Simulation Led Performance Evaluation and Design of Polymer Composite for Encapsulation of Low-Concentration Photovoltaic Modules

This work is focused on optimizing the properties of encapsulant for low-concentration photovoltaic (LCPV) modules leading to improved electrical power and module life. Thermal conductivity (TC), long-term shear modulus (G_∞) and coefficient of thermal expansion (CTE) of backside encapsulant are optimized using finite element (FE) simulations on LCPV module. It is found that as compared with ethylene-vinyl acetate (EVA), increased TC can improve electrical power, while decreased CTE and G_∞ can improve module life. Polymer composites with improved properties are computationally designed using in-house built design codes. Thermoplastic polyurethane (TPU) and ceramic fillers (particularly Al₂O₃ and AlN) with designated particle’s geometry and volume fraction are predicted as the most suitable constituents. The selected compositions are processed, and their properties are measured accordingly. The measured properties are used in the parent FE simulations to predict the expected values of electrical power and module life to confirm the feasibility of replacing EVA with TPU-composites. The proposed composite has a combination of high TC and tailored CTE and G_∞, which lowers the cell temperature and thermal strains enhancing the electrical power by 4.38% and the module life by 93%, respectively.