Landmark Court Ruling Shakes US Solar Industry: Retroactive Tariffs Back in Force

The US solar industry it seems, can't catch a break ever since the new administration of Donald Trump came in. Now, in a ruling with sweeping implications for the renewable energy industry, the US Court of International Trade has vacated the Biden Administration’s two-year suspension of solar tariffs on imports from Southeast Asia, dealing a major blow to developers and importers who benefited from the tariff holiday. The suspension had been ordered after it became clear that costs would rise to unacceptable levels for both developers and consumers if it was not done. It is a question that will come back to torment the market yet again, seriously risking furure investments into the sector, possibly pushing back momentum by years. 

The court sided with Auxin Solar, a California-based manufacturer that had challenged the suspension, restoring the full force of US trade law and opening the door to billions of dollars in retroactive duties.

Background

In June 2022, then US President Biden issued Proclamation 10414, exempting solar panels imported from Cambodia, Malaysia, Thailand, and Vietnam from antidumping duties and countervailing duties (AD/CVD). The moratorium was intended to ensure stable supply lines for US solar deployment amid concerns of project delays and rising energy costs.

Auxin Solar, however, argued that the pause allowed Chinese manufacturers to sidestep existing trade duties by routing products through Southeast Asia, an assertion the court has found persuasive now.

The Decision

On August 22, the court ruled that the Department of Commerce’s implementation of the tariff suspension was unlawful. As a result, tariffs will once again apply to imports determined to be circumventing Chinese AD/CVD orders. To make it worse, these duties will be retroactive.

The ruling places the financial burden squarely on the importers of record, a category that includes foreign manufacturers’ US subsidiaries, major solar developers, and distributors who arranged imports under the two-year moratorium.

It is estimated that 71-88 gigawatts of solar modules entered the US during the suspension, valued between USD 54 and USD 67 billion. That translates into potentially tens of billions of dollars in retroactive tariffs now owed.

Industry groups, including SEIA, ACP, NextEra, Invenergy, Canadian Solar, Trina, Risen Energy, and BYD, are reportedly weighing their options, which may include: appealing the decision to the Federal Circuit, seeking an emergency stay to delay the retroactive duties, or pressuring lawmakers in Washington for a policy intervention. Their task is made doubly hard by the systemic purging of departments, including officials who would have been sympathetic to the cause. Now they face the prospect of seeking support from officials who seem to be gung ho on only one thing, and that is oil and gas. 

A Turning Point in Solar Trade Policy

The decision marks a watershed moment in US solar policy, resetting trade dynamics just ahead of the 2026 rules on foreign entities of concern (FEOC) and reinforcing that tariff enforcement is back, retroactively.

For developers, importers, and financiers, the era of tariff relief appears to be over. The priority now: reassessing supply chain strategies amid one of the most significant trade enforcement shifts in the clean energy sector to date. It might take years beyond the end of the Trump presidency for the damege to be undone, in terms of slowdowns in fresh solar capacity additions and unraveling the mess existing projects are likely to face.