Archive · 17 Sep 2026
First Solar Drops ITC Patent Case, Targets Rivals in Court
First Solar makes solar panels using cadmium telluride, while TOPCon is a different solar technology based on silicon.
First Solar owns patents related to TOPCon because it bought a company called TetraSun in 2013.
It had accused several solar companies of possibly using its patented technology without permission.
The company is now dropping that complaint at the U.S. International Trade Commission.
However, it still plans to pursue similar patent cases in federal court.
The cases involve companies connected to Canadian Solar, Jinko Solar, T1 Energy and Trina Solar.
First Solar said new U.S. trade measures helped lead to its decision.
T1 Energy welcomed the withdrawal and said it would defend itself against any remaining claims.
Investors reacted negatively, sending First Solar’s shares down about 5%.
First Solar will withdraw its patent complaint from the U.S. International Trade Commission and seek to end the investigation without prejudice.
The company will continue federal patent lawsuits against affiliates of Canadian Solar, Jinko Solar, T1 Energy and Trina Solar.
The disputes concern TOPCon, a high-efficiency crystalline silicon solar-cell technology that First Solar acquired patents for through its 2013 purchase of TetraSun.
First Solar said its decision followed the Trump administration’s new trade measures on imported polysilicon and related solar products.
First Solar shares fell about 5% and reached their lowest level in roughly five months on Wednesday.
- Who
- First Solar and rival solar companies including Canadian Solar, Jinko Solar, T1 Energy and Trina Solar.
- What
- First Solar is withdrawing its U.S. International Trade Commission patent complaint while continuing related federal lawsuits.
- When
- The decision was announced on Wednesday, Sept. 16.
- Where
- The withdrawn case was before the U.S. International Trade Commission; the remaining cases are in federal court.
- Why
- First Solar said the decision followed the Trump administration’s trade measures on imported polysilicon and related solar products.
First Solar’s Litigation Strategy
T1 Energy’s Defense
Withdrawal of the ITC complaint
First Solar’s Litigation Strategy
First Solar said it would withdraw the complaint and seek termination of the investigation without prejudice, preserving the possibility of refiling later while pursuing federal lawsuits.
T1 Energy’s Defense
T1 Energy welcomed the voluntary withdrawal, saying it believed the Section 337 complaint was flawed and could have slowed needed U.S. energy production.
Patent dispute
First Solar’s Litigation Strategy
First Solar is continuing lawsuits alleging patent infringement against affiliates of several solar manufacturers, including T1 Energy.
T1 Energy’s Defense
T1 Energy said it would defend itself against any remaining claims and said it is the only American company that owns patents to high-efficiency TOPCon solar and currently manufactures TOPCon modules.
- Company
- First Solar, a Phoenix-based U.S. solar-panel maker.
- Withdrawn action
- A Section 337 patent-infringement complaint before the U.S. International Trade Commission.
- Remaining litigation
- Federal lawsuits against affiliates of Canadian Solar, Jinko Solar, T1 Energy and Trina Solar.
- Technology
- TOPCon, short for tunnel oxide passivated contact, a high-efficiency crystalline silicon solar-cell technology.
- Patent origin
- First Solar acquired the TOPCon patents through its 2013 purchase of TetraSun.
- Company technology
- First Solar makes cadmium telluride panels rather than silicon-based products.
- Market reaction
- First Solar shares fell about 5% and reached a roughly five-month low.