President Joe Biden extended Trump-era tariffs on imported solar energy equipment by four years, but excluded bifacial cells, which increasingly are used in utility-scale projects.

The extension doubles the import quota on solar cells to 5 GW, and opens the door for duty-free imports from Canada and Mexico.

In May 2017, a group of U.S. solar panel manufacturers filed what is known as a Section 201 safeguard petition with the International Trade Commission (ITC). The petition sought global tariffs in response to what it claimed were unfair trade practices, particularly by China. The ITC unanimously found that the imports had injured U.S. solar panel producers. In January 2018, President Trump concurred with the ITC recommendation to impose a four-year “safeguard measure” on foreign solar panels. The tariffs began at 30% but declined over time to 15%.

Last fall, the ITC again unanimously recommended that the tariffs be extended for another four years.

The Reuters news agency in late January reported that the administration was weighing a plan to double the amount of solar modules that could be imported before duties were applied from 2.5 GW to 5 GW. The proposal would entirely exempt bi-facial modules.

In a statement after the tariff extension was announced, Abigail Ross Hopper, president and CEO of the Solar Energy Industries Association (SEIA) expressed disappointment with the decision, but said that administration officials arrived at a “balanced solution” in upholding the exclusion for bifacial panels and increasing the tariff rate quota for cells.

“SEIA has been fighting for more than three years to preserve the exclusion for bifacial panels, a product not available in the United States at scale,” Hopper said. The decision recognizes the “importance of this innovative technology” in helping to improve power output and lower costs in the utility segment.