Thermo-mechanical analysis in silicon PV modules with interconnect geometry effects under thermal stress

Microcracks induced by mechanical or thermal loads significantly degrade the electrical performance and long-term reliability of photovoltaic (PV) modules. While previous studies have examined the effects of microcracks on power output, limited attention has been paid to the underlying mechanisms governing crack initiation and propagation under thermo-mechanical stress. In this study, a three-dimensional finite element (FE) model was developed to investigate crack behavior in silicon cells within PV modules. The extended finite element method (XFEM) was employed to simulate crack initiation and propagation. The numerical model was validated against experimental data and manufacturer-provided material parameters to ensure its accuracy. The results show that temperature gradients significantly affect both the threshold for crack initiation and the distribution of maximum principal stress in the silicon cells. Furthermore, the geometry of the interconnector, particularly its thickness and width, plays a critical role in crack initiation. This study provides a validated numerical framework for analyzing crack evolution in PV modules and offers design insights for optimizing interconnectors to balance mechanical reliability and electrical performance.