EVs can power the grid. Why aren’t more of them doing it?

When some EV owners in California and Massachusetts plug in their cars, the large batteries inside now serve a second purpose: sending power back to the grid when the vehicles do not need it and earning cash for their owners in the process. In one Massachusetts pilot program, that could mean as much as $3,000 this summer as EVs help ease strain on the grid during heat waves. It’s a use for EVs that has technically been possible for years. It could play a significant role in supporting the grid if it was rolled out at scale. But the programs in California and Massachusetts are still just pilots. What would it take for vehicle-to-grid (V2G) systems to actually be widely used? The hardware challenge More EVs are becoming capable of sending power back to the grid. GM already had 12 models designed to send power directly to homes, and a recent software update made it possible for those vehicles to work with the grid as well. About 250,000 of those GM vehicles are on the road, which the company says represents around a gigawatt of power—enough, by its estimate, to power the city of San Francisco for about two days. Tweaking the software in an EV is fairly straightforward. The bigger hurdle is the cost of installing a bidirectional charger. “We’re seeing an average cost for customers all-in that’s over $20,000,” says Rachel Ackerman, senior program director at the Massachusetts Clean Energy Center, the agency managing the pilot there. “The installation cost alone can be $16,000—part of that is panel upgrades and making sure you have all the right systems connected.” In the Massachusetts pilot, government funding is covering the cost of the equipment. But for other drivers, the cost is a major barrier. Some homeowners might invest in a bidirectional charger because they want backup power for their house; the same technology can double as grid support. Buying a charger solely to send power to the grid likely doesn’t make economic sen