US ITC Upholds Partial Ruling in Solar Cable Patent Dispute

On August 19, 2025, the United States International Trade Commission (ITC) announced its final ruling in Investigation No. 337-TA-1438 concerning certain photovoltaic trunk bus cable assemblies and related components. The ITC stated that it would not review the preliminary ruling (Order No. 19) issued by the administrative law judge (ALJ) on July 21, 2025. This means the ALJ's findings remain in effect: the applicant's motion was partially granted, and it was determined that the allegedly concealed information did not meet the "but-for materiality" standard necessary to establish patent unenforceability.

The ALJ acknowledged that allegations of unenforceability, including claims of serious misconduct and unclean hands, had raised significant factual issues. However, these accusations were ultimately rejected.

The case originated earlier in the year. On January 10, 2025, Shoals Technologies Group, LLC of Portland, Tennessee, filed a complaint with the ITC, alleging violations of Section 337 of the Tariff Act of 1930. Shoals claimed that certain imported and sold photovoltaic trunk bus cable assemblies infringed two of its U.S. patents (Nos. 12,015,375 and 12,015,376). The company requested that the ITC issue a limited exclusion order and cease-and-desist orders against the accused products.

Subsequently, on February 11, 2025, the ITC voted to formally initiate the investigation, assigning it the case code 337-TA-1438. The named respondents include Voltage, LLC, based in Chapel Hill, North Carolina, and Ningbo Voltage Smart Production Co., Ltd., based in Ningbo, China.

With the August 19 ruling, the ITC has upheld the ALJ's determination, leaving Shoals' claims partially supported but rejecting broader allegations of misconduct. The case underscores both the complexity of Section 337 patent disputes and the significant role ITC rulings play in regulating imports of solar and photovoltaic components into the U.S.