A Massachusetts V2G pilot is moving vehicle-to-grid charging from grid-nerd slide decks into customers’ garages. Eversource, National Grid, EnergyHub, Sunrun and the Mobility House are launching an early test that lets participating utility customers send electricity from compatible EV batteries back to the grid during high-demand periods, with compensation for doing it.
The project plugs into ConnectedSolutions, an existing demand-response program used by National Grid and others for home batteries and related equipment. In this version, an EV with the right hardware can act less like a parked appliance and more like a dispatchable battery, although only during events called by the utility.
Chip Silverman, Sunrun’s director of grid services, said Massachusetts’ test could produce the operational lessons needed to expand the technology. That is the unglamorous part of V2G: utilities do not just need batteries, they need software, customer controls, charger standards and enough predictable participation to trust the resource when the grid is tight.
How does vehicle-to-grid charging work?
Vehicle-to-grid charging, often shortened to V2G, uses a bidirectional charger so power can flow both into an electric vehicle and back out to a home or the grid. During a demand-response event, such as a heat wave with heavy air-conditioning use, the utility can draw limited power from enrolled EVs instead of relying only on power plants or grid-scale storage.
Russell Vare, vice president of vehicle-grid integration at the Mobility House North America, said the battery discharge is limited to a small number of hours each year and is not meant to be a daily drain. The point is to hit the awkward peaks, when electricity demand rises faster than the grid would prefer.
Participants in the Massachusetts program can specify when they normally need their cars, according to the companies involved. That detail matters. A grid program that strands someone before a commute is not a grid program, it is a cancellation machine with a plug.
The broader pitch is that many EVs sit idle for long stretches, while their batteries hold far more energy than a typical home backup unit. The companies argue that aggregating many vehicles into a virtual power plant lets utilities pull a small amount from each battery and still create a useful grid resource.
Utilities are looking at V2G while electricity demand is being pushed up by data centers, EV adoption and heat pumps. At the same time, power companies are adding more wind and solar, which need storage or other flexible resources because generation changes with weather and daylight. Grid upgrades, battery facilities and transmission lines all cost money, and those costs often land on customer bills.
Vare described EV batteries as a low-cost flexible storage option for the grid. That remains a claim the pilots have to prove at scale, because hardware costs, installation complexity and standards still matter. EnergyHub president Seth Frader-Thompson said in a statement that bidirectional charging should become more accessible as equipment gets cheaper, installation becomes easier and standards mature.
Compatibility is still a constraint. Not every EV can export power to the grid, though more models are being built with bidirectional capability. Nissan has approved a bidirectional charger for the Leaf in the United States, according to Nissan.
The Massachusetts test also pairs naturally with managed charging, which staggers when EVs charge overnight so drivers do not all plug in at the same high-load moment. If the pilots work as advertised, EV owners get paid, utilities get a controllable buffer, and non-EV customers could benefit if the system avoids some pricier grid investments. That is the theory. The pilot is where the spreadsheet meets the driveway.
This story draws on original reporting from WIRED.
