Modeling Cracks in Silicon-Heterojunction Photovoltaic Modules: A Real-World Case Study

This work investigates the impact of cracks on silicon heterojunction photovoltaic (PV) modules by analyzing their electrical and thermal behavior under low and high current conditions. The analysis was conducted on PV modules affected by a severe hailstorm, which produced hailstones up to 16 cm in diameter, far exceeding the standard test sizes (IEC 61215). A combination of electroluminescence (EL) and infrared (IR) thermography, along with dark and light current-voltage characterization, was employed to examine both hail and operator-induced cracks. The findings revealed that these cracks, which are latent damages not visible to the naked eye but only with EL and IR investigations, lead to localized temperature increase near open circuit voltage, and to a more uniform distributed temperature increase near short circuit conditions. A Simulink/Matlab model was developed to reproduce the thermal behavior of cracked cells in series with intact ones, to reproduce what happens in a real-world scenario. The results emphasize the importance of identifying latent defects in PV modules to ensure long-term reliability, safety, and efficiency, offering insights into their electrical and thermal behavior in low and high current regime.