According to a global field test, TOPCon modules provide an average power generation gain of 3.15% per watt over XBC modules, with a relative gain of up to 3.4% every month. The result is compelling evidence of TOPCon modules’ superior power generation capability and customer value.

The field test occurred between July 16 and September 10, using Vertex N 600W bifacial dual-glass modules with TOPCon technology and 620W bifacial dual-glass TBC modules. To ensure accuracy, the test site closely simulated regular installation conditions. The site featured a cement ground with about 30% reflectivity, with modules mounted on fixed racking systems with a 23° tilt angle and installed 0.5 meters above the ground. There was no shading on the front or rear rows, and power generation data was collected using an IV-tracker. 

After analyzing power generation data at different times of the day, TOPCon modules were proven significantly superior in low-irradiance conditions, such as early morning and late evening. From 7 AM to 8 AM, TOPCon’s power generation per watt was 6.9% higher than that of TBC, and from 5 PM to 7 PM, the relative gain was 8.3%-8.4%. The outcome aligns with earlier field tests indicating that TOPCon modules outperform XBC by about 5% in low-irradiance conditions.

TOPCon’s higher bifaciality is another key reason for its superior power generation. TOPCon modules demonstrate a 2.6% power generation advantage over TBC modules, even at midday, when sunlight is strongest, which can be attributed to their bifaciality.

The high bifaciality and excellent low-irradiance performance allow TOPCon modules to deliver a 2-3% power generation gain per watt over XBC modules in actual operating conditions. These findings are consistent with results from the National Photovoltaic and Energy Storage Experimental Platform and the National Centre of Inspection on Solar Photovoltaic Products Quality.

According to a field test for 2023 by the National PV and Energy Storage Experimental Platform (Daqing Base) in March, when modules with similar wafer sizes were compared, TOPCon modules outperformed IBC modules by 2.72% in energy yield.

According to a CPVT field test conducted in Yinchuan, Ningxia Hui autonomous region, from January to July, the front-side power generation of half-cut bifacial TOPCon modules was 1.76% higher than that of XBC modules after excluding backside generation data, based on STC front-side power.

TOPCon is set to dominate for the next five years, enhancing both efficiency and cost-effectiveness. TOPCon cells can boost efficiency by 1%, and modules can gain over 30W in power output. Following this period, n-type TOPCon-based perovskite-silicon tandem cells will push the PV industry towards superior development.