First Solar has a Sec. 337 investigation request filed with the U.S. International Trade Commission (ITC) on a series of crystalline silicon panel competitors for alleged infringement of First Solar’s TOPCon patents. One sec. 337 of the Tariff Act infringement states that the infringement of certain patents creates unfair competition in the import trade.
Canadian Solar TOPCon module
First Solar filed the investigation request last week against Axitec, Canadian Solar, JA Solar, Jinko Solar, Mundra (Adani), Philadelphia Solar, Qcells, Runergy, Trina Solar (including T1 Energy) and VSUN (Toyo). First Solar, a manufacturer of cadmium telluride (CdTe) thin-film solar panels, has patented silicon solar panels using TOPCon (tunnel oxide passivated contact) technology – U.S. Patent No. 9,130,074.
Near the end of 2025, the U.S. Patent and Trademark Office validated First Solar’s TOPCon patent after Jinko, Mundra and Canadian Solar tried to argue that the designs were unpatentable.
First Solar has continued with the Sec. 337 research request based on the licensing of the TOPCon patent to solar cell startup Talon PV. Talon is setting up a cell manufacturing company outside of Houston and expects to supply U.S. solar panel installers with M10 and G12 TOPCon cells sometime next year. So now that a domestic industry has been established, First Solar can ask the US government to review the TOPCon imports for patent infringement.
First Solar has asked the ITC for a blanket exclusion order covering all TOPCon solar cells entering the United States that are manufactured using First Solar’s patent – including all solar panels made using the cells.
There has been a lot of back and forth in the industry regarding TOPCon solar patents, with most manufacturers involved in lawsuits in one way or another. It’s already changing the domestic manufacturing landscape, with the country’s only mobile manufacturers sticking to PERC designs to avoid the IP mess. Who has the right to produce advanced n-type solar panel designs in the United States means more than just determining ownership of a new technology. Protracted legal battles could put the United States even further behind China in solar panel production capacity.
Trina Solar has its own Sec. 337 request regarding TOPCon patents against Runergy, Mundra/Adani and Canadian Solar in 2024. Investigation concluded in February 2026 completely ended, at Trina’s request.
Another sec. The ongoing investigation in the solar industry is the case of Shoals v. Voltage. The ITC initially determined that Voltage’s cable management products infringed Shoals’ patents. A final decision on this is scheduled for June 2026.
