Nadine Figueiredo Braz

Always committed to improving the performance and reliability of its photovoltaic modules, CSI Solar is constantly working on developing technologies to maximize the efficiency of its products. Since 2019, it has been dedicated to the development of N-type TOPCon (Tunnel Oxide Passivated Contact) technology, with modules based on different cell sizes, such as 182 x 210 mm and 210 x 210 mm, offering flexibility for various applications. Based on 182 x 210 mm rectangular cells, the 182 Pro TOPCon bifacial modules have 66 cells, dimensions of 2382 x 1134 mm with power of up to 630Wp and efficiency of up to 23.3%, and can be applied in C&I or Utility segments. Due to the optimized dimensions and storage method, it is possible to maximize the utilization rate of the containers with utilization of up to 99.8%. This means that the power per container for 182 Pro TOPCon modules can reach up to 453.6kW, representing an increase of approximately 8,0% when compared to modules based on 182 x 182 mm cells. By delivering more power per container, it is possible to reduce BOS (Balance of System) and LCOE (Levelized Cost of Energy) costs, which adds significant value for customers. Furthermore, when compared to 182N 72-cell modules, the 182 Pro module allows increasing the number of modules per string for both fixed systems and installations with trackers, due to its lower open circuit voltage (Voc), which also contributes to reducing system costs. However, a factor that significantly influences the performance of photovoltaic modules is the operating temperature. TOPCon 182 Pro modules utilize N-type silicon wafers with extended minority carrier lifetimes, combined with the implementation of advanced tunnel oxide passivated contact technology. This approach involves improving the cell's open circuit voltage (Voc) by depositing an ultrathin oxide layer and doping a polysilicon layer on the backside of the cell, facilitating effective interface passivation and contributing to a more favorable temperature coefficient in the module. As a result, TOPCon modules outperform PERC modules in high-temperature environments, as demonstrated in Figure 2. Figure 2 - Influence of Module Temperature on its Energy Generation In the cell design, narrower and more numerous fingers (small metal lines that collect the energy generated in the photovoltaic cells and deliver it to the busbars) are implemented. This minimizes transmission distances, reduces shadowing areas, and effectively decreases series resistance and silver paste consumption. Through simulations and experimental validations, it was determined that 16 busbars represent the ideal configuration to maximize output power in the 182 Pro TOPCon modules, as seen in Figure 3. Figure 3 - Relationship between the number of busbars and the output power The TOPCon cell was developed with a symmetrical design on the front and back faces of the cell, allowing a smaller shading area compared to PERC. By combining multiple bifaciality-enhancing technologies at both the cell and module levels, TOPCon 182 Pro modules can achieve bifaciality of up to 85%, a significant gain when compared to PERC technology. In terms of reliability, in addition to being certified by external laboratories, these modules undergo an internal testing protocol that is 2 to 3 times more rigorous than IEC standards, ensuring high product reliability (Table 1). Table 1: Internal test protocol IEC 61730/61215 tests Internal Protocol CSI DH (Damp Heat) 1000 hours 2000~3000 hours TC (Thermal Cycling) 200 cycles 400~600 cycles HF (Humidity Freeze) 10 cycles 20~30 cycles PID (Potential Induced Degradation) 96 hours 192 hours As shown in Table 1, the test results evidence that TOPCon modules exhibit superior performance compared with PERC modules. Taking the Damp Heat (DH) test as an example, TOPCon bifacial modules showed less than 2% power degradation after the DH2000 test, which was well below the 5% required by the IEC standard after the DH1000 test. CSI Solar has also developed a cell-level UV assessment method for daily monitoring. After UV irradiation of 60kWh/m², TOPCon cells showed approximately 0,2% less degradation compared to PERC cells, as can be seen in Figure 4, once again ensuring the reliability of the tested products. Figure 4 - Results of accounting tests of PERC and TOPCon modules. Finally, another great advantage of the 182 Pro modules is related to system compatibility, since they are mechanically compatible with traditional mounting systems and electrically compatible with the main brands of string inverters (including Canadian inverters).

Nadine Figueiredo Braz

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Key Benefits of Canadian Solar's 182 Pro Modules