By Todd Woody
If you’re planning to buy an electric car in 2024, you’ll want to compare models’ price, range and charging speed. But you should also ask whether the car is capable of powering your home in a pinch. A growing number of EVs coming on the market can tap the considerable energy stored in their batteries to keep the lights on during a blackout and lower your utility bill when rates spike.
This “bidirectional charging” capability also promises to transform electric vehicles into a significant source of energy for utilities struggling to balance renewable energy production and climate-caused power disruptions. As EV sales grow, utilities can aggregate batteries into virtual power plants to avoid firing up fossil fuel power stations when demand spikes.
The 2.1 million electric vehicles now on the road in the US boast an estimated 126 gigawatt-hours of battery storage, according to a paper published in September by the nonprofit Smart Electric Power Alliance (SEPA). That’s five times the amount of battery storage currently connected to the grid.
“The need for backup power and resilience is becoming more front and center as we see more of these extreme weather events and grid outages in different areas in the US,” says Garrett Fitzgerald, a senior director at SEPA. California, for example, is routinely impacted by blackouts from wildfires and heat waves. A quarter of new car sales in the state are now electric, and EVs account for more than 40% of sales in some Bay Area zip codes.
When Ford Motor Co. launched its electric F-150 Lightning pick-up in 2022, the automaker touted the truck’s 131-kilowatt-hour battery pack, which can power a dwelling for days with the installation of a bidirectional charger and a home power-management system. A Tesla Powerwall home battery, on the other hand, generates 13.5 kWh.
“It’s basically 10 stationary battery storage units on one truck,” says Ryan O’Gorman, energy services business strategy lead at Ford. As more people work from home, bidirectional charging also lets vehicle owners capitalize on an expensive asset that would otherwise sit idle in their driveway, he adds.
Hyundai Motor Co.’s Ioniq 5 and Kia Corp.’s EV6 also feature bidirectional batteries, as does the EV 9, Kia’s forthcoming full-size SUV. General Motors Co. recently announced that its new line of Ultium electric vehicles will be bidirectional. The Nissan Leaf is bidirectional and Rivian has said its trucks and SUVs are equipped for two-way charging.
The elephant in the garage is Tesla Inc. The company, which sells 61% of electric vehicles in the US, has previously eschewed bidirectional charging. But at its March Investor Day event, Tesla executive Drew Baglino said he expected the company’s cars to be bidirectional-enabled within two years. “We’ve found ways to bring bidirectionality while actually reducing the cost of power electronics in the vehicle,” Baglino said.
Elon Musk, however, still seemed somewhat doubtful. “I don’t think many people are going to use bidirectional charging unless you have a Powerwall, because if you unplug your car your house goes dark,” he said at the investor meeting. Musk did allow that there’s “some value there as a supplemental energy source down the road.”