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Patents and Solar Technology

Uncertainty and Doubt About Infringing Products

This blog is authored by Marc Robinson, Associate General Counsel, Products and Technology, at Maxeon Solar Technologies, Ltd. Mr. Robinson is a registered patent attorney in the U.S and oversees all intellectual property programs at Maxeon.

While this blog contains a discussion on legal topics, no portion of this blog should be construed as legal advice and no portion of this blog establishes an attorney-client relationship with the reader. The reader is strongly encouraged to consult with the reader’s own legal counsel to obtain legal advice.

What’s special about patents?
A patent is an exclusive grant of rights to an invention – granting the patent holder exclusive rights to prevent others from exploiting the patented invention. These rights for invention patents (or “utility patents” as they are called in the U.S.) generally last for 20 years. The World Intellectual Property Organization (WIPO) has published FAQs on patents and patent systems.

Patents incentivize technological innovation. Maxeon’s leadership in solar technology is the result of nearly 40 years of research of development and over half a billion dollars of investment since 2007, leading to major advances in solar cell and panel efficiency and cost. Many of these advancements have benefited the entire solar industry, while others are covered by Maxeon’s patents. Gaining market advantage from our investments for these patents is essential to Maxeon’s continued innovation and success.

Not all patents are the same. In China and elsewhere, one can apply for a so-called “utility model” patent. Utility model patents in China do not require any substantive examination, have a lower standard for inventiveness, and are valid only for 10 years. Due to concerns around enforceability and examination, utility model patents are generally viewed as much less valuable than invention or utility patents. Maxeon currently holds over 1,600 granted patents and hundreds of pending patent applications. These patent assets span various solar cell and solar module technologies, including Interdigitated Back Contact (IBC) and TOPCon solar cell technologies, as well as Shingled Hypercell solar module technology. Only four of Maxeon’s patents are utility models. For comparison, a Google Patents search shows one of our Chinese competitor’s patent portfolio as largely comprised of utility model patents, accounting for over 90% of the total granted patents identified on Google Patents.

Further, while patents can cover a number of different types of inventions, in our industry a patent is likely to cover either: (1) a device, such as a solar cell, panel, or a structure, component, or material present in a solar cell or panel; or (2) a manufacturing process. Patents with claims that cover fundamental solar cell architectures are particularly powerful, as infringement can be objectively reviewed by analysis of the final product.

Why is Maxeon’s patent portfolio so strong?

Maxeon’s patent applications or patents serve as “prior art” against competitors. Specifically, a competitor would not be able to obtain a valid, enforceable patent on a solar invention unless it was new and non-obvious over Maxeon’s (and others’) prior art. Maxeon has been active in solar technology research and development for almost 40 years and has been developing technology solutions to enable high efficiency, low-cost solar cells for decades, before most of our current competitors even existed.

Let’s take TOPCon solar cell technology as an example, where Maxeon has a notable patent portfolio. A recent paper by Tsai et al. from the College of Engineering, National Kaohsiung University of Science and Technology in Taiwan, examined 167 patents relating to TOPCon technology filed by 11 companies in seven countries. Their paper stated: “[Maxeon] is the earliest patent assignee among the top six companies. It is estimated that its early patents [in 2007 and 2008] might be the parent applications of the initial structure of the TOPCon solar cell.” Maxeon also has early patent positions on fundamental aspects of IBC solar cell technology and Shingled Hypercell module technology.

The result? A strong patent portfolio with opportunities to block the manufacture, import, sale, and use of infringing products. Maxeon has filed 5 legal actions against 10 companies across 3 countries relating to patent infringement of IBC and Shingled Hypercell patents. Maxeon is now investigating TOPCon products for patent infringement and is planning to take legal action against a number of TOPCon manufacturers to protect our investments and assure our customers.

Why are patents important to customers, importers, and distributors?

Patent infringement risk is not limited to manufacturers. Any party who makes, imports, uses, or sells an infringing product is at risk of a patent infringement claim. Customers must navigate these complex issues to minimize their risks – an infringer may be subject to an injunction, damages, and/or the seizure and destruction of goods. In the U.S., patent claims can be brought before U.S. District Courts or the U.S. International Trade Commission (the “ITC”). The ITC has the authority to issue an exclusion order to block the importation of infringing products into the U.S.

Maxeon’s early and mature patent portfolio limits the risk of Maxeon product disruption and customer costs due to a patent dispute. Alternatively, customers accept significant business risk by purchasing potentially infringing product from unauthorized sources.

Maxeon announced a TOPCon investigation in November 2023 – what does this mean?

Further to Maxeon’s TOPCon investigation announcement on November 28, 2023, Maxeon has procured TOPCon solar cells and modules from multiple sources and is reviewing opportunities for TOPCon patent enforcement, including via U.S. District Courts and the ITC. If Maxeon is successful in these efforts, the importation, sale, and use of infringing TOPCon products will be critically impacted.

Maxeon has currently not licensed its TOPCon patents to any third parties, but intends to implement a licensing program to authorize other companies to manufacture and sell TOPCon products.

1Tsai, Chieh-Wa, Tung-Kuan Liu, and Po-Wen Hsueh. 2020. “Patent Analysis of High Efficiency Tunneling Oxide Passivated Contact Solar Cells.” Energies 13, no. 12: 3060. Available at (Last accessed 15 January 2024). Original quote referenced “SunPower,” but all applicable patents are now owned by Maxeon.