“While we are disappointed with the decision to extend Section 201 [under the 1974 Trade Act] tariffs on imported solar cells and panels, we are grateful to the Biden administration for clearly considering the range of issues affected by this decision," the Solar Energy Industries Association, which represents manufacturers of solar technology, said in a statement.

About two-thirds of solar modules on rooftops and in utility installations are made in China, and about 15% are made in southeast Asia by Chinese-owned companies, with only 2% made by U.S.-based solar manufacturers, according to data from IHS/Markit.

The four-year extension also doubles the import quota on solar cells—the main energy-generating component of photovoltaic panels—to 5 GW before tariffs kick in. The U.S. imported around 2.7GW of solar cells and panels last year, says data from U.S. Customs and Border Protection.

While the proclamation says negotiations with the US. Depts. of Energy and Commerce must precede any action, it also instructs the U.S. Trade Representative to negotiate with Mexico and Canada to open a pathway for duty-free supply of cells and panels from the other North American countries.

The National Electrical Contractors Association, whose members are responsible for most residential and utility-scale installation of solar panels, declined to comment on the extension of the tariffs. Messages to the International Brotherhood of Electrical Workers, the union that represents workers responsible for major panel installation projects, were not immediately returned Feb. 4.