The US company has alleged that Waaree’s TOPCon cells, which is the most popular solar cell technology today, violate two of its patents. It has asked the company to either stop manufacturing these cells or license the technology from it. First Solar has threatened legal action if Waaree doesn’t comply with its warning.

The dispute threatens to disrupt Waaree’s lucrative exports business to the US. The company has nearly ₹30,000 crore worth of export orders, mostly to the US, as per its latest investor presentation. Exports account for nearly three-fifths of Waaree’s 25-gigawatt pending orders.

Indian solar cell makers’ exports to the US have boomed after president Donald Trump imposed a 50% tariff on Chinese solar cells and polysilicon. Solar cells have been exempted from the 50% tariffs levied by Trump on India.

Stock Waaree Energies ended little changed at ₹3198.35 on the BSE on Tuesday.

At 24-25 cents/watt, exports of solar cells are at a premium of around 40% to the sale price in India for Waaree Energies, as per a 9 June research report from brokerage Nirmal Bang.

Wider patent battles

It is not clear when the letter was sent to Waaree, but First Solar has sent such notices to several other solar companies as well, including to the Adani Group in April this year. The Adani Group has challenged First Solar’s claims in a Delaware court, seeking a declaration from the court that it was not in violation of the American firm’s patents. The case is ongoing.

Queries emailed to Waaree Energies, First Solar and its legal counsel went unanswered.

First Solar has also sued Shanghai-headquartered and NYSE-listed JinkoSolar over the alleged patent infringement. The company stands to benefit if solar panel supplies to the US from overseas firms go down.

Technology shift

TOPCon stands for Tunnel Oxide Passivated Contact. The solar cells made with this technology are the most efficient available in the market, and their sales are fast outpacing the previously-popular technology called Mono PERC (Monocrystalline Passivated Emitter and Rear Cell).

“First Solar has been actively enforcing its patents globally, particularly in relation to its TOPCon solar cell technologies,” said Swapna Sundar, director-legal, IP DOME Strategy Advisors. This pattern reflected a technology-driven enforcement strategy rather than a company-specific targeting approach, she said.

The spate of patent infringement allegations underscores the increasing competitive pressures within the solar manufacturing sector, Sundar said. As advanced solar cell technologies such as TOPCon, HJT, and perovskite cells gain market traction, she expects an increase in disputes, heightened cross-licensing negotiations, and more robust defensive intellectual property (IP) strategies among both Indian and global manufacturers.

Waaree Energies has about 4-gigawatts-a-year of TOPCon solar cell manufacturing capacity at its new plant at Chikhli, Gujarat. It also has 1.2-gigawatts-a-year of Mono PERC capacity at the same plant. Solar cells are the fundamental units which are assembled together to make solar panels that generate electricity from sunrays.

“Our current mix continues to veer more and more towards TOPCon as more and more customers want to have TOPCon panels,” Amit Paithankar, chief executive of Waaree Energies, said in an analyst call on 30 July.

Waaree Solar Americas Inc., a subsidiary of Waaree Energies, has a 1.6-gigawatt-per-annum solar module line in Texas that began production in January this year. The company is already working on doubling this capacity to 3.2 gigawatts and has plans to invest $1 billion in the US.