- TOPCon modules achieved a 3.16% cumulative power gain per watt over BC modules during nearly four months of monitoring.
- Modules demonstrated exceptional low-light performance, with gains of up to 5.39% in November and 4.30% in December.
- High bifaciality enabled effective use of reflected and scattered light, boosting overall energy yield in winter conditions.
JinkoSolar’s high-power TOPCon modules have demonstrated a consistent performance advantage over conventional BC modules in a field test conducted at a distributed ground-mounted station in Yantai, Shandong. Over a monitoring period from November 6, 2025, to February 28, 2026, TOPCon modules achieved an average cumulative power gain of 3.16% per watt. Cumulative generation per watt reached 310.26 kWh/kW for the 650W TOPCon module compared to 300.76 kWh/kW for the 650W BC module, which served as the control. Gains remained positive every month, underscoring the modules’ reliable performance through autumn and winter under varying weather conditions.
The field test highlighted TOPCon modules’ strong low-light capabilities. During November and December, Yantai experienced 43–47 days of irradiance below 400 W/m², accounting for 70%–77% of the period. During these low-irradiance days, the 650W TOPCon modules recorded power gains of 5.39% and 4.30%, respectively. This confirms the superior ability of TOPCon technology to control leakage current and maintain output under suboptimal sunlight conditions.
The project also demonstrated the advantages of high bifaciality. Fixed-mount structures with modules positioned 1.5 meters above ground allowed the rear side to capture reflected and scattered light, particularly from sandy terrain with a ground albedo of 22%–25%. This contributed significantly to cumulative power gains and enhanced overall energy output without increasing installed capacity.
Yantai’s warm temperate monsoon continental climate, characterized by cloudy and hazy autumn and winter conditions and low solar angles, provided an ideal test environment for comparing module performance. The nearly four-month study covered string-level comparisons with identical 650W TOPCon and BC modules, fixed south-facing at a 15° tilt. Data was collected continuously at one-minute intervals, capturing power generation, irradiance, module and ambient temperature, and humidity.
Results confirmed that TOPCon modules outperform BC alternatives across multiple metrics: cumulative yield, low-light performance, and monthly stability. Even as sunlight intensity increased in late winter and early spring, monthly gains remained positive, with 1.82% and 1.69% increases recorded in January and February. The structural design of TOPCon cells, featuring front and back electrode distribution and concentrated leakage pathways, reduces energy loss under low irradiance compared to N-type BC modules with denser back-side electrode structures.
For power plant investors, sustained positive gains and cumulative returns over the module lifecycle are key indicators of value. TOPCon modules’ combination of superior cumulative returns, reliable low-light performance, and bifacial efficiency positions them as a high-value choice in regions with similar climatic conditions, helping operators maximize long-term energy yield.
Author: Bryan Groenendaal
