Micro–macro analysis for mapping hail-induced damage in lightweight flexible photovoltaic modules

Flexible photovoltaic (PV) modules with thin frontsheet are increasingly demanded for lightweight and curved applications but remain susceptible to hail-induced damage under extreme weather conditions. This study presents a combined experimental and numerical approach to evaluate the hail impact response of lightweight flexible PV modules using a representative hail size derived from historical statistics. Based on microscopic characterization of the PV module, an enhanced numerical model that incorporates the elastic-plastic behavior and phase transition of hail is developed to reveal the stress propagation and transfer within the layered structure during impact. The model is validated against macroscopic impact experiments, which show localized cell damage with negligible electrical degradation. Stress analysis demonstrates that the thick encapsulant mitigates stress through the cushioning mechanism, whereas the stiff backsheet contributes to the global stress redistribution. The simulations capture a peak cell stress of approximately 116 MPa and estimate a corresponding fracture probability of 23.5% according to a statistical model. By quantitatively linking hail parameters, module design, and cell-level damage, this study can provide a comprehensive assessment for evaluating the impact resilience of advanced flexible PV modules from laboratory-scale testing to real-word deployment.