Comparative studies of encapsulation and glass surface modification impacts on PV performance in a desert climate

PV module encapsulation and glass covering processes play big role in reliability and performance of PV modules, especially under desert climatic conditions. In the present study, tests were carried out to compare the performance of five types of commercial glass cover and three types of commercial PV module encapsulates. The relative advantages of anti-reflective coated and textured glass cover, as well as, silicone and Ionomere encapsulant under clean and dusty conditions were examined in terms of PV module's power output and temperature. The results revealed that silicone and Ionomere encapsulant do boost the power output of a clean PV module by 2-3% on average. However, ethylene-vinyl acetate (EVA) encapsulant dust-covered modules showed relatively better performance as compared to dust-covered Ionomere and silicone encapsulant modules. Clean modules encapsulated with silicone or Ionomere material exhibited higher module temperature relative to that of EVA encapsulant modules. Adding an anti-reflective coating and texturing module's surface in some cases boosted the power output of a clean PV module by 6% on average. In addition, the study confirmed the fact that dust fouling can lead to a significant reduction in PV module power output (40% reduction after 10 months of exposure without cleaning). Anti-reflective coating of PV modules glass cover can relatively mitigate power reduction due to dust coverage.