Impact of Thermal Mismatch on Photovoltaic Module Performance: A Novel Modeling Approach and Configuration Analysis

Abstract This study investigates the effects of uneven temperature distribution on the performance of photovoltaic (PV) modules in series, parallel, series–parallel, and parallel–series electrical configurations. A novel cell-level mathematical model is introduced, which uniquely integrates the IEC 60891 translation standard with cell-level diode equation solving to predict performance under specified, nonuniform temperature patterns. The results quantitatively demonstrate that hybrid configurations (series–parallel and parallel–series) significantly mitigate thermal mismatch losses compared to pure series or parallel connections. For a representative gradient where half the cells operate at 50 °C and the remainder at 25 °C, the hybrid topologies reduce power loss by approximately 30–50% relative to a pure series string. This highlights their superior tolerance to the thermal nonuniformity commonly found in field installations due to junction box heating or mounting effects. The work underscores that configuration selection and thermal management are critical design levers for minimizing energy loss in large-scale PV systems, where perfect thermal uniformity is unattainable. Experimental validation shows good agreement with the simulation model.