https://qz.com/1288623/solar-energy-companies-are-using-california-homes-as-batteries-to-power-the-grid/

Every new home in California is going solar by 2020. If solar-energy companies have their way, those homes also will come with batteries.

Companies like Tesla and SunRun are starting to bid on utility contracts that would allow them to string together dozens or hundreds of systems that act as an enormous reserve to balance the flow of electricity on the grid. Doing so would accelerate the grid’s transformation from 20th century hub-and-spoke architecture to a transmission network moving electricity among thousands or millions of customers who generate and store their own power. “It’s less like broadcast and more like the internet,” says Haresh Kamath at the Electric Power Research Institute (EPRI).