Experimental Evaluation of Performance of a Gray-Colored BIPV System on a Full-Scale Building

This study analyzes the temperature characteristics and electrical performance of conventional and colored Building-Integrated Photovoltaic (BIPV) systems installed in a full-scale mock-up building. Outdoor experiments revealed that the maximum temperature of the PV modules in the conventional BIPV system reached 75 °C, whereas the colored BIPV system remained lower at 67 °C. The temperature difference between the two systems ranged from 3 to 8 °C with varying solar radiation. This difference is primarily attributed to the retention of thermal energy in the rear insulation structure of BIPV systems, unlike conventional PV modules, which directly affects the operating temperature of the PV modules. Notably, differences in the incident energy on the front side and its conversion into electricity and heat further contributed to the higher module temperatures observed in the conventional BIPV system compared to the colored BIPV system. Consequently, these temperature variations directly influenced the power generation and electrical efficiency of the BIPV systems. Relative to STC conditions, the electrical efficiency decreased by approximately 15% for the conventional BIPV system and 10% for the colored BIPV system under real building-applied conditions. Thus, the colored BIPV system demonstrates an advantage in mitigating the adverse effects of temperature rise on electrical efficiency.