<p>A solar panel or photovoltaic module is a device that converts solar energy into electricity. To ensure effective energy generation, it is crucial for a PV plant that the functioning of the photovoltaic module is fault-free, or at the very least that the defects can be recognized early. The performance of a PV module is adversely affected by degradation. In this paper, visual degradation investigations and expert opinions were adopted to identify the defects and degradation rates of PV modules installed in five climatic zones in India. This study employs the Analytic Hierarchy Process (AHP) to determine the weights and priority rankings of each defect. Additionally, the SPSS software was utilized to analyze the reliability, internal consistency, and normal distribution of respondents’ data. Furthermore, defects occurring in different climatic zones are discussed in details.</p>