Adani accused of solar cell patent infringement by US-based First Solar

Mint

18 hours ago

An intellectual property rights dispute hangs over the Adani Group's ₹3,000-crore-a-year solar panel exports to the US after First Solar, the largest American solar cell maker, accused group company Mundra Solar PV Ltd (MSPVL) of patent violation.
In a Delaware court, First Solar alleged the Indian company had infringed upon two patented technologies for solar panel manufacturing, demanding compensation for damages it hasn't specified yet. MSPVL has denied the charges. Mint has seen the court filings.
First Solar has already sued a Chinese solar maker over the same charge, and sent warning letters to several others over the alleged patent violation. The Nasdaq-listed company stands to benefit if solar panel imports to the US are curtailed.
The dispute comes at a time when Indian firms have gained from America's 50% tariff on Chinese solar cells and polysilicon. The US, which has imposed stiff tariffs on a host of Indian goods, has kept solar cells out of these tariffs.
Queries sent to the Adani Group and First Solar on Monday remained unanswered.
The case
Nasdaq-listed First Solar wrote to the Adani Group on 1 April, accusing it of copying the two technologies. MSPVL swiftly moved a Delaware court on 15 April, where First Solar has also sued a Chinese company on similar charges, urging the judge to declare that it does not infringe on First Solar's patents. The company claimed that its manufacturing process is different from First Solar's patented technology, and highlighted several differences between the two processes, including on heat treatment.
Following this, the US company on 1 August filed a counterclaim against the Adani Group in the same court, alleging infringement of its patents and seeking damages, the quantum of which is yet to be calculated.
Both companies have demanded a jury trial.
Under US patent law, an entity can avoid literal infringement if it does not follow every step of a patented process exactly, said Swapna Sundar, founder and director, IP Dome. But she cautioned that infringement can still be found under the doctrine of equivalents if the changes perform the same function, in the same way, and achieve the same result as the original process.
She noted that the Adani Group has a strong technical case, arguing that skipping the heat treatment step in First Solar's patented process produces a fundamentally different product. 'The temperature change (higher temperature range) by Adani could be enough to avoid even equivalence," she said. 'However, First Solar may still argue it's close enough to count as infringement."
The technology
At the heart of the matter is TOPCon, a technology for making more efficient solar cells. Between 2015 and 2017, the US patent office awarded two patents for TOPCon manufacturing to Tetrasun, Inc., a company acquired by First Solar in 2013.
First Solar, which uses a different thin-film technology for its own panels, began investigating potential patent infringement by competitors using TOPCon in June 2024. The company sent warning letters to several rivals, including JinkoSolar, Longi Solar, Trina Solar, JA Solar, and Canadian Solar last year. In February, it escalated the issue by suing JinkoSolar in a Delaware court.
Adani, however, claims First Solar's patent was initially limited to a different solar cell technology, HJT cells, and did not cover TOPCon. MSPVL also claims it doesn't use a heat treatment process that is central to First Solar's technology.
The implications
Out of Adani's annual 4 GW solar manufacturing capacity, MSPVL accounts for half, while the rest comes from Mundra Solar Energy Ltd (MSEL), which is not part of the lawsuit. MSPVL doubled revenue in FY25 to ₹6,353 crore, while profit jumped over fivefold to ₹1085 crore. According to India Ratings, more than half of MSPVL's business comes from the US.
"Export sales have been yielding higher margins on account of robust demand, specifically from the US, which has disincentivized imports from China. As a result, India has become a key exporter of solar modules to the US," the rating agency said in a note on 2 April.
MSPVL is fully owned by Adani Green Technology Ltd, which is majority-owned by Adani Tradecom Ltd, which in turn is a 100% subsidiary of Adani Enterprises Ltd. It has a manufacturing capacity of 2 GW per year of TOPCon solar cells and modules.
MSEL, another unit of Adani Enterprises, makes 2 GW of monopassivated emitter and rear contact (mono-PERC) technology solar cells and modules a year. That technology is not accused of any violation.
Both companies are part of Adani New Industries Ltd which, along with solar cell manufacturing, houses the group's other green energy businesses including the manufacturing of green hydrogen, wind turbines and electrolyzers.
The Adani Group is looking to ramp up its solar cell making capacity to 10 GW a year, chief financial officer Robbie Singh said in an Adani Enterprises earnings call on 31 July.
First Solar, which follows a January-December financial year, ended with $4.21 billion in revenue and $1.29 billion in profit in 2024. Its shares were trading at about $184.65 on the NASDAQ, down about 1% since the beginning of the year.
In November 2024, the US Securities and Exchange Commission and the Department of Justice filed a case against billionaire Gautam Adani and his nephew Sagar for allegedly paying more than $250 million in bribes to Indian government officials between 2020 and 2024 to obtain lucrative solar-energy contracts. The SEC's case is whether Adani broke the US Securities Act when Adani Green raised money from US investors, as it did not disclose a justice department probe into allegations of bribes paid by the company's directors to unnamed Indian officials between 2020 and 2024.
The Ahmedabad-based conglomerate, which counts 10 listed companies, has denied the allegations by the DoJ and the SEC, describing the accusations against its directors as 'baseless."