Drawing on a wide range of academic studies, the paper systematically analyses the key factors affecting the performance of photovoltaic (PV) systems to provide in-depth understanding of degradation mechanisms along with effective countermeasures. This paper presents a comprehensive review of solar panel performance degradation in both industrial and residential sectors. Experimental results indicate that. Characterize performance precisely – Evaluate reliability carefully – Recognize causes of damage Characterize performance precisely – Evaluate reliability carefully – Recognize causes of damage Characterize performance precisely – Evaluate reliability carefully – Recognize causes of damage. This paper reviews recent progress in fault detection, reliability analysis, and predictive maintenance methods for grid-connected solar photovoltaic (PV) systems. However, the efficiency and longevity of these systems are often compromised by various faults, such as hotspots, which can lead to significant.