The USITC has initiated a new patent investigation under Section 337 following a complaint by First Solar, alleging patent infringement related to TOPCon solar technology
The case involves 47 respondents, including manufacturers from the US, China, India, Vietnam, Japan, and Germany
First Solar is seeking exclusion and cease-and-desist orders that could restrict the import and sale of the products in the US if violations are found
The US International Trade Commission (USITC) has launched a new Section 337 investigation into imports of certain TOPCon solar cells, modules, and related products.
The 337-TA-1494 probe follows a complaint from solar PV manufacturer First Solar, which alleges that certain imported products sold in the US infringe on its patents related to TOPCon technology, in violation of Section 337 of the Tariff Act of 1930.
The company filed the complaint on February 24, 2026 (see First Solar 2025 Sales Hit $5.2B, Signs Perovskite Licensing Deal).
First Solar has requested that the USITC issue a general exclusion order or, alternatively, a limited exclusion order, along with cease-and-desist orders to restrict the sale and distribution of the products in the US.
The list of respondents in the investigation consists of 47 names, and includes manufacturers from the US, China, India, Vietnam, Japan, and Germany, among others. It comprises several leading solar PV manufacturers and their national and international subsidiaries, namely AXITEC, Canadian Solar, JA Solar, JinkoSolar, Trinasolar, Adani Green Energy, Hanwha Q CELLS, Runergy, T1 Energy, Vietnam Sunergy, VSUN, and Toyo.
The companies named in the investigation must respond to the complaint within 20 days of the date the notice is served. Failure to do so will lead to the commission issuing an exclusion order or a cease-and-desist order, or both, as requested by First Solar.
Going forward, the USITC will assign the case to an Administrative Law Judge (ALJ) to make an initial determination on whether there is a violation of Section 337, which will then be reviewed by the commission for final determination.
The USITC will set a target date to complete the investigation within 45 days and will later issue a final decision. Any remedial orders would take effect immediately, but could be overturned by the US Trade Representative within 60 days.
If the USITC finds patent infringement as alleged, it could result in TOPCon solar cells and modules being barred from entry into the US, further disrupting an already challenging supply chain.
First Solar lays claims to some TOPCon patents through its 2013 acquisition of TetraSun. It is already pursuing TOPCon patent infringement lawsuits against several companies, including Adani, Canadian Solar, and JinkoSolar. In January 2026, First Solar earned a major win when the USPTO rejected Inter Partes Review applications filed by the trio (see USPTO Rejects IPRs Against First Solar’s TOPCon Patents).
