Electric Vehicles Could Bolster Power Grid Backup

New study suggests EVs could act as mobile batteries to store excess renewable energy and feed it back to the grid when needed.

Apr. 3, 2026 at 2:07am by Ben Kaplan

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A bold, abstract painting in soft blues, greens, and grays, featuring sweeping geometric arcs, concentric circles, and precise spirals, conceptually representing the complex interplay of electric vehicles, renewable energy, and the power grid.A conceptual illustration of how electric vehicles could serve as mobile energy storage to help balance the power grid and integrate more renewable energy sources.San Francisco Today

A new study published in the journal Joule suggests that electric vehicles (EVs) could serve as a vast network of mobile batteries, storing excess energy from renewable sources like solar and wind and feeding it back to the power grid when demand surges. Researchers examined the potential of this vehicle-to-grid (V2G) technology in the San Francisco Bay Area, finding that proactively upgrading the grid to support V2G could significantly reduce carbon emissions and generate revenue, compared to a phased approach.

Why it matters

As more renewable energy sources like solar and wind are integrated into the power grid, there is a growing need for energy storage solutions to handle the intermittency and unpredictability of these sources. V2G technology could help address this challenge by turning EVs into mobile batteries that can store excess renewable energy and discharge it back to the grid when needed, easing strain on the grid and reducing emissions.

The details

The study examined different scenarios for EV adoption and solar energy growth in the San Francisco Bay Area, mapping when and where vehicles would charge and evaluating the cost-effectiveness of upgrading the grid proactively versus in phases. The researchers found that the optimal solution is to upgrade the power system as soon as possible to support V2G. With proactive grid upgrades, each charger would only need to generate $0.12 to $0.18 per day to offset V2G costs, compared to $1.49 to $1.78 under a phased approach. The model also estimates that annual carbon emissions between 2030 and 2045 could be reduced by up to 59,200 metric tons of CO2 equivalent with V2G and proactive grid upgrades, potentially yielding up to $47.5 million in cumulative carbon rebate revenue.

  • The study was published in the journal Joule on April 2, 2026.
  • The researchers examined potential scenarios for the San Francisco Bay Area between 2030 and 2045.

The players

Ziyou Song

Senior author and energy engineer at the University of Michigan.

Shunbo Lei

Energy engineer and co-author from the Chinese University of Hong Kong, Shenzhen.

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What they’re saying

“People have debated whether electric vehicles are truly green and sustainable because much of our electricity still comes from fossil fuels. At the same time, the grid is struggling to absorb intermittent and unpredictable renewable energy sources like solar and wind.”

— Ziyou Song, Senior author and energy engineer

“V2G is a promising technology to handle many issues in the power system, especially as we integrate more renewable energy. As renewables grow, we face imbalances of different timescales. I envision that EVs could play an important role in energy storage coordination to build a reliable power system.”

— Shunbo Lei, Energy engineer and co-author

What’s next

The researchers note that much of their work relies on forecasts, and political shifts, especially regarding EV incentives, could change the timeline for V2G adoption. Further research and policy support will be needed to fully realize the potential of this technology.

The takeaway

This study highlights the promising role that electric vehicles could play in supporting the power grid and integrating more renewable energy sources, but only if the grid is proactively upgraded to enable vehicle-to-grid technology. Coordinating EV charging with the grid could help balance intermittent renewable energy, reduce emissions, and generate revenue.