American manufacturing of solar modules has increased in the face of tariffs that have raised the costs of importing foreign supplies, the US International Trade Commission said in a report Tuesday. 

At issue are tariffs first imposed by former President Donald Trump in 2018 and extended by President Joe Biden four years later. Under the so-called Sec. 201 safeguard tariffs — known for their place in US trade law — imports of one-sided crystalline silicon photovoltaic cells and modules face 14.25% duties the rest of this year and 14% for most of 2025.

“The safeguard measure has resulted in positive industry adjustments in terms of significant expansion and investment in domestic CSPV module manufacturing and announced plans to restart domestic CSPV cell manufacturing,” the ITC concluded in its 408-page assessment. Even so, the industry faces headwinds, with domestic manufacturers operating at a loss between 2020 and 2022, the commission said.  

The review could prompt action by Biden, potentially laying the foundation for changes or an end to the tariffs. 

The report caps a months-long review of the impact of the tariffs on industry, amid a swell of investment in domestic solar manufacturing facilities spurred by subsidies in the 2022 Inflation Reduction Act. Yet domestic panel makers are still confronting challenges, including a surge of cheap imports, that some say merit more vigilance and trade protection.  

The review, coming as the Biden administration reassesses a raft of other trade measures, underscores the tension between competing goals of rapidly deploying solar power in the US and nurturing a domestic solar supply chain divorced from China.

Jobs, output and other economic indicators tied to US solar module manufacturing have generally climbed since 2017, the year before the tariffs were first imposed, the ITC said. Improvements were seen by 2022 in apparent US consumption, market share, capacity, production and employment, the commission found. 

But the gains for module manufacturing haven’t extended evenly to photovoltaic cells, which are bundled together into modules and panels. There has been no domestic production of CSPV cells since Biden renewed the tariffs, the ITC said. At least 11 potential US cell manufacturing plants have been announced or are under consideration. 

The agency documented continued challenges for domestic manufacturing. While solar module producers gained market share overall from 2020 to 2022, their share of the market declined between 2021 and 2022 — and it was lower in the first half of 2023 than the same period the prior year. “Module producers continue to experience operating and net losses,” the commission said. Even with net sales increasing by quantity and value between 2020 and 2022, gross profits improving and capital expenditures increasing, the industry was “operating at a loss throughout the review period.”

Biden faces calls from some domestic manufacturers and renewable developers to quadruple an existing exemption for the first 5 gigawatts of imported silicon solar cells. Advocates of an increase say the current allowance doesn’t provide enough headroom for domestic panel makers that will be reliant on foreign cells in the near term. There’s not enough domestic supply to keep pace with a wave of planned and announced US panel manufacturing, they argue. 

Biden also is under pressure to do away with an exemption for two-sided solar panels that some US manufacturers say undermines the trade protection and the IRA incentives. 

US imports shifted from single-sided solar products to two-sided models “beginning in 2020 — and accelerating markedly between 2021 and 2022,” the ITC said.

The existing carveout for two-sided, or bifacial, models was initially intended to ensure a steady flow of the supplies for large, utility-scale solar projects. But now, those two-sided models are being widely imported and used for residential projects, even though there’s no practical advantage in using bifacials on rooftops where just one side is able to generate power.