Vineyard Wind and Revolution Wind reach full operation

Federal data put Vineyard Wind’s past-year capacity near 25%

The developers of Vineyard Wind and Revolution Wind announced this week that the offshore wind farms are fully operational and can power a combined 750,000 homes in Connecticut, Rhode Island and Massachusetts. Vineyard Wind spokesperson Craig Gilvarg confirmed in an email to The Light on Friday that the project reached full operation Oct. 29; Revolution Wind announced Thursday that it had come fully online after three years of construction.

Both projects finished installing their wind turbines earlier this year, Vineyard Wind in March and Revolution Wind in September. The milestone means all of the turbines are fully functional and capable of delivering power to the grid.

Vineyard Wind is a 62-turbine farm roughly 15 miles south of Martha’s Vineyard and delivers power to Massachusetts. Revolution Wind is a 65-turbine farm south of Block Island and delivers power to Rhode Island and Connecticut. The projects are key to the states’ clean-energy goals because New England lacks the open space needed for large-scale solar or onshore wind projects.

Both projects encountered stops and starts involving the federal government, including an attempt last month to pull Revolution Wind’s permit after the project had already been completed. Green energy advocates celebrated the milestone and said the projects would eliminate 1.6 million metric tons of carbon pollution annually, equivalent to taking 325,000 cars off the road.

Conservation Law Foundation staff attorney Anxhela Mile said in a Friday statement, “A fully operational Vineyard Wind means New England families have another clean, affordable, local source of energy being delivered to their homes through the coming winter season.” She added, “Federal and state leaders should be preparing to build out more of these projects to help lower energy costs and keep our air clean.”

Although both projects only recently became fully operational, each had been delivering power for much longer, though at reduced capacity. Recently released Federal Energy Regulatory Commission data show Vineyard Wind produced 336,382 megawatt-hours between July and September of this year. The Light’s analysis estimated that output could power approximately 193,300 Massachusetts homes. The project’s developer says Vineyard Wind will power 400,000 homes once fully operational.

Revolution Wind delivered 314,321 megawatt-hours between July and September of this year, roughly 22,000 megawatt-hours less than Vineyard Wind. Its developer says the project will power 350,000 homes once fully operational.

Gordon Stewart, a Roger Williams University engineering professor, cautioned that averages do not tell the full story because wind energy is cyclical and generally less predictable than other forms of energy. Power generation is generally expected to peak in the winter months, when winds are stronger, and fall during the summer. That pattern held for Vineyard Wind, which produced approximately 410,400 megawatt-hours from October through December 2025, compared with 323,600 from April through June 2026.

The Light wrote: “But just because there is wind doesn’t mean that all the turbines are capturing it — and private companies tend to be secretive about engineering setbacks.” Vineyard Wind took 7½ months to go fully online after completing construction, compared with 1½ months for Revolution Wind.

The Light reported that Vineyard Wind’s lawsuit against GE Vernova earlier this year seemed to blame the turbine supplier for the project’s struggles to reach full capacity. In May, Vineyard Wind said in court filings and hearings that the project was producing “less than half of its expected capacity” and that 36 of the 62 turbines were not spinning. The lawsuit sought to prevent GE Vernova from exiting its contract to service and maintain the turbines before final commissioning work was complete. The parties settled in September after GE Vernova withdrew its notice of contract termination.

Stewart said next quarter’s data, as New England enters its windiest season, would be more revealing about whether the projects remained fully operational. “It’ll be interesting to see if (the projects) are fully operational,” he said. “And I think we’ll be able to see that.”

Stewart said wind farms are not expected to operate at 100% efficiency even when everything goes right, noting that no energy project is expected to operate at 100%. In a previous Light analysis of Vineyard Wind’s output data, Stewart calculated that the developer’s estimate that the project would power 400,000 homes roughly corresponded to a 50% capacity factor, meaning the wind farm would operate at 50% efficiency on average. Most offshore wind farms have capacity factors between 40% and 50%.

Stewart said onshore wind farms tend to have lower capacity factors because their turbines are smaller and wind generally has less power on land. Nuclear power plants, meanwhile, have a capacity factor of 90% or more, while coal plants average around 42%, according to federal data.

Craig Gilvarg did not answer The Light’s question about how many turbines were operational as of Sept. 1. Federal data indicated that Vineyard Wind operated at closer to 25% capacity over the past year as it worked to get up and running. “My gut feeling looking at these numbers is that roughly half of their turbines were operating at any one time,” Stewart said.

A third completed wind project, South Fork Wind, offers a glimpse into Vineyard Wind and Revolution Wind’s potential future. The 12-turbine farm, completed in 2024 and located 35 miles east of Long Island, generated roughly one-third as much power as Vineyard Wind and Revolution Wind despite being one-fifth their size. South Fork reached a capacity factor nearly double that of the two larger projects while they were still coming online.

Stewart said it would take months or years to determine how efficient the wind farms were, given the capriciousness of Mother Nature and manmade technology. The companies are still working out how to respond to changing winds. Stewart explained that although each turbine’s position is fixed, companies can program some turbines’ blades to face different directions and power down front-facing turbines that could block wind from reaching the rest of the farm. He said those decisions would have a negligible effect on overall wind patterns but could help deliver more power to consumers. “We’re going to learn a lot from these first two large-scale farms, and next year, it’ll be really interesting to see what kind of power they make,” he said.