When the Trump administration last year sought to freeze construction of offshore wind farms by citing concerns about interference with military radar and sonar, the implication was that these were new issues. But for more than a decade, the United States, Taiwan, and many European countries have successfully mitigated wind turbines’ security impacts. Some European countries are even integrating wind farms with national defense schemes.
“It’s not a choice of whether we go for wind farms or security. We need both,” says Ben Bekkering, a retired vice admiral in the Netherlands and current partner of the International Military Council on Climate and Security.
It’s a fact that offshore wind farms can degrade radar surveillance systems and subsea sensors designed to detect military incursions. But it’s a problem with real-world solutions, say Bekkering and other defense experts contacted by IEEE Spectrum. Those solutions include next-generation radar technology, radar-absorbing coatings for wind turbine blades and multi-mode sensor suites that turn offshore wind farm security equipment into forward eyes and ears for defense agencies.
How Do Wind Farms Interfere With Radar?
Wind turbines interfere with radar because they’re large objects that reflect radar signals. Their spinning blades can introduce false positives on radar screens by inducing a wavelength-shifting Doppler effect that gets flagged as a flying object. Turbines can also obscure aircraft, missiles and drones by scattering radar signals or by blinding older line-of-sight radars to objects behind them, according to a 2024 U.S. Department of Energy (DOE) report.
“Real-world examples from NATO and EU Member States show measurable degradation in radar performance, communication clarity, and situational awareness,” states a 2025 presentation from the €2-million (US$2.3-million) offshore wind Symbiosis Project, led by the Brussels-based European Defence Agency.
However, “measurable” doesn’t always mean major. U.S. agencies that monitor radar have continued to operate “without significant impacts” from wind turbines thanks to field tests, technology development, and mitigation measures taken by U.S. agencies since 2012, according to the DOE. “It is true that they have an impact, but it’s not that big,” says Tue Lippert, a former Danish special forces commander and CEO of Copenhagen-based security consultancy Heimdal Critical Infrastructure.
To date, impacts have been managed through upgrades to radar systems, such as software algorithms that identify a turbine’s radar signature and thus reduce false positives. Careful wind farm siting helps too. During the most recent designation of Atlantic wind zones in the U.S., for example, the Biden administration reduced the geographic area for a proposed zone off the Maryland coast by 79 percent to minimize defense impacts.
Radar impacts can be managed even better by upgrading hardware, say experts. Newer solid-state, phased-array radars are better at distinguishing turbines from other objects than conventional mechanical radars. Phased arrays shift the timing of hundreds or thousands of individual radio waves, creating interference patterns to steer the radar beams. The result is a higher-resolution signal that offers better tracking of multiple objects and better visibility behind objects in its path. “Most modern radars can actually see through wind farms,” says Lippert.
One of the Trump administration’s first moves in its overhaul of civilian air traffic was a $438-million order for phased-array radar systems and other equipment from Collins Aerospace, which touts wind farm mitigation as one of its products’ key features.
Saab’s compact Giraffe 1X combined surface-and-air-defense radar was installed in 2021 on an offshore wind farm near England.Saab
Can Wind Farms Aid Military Surveillance?
Another radar mitigation option is “infill” radar, which fills in coverage gaps. This involves installing additional radar hardware on land to provide new angles of view through a wind farm or putting radar systems on the offshore turbines to extend the radar field of view.
In fact, wind farms are increasingly being tapped to extend military surveillance capabilities. “You’re changing the battlefield, but it’s a change to your advantage if you use it as a tactical lever,” says Lippert.
In 2021 Linköping, Sweden-based defense contractor Saab and Danish wind developer Ørsted demonstrated that air defense radar can be placed on a wind farm. Saab conducted a two-month test of its compact Giraffe 1X combined surface-and-air-defense radar on Ørsted’s Hornsea 1 wind farm, located 120 kilometers east of England’s Yorkshire coast. The installation extended situational awareness “beyond the radar horizon of the ground-based long-range radars,” claims Saab. The U.K. Ministry of Defence ordered 11 of Saab’s systems.
Putting surface radar on turbines is something many offshore wind operators do already to track their crew vessels and to detect unauthorized ships within their arrays. Sharing those signals, or even sharing the equipment, can give national defense forces an expanded view of ships moving within and around the turbines. It can also improve detection of low altitude cruises missiles, says Bekkering, which can evade air defense radars.
Sharing signals and equipment is part of a growing trend in Europe towards “dual use” of offshore infrastructure. Expanded dual-use sensing is already being implemented in Belgium, the Netherlands and Poland, and was among the recommendations from Europe’s Symbiosis Project.
Baltic Power
In fact, Poland mandates inclusion of defense-relevant equipment on all offshore wind farms. Their first project carries radar and other sensors specified by Poland’s Ministry of Defense. The wind farm will start operating in the Baltic later this year, roughly 200 kilometers south of Kaliningrad, a Russian exclave.
The U.K. is experimenting too. Last year West Sussex-based LiveLink Aerospace demonstrated purpose-built, dual-use sensors atop wind turbines offshore from Aberdeen. The compact equipment combines a suite of sensors including electro-optical sensors, thermal and visible light cameras, and detectors for radio frequency and acoustic signals.
In the past, wind farm operators tended to resist cooperating with defense projects, fearing that would turn their installations into military targets. And militaries were also reluctant to share, because they are used to having full control over equipment.
But Russia’s increasingly aggressive posture has shifted thinking, say security experts. Russia’s attacks on Ukraine’s power grid show that “everything is a target,” says Tobhias Wikström, CEO for Luleå, Sweden-based Parachute Consulting and a former lieutenant colonel in Sweden’s air force. Recent sabotage of offshore gas pipelines and power cables is also reinforcing the sense that offshore wind operators and defense agencies need to collaborate.
Why Is Sweden Restricting Offshore Wind?
Contrary to Poland and the U.K., Sweden is the one European country that, like the U.S. under Trump’s second administration, has used national security to justify a broad restriction on offshore wind development. In 2024 Sweden rejected 13 projects along its Baltic coast, which faces Kaliningrad, citing anticipated degradation in its ability to detect incoming missiles.
Saab’s CEO rejected the government’s argument, telling a Swedish newspaper that the firm’s radar “can handle” wind farms. Wikström at Parachute Consulting also questions the government’s claim, noting that Sweden’s entry into NATO in 2024 gives its military access to Finnish, German and Polish air defense radars, among others, that together provide an unobstructed view of the Baltic. “You will always have radars in other locations that will cross-monitor and see what’s behind those wind turbines,” says Wikström.
Politics are likely at play, says Wikström, noting that some of the coalition government’s parties are staunchly pro-nuclear. But he says a deeper problem is that the military experts who evaluate proposed wind projects, as he did before retiring in 2021, lack time and guidance.
By banning offshore wind projects instead of embracing them, Sweden and the U.S. may be missing out on opportunities for training in that environment, says Lippert, who regularly serves with U.S. forces as a reserves liaison officer with Denmark’s Greenland-based Joint Arctic Command. As he puts it: “The Chinese and Taiwanese coasts are plastered with offshore wind. If the U.S. Navy and Air Force are not used to fighting in littoral environments filled with wind farms, then they’re at a huge disadvantage when war comes.”
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