Northern Shaanxi Desert Field Tests: Jinko TOPCon Delivers Up to 10.79% Higher Power Generation Than BC Modules in Ground-Mounted PV Projects

Recently, to study the practical application performance of TOPCon modules and BC modules in desert areas, a comparative analysis was conducted on the actual power generation data of a PV power station in the desert environment of northern Shaanxi, which simultaneously adopts Jinko N-type TOPCon bifacial modules and the latest generation of N-type BC bifacial modules.

Project Overview

This project was recently grid-connected, with its construction site situated in Shaanxi Province. The site is characterized by relatively open terrain, accompanied by large and irregular sand dune undulations, which qualifies it as a centralized PV power station in the desert scenario of Shaanxi. The power station is equipped with both Jinko N-type TOPCon modules and N-type BC modules with a rated power of 640Wp.

Empirical Comparison

To better compare and analyze the power generation performance of Jinko TOPCon modules and competing N-type BC modules, photovoltaic sub-arrays with the same capacity (on the AC side) were selected for both types of modules. These two sub-arrays are adjacent in area, with basically the same landform—typical dune landform and relatively flat terrain. Both arrays adopt the fixed support installation method with the same inclination angle and the same model of string inverter solution.

Comparison Results

The empirical data consists of seven consecutive days of power generation figures collected from the inverter terminal, which were retrieved from the power station’s operation and maintenance system platform as the daily reporting data acquisition interface. Among the test period, Days 1, 5, 6 and 7 were sunny with abundant sunlight; Days 2 and 3 were dominated by cloudy or overcast weather with poor solar irradiance; on Day 4, there was heavy snowfall, leaving a thick layer of snow covering the module surfaces. Based on the average data of the entire week, Jinko TOPCon modules achieved an average power generation gain of 7.25% per watt compared with BC modules, with the maximum single-day power generation gain reaching 10.79%!

Conclusion and Analysis

The findings of this empirical comparison offer substantial reference significance for module selection in desert PV power station construction scenarios. In the high-latitude regions of Northwest China, characterized by frequent sandstorms and a surface environment dominated by desert landforms (e.g., sandy soil and gobi), the surface refection rate can exceed 30%. By leveraging the unique local geographical and climatic conditions, TOPCon modules fully exploit the power generation gain advantage endowed by their high bifaciality, realizing a dual power generation mechanism of “direct solar irradiance absorption on the front side + reflected light capture on the back side”. The core of TOPCon technology resides in the integration of patterned enhancement technology at the cell level, which optimizes the backside structure of the cells. Additionally, TOPCon technology possesses a more efficient carrier transport pathway, which effectively mitigates leakage current losses and ensures high conversion efficiency under low-irradiance conditions, thereby establishing itself as an optimal technical solution for desert construction scenarios.

Empirical data from desert PV power station projects show that TOPCon modules demonstrate superior power generation capacity and economic efficiency, owing to their significant bifacial power generation gain, excellent low-irradiance performance and weather resistance. In contrast, the inherent manufacturing process of BC modules inevitably leads to increased leakage current, of which disadvantages greatly reduce the power generation per watt. Coupled with BC modules’ lower bifaciality, these problems are exacerbated in centralized projects. Furthermore, the yield control challenges of BC technology and the inherent back-side process defects result in compromised module reliability. When applied in ground-mounted power stations, these issues further cause a reduction in string current, leading to a severe decline in the overall power station output. Therefore, the instability of BC modules makes them unsuitable for desert scenarios with high surface reflection rate. In contrast, the high bifaciality and low-irradiance performance advantages of N-type TOPCon modules bring greater power generation benefits to desert construction projects, making them the preferred module type for such projects.