U.S. solar manufacturers said they have filed new trade petitions against India, Indonesia and Laos, alleging illegal practices by largely Chinese-owned companies operating in those countries. 

The new anti-dumping and countervailing duty petitions were filed by the Alliance for American Solar Manufacturing and Trade, which includes First Solar Inc., Mission Solar Energy and Qcells. The trade group alleges China is flooding the market with unfairly cheap goods made in factories in the three Asian countries.

The latest trade case adds new uncertainty to a U.S. solar industry hit by tariffs and moves by President Donald Trump to arrest the growth of renewables. It also comes after the US slapped new duties on equipment made in Malaysia, Thailand, Vietnam and Cambodia.

The U.S. has seen a massive shift in its solar supply chain after a years-long investigation into tariff circumvention led to higher duties on solar equipment from the recently-tariffed former top suppliers in Southeast Asia. 

As shipments from those nations shrank, Indonesia and Laos filled the gap. The two countries accounted for 44% of U.S. cell and module imports in May, up from 1.9% in the same month last year, according to data from BloombergNEF. India has also seen solar exports to the U.S. rise since mid-2022.

The trade petition triggers a process in which the U.S. Department of Commerce investigates whether imports are unfairly priced or subsidized by a foreign government, while the U.S. ITC determines whether those imports have injured the domestic industry. If successful, the cases could result in new duties.