First Solar Accuses Waaree of Infringing TOPCon Patents

The solar industry faces another patent clash. U.S. solar giant First Solar has accused Waaree Energies, India’s biggest module exporter, of infringing patents linked to TOPCon technology.

The American firm issued a warning letter to Waaree. It claims that Waaree’s TOPCon (Tunnel Oxide Passivated Contact) solar cells violate two of its U.S. patents. First Solar asked Waaree to stop production or obtain a license. If not, it may file a lawsuit in the United States.

Why TOPCon is Critical

TOPCon is the fastest-growing solar cell technology. It reduces power loss and increases panel efficiency. Many manufacturers, including LONGi, JinkoSolar, and Trina, are scaling production.

First Solar entered the high-efficiency segment in 2013 after acquiring TetraSun. That deal gave it a strong patent base. The company is now using those rights to challenge rivals.

Waaree’s Stakes

Waaree has export orders worth about ₹30,000 crore. A majority of these shipments are headed for the U.S. Any restriction could hurt deliveries and margins.

The company also faces a separate case. In February 2025, JinkoSolar filed a lawsuit in Texas. The case alleges Waaree copied its n-type TOPCon design, protected under U.S. Patent No. 11,824,136 B2.

Industry-Wide Disputes

Patent fights around TOPCon are spreading fast. First Solar has already sued JinkoSolar in Delaware over a different patent.

Other players, such as Canadian Solar and LONGi, have also been drawn into disputes. Analysts say the trend shows how critical intellectual property has become for solar growth.

What’s Next

Waaree has not issued an official response to First Solar’s claims. Industry watchers expect talks on licensing before a court battle begins.

The outcome could reshape how Indian firms compete in the U.S. solar market. It may also decide how patents influence the next wave of renewable energy expansion.