Reliability assessment of Fresnel lens under UV light for concentrated photovoltaic applications in Saudi Arabia

Reliability testing is an important part of the life cycle of any product. Before launching a product for public use, it is very important to perform a reliability test under severe conditions. A concentrated photovoltaic (CPV) plant consists of many components that undergo hours of accelerated testing before making their way to the market. A typical refractive CPV module consists of a Fresnel lens, a secondary optical element (SOE), and a solar cell. The Fresnel lens collects light and focuses it onto the solar cell through SOE. Continuous operation in sunlight has deteriorating effects on the lens and all the components inside the module. The Fresnel lens must be tested for reliable performance in ultraviolet light and other weather conditions like rain, hails, wind, sand, etc. The purpose of this research is to observe and analyse the effect of ultraviolet rays with different intensities on the poly methyl methacrylate (PMMA) Fresnel lens that is used frequently in refractive CPV designs. UV radiation causes photolysis in PMMA and hence breaks down large PMMA chains into smaller MMA monomers. Hence, the transmissivity dropped by 6% on average by the end of 50 kWh/m2. This is because of increased yellowness, and the efficiency dropped depending on how much light is converted by the CPV.