Investigating Long‐Term Degradation and Defects of Solar Photovoltaic Modules in Tropical Climates: A Case Study of Malaysia

ABSTRACT Photovoltaic (PV) modules are vital components of renewable energy systems, yet their performance tends to decline over time due to exposure to various environmental conditions. In Malaysia's tropical climate, where high humidity, intense sunlight, and frequent rainfall prevail, identifying the key factors contributing to this degradation is crucial. This paper examines the primary degradation modes in four monocrystalline silicon PV modules after nine years of outdoor exposure in Kuala Lumpur, Malaysia, offering insights into real‐world degradation mechanisms that can help manufacturers enhance durability and performance of solar energy systems in similar climates. The outcomes are compared with other studies that analyse the degradation of PV modules under similar tropical conditions with nearly identical exposure periods of 8, 11, and 12 years. The analysis was carried out using visual inspection, electroluminescence, and electrical performance evaluation to assess the extent of degradation. The findings indicated a substantial average power degradation of 40.35%. The most significant factors contributing to this severe power loss were encapsulant discolouration and the presence of snail trails with cracks. Notably, the extreme discolouration of the encapsulant documented in this research aligns with results from a Spanish study, in which PV modules underwent 22 years of exposure. This comparison highlights how humidity and temperature accelerate deterioration, making the findings relevant for other tropical regions. These results underscore the rapid deterioration of PV modules in tropical regions and provide crucial insights for improving PV system performance in high‐humidity climates.