Shading impact modeling on photovoltaic panel performance

The performance of photovoltaic modules is strongly influenced by environmental factors, with shading from surrounding obstacles being particularly impactful. By installing photovoltaic modules outdoors, shading becomes inevitable. Shading reduces solar irradiance incident on the module surface, leading to reduced electricity generation. The position of obstacles is a key determinant of performance degradation. This study evaluates the impact of shading on a 100-W photovoltaic module located in northeast Tehran, Iran, focusing on static obstacles with fixed-geometric shapes. Five distinct methods, integrating various existing shading and solar radiation models with the single-diode model, were employed to predict photovoltaic energy output under shading conditions. MATLAB was used to implement the models and analyze shading effects caused by a rectangular cuboid obstacle positioned to the north, south, east, and west of the module. The results revealed that obstacle positioning significantly affects the degree of energy loss. The obstacle to the south caused the most severe shading, often reducing energy generation by over 50 %, while the northern obstacle had the least detrimental impact. The study also highlights that the choice of shading model plays a critical role in prediction accuracy. Using the most precise shading model improved energy prediction accuracy by up to 53 %. Although radiation model accuracy contributes to the overall prediction, its effect is less pronounced. Enhancements from the more accurate radiation model were comparatively smaller, ranging from 13 % to 15 %. These findings underscore the importance of carefully optimizing photovoltaic module placement with its surrounding environment to minimize energy losses under shading conditions.