First Solar, the Arizona-based maker of cadmium telluride thin-film solar panels, has been through one very large securities case and is now in the middle of several more. The company’s litigation history is anchored by a $350 million securities fraud class action that settled in 2020, and its current docket is dominated by patent infringement suits over TOPCon solar cell technology, a parallel U.S. International Trade Commission investigation, a breach-of-contract action against Lightsource BP seeking more than $400 million, trade tariff petitions against imported solar cells, and two early-stage securities investigations opened after sharp stock drops. Here is where each of the major First Solar lawsuits stands.
The $350 Million Securities Fraud Class Action
The largest case in First Solar’s history is Smilovits v. First Solar, Inc., filed in March 2012 in the U.S. District Court for the District of Arizona (Case No. 2:12-cv-00555). Investors alleged the company hid manufacturing and design defects in its solar modules and fed the market misleading financials during a class period running from April 30, 2008, through February 28, 2012.
The core allegation was that First Solar’s modules were degrading faster than advertised, especially in high-heat environments. The company had disclosed a “manufacturing excursion” in mid-2010 and initially pegged the fix at $23.4 million, affecting no more than 4% of its panels. By February 2012, First Solar disclosed that remediation would actually exceed $200 million. Investors also alleged the company manipulated its “cost per watt” metric, misstated warranty reserves, and distorted revenue figures. The claims were brought under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 10b-5.
After nearly eight years of litigation, the parties settled for $350 million the day before jury selection was scheduled to begin. Judge David G. Campbell granted final approval on June 30, 2020.
The Maverick Opt-Out and Insurance Fight
A group of institutional investors opted out of the Smilovits class in March 2014 and filed their own suit in June 2015, covering purchases from May through December 2011. That Maverick Action settled for $19 million.
First Solar then sued its insurers in Delaware Superior Court in October 2020, seeking coverage under a policy that was in force when Maverick was filed. In June 2021, Judge Mary M. Johnston ruled against the company, finding the Maverick Action “fundamentally identical” and “interrelated” with Smilovits. Because the two were interrelated, the court treated the Maverick claims as “first made” in 2012, outside the later policy’s coverage window.
The TOPCon Patent Infringement Campaign
First Solar’s most active legal front concerns Tunnel Oxide Passivated Contact, or TOPCon, a manufacturing method widely used to produce high-efficiency crystalline silicon solar cells. First Solar acquired the patents through its 2013 purchase of TetraSun, Inc. The two key patents are U.S. Patent No. 9,130,074 (issued 2015) and U.S. Patent No. 9,666,732 (issued 2017).
In November 2024, First Solar publicly warned that Longi, Trina Solar, JinkoSolar, JA Solar, and Canadian Solar were using its patented TOPCon methods without a license. Litigation followed.
Delaware Federal Court Cases
First Solar has filed three patent infringement suits in the U.S. District Court for the District of Delaware, all before Judge Jennifer L. Hall:
- JinkoSolar, filed February 25, 2025 (Case No. 1:25-cv-00223), asserting U.S. Patent No. 9,130,074. Stayed on April 2, 2026, pending the ITC investigation.
- Mundra Solar, an Adani affiliate, filed April 15, 2025 (Case No. 1:25-cv-00462), asserting U.S. Patent No. 9,666,732. Stayed on March 27, 2026, pending the ITC investigation.
- Canadian Solar, filed May 9, 2025 (Case No. 1:25-cv-00582), asserting U.S. Patent No. 9,130,074. Not stayed. A Markman hearing is set for January 2027, with a five-day jury trial scheduled for March 2028.
USPTO Rejects Patent Challenges
All three defendants tried to invalidate First Solar’s patents through inter partes review at the U.S. Patent and Trademark Office. The USPTO denied all three petitions on discretionary grounds between November and December 2025. First Solar’s general counsel, Jason Dymbort, said the denials tracked the USPTO’s “Settled Expectations” doctrine, which treats long-unchallenged patents as more firmly established. JinkoSolar called the discretionary denial “wholly divorced from the merits” and said it expected federal court to find the patent invalid on full review.
The ITC Section 337 Investigation
On February 24, 2026, First Solar filed a complaint with the U.S. International Trade Commission under Section 337 of the Tariff Act of 1930. The ITC instituted Investigation No. 337-TA-1494 on March 26, 2026. The complaint targets imported TOPCon solar cells and modules that First Solar says infringe claims 1, 2, 4, and 8 of U.S. Patent No. 9,130,074.
The investigation names 47 respondents across ten manufacturer groups: AXITEC, Canadian Solar, JA Solar, JinkoSolar, Mundra Solar/Adani Green Energy, Philadelphia Solar, Hanwha Q CELLS, Runergy, Trina Solar (and T1 Energy), and VSUN/Toyo. BYD America intervened as a respondent in April 2026, followed by Tesla.
First Solar is seeking a general exclusion order barring importation of any infringing TOPCon products, or alternatively a limited exclusion order targeting specific respondents, plus cease and desist orders against sale of infringing products already in the country. CEO Mark Widmar described the campaign as enforcing a “level playing field” for American-developed technology.
An evidentiary hearing before an administrative law judge is scheduled for November 16–20, 2026. An initial determination is due March 15, 2027, with a target completion date of July 15, 2027.
Licensing Deals Outside the Litigation
Not every TOPCon user has been sued. In February 2025, First Solar signed its first U.S. TOPCon licensing agreement with Talon PV, a Texas-based manufacturer with a 4-gigawatt cell facility. In February 2026, First Solar signed a non-exclusive licensing agreement with Oxford PV covering perovskite solar technology for U.S. markets. Financial terms were not disclosed for either deal.
The $400 Million Lightsource BP Contract Suit
On June 11, 2026, First Solar sued Lightsource BP Renewable Energy Investments Ltd. and BP p.l.c. in the U.S. District Court for the Northern District of Ohio. The complaint alleges that Lightsource BP breached multiple long-term module supply agreements by “abruptly and unilaterally” trying to cancel them in 2024 so it could buy cheaper modules elsewhere, invoking a “force majeure” clause that First Solar calls meritless. The company is seeking more than $400 million in damages, including lost profits. The case is pending.
Trade Tariff Petitions
First Solar is a founding member of the American Alliance for Solar Manufacturing Trade Committee, a coalition that has pushed antidumping and countervailing duty actions against foreign solar producers. In April 2024, the alliance petitioned for tariffs on crystalline silicon solar cell imports from Cambodia, Malaysia, Thailand, and Vietnam, arguing that Chinese-owned companies were routing subsidized production through those countries to dodge existing U.S. duties.
The Commerce Department finalized rates in April 2025. Combined antidumping and countervailing duty rates ran from roughly 14% to 250% for Malaysia, 120% to over 800% for Vietnam, 375% to nearly 1,000% for Thailand, and 650% to 3,500% for Cambodia, depending on the exporter. The ITC issued an affirmative injury determination supporting the tariffs.
The alliance filed a second petition in July 2025 targeting imports from Indonesia, India, and Laos, alleging Chinese manufacturers had shifted production to those countries in response to the earlier duties. According to the petition, imports from the three countries rose from $289 million in 2022 to $1.6 billion in 2024. These cases typically take about a year to reach final rates.
Newer Securities Investigations
Two law firms have announced investigations into potential securities law violations, but no complaint has been filed in either matter. Levi & Korsinsky opened an investigation in October 2024 after Jefferies lowered expectations for First Solar’s third-quarter results, citing potential delivery delays, volume misses, and the effect of antidumping duties on module pricing. The stock fell more than 9%. In January 2026, Pomerantz LLP opened a separate investigation after Jefferies downgraded the stock from “buy” to “hold,” triggering a roughly 10% decline. Both firms are still soliciting potential lead plaintiffs.