Wind turbines create two problems for radar on ships and for ground-based systems looking for aircraft. The steel support towers can reflect electromagnetic waves, making it more difficult for radar to pick up nearby objects, while the rotating blades can create a “blade flash” on a radar screen, appearing to be another object where there is none.
Pentagon officials in recent weeks have blocked reviews of 150 onshore wind farms, citing issues of national defense and radar interference. President Trump has called wind farms ugly and expensive, and has vowed not to allow them to be built.
But researchers who study radar interference say the problem is manageable, by using new technologies and by adjusting where companies build wind turbines.
Hao Ling, a professor emeritus of engineering at the University of Texas at Austin, participated in government studies looking at radar interference from wind farms in 2013 and 2022. “There will be some interference,” Dr. Ling, an expert in radar signal processing, said. “That’s the nature of the physics. But it’s a solvable situation.”
A 2024 report by the Energy Department stated that new technologies and collaboration between federal agencies and the wind industry have “enabled federal radar agencies to continue to perform their missions without significant impacts, and have also enabled significant wind energy deployments throughout the United States.”
To cope with wind farm interference, newer solid state radar systems can be adjusted to eliminate some of the disturbance from the rotating blades. Turbine blades can also be coated with radar-absorbing carbon or other composite materials used on stealth aircraft to dampen some of the distortion.
Experts also say the shape of towers and blades can also be designed to make them a smaller target for radar signals and can lessen the scattering effect.
In 2023, Republican lawmakers asked Congress’s watchdog arm, the Government Accountability Office, to look at the potential impacts of offshore wind farms, including how they might affect military operations and maritime navigation. The G.A.O. convened a panel of 23 experts and consulted with the Defense Department.
The G.A.O. study found several ways to solve the problem, including making some areas off limits or temporarily turning off turbines during military operations, according to Frank Rusco, director of natural resources and environment at the G.A.O. and an author of its 2025 report.
Dr. Rusco said the interference issues are the same whether the turbines are on land or at sea. “The physical properties of the wind farm that can disrupt some radar would be the same,” Dr. Rusco said.
Interference from wind farms can cause problems for ground-based radar used to track aircraft, but does not affect radar used by aircraft flying above the turbines, he noted.
Since late last year, the Interior Department has tried unsuccessfully to halt five offshore wind farms in various stages of construction along the Atlantic coast, citing national security concerns. But federal judges dismissed those arguments.
Scientists, engineers and federal regulators have worked together for more than 15 years to manage interference. The Energy Department tracks the location of 75,727 wind turbines in 45 states and territories to help military and civilian planners.
Dr. Rusco said wind farm developers and the military had discussed the issues of radar interference before, during and after the process of picking a site for proposed wind turbines. “That’s a really important piece from a national security standpoint,” he said.
