On Oct. 8, Trina Solar filed a patent infringement complaint against Canadian Solar in the U.S. District Court for the District of Delaware, claiming that Canadian Solar was infringing on two of Trina’s patents related to TOPCon technology used in solar panel manufacturing. The two mentioned patents (Nos. 9,722,104 and 10,230,009) are the same ones Trina is alleging Runergy is also infringing on.

Canadian Solar TOPCon module

Canadian Solar has now responded to the patent infringement complaint and vows to continue to deliver its solar products to the United States and globally.

“Canadian Solar respects and takes very seriously its own intellectual property rights and those of third parties. In our view, this is a frivolous lawsuit, and we expect the court will find that our proprietary TOPCon technology does not infringe on the patents claimed by Trina,” remarked Adam Walters, general counsel for the Americas for Canadian Solar’s modules and systems solutions business.

Trina escalated its case against Runergy earlier this month by requesting the U.S. International Trade Commission complete an investigation under Section 337 of the Tariff Act of 1930, which would direct U.S. Customs to stop infringing imports from entering the United States. Trina also included Adani Green Energy as an infringing party in its Sec. 337 investigation request.

Runergy responded by asking the U.S. Patent and Trademark Office to “cancel” the two patents and deem them “unpatentable.” Runergy said that the two patents did not result from Trina’s own work but instead were purchased by Trina in 2024. The Fraunhofer Institute for Solar Energy Systems had already published details of TOPCon solar cells in 2013, and the two patents Trina acquired were filed a year after Fraunhofer’s publication, Runergy said, thus making the technology unpatentable.

Alleged TOPCon patent infringement has been a hot topic in the solar market this year. Maxeon acquired a batch of TOPCon patents from Solaria after Solaria sold its intellectual property portfolio last year. Maxeon has since filed patent infringement complaints against Canadian Solar, REC and Hanwha Qcells related to TOPCon technology.

Although a thin-film panel manufacturer, First Solar also has patents related to TOPCon technology, and the company said this summer it would begin investigating possible infringement and file any necessary complaints.