Key takeaways:
JinkoSolar showed long-term field data with TOPCon module maintaining specific power generation advantage over BC modules at the TaiyangNews conference
The results attributed TOPCon’s advantage to higher bifaciality, with additional gains observed under higher temperatures and low-irradiance levels
A separate third-party field test comparing 650 W TOPCon and BC modules also showed higher specific power generation for the TOPCon module
Irrespective of how advanced a cell or module technology is in terms of efficiency, real-time deployment provides an important overview of the module’s performance.
At the TaiyangNews Global PV System Technology Trends H1/2026 Conference, Senbo Yan, Senior Manager of PV Solutions at JinkoSolar, presented long-term field performance data comparing TOPCon and back-contact (BC) technologies. The results were shared by China’s State Power Investment Corporation (SPIC) from its Daqing field in Heilongjiang province, which has an annual irradiance of 900-1,000 W/m².
The results were presented from two sets of data, the first from the projects commissioned in 2022, designated as phase 1. Yan compared the data collected between 2022 and 2025 for the phase 1 projects and presented cumulative power generation between the TOPCon and BC systems. The average power generation per watt of TOPCon was about 2.27% higher than that of BC over the four-year period. The modules compared were TOPCon on an 182 mm wafer format in a 144 half-cell configuration, whereas the BC modules were based on a 158 mm wafer in a 156 half-cell configuration. The gain in power generation for TOPCon was attributed to its bifaciality, which at that time was about 74% compared to 64% for BC modules.
Yan also presented the power generation results under fixed ambient temperature with varied rear-side irradiance levels, and under fixed rear-side irradiance with varied temperatures. In the former scenario, the data show that TOPCon’s power generation increases with increasing rear-side irradiance, reaching beyond 2%. Similarly, with increasing temperature under fixed rear-side irradiance, the difference in power generation reached a maximum of 4.12% at a certain level of temperature.
Extending these tests, Yan also presented results from phase 3 from the Daqing site in 2025, which compares relatively latest modules based on TOPCon and BC. The bifaciality of TOPCon modules ranged between 77% and 80%, whereas BC modules had 72% bifaciality in this field test. The results showed that TOPCon still had an average power generation advantage over BC modules, with a 0.75% difference in 2025. It is apparent that if the best TOPCon module was compared with a BC module in phase 3 testing, this gain would have been slightly higher.
To make a more equal comparison between the modules, JinkoSolar commissioned a third-party organization to conduct field tests using the company’s TOPCon module Tiger Neo 3.0 modules with the latest BC modules, both featuring 650 W power output. The tests were performed at Wuyi in Gansu province, where temperatures can exceed 60 °C and occasional snow and sandstorms occur.
The test period was for about a month, from March 31 to April 29, 2026. The data show that JinkoSolar’s TOPCon had an average power gain per watt of 1.28% in this period. Although these results are not as extensive as the previous comparisons between TOPCon and BC, Yan highlights that the low-irradiance performance in this test was calculated with TOPCon surpassing BC by 2.23% in the 100-200 W/m² range and by 3.33% in the 0-100 W/m² irradiance range.
JinkoSolar plans to build more such test sites worldwide for a better and more comprehensive comparison between technologies under real-world conditions.
