Temperature Coefficients and Operating Temperature Verification for Passivated Emitter and Rear Cell Bifacial Silicon Solar Module

In this article, the temperature coefficients of the bifacial passivated emitter and rear cell (PERC) solar module and the full-area aluminum back surface field (Al-BSF) solar module were calculated based on the theoretical model under different module temperatures and irradiances. Meanwhile, the measured temperature coefficients were obtained by testing the performance of bifacial PERC solar module and conventional Al-BSF solar module under different module temperatures and irradiances. The results show that the laboratory measurements are close to the calculated values, and the normalized temperature coefficients of output power for the bifacial PERC solar module are lower than that of the conventional Al-BSF solar module under the same operating conditions. An interesting finding is that the normalized temperature coefficients of short-circuit current for the bifacial PERC solar module are larger than that of the conventional Al-BSF solar module under the same irradiance. This is attributed to lower back surface recombination velocity and higher carrier collection efficiency of PERC solar cells compared with conventional Al-BSF solar cells. Additionally, the operating temperatures of the bifacial PERC solar module and conventional Al-BSF solar module were surveyed outdoor. It is found that the operating temperature of the bifacial PERC solar module is higher than that of the conventional Al-BSF solar module in some cases. However, this tendency is reversed in other cases when these two solar modules work under the same environmental conditions. The conclusion was explained reasonably according to the actual operating conditions of solar modules. The obtained results in this work can provide useful insight into evaluating the field performance of the bifacial PERC solar module.