The fact that millions more EVs will be on the road in the coming years has stoked concerns about a US electric grid that is already overtaxed as the climate crisis exacerbates power reliability issues across the country.

But what if EVs could actually make the grid more resilient and reliable?

That’s one of the multibillion-dollar questions shaping the transition away from fossil-fuel-powered vehicles to battery-powered ones. It’s the subject of federal research and investment, pilot programs by utility companies, and interest among stakeholders looking to leverage EVs’ mobile power storage—their batteries—to help shore up an already-stressed grid.

“EVs could be a burden,” Ryan Gallentine, managing director of Advanced Energy United (AEU), a trade group representing the advanced energy industry, told Tech Brew, “or they could be an additive resource, depending on how well we manage it.”

AEU has model policies and regulations it’s pushing to get enacted. The group backed a bill in Maryland, the DRIVE Act, that will require utility companies to support vehicle-to-grid (V2G) technologies.

If millions of vehicles suddenly start plugging into the grid all at once, it could create additional capacity constraints. But industry stakeholders are optimistic about the opportunities around vehicle grid integration, or VGI, which encompasses policies and technologies that enable EV charging to benefit the grid.

“Picture EVs as mobile battery-storage systems. EVs can absorb excess power when available and store that energy for future needs,” Paul Gasper, a battery degradation scientist at the National Renewable Energy Laboratory, said in a statement. “There is potential to store renewable energy within the global EV fleet to improve the flexibility and resilience of our power grid.”