"11\u2011Year Performance Degradation of PV Systems in Desert Climates"

"This study investigates the performance evolution and failure mechanisms of a multi-crystalline silicon PV system installed in Doha, Qatar, after 11 years of outdoor exposure in a desert climate. A long-term outdoor PV system performance showed a drop in the performance ratio of 1.81 %\/year. Indoor current-voltage measurements after field exposure showed an average degradation rate of 3.5 %\/year. The drop in Pmax is primarily attributed to a drop in the Voc. Snail trails, micro-cracks, defective bypass diodes, and encapsulant degradation are the most common failures observed. The electroluminescence imaging showed micro-cracks that affect the maximum power, increase series resistance, and decrease shunt resistance. The ultraviolet fluorescent images show degradation patterns of the encapsulant. The findings demonstrate how prolonged exposure to high irradiance, elevated temperature, and severe soiling conditions can accelerate PV module degradation in desert environments. By combining long-term operational monitoring with detailed module-level diagnostics, this study provides insights into dominant failure modes affecting PV system reliability. It highlights the importance of preventive maintenance and module design optimization for solar installations in desert regions."