TOPCon Patent Ownership War Heating Up, Now Moving To China

As the Tunnel Oxide Passivated Contacts (TOPCon) solar technology increasingly takes over from hitherto industry workhorse PERC, solar PV manufacturers are making a beeline to stake claim to its patents. Patent infringement lawsuits regarding this new mainstream technology are now gaining traction in China, the world’s largest solar PV market. 

The latest news comes from a leading Chinese solar module manufacturer having launched patent infringement proceedings against a competing module manufacturer at the Unified Patent Court (UPC).  

According to Chinese media outlets, the fight here is for Solar Cell Patent Number EP2787541 B1 and EP 4092759 B1. A quick search on the UPC website brings up case details for the infringement action taken by JingAo Solar Co. Ltd.—Chinese for JA Solar—against Chint New Energy Technology and its subsidiary Astronergy including the latter’s Europe, Netherlands and German entities, for Patent Number EP2787541.  

While Patent Number EP2787541 B1 is related to the structuring of TOPCon solar cells, the other number, EP 4092759 B1, concerns the arrangement of electrodes on the solar cells and connecting these in the panel. Both these patents are valid till 2034 and 2035, respectively.  

The infringement action application was filed by JA Solar on July 19, 2024. The 2 companies named in the proceedings haven’t yet released any official statement regarding the matter.  

According to the European Patent Office (EPO), Patent Number EP2787541 B1 relates to the TOPCon solar cell technology. TOPCon, a proprietary name for passivated contacts from the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE), hit the limelight after the institute attained then-high efficiency of 25.1% in 2013. 

Since then, it has undergone major technical improvements by various manufacturers leading to high efficiency. As the existing PV production equipment for PERC can be utilized for TOPCon manufacturing, several solar manufacturers are increasingly expanding its share in their portfolio. 

The rapid development of TOPCon solar cell technology into the mainstream has also increased the number of competing players leading to a major price war amidst an overcapacity situation. One way for the manufacturers to maintain their technological leadership in this space is to ensure the patents are protected.   

Several companies have issued ownership claims for TOPCon patents, especially over the last few quarters. SunPower Corporation spin-off Maxeon Solar Technologies has launched a patent lawsuit regarding TOPCon technology against Hanwha Qcells, Canadian Solar, and REC Solar Holdings (see Maxeon Solar Technologies Launches Another Patent Lawsuit).  

In July 2024, American Cadmium Telluride (CdTe) solar technology company First Solar said it has TOPCon cell technology patent ownership through its 2013 acquisition of TetraSun. It launched patent infringement investigations against several manufacturers who were not identified (see First Solar Initiates Infringement Investigation). 

Another tier I Chinese manufacturer Trina Solar announced its ownership of over 2,000 patents including those for TOPCon, PERC and heterojunction (HJT) technologies. In May 2024, it reportedly filed a lawsuit against fellow Chinese manufacturer Runergy and Canada-headquartered Canadian Solar accusing them of infringing on its TOPCon technology patents.