A new study modeling the San Francisco Bay Area concludes that vehicle-to-grid technology from electric vehicles can stabilize the power grid but requires proactive infrastructure upgrades. Researchers project rising EV and solar adoption will strain the system without new transformers and transmission lines. The findings emphasize combining V2G with grid improvements to support renewables.
Electric vehicles could transform into a vast network of backup power through vehicle-to-grid, or V2G, technology, according to a new paper by researchers including Ziyou Song, an energy systems engineer at the University of Michigan. As more EVs charge during evening peak hours, they add load to the grid alongside household appliances. V2G allows these vehicles to send energy back during high demand and recharge overnight, forming distributed batteries across cities. Song stated, “V2G is really helpful, for sure — 100 percent. But just to some extent, V2G itself cannot resolve the charging demand of so many electric vehicles in the future.” The study modeled EV adoption rates, solar growth, charging patterns, and upgrade costs in the San Francisco Bay Area. Proactive grid enhancements, such as new transformers and lines, emerged as the cheapest approach over phased reactions. This strategy enables V2G to fully offset peak loads while smoothing renewables' intermittency, unlike fossil fuels that ramp easily. Song added, “V2G plus the proactive power system upgrade will address the entire issue.” Utilities already tap large batteries, meeting 43 percent of California demand late last month—six times Hoover Dam's output. V2G distributes this capacity via EVs and pilots like electric school buses. Participants earn payments, and programs explore battery swaps to counter cycle wear. Chris Rauscher, vice president at Sunrun, noted, “When you’re operating 3,000, 30,000, 300,000, then any individual customers having different behavior won’t matter.” Active managed charging staggers nighttime loads using algorithms. Song reiterated, “We have to upgrade our power system as soon as possible, because V2G is not a silver bullet.”