Trump administration pauses five large offshore wind projects

The US government is halting development on several offshore wind leases. On Monday, Interior Secretary Doug Burgum announced that the Trump administration is pausing leases for five large offshore wind projects. The Department of the Interior justified the action by citing unclassified government reports and recently completed classified reports from the Pentagon. According to the Department of the Interior, the pause addresses “emerging national security risks” and the “vulnerabilities created by large-scale offshore wind projects” near population centers on the US Eastern seaboard.

The pause impacts nearly 6 gigawatts of generating capacity for the Eastern seaboard, a hotspot of data center development. The decision halts development for five large projects:

• Revolution Wind
• Coastal Virginia Offshore Wind
• Vineyard Wind
• Empire Wind
• Sunrise Wind

The Department of the Interior cited classified reports from the Pentagon to justify the pause, stating that the suspension will give the government time to work with stakeholders to address national security concerns. However, the department’s statement did not acknowledge the ongoing work that government agencies and wind developers have conducted for years to address these radar concerns.

The core issue stems from radar interference caused by wind turbines, a known phenomenon that researchers have studied for over a decade. Wind turbines present a unique challenge to radar systems because their moving blades create a complex Doppler signature—a pattern of frequency changes in radar signals caused by a moving object. “The motion of a wind turbine gives it a complex Doppler signature,” said Nicholas O’Donoughue, a senior engineer at the Rand Corporation. These complex signatures can make it difficult for radar operators to detect targets near wind farms.

To manage these signals, operators can use mitigation techniques like Space-Time Adaptive Processing, which is an algorithm designed to filter out radar interference by learning the structure of a wind farm’s reflections over time. This process allows radar systems to identify and suppress interference patterns. Additionally, developers often employ wind farm siting, which involves modifying the layout of a proposed wind farm to keep turbines out of the radar’s direct line of sight. However, fully resolving the issue remains difficult. A February 2024 report issued by the Department of Energy noted that, to date, no mitigation technology has been able to fully restore the technical performance of impacted radars. While federal agencies and the wind industry in the United States have previously collaborated to deploy wind energy without significant radar impacts, this new pause introduces a complete halt to the five projects.

Why it matters

This pause creates significant uncertainty for the Eastern seaboard’s energy infrastructure, highlighting the ongoing tension between renewable energy expansion and national security requirements for radar performance.