Offshore wind wake losses reached 38% and extended 34 miles downwind
Offshore wind turbines can steal power from each other — with losses reaching 38% and stretching 34 miles downwind.
The U.S. is building thousands of offshore wind turbines across the Atlantic, enough to power more than 10 million homes. It’s one of the most ambitious clean energy expansions in the country’s history.
But researchers at the University of Colorado Boulder have identified a problem hiding in plain sight: the turbines may be working against each other. Machines at the front of a wind farm strip energy from the air before it ever reaches the ones behind them — and the losses may be far larger than the industry had accounted for.
In December 2023, they traveled to islands off the New England coast and installed a suite of instruments: weather monitors, radar sensors, and related equipment.
A hidden drag built into the design
When a wind turbine spins, it doesn’t just generate electricity — it also changes the air around it. The blades extract energy from the wind, leaving behind a slower, more turbulent stream. Every turbine downwind then has to work with that depleted air. That’s the wake effect, and it’s a fundamental physics problem that no engineering fix has fully solved.
Offshore environments make this worse, not better. On land, trees, buildings, and uneven terrain constantly stir the atmosphere, helping wakes break apart before they travel too far. Out on the open ocean, none of that exists. The surface is flat, the air is smooth, and wakes persist far longer than they would over land.
Using computer simulations and observational atmospheric data, doctoral student Dave Rosencrans and professor Julie Lundquist calculated that the wake effect could reduce total power output by 34% to 38% at a proposed offshore wind farm along the U.S. East Coast. Most of that loss comes from turbines interfering with each other within a single farm — not from one farm stealing wind from another.
Summer is the worst time for wakes — and the most critical for the grid
Not all seasons are equal when it comes to wakes. During hot summer days, the air sitting just above the cool ocean surface tends to be unusually stable. That stability means turbulence doesn’t mix the air the way it normally would, so wakes hold their shape longer and travel farther.
The researchers found that under these conditions, wakes can reach turbines as far as 55 kilometers — roughly 34 miles — downwind. That’s enough to affect not just turbines within the same farm, but neighboring wind farms entirely.
The timing isn’t convenient. Summer is also when electricity demand peaks across the U.S., as millions of air conditioners run simultaneously. Grid operators are counting on offshore wind to help carry that load — but that’s precisely when wakes are doing their most damage to output.
“Unfortunately, summer is when there’s a lot of electrical demand,” Rosencrans said. “We showed that wakes are going to have a significant impact on power generation. But if we can predict their effects and anticipate when they are going to happen, then we can manage them on the electrical grid.”
Still enough to power New England — if managed well
The losses are real, but they don’t make offshore wind unviable. Even after accounting for the full wake effect, the researchers estimated that the proposed Atlantic wind farms could still supply approximately 60% of New England’s electricity demand — a substantial share for a region covering six states: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.
The Biden Administration set a target of 30 gigawatts of offshore wind capacity by 2030, enough to power more than 10 million homes for a year. In early 2024, the country’s first large-scale offshore wind project, off the Massachusetts coast, began delivering power to the New England grid. More turbines are under construction off Rhode Island, Virginia, and New York.
The gap between what’s possible and what’s actually delivered depends heavily on how well operators can predict and manage wake losses. A 38% reduction that arrives as a surprise is a crisis. That same reduction, anticipated and planned for, becomes a manageable engineering constraint.
Measuring the ocean wind — from the inside
The core problem with predicting offshore wind has always been data. Forecasting models relied for years on intermittent readings from passing ships and satellite observations — useful, but too sparse and inconsistent to build reliable predictions around.
Lundquist’s team moved to change that. In December 2023, they traveled to islands off the New England coast and installed a suite of instruments: weather monitors, radar sensors, and related equipment. The work is part of the Department of Energy’s Wind Forecast Improvement Project 3, a collaboration between CU Boulder, Woods Hole Oceanographic Institution, and several national laboratories. The instruments are designed to collect continuous data for at least a year.
Why accurate wind forecasting is now a grid-stability issue
The power grid operates on a razor-thin real-time balance between supply and demand. When that balance breaks, the consequences can be severe — as the 2021 Texas winter storm demonstrated, when power outages killed nearly 250 people.
Electricity demand in the U.S. is only going to grow. Analysts project consumption will rise nearly 5% over the next five years, driven by electric vehicles, data centers, heat pumps, and expanded manufacturing. That’s a sharp acceleration from the roughly 0.5% annual growth rate of the past decade.
Grid operators integrating more renewable energy need precise forecasts to safely reduce dependence on fossil fuel backup sources. A surprise shortfall from offshore wind on a hot August afternoon is exactly the kind of gap that forces operators back to gas peaker plants. Better wake models could let operators see those shortfalls coming hours in advance — and the sensor network now collecting data off New England is a first step toward that kind of foresight.
The results of the research were published here David Rosencrans, Julie K. Lundquist, Mike Optis, Alex Rybchuk, Nicola Bodini, Michael Rossol. Seasonal variability of wake impacts on US mid-Atlantic offshore wind plant power production. Wind Energy Science, 2024; 9 (3): 555 DOI: 10.5194/wes-9-555-2024
Daniel García is an Editor-in-Chief with strong expertise in structural work and engineering principles. He combines this technical foundation with deep knowledge of energy, spatial design, and emerging technologies, bringing a forward-thinking and analytical approach to editorial leadership.
