called Powerwall, and Tesla will sell the 7kWh unit for $3,000 (£1,954), while the 10kWh unit will retail for $3,500 (£2,275) to installers.
Energy comparison firm USwitch estimates that one kWh can power two days of work on a laptop, a full washing machine cycle or be used to boil a kettle 10 times.
Mr Musk said the company would partner with SolarCity to install the home batteries, but there would be more companies announced.
Mr Musk is SolarCity’s chairman and largest shareholder.