How future cars could power homes
Electric vehicles provide energy storage, on wheels. But it has been an untapped resource, unable to help shore up the power grid and back up homes and businesses during outages.
Last weekend, California Gov. Gavin Newsom signed a new law that will help harness that energy. The bill, proposed by State Sen. Nancy Skinner, D-Berkeley, authorizes the California Energy Commission, the state agency in charge of energy policy, to require that all new electric vehicles sold in the state are equipped with so-called “bidirectional” charging by 2027 — not just pulling energy, but sending it back.
Electric car batteries can hold about 60 kilowatt-hours of energy, enough to provide backup power to an average U.S. household for two to three days — or far longer, if the home’s electrical use is conserved.
Meanwhile, Americans face a growing threat of rolling blackouts as the power grid is overtaxed during periods of peak demand, such as during heat waves.
Most EVs today have one-direction charging. Power is taken from the grid and charges the car’s battery.
By harnessing the untapped battery storage capacity of electric vehicles, states can address three challenges at once: cleaning up the air while keeping the lights on and reducing energy bills.
Only the Nissan Leaf, Kia EV-6, Hyundai Ioniq 5 and Ford F-150 Lightning offer built-in “bidirectionality” to homes or the grid. Tesla recently announced that its vehicles will be “bidirectional” by 2025.
Santa Cruz Mountains resident Tammy Snyder, who plugged in her EV during last year’s fierce winter storms said “bidirectional charging will be a game changer.”
“If a power outage occurs, people with bidirectional charging can ride out the outage in relative comfort for quite a long time,” said Snyder, whose home is more than a dozen miles away from the nearest town. “One EV battery can power a refrigerator and other important devices for days.”
California is already far ahead. Last year, 25% of new cars sold in California were zero-emission, far outpacing the nationwide rate of 9.3%.
The California effort comes as the Biden administration sets the stage for a major national expansion of EV use. The U.S. Environmental Protection Agency proposed strict new limits on emissions that would require as many as two-thirds of new vehicles sold in the U.S. to be electric by 2032. That’s a nearly tenfold increase over current electric vehicle sales.
Because California has such a large market for cars, the new law could lead to a nationwide change in auto standards, said Kat Snyder of 350 Silicon Valley — Palo Alto Climate Action, an environmental group.
“Bidirectional charging will help with electric grid stability and, as is often the case with wildfires, can help local communities keep the lights on when the power goes down,” she said.