Swift Current alleges widespread module defects in lawsuit against First Solar

Renewable energy developer Swift Current Energy is suing First Solar in New York state court, alleging the manufacturer knowingly supplied defective solar modules and used deceptive testing to hide significant performance issues.

The complaint, filed in Sept. 2026, alleges that First Solar supplied over 2.4 million defective Series 6 Plus and Series 7 thin-film cadmium telluride modules across three major U.S. solar installations, including the 800 MW Double Black Diamond project in Illinois. 

The developer states it paid more than $360 million for the equipment, which it claims has consistently failed to meet promised power output metrics.

According to the complaint, the modules experienced increased degradation and significantly lower-than-expected output immediately upon installation in 2023 and 2024. Swift Current says it initially submitted formal warranty claims on Dec. 23, 2024, after discovering the widespread underperformance. 

First Solar formally responded on May 2, 2025, stating that the developer had not adequately described or provided evidence of the claimed defects, and noted that evaluating power output claims based on system-level performance data is invalid under the warranty terms.

The module maker requested that Swift Current coordinate with its technical support to conduct individual module power output measurements in a laboratory. Swift Current’s court filing called this proposed remedy “commercially impossible,” arguing it would require shipping more than 1.5 million modules back to First Solar at a cost exceeding the value of the claims.

In the complaint, Swift Current points to its inability to meet commitments to its commercial offtakers under power purchase agreements as a result of the power output loss. In addition, the developer says it has lost revenue from decreased compensation under capacity contracts it signed for two of the projects in question.

Defect allegations

Swift Current claims that First Solar identified two primary errors in its manufacturing process that led to lower power output in 1.6 million of the modules it purchased from the module maker.

The developer alleges First Solar knew about the defects at the time it shipped modules to its sites, but concealed them from the developer until October 2024. Importantly, one of the defects alleged in the complaint appears never to have been publicly acknowledged by the module maker.

The first type of these errors, which Swift Current calls “Edge Grind Defects” is related to a flaw in the manufacturing process for Series 7 modules first publicly disclosed by First Solar in an Oct. 2024 earnings call. 

In the call, First Solar CEO Mark Widmar provided details how the company identified the issue early in Series 7 production, in which materials that have been ground from the edge of module glass “calcify” onto the glass during the “dwell time” between the grinding step and a module washing step that occurs after.

At the time, First Solar said it had identified and taken actions to address the edge grind issues and was taking a warranty charge of $50 million in anticipation of providing service to buyers of affected modules.

The second, previously-undisclosed type of defect is referred to in the complaint as “Substrate Defects,” which Swift Current alleges arose from a change to the manufacturing process initiated by First Solar in 2021, which prevented the absorber layer for its Series 6 Plus and 7 modules from forming as designed. The complaint states these defects “impacted the annealing process, film quality, recombination rates, and ultimately, module power output.”

Swift Current says it was presented with an investigative report First Solar commissioned from Leidos Engineering, LLC to examine its Series 7 modules, which identifies the two defects being present in the modules. The complaint says the Leidos report found an average power loss of approximately 8 percent for modules tested after nearly one year of field deployment.

The complaint also goes further, alleging “metastability losses inherent in First Solar’s thin film cadmium telluride technology,” which can result in seasonal loss of power output during cold periods of the year. 

Swift Current alleges that First Solar artificially inflates its modules’ nameplate power ratings using a secret, proprietary “preconditioning” testing method that masks the metastability loss by testing module power output immediately after subjecting the panels to at least eight hours of extreme heat, voltage and irradiance.

The complaint says that while the edge grind and substrate defects were present in more than 1.6 million of the modules it received, all 2.4 million failed to perform as promised, with the alleged metastability issues solely at fault for lower-than expected production from the remaining modules. 

Swift Current is seeking damages and restitution due to the alleged defects. In addition, it has asked the New York court to apply penalties under a Massachusetts law regarding willful misconduct, because the Swift Current employees who evaluated the modules and negotiated the deal to purchase them are based at the company’s headquarters in Massachusetts and the commercial relationship between the two companies was managed there.

The case is active and ongoing, with the parties scheduled to appear before Justice Andrew Borrok of the New York county commercial division of the New York state supreme court on Nov. 16, 2026.