Key takeaways:
Tongwei introduced TNC 3.0 technology with rear-side polyfingers, rear-side texturing, edge passivation, and quarter-cut cell modules at SNEC and Intersolar Europe 2026
The new module architecture incorporates overlapped cell interconnection and a dual junction box design to reduce electrical losses and rear-side shading
Tongwei currently offers these modules in G12 and G12R formats, both rated at 24.8% efficiency, with maximum power outputs of 770 W and 670 W, respectively
China-based integrated PV manufacturer Tongwei launched its latest TOPCon modules based on the company’s TNC 3.0 technology at SNEC and Intersolar Europe 2026. TNC stands for ‘Tongwei N-type passivated contact Cell’. The company’s Product Marketing Manager, Jason Yang, presented the technical details at the TaiyangNews Global PV System Technology Trends H1/2026 Conference.
The company says this technology features several developments at both cell and module levels. At the cell level, Tongwei uses rear-side polyfingers instead of covering the entire area with doped poly-Si. This reduces parasitic absorption of the light reflected onto the rear side. It also features enhanced light absorption with the rear-side texturing employed in this latest iteration. Edge passivation is another approach that the company implements, which it markets as ‘360° passivated cell’.
At the module level, Tongwei developed a quarter-cut cell layout and a dual junction box approach in contrast to mainstream modules that use three junction boxes. During interconnection, the cells overlap by about 0.5 mm, and a flattened ribbon is used at the interconnection, which minimizes stress at the cell edges. Additionally, a film is added between the cells in the overlap region, which acts both as a separator layer and also helps absorb mechanical impact, minimizing microcracks to some extent. The dual junction box approach aims to reduce shading on the rear side. Tongwei also claims that the unique design of these junction boxes further minimizes the overall shading. Jason Yang, Product Marketing Manager at Tongwei, said this optimized junction box design, along with the use of only two such boxes, has reduced rear-side shading by 16.7%.
With these developments at the cell and module level, the company’s objective is to enhance the module's power output and energy yield. This design, complemented by cell-level developments such as polyfingers and rear-side texturing, delivers 15% higher bifaciality than mainstream half-cut TOPCon modules, reaching 90%. This higher bifaciality translates into about 1.2% higher energy yield than a mainstream module with similar power output, said Yang.
Additionally, the quarter-cut cell layout reduces electrical losses to one-quarter of those associated with half-cut cells, resulting in about 4 W of additional module power. The overlapped cell interconnection, which the company calls louvered interconnection, adds another 5 W to the module power.
The company currently offers two modules based on TNC 3.0. The first is built with 132 half-cells of the G12 wafer format. It can deliver a maximum power of 770 W with a conversion efficiency of 24.8%. The second module, also a 132 half-cell configured module with a similar efficiency of 24.8%, is based on the G12R wafer, delivering a lower power of 670 W. Yang explained the above advantages of bifaciality, higher power, and eventually a higher energy yield contribute to a lower LCOE for the systems using these modules, a 2.8% reduction with G12R-based module and about 3% reduction with G12-based modules.
