Offshore wind turbines may reduce nearby power output

Offshore wind turbines may reduce nearby power output

by Clarence Oxford

Los Angeles CA (SPX) Apr 26, 2024

As electricity demands soar with the onset of summer, East Coast cities in the U.S. look towards offshore wind projects in the Atlantic Ocean to bolster their power supplies. These projects, critical for meeting increasing electricity demands, face challenges in power prediction due to the wake effect, according to research from the University of Colorado Boulder and collaborators.

A study published on March 14 in Wind Energy Science by doctoral student Dave Rosencrans and Professor Julie K. Lundquist of the Department of Atmospheric and Ocean Sciences shows that newly built offshore turbines could reduce the power output of existing ones by over 30% due to the wake effect. This phenomenon occurs when turbines upstream slow the wind, affecting those downstream within the same farm and potentially neighboring farms up to 55 kilometers away.

Despite these challenges, the research estimates that the proposed wind farms could supply about 60% of the New England grid’s demand, covering states like Connecticut and Massachusetts. “The U.S. is planning to build thousands of offshore wind turbines, so we need to predict when those wakes will be expensive and when they have little effect,” said Lundquist, who is also a fellow at CU Boulder’s Renewable and Sustainable Energy Institute.

The wake effect is more pronounced offshore, where natural landscape features that help dissipate the wakes, like houses or trees, are absent. The team utilized computer simulations and atmospheric data to assess the impact, finding a reduction in power generation between 34% and 38% under certain conditions. This effect is crucial during summer when electricity demand peaks due to higher temperatures.

“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.”

In response to the variability of wind and solar power, grid operators are tasked with maintaining a delicate balance to prevent outages like those experienced in Texas in 2021. The ongoing expansion of renewable energy projects necessitates precise energy predictions to ensure grid stability.

To enhance these predictions, Lundquist’s team participated in the Department of Energy’s Wind Forecast Improvement Project 3, deploying instruments on islands off the New England coast last December. This effort aims to collect continuous data to refine models for better integration of offshore wind into the power system.

The rising demand for electricity in the U.S., spurred by the proliferation of electric vehicles and data centers, underscores the need for a diverse mix of renewable energy sources. “We need a diverse mix of clean energy sources to meet the demand and decarbonize the grid,” Lundquist said. “With better predictions of wind energy, we can achieve more reliance on renewable energy.”

Research Report:Seasonal variability of wake impacts on US mid-Atlantic offshore wind plant power production