The Trump administration has launched an investigation into imported wind turbines and parts, a potential precursor to adding more tariffs on the clean-energy components.

The U.S. Commerce Department started a national security probe on August 13 into whether wind energy imports harm national security and undermine domestic production, according to a notice posted by the agency August 21. 

Earlier this week, the agency said it was including wind turbines and related parts among the products facing 50% steel and aluminum tariffs. 

The U.S. wind industry is heavily dependent on imports for parts such as blades, drivetrains and electrical systems, according to research firm Wood Mackenzie. In 2023, wind-related equipment imports to the U.S. were valued at $1.7 billion, with 41% coming from Mexico, Canada and China, the firm said.

The investigation will likely lead to tariffs of up to 50% on an expedited timeline, a move that could be especially painful for offshore wind developers such as Vestas Wind Systems A/S and Equinor ASA because offshore wind projects tend to rely more heavily on imports, research firm Capstone LLC said in a note. 

“We believe this probe is an attempt to further hamper wind build out,” Capstone wrote, adding that the “wind sector is significantly exposed to tariff risk.”

President Donald Trump and his administration have repeatedly attacked wind energy, saying turbines have ruined the views at some of his golf properties and making unsubstantiated claims about their roles in the deaths of birds and whales. 

Trump on August 20 said the U.S. would not approve solar and wind projects that hurt farmland, saying they increase energy prices. He indefinitely halted the sale of new offshore wind leases on his first day in office, and paused permitting of all wind projects on federal lands and waters.

The announcement on August 21 adds to the list of industries facing potential tariffs under Section 232 of the Trade Expansion Act, which allows the president to regulate imports that are deemed to threaten national security. 

The president has said that duties on pharmaceutical and semiconductor imports could be rolled out in the coming weeks. Other industries under investigation include commercial aircraft, critical minerals and lumber. 

Trump has already announced duties on steel, aluminum, copper and automobiles.