Energy Musings - December 26, 2025

The Trump administration instituted a pause for the five under-construction offshore wind farms over national security issues, believed to be issues with radar interference from wind turbines.

Offshore Wind Gets Coal In Its Stocking

Monday morning was not a nice opening to Christmas week for U.S. offshore wind developers. It was as if they discovered a truckload of coal in their stocking hung by the chimney with care.

Secretary of the Interior Doug Burgum announced a 90-day pause for all under-construction offshore wind farms as the government works with developers to resolve radar interference and other national security issues that were ignored during the Bureau of Ocean Energy Management (BOEM) ‘s initial approval process. The order impacts the five leases under development: Vineyard Wind I, Revolution Wind, Sunrise Wind, Empire Wind, and Coastal Virginia Offshore Wind (CVOW).

“The prime duty of the United States government is to protect the American people,” Interior Secretary Doug Burgum said in a statement. “Today’s action addresses emerging national security risks, including the rapid evolution of the relevant adversary technologies, and the vulnerabilities created by large-scale offshore wind projects with proximity near our east coast population centers.”

The 90-day pause may be extended, leaving the wind developers with an uncertain future. It comes about two weeks after Judge Patti Saris of the U.S. District Court for the District of Massachusetts ruled Trump’s Jan. 20 executive order blocking all wind energy projects on land and in the nation’s waters as “arbitrary and capricious” and violates U.S. law. The ruling concerned a lawsuit filed by 17 states and the District of Columbia against the administration’s action.

Burgum indicated that the Department of War had completed its studies of offshore wind farm issues impacting the military’s ability to fulfill its mission. These studies were initially ordered in January. Burgum referenced classified military studies on national security matters. He also noted that there had been previous unclassified studies about radar interference and efforts to mitigate the problem.

The military has raised the radar interference issue since the early 2000s, when the Cape Wind project was proposed in Nantucket Sound, near Joint Base Cape Cod, the site of radar that is part of the NORAD system to protect North America from attacks. The radar interference could also affect other military installations, including the Naval Submarine Base in New London, several technical centers, and National Guard installations. It can also interfere with the military’s Narragansett Bay Operating Area and the Naval Undersea Warfare Newport Testing Area.

Atlantic fleet New England training and testing areas are subject to radar interference.

When Denmark installed the industry’s first offshore wind farm in 1991, it immediately discovered issues with radar and its impact on marine navigation. The government ordered changes to the wind farm’s operating procedures to require human monitoring 24/7. Humans needed to be available to shut down the wind turbines in case of emergencies. Future Danish wind farms had turbine sitings adjusted to provide navigation lanes for ships, a model followed by other nations. Still, there were always issues caused by the generation of false images on radar screens, referred to as “clutter.”

The false images make it impossible for ships to determine whether the image on their radar screen is real or imaginary. How do you drive a ship through a contested area (wind farm), not knowing if another ship is on a collision course?

Planes and helicopters conducting search and rescue operations over a wind farm are prevented from getting low enough to complete their missions. Therefore, the U.S. Coast Guard has announced it will not conduct search and rescue operations in wind farms, putting the lives of mariners and ordinary boaters at risk.

When the military expressed concerns about potential radar interference from Cape Wind, the government began searching for solutions. One solution is to triangulate the radar signal with other shore-based radar systems. However, this solution becomes impossible when there is no coast extending far enough into the ocean to allow triangulation. This is the key radar interference issue that East Coast offshore wind farms have not been able to resolve.

The radar interference issue is impacted by the height of wind turbines and the reach of their blades. As newer offshore wind farms have deployed larger turbines to harvest more power, they have created interference issues. This disruption issue also impacts airports and missile launch sites. The Defense Department has relocated wind turbines from areas surrounding missile bases to mitigate radar interference.

In approving offshore wind farms near airports, the issue is supposed to be adjudicated by the Federal Aviation Administration (FAA), which is responsible for aviation safety. In the case of Empire Wind in New York Bight, which is close to Kennedy, LaGuardia, and Newark, as well as smaller airports such as Teterboro, Westchester County, and Long Island MacArthur, the FAA deferred to BOEM, even though it is the primary responsibility of the former agency.

A report, Cancelling Offshore Wind Leases, prepared last May by Washington, D.C., consulting firm Planet A* Strategies for Green Oceans, a Newport, R.I., non-profit fighting offshore wind farms, explores the radar interference issue and how the BOEM approval process has allowed projects to move forward without addressing it.

The report cited the 2011 National Defense Authorization Act, which established the DoD Siting Clearinghouse. It “was created to provide a timely, transparent, and repeatable process to evaluate potential impacts and mitigation options related to alternative energy project development,” the report noted. The purpose of the Clearinghouse was to provide a structured, formal review process that enables a mission-compatible evaluation of proposed wind projects. Developers were urged to seek a preliminary determination before submitting an application to the FAA.

According to the DoD Siting Clearinghouse’s website, if siting issues are identified, the organization works with the developer to mitigate them, overcoming risks to national security while fostering domestic energy development. According to the report, the Clearinghouse website has 126 active Mitigation Agreements in place, but only one dealing with offshore wind. That agreement is with Vineyard Wind I.

To overcome the interference from Vineyard Wind’s spinning wind turbine blades, the parties agreed to limitations on Vineyard Wind’s construction, operations, and compensation. These limitations included:

• A limit of 62 project wind turbines and one substation.

• A limit on structure height to a maximum of 837 feet above sea level.

• A construction area restricted to specific geographic coordinates.

• A Vineyard Wind voluntary contribution to DoD of $80,000 to offset the cost of measures undertaken by DoD to mitigate the adverse impacts of Vineyard Wind or to conduct studies of potential measures to reduce such effects.

• Immediate curtailment of Vineyard Project wind turbine operations for national security or defense purposes upon request by NORAD.

• Requirements for the protection of national defense capabilities and military operations from being compromised and exploited by activity under foreign control operating in the vicinity of national defense capabilities and military operations. This includes military installations, research, development, test and evaluation activities, and military readiness activities. (A foreign company owns Vineyard Wind.)

• Protection requirements include advance written notice from Vineyard Wind’s owners to the Department of the Air Force (DAF) of the following:

• Names of entities and persons with direct ownership in Vineyard Wind.

• Names of the material vendors, entities, and persons with which Vineyard Wind will potentially execute contracts to construct, supply turbines, or conduct operations at the wind farm site.

• Names of any foreign entities and persons being allowed to access the wind turbine structures and associated data systems.

This agreement restricted certain aspects of the Vineyard Wind farm structure, its operations, and owner actions, virtually all of them in the name of protecting national security. However, Vineyard Wind is the only one of the five offshore wind farms under construction to have reached such an agreement. Interestingly, the three operating wind farms in the U.S. ‒ South Fork Wind, Block Island Wind, and the first phase of CVOW – have not entered into agreements.

Planet A* Strategies reported that Westlope Consulting prepared an analysis of national security and aviation issues related to radar interference for Revolution Wind and SouthCoast Wind. The report noted, “Neither project includes a Clearinghouse Agreement as to turbine height limits, placement requirements, or operational mitigation such as curtailment that could be enforced to prevent risk to national security operations.”

The report noted that Westlope conducted multiple analyses of Revolution Wind using various radar systems. It found that wind turbines in the majority of the study area would be within line-of-sight of the Cape Cod radar and could significantly impact its operations at a blade-tip height of 873 feet above sea level. It also found 873-foot-tall turbines located in the northeastern two-thirds, eastern half, and the entire wind farm area interfere with commercial aviation Air Surveillance Radars at Falmouth, Nantucket, and Providence airports.

The SouthCoast (named Mayflower at the time) Wind study concluded that wind turbines in the planned wind farm could have a significant impact on radar systems at turbine heights of 808 feet or higher. Its turbines would also impact Air Route Surveillance Radar and Airport Surveillance Radar at Falmouth and Nantucket airports. Falmouth’s airport is subject to the Clearinghouse agreement for Vineyard Wind.

Nevertheless, Planet A* Strategies reported that BOEM approved the SouthCoast Wind Construction and Operations Plan (COP) on January 17, 2025, after signing the Record of Decision (ROD) on December 20, 2024. They wrote: “Although the Westlope expert analysis revealed radar interference was likely, BOEM apparently approved the COP before any Clearinghouse agreement with DoD was reached. The ROD acknowledged the project would create ‘minor impacts for aviation and air traffic, radar systems, and most military and national security uses’ and required the SouthCoast lessee to mitigate risks to Department of the Navy (DON) operations from acoustic monitoring devices, and to execute a mitigation agreement with the DoD/NORAD for Radar Adverse Impact Management (RAM).”

The Planet A* Strategies report is replete with citations of potential violations of U.S. laws and regulatory requirements related to offshore wind farm approvals. Those claims are not the subject of this Energy Musings. However, for those interested in understanding how possible short-cuts were taken or favorable interpretations of the requirements were provided in the BOEM approval process for offshore wind farms, this report on their website is a must-read.

Interior Secretary Burgum’s order to pause offshore wind farm construction has upset the developers. It has outraged the political establishment in New England, which has staked its state’s clean energy plans on the construction of massive offshore wind farms. They bet that renewable energy sites located offshore and out of sight of residents were the preferred alternative to building additional pipelines or expanding existing ones.

The Wall Street Journal article about the offshore wind pause quoted Connecticut Governor Ned Lamont (D) from his conversation with Secretary Burgum on Monday. Burgum confirmed that the national security issue stemmed from the compromise of ground-based radar. Lamont said, “He said, ‘We’ll try and get to the bottom of this as soon as we can, but probably everything’s got to stop in the meantime.’” Lamont went on to claim, “I just think they’re making stuff up and it’s a really tough group to do business with.”

That is an interesting claim in light of the decades-long effort to find a solution to a problem that has been known for 35 years. A Wall Street Journal editorial noted that Democrats are so outraged by the offshore wind pause that they will fight the passage of the energy permitting reform legislation (SPEED Act). That legislation would actually prevent administrations from stopping approved projects unless their objections are made within a limited time after the project’s approval.

The WSJ wrote about the radar interference issue, putting it in perspective that many promoters would find uncomfortable acknowledging.

“A Biden Energy Department report in 2024 noted that reducing false alarms from wind interference could cause threats to the homeland to fly, literally, under the radar. ‘To date, no mitigation technology has been able to fully restore the technical performance of impacted radars,’ the report said.”

All these facts do little to dissuade Massachusetts Governor Maura Healey (D) from calling the

Interior Department’s action “unlawful.” She said she was “working closely with impacted states and developers to ensure the projects are completed.”

We are confident that the lawyers are working over the Christmas holiday to figure out how and where to sue the Trump administration over this pause. The saga of U.S. offshore wind will go on in 2026.