The Tesla Powerwall can store power from solar panels and from the electricity grid and provide a secure backup in the case of a power outage.
In theory, the device, which will fit on the wall of a garage or inside a house, could make solar-powered homes independent of traditional energy grids.
“The goal is complete transformation of the entire energy infrastructure of the world, to completely sustainable zero carbon,” Musk told reporters before unveiling the Powerwall in a stylish warehouse space outside Los Angeles.
Examples of the sleek device – available in a range of colours – were lined up in the hall. “It looks like a beautiful sculpture on the wall,” said Musk.
All the power for the evening demonstration came from his new batteries, hooked up to solar panels on the roof, he said.
The device, which will cost about R41500, will go on sale in the US later this year.
It will be rolled out internationally next year, with Germany seen as a key market. The device is about 15cm thick, 1.2m tall and 90cm wide.
The battery could be a huge boon for underdeveloped regions, where power is often unreliable despite abundant solar energy, said Musk. “This is going to be really great for the poorest communities in the world. This allows you to be completely off-grid.”
Musk stressed, however, that moving advanced economies such as the US away from unsustainable fossil fuels was a key goal. “I think we should collectively do something about this … we have this handy fusion reactor in the sky, called the sun,” he said.
The Powerwall comes in 10kilowatt-hour weekly-cycle and 7kWh daily-cycle models, both of which are guaranteed for 10 years and are sufficient to power most homes during peak evening hours.
Last year, Tesla announced the construction of the world’s largest lithium-ion battery plant in Nevada, a $5-billion (about R60-billion) “gigafactory” with Japanese electronics giant Panasonic.
Tesla will run operations, while its Japanese partner will make battery cells destined for the plant and invest in equipment and machinery.