Musk unveiled Powerwall device at press conference in California . Daily use version will be able to store 7 kilowatt-hours of electricity . It will let users store renewable energy , or pay lower , off-peak rates . Comment:
Musk unveiled Powerwall device at press conference in California . Daily use version will be able to store 7 kilowatt-hours of electricity . It will let users store renewable energy , or pay lower , off-peak rates . Also revealed a larger model which is a 'infinitely scalable system '