What Offshore Wind Adds to a Grid Under Pressure
Electricity demand hasn’t grown like this in decades. Charles River Associates studied whether offshore wind—alongside other resources—can help the grid keep up.
In every U.S. market this study examined, offshore wind was more reliable than any other renewable source. In three of those markets, it holds its own against power plants that run whenever they’re needed.
Demand growth is outpacing supply, and the riskiest time is shifting to winter
NERC now expects demand to increase by 120 GW in the U.S. this decade. Data centers are the single biggest driver, alongside factories moving back to the U.S. and households shifting to electric heat and driving more electric cars. New power plants simply aren’t getting built fast enough to keep up, and that gap is already showing up as higher prices in capacity auctions around the country.
The type of risk is shifting too. Grid stress used to concentrate on scorching summer afternoons when AC units run full blast. CRA’s analysis finds that risk is now moving toward winter, as electric heat pumps add load in the coldest months (when solar contributes the least) and natural gas plants compete for fuel with home heating during cold snaps. The consequences of those pressures have already been demonstrated: Winter Storm Uri cut power to millions of Texans in 2021, and Winter Storm Elliott did the same across the eastern U.S. a year later.
No single power source—not gas, batteries, or renewables alone—can close a gap this size. The report calls for a mix of resources, and finds that offshore wind is one of the few that produces power exactly when the grid needs it most.
It runs hardest when the grid needs it most
Wind blows stronger and steadier over open water than over land, and offshore turbines stand taller, reaching higher into that faster wind. That translates directly into capacity factor, the share of maximum possible output a resource actually produces.
Two U.S. offshore wind farms are already proving this out. South Fork Wind, off Long Island, ran at a 46.4% capacity factor in its first full year. Block Island has run at 41.4%, even counting a maintenance shutdown in 2021. Winter is where the difference grows most. South Fork’s capacity factor climbed to 47% in December 2025; Block Island’s hit 50.9% that same month.
Offshore wind also has a location advantage: It can be built close to the coastal cities that need power most; places like Long Island, Boston, and Northern Virginia’s data center corridor, where building new power plants, pipelines, and transmission lines can be difficult or impossible.
Every grid is different, and so is offshore wind’s role in each one
Each grid operator calculates reliability scores its own way, so the report doesn’t compare raw numbers across markets directly. What holds true everywhere: offshore wind consistently ranks near the top among renewables, and its edge is sharpest where reliability risk is highest.
PJM has retired 47 GW of dispatchable generation while facing some of the country’s steepest demand growth, largely driven by data centers. Risk is now concentrated in winter.
Its reliability score hit 69% in PJM’s latest capacity auction, higher than 8-hour battery storage and gas plants that can’t switch fuels.
New York’s grid risk is shifting toward winter by the late 2030s. Gas infrastructure is constrained, and congestion is increasing downstate.
Its reliability accreditation runs about 32%, the highest of any renewable in the state and 2 to 3 times solar or onshore wind. South Fork Wind delivers power straight into constrained downstate areas.
Winter peak demand in New England is growing three times faster than summer peak. Gas pipelines run at full capacity during the heating season, and batteries struggle through long cold spells.
At low levels of deployment, reliability scores reach near 95%, rivaling dispatchable generation. That falls to about 50% once 3.3 GW is online, still meaningful. Revolution Wind is under construction; a federal stop-work order paused it for part of 2025, and work has since resumed.
California’s toughest hours are summer afternoons and evenings, as grid operators have to manage the fast drop in solar output each evening.
Coastal winds blow strongest in the late afternoon and evening, right as solar fades. That makes offshore wind a natural complement to California’s large solar fleet.
Texas’s peak demand is projected to nearly double by 2044, with heavy exposure to extreme weather and natural gas supply disruptions.
Still costs more here than other options today. Early data on wind patterns and winter performance point to the potential of a bigger role as costs come down.
Cheapest per megawatt-hour isn’t the same as cheapest per reliable megawatt
Offshore wind does cost more per megawatt-hour than solar or onshore wind, but that’s not the full story. Its reliability factor means it’s a more valuable resource than cheaper alternatives.
A 2025 analysis by Lazard puts offshore wind’s cost at $70 to $157 per megawatt-hour, overlapping with gas plants built to run during peak hours ($138–$262) and nuclear power ($138–$222), and above solar ($38–$78) and onshore wind ($37–$86). Real offshore wind contracts are landing at the low end of this range: Coastal Virginia Offshore Wind, a 2.6 GW project set to open by the end of 2026, is contracted at $62 per megawatt-hour including credit sales, as of the report’s release date.
CRA built a second metric called N-ELCC, a reliability-adjusted cost. It takes the standard cost-per-megawatt-hour number and divides it by a technology’s reliability score, so a resource that shows up reliably during grid stress scores better than one with the same price but weaker reliability.
Offshore wind’s strong reliability score, combined with a mid-range price, outperforms the gas peaking plants that operate at similar costs per megawatt-hour. Solar’s low price gets offset by its weak reliability contribution. Nuclear’s near-perfect reliability gets offset by one of the highest price tags in the mix.
Five projects already on the water
Three U.S. offshore wind farms are generating power right now, as of the report’s release date, and two more are under construction.
Online since March 2024. Posted a 46.4% capacity factor in its first full year and feeds directly into the constrained Long Island grid.
The nation’s first offshore wind project, running since 2016. Allowed the island to retire its diesel generators.
The first utility-scale U.S. offshore project. Began partial operation in 2024.
Under construction. A federal stop-work order paused work for part of 2025; construction has since resumed.
On track for full commercial service by the end of 2026, contracted at $62/MWh including credit sales.
“As concerns grow over our ability to maintain reliability and build new capacity in the near term, it’s clear we need offshore wind to support natural gas and other key power sources that are already working around the clock to keep our economy online.”Hillary Bright, Executive Director, Turn Forward
Everything on this study, in one place
Research by Charles River Associates, released through Turn Forward’s Energy Research Exchange. Figures on this page are drawn from the November 2025 report, “The Contribution of Offshore Wind to Grid Reliability and Resource Adequacy,” and its companion executive findings summary. Reliability scores (ELCC) are market-specific and not directly comparable across regions; see the full report for methodology.