Accuracy of 2D vs. 3D modeling for stress assessment in thin lightweight PV modules

To meet the demands for weight reduction and shape flexibility, lightweight photovoltaic (PV) modules replace traditional glass covers with flexible materials. This modification may increase the risk of stress-induced cracking during manufacturing, but the relevant theoretical analysis is limited. To investigate this issue, we developed a simplified 2-dimensional model and a detailed 3-dimensional model of novel ethylene-tetrafluoroethylene (ETFE)-encapsulated PV modules. The 3D model faithfully captures the misalignment between Cu-interconnects and cell edges in actual modules, while the 2D model does not. This oversight in 2D model leads to significant discrepancies in stress predictions, which become increasingly pronounced as cell thickness decreases. Notably, the deviation reaches 16.8 % at 100 µm cell thickness, highlighting the necessity of 3D modeling for thinner solar cells. Based on parametric analysis and experimental validation, the stress evolution and influencing mechanisms are clarified. These findings enable the proposal of concrete optimization strategies to reduce cell damage and improve module power output: use thicker cells, reduce interconnect width, and lower the cooling temperature.