The Patent Trial and Appeal Board of the U.S. Patent and Trademark Office (USPTO) has invalidated all claims by Trina Solar on two TOPCon (Tunnel Oxide Passivated Contact) solar cell patents against certain subsidiaries of Canadian Solar.

The USPTO also named three of Canadian Solar’s U.S. subsidiaries as directly or indirectly infringing on two of its TOPCon-related U.S. patents.

However, Colin Parkin, President of Canadian Solar and President of e-STORAGE, a subsidiary of Canadian Solar, said that the company firmly opposes the abusive use of intellectual property to extort or hinder competition and will continue to defend its legitimate business interests vigorously.

In 2024, Trina Solar filed a lawsuit in the U.S. District Court of Delaware and a complaint with the U.S. International Trade Commission (USITC) to protect its TOPCon technology patents from infringement by Canadian Solar and related entities. It requested that the USITC issue a limited exclusion order and a cease-and-desist order against the imports of Canadian Solar and its related entities into the U.S.

Both Canadian Solar and Trina Solar were among the companies named in the USITC’s Section 377 Investigation into imports of TOPCon solar cells and modules into the U.S.

Over the past 25 years, Canadian Solar has delivered over 174 GW of solar photovoltaic modules to customers worldwide. Through its subsidiary e-STORAGE, it has also shipped over 18 GWh of battery energy storage solutions to global markets as of December 31, 2025, boasting a $3.6 billion contracted backlog as of March 13, 2026.

Since entering the project development business in 2010, Canadian Solar has developed, built, and connected approximately 12 GW of solar power projects and 6.2 GWh of battery energy storage projects globally.

Its geographically diversified project development pipeline includes 24 GWp of solar and 83 GWh of battery energy storage capacity in various stages of development.

In the fourth quarter (Q4) of 2025, Canadian Solar’s revenue declined 20% year-over-year to $1.22 billion, from $1.52 billion the previous year. Revenue was below guidance due to project sales being delayed into 2026 and lower-than-expected volumes in both solar and storage.