ABSTRACT The number of photovoltaic (PV) installations has grown rapidly in the last 10 years in Pakistan due to the growing electricity demand, the availability of favourable solar resources, and the national renewable energy objectives. With the growing installed capacity of PV modules on the gigawatt scale, the long‐term reliability and durability of the PV modules to local climatic conditions have taken on critical importance. High solar irradiance, high temperature, seasonal humidity, and thermal cycling are the humid subtropical climate factors that create a serious challenge to the performance of PV modules in Pakistan. This paper presents a systematic degradation analysis of field‐aged PV modules in the oldest running solar facility in the country by analysing electrical, optical and material‐level degradation. Performance characterisation was done on five module types (Types A, B, C, D, and E), and these included power output (Pmax) retention, efficiency decline, and failure‐mode analysis. The findings have shown significant deterioration: Type B modules showed a 29% decrease in Pmax and a corresponding 3% decrease in conversion efficiency, which was mainly due to severe encapsulant (EVA) browning. Type C modules exhibited a 22% loss in Pmax and a 4% decrease in efficiency, which could be attributed to material flaws inherent in the product, junction box failure, discolouration of the backsheet, delamination, and corrosion. The results clarify how high irradiance, humidity, and thermal cycling in Pakistan contribute to the acceleration of the process of failures. The present paper raises the issue of critical reliability concerns, the need to design climate‐adjusted material choice and preventive maintenance systems, and sets a standard to improve durability through PV infrastructure in developing energy markets.
Khan et al. (Tue,) studied this question.