Application of a phase-change material to improve the electrical performance of vertical-building-added photovoltaics considering the annual weather conditions

•Improved performance in a vertical PV module via a PCM was assessed.•The optimal PCM melting temperature was determined according to weather conditions.•The PCM thickness was also determined to maximize the performance of the PV module.•The electrical power out of the PV/PCM module was increased by 1.5%. The performance improvement of a vertical PV module with the application of a phase-change material (PCM) in a device known as a PV/PCM module was examined in an experiment. The PCM could prevent the PV module from overheating by absorbing a considerable amount of heat during the phase change. A simulation was also carried out to analyze the annual electric energy generation with changes in the installation direction of the PV/PCM module and the melting temperatures and thicknesses of the PCM. Through an analysis of the results, the optimal melting temperatures and thicknesses of the PCM according to the installation directions were introduced. When the amount of vertical solar radiation was high and when the outdoor air temperature was moderate, the electric power output of the PV module was increased by at most 3% using the PCM. However, during the winter, the effect of the PCM was decreased. The optimal melting temperature was determined to be 298K in all installation directions. The optimal PCM thickness varied slightly depending on the installation direction of the PV/PCM module. The amount of electric power generation was increased by 1.0–1.5% compared to that of the conventional PV module. It is hoped that the results will used as important reference data for the improvement and commercialization of PV/PCM modules.