Offshore wind is cutting blackout risk and power costs across the Northeast
Charles River Associates modeled the New England and New York power grids with offshore wind in the mix and without it, tracking what happens to reliability and cost during the toughest weeks of winter.
Without offshore wind, New York’s blackout risk climbs roughly 25% and New England’s energy costs rise about 10%.
The Northeast’s grid is flipping from a summer problem to a winter one
For decades, New England and New York built their power systems around summer afternoons, when air conditioning pushed demand to its yearly peak. That’s changing fast. As homes and cars switch from oil and gas to electricity, both grids are shifting toward winter peaking. When heating demand spikes on the coldest days, it strains the same natural gas pipelines that power plants also depend on to keep the lights on.
ISO-NE’s winter peak demand is projected to climb from 20.0 GW in 2025 to 26.4 GW by 2034, growing more than three times faster than its summer peak. NYISO is on a similar path, with winter demand expected to approach 50 GW by the late 2030s. Much of that New York growth concentrates downstate, in and around New York City, where demand is highest and local generation is scarcest.
Layer on the retirement of aging traditional fuel plants and tightening gas supply during cold snaps, and both regions face a narrowing set of options for keeping the grid stable and costs in check.
CRA modeled four futures for each grid, and only one keeps offshore wind in the mix
The analysis compares a Base Case, where offshore wind is built as currently planned, against three counterfactuals: canceling offshore wind with no replacement (“No Alternatives“), swapping it for onshore wind and solar (“Renewables Only“), and swapping it for natural gas (“Gas Only“). Every scenario holds reliability standards constant, so the comparison shows what it costs in dollars or in risk to go without offshore wind’s specific contribution.
In ISO-NE, canceling offshore wind and building nothing to replace it pushes modeled energy prices up 10%, from $62.0B to $68.2B. Swapping to gas gets close to the same problem. Only the Renewables Only path avoids a price increase, and even that comes with its own capital cost trade-offs described below.
ISO-NE and NYISO face the same pressure, but the numbers don’t translate directly between them
The two grids use different baseline assumptions and reliability metrics, so CRA’s scorecards for each shouldn’t be read side by side as a single ranking. Here’s what the report finds in each market on its own terms.
18 GW of offshore wind is in the plan
9 GW of offshore wind is in the plan
Where the savings from skipping offshore wind show up
Cancel offshore wind in NYISO and near-term capital spending drops 31%, from $63.1B to $43.9B. But near-term cost savings don’t tell the whole story. While capital spending may drop, the resource adequacy premium, the price of insuring against an energy shortfall, rises 32%. This means the region will spend less to build the grid but will also have to spend more covering the risk that it falls short, essentially wiping out any savings.
That extra reliance on gas matters most on the coldest days, when the pipelines are also feeding home heating and utilities have to burn pricier fuel oil to keep plants running. Offshore wind output tends to hold up during these adverse conditions, which is why removing it doesn’t just raise a single number on a scorecard. It shows up as thinner margins across the whole winter.
Winter demand growth is outpacing summer growth in both systems
ISO-NE’s own forecast shows the crossover happening this decade. Winter load isn’t just catching up to summer. In both regions, it’s growing roughly three times as fast.
Offshore wind isn’t hypothetical in the Northeast anymore
Five projects account for most of the near-term capacity CRA’s Base Case relies on.
The first offshore wind farm in the U.S., running since December 2016 and still powering Block Island a decade later.
The first utility-scale U.S. offshore wind project, delivering power to Long Island since early 2024. It hit a 90% capacity factor on the hottest day of summer 2026.
America’s first large-scale offshore wind farm. Finished construction in March 2026 and delivering power to the Massachusetts grid.
Sending power to the New England grid since March 2026, with remaining turbines set to bring it to full capacity later in 2026.
Over 70% built and sending power to the grid as of March 2026, on track to be completed in 2027 as the largest offshore wind project in the U.S.
“CRA’s new report highlights how locally generated resources like offshore wind can provide large-scale power during high-stress periods on the Northeast grid, boosting its reliability while helping to control power costs across New England and New York.”Hillary Bright, Executive Director, Turn Forward
Everything on this study in one place
Findings on this page come from “Impacts of Offshore Wind on Reliability and Affordability in ISO-NE and NYISO,” an independent analysis by Charles River Associates published through Turn Forward’s Energy Research Exchange on December 4, 2025. CRA used a least-cost integrated resource planning model to build a Base Case for each grid, then modeled counterfactual scenarios in which planned offshore wind is canceled, replaced with onshore renewables, or replaced with natural gas. ISO-NE and NYISO figures are drawn from separate scorecards with different baseline assumptions and reliability metrics and shouldn’t be read as a direct comparison between the two markets. Load forecasts reference ISO-NE’s 2025 CELT Report and NYISO’s 2025 Gold Book.