Experimental Evaluation of a Gray-Colored Building-Integrated Photovoltaic Facade System

The rising operating temperature of Building-Integrated Photovoltaic (BIPV) systems is a critical factor that limits their electrical efficiency in real building applications. Addressing this issue is essential for improving both the performance and the reliability of BIPV systems under outdoor conditions. In particular, the demand for colored BIPV has been increasing due to its aesthetic integration with building façades, making it important to clarify its temperature behavior and electrical performance. However, most existing studies have focused on conventional BIPV modules, and research on the thermal and electrical characteristics of colored BIPV remains relatively limited. This study analyzes the temperature characteristics and electrical performance of conventional and colored BIPV systems installed in a full-scale mock-up building. Outdoor experiments showed that the maximum module temperature of the conventional BIPV system reached 75 °C, whereas the colored BIPV system remained lower at 68 °C. The temperature difference between the two systems ranged from 3 to 8 °C depending on solar radiation, mainly due to the retention of thermal energy in the rear insulation structure of BIPV systems and differences in incident energy conversion. These variations directly influenced the power generation and electrical efficiency of the modules. Compared with Standard Test Conditions (STCs), electrical efficiency decreased by approximately 15% in the conventional BIPV system and 10% in the colored BIPV system. The results demonstrate that colored BIPV systems not only mitigate the adverse impact of temperature rise on efficiency but also provide reliable performance and enhanced aesthetic adaptability, offering a promising solution for real building applications.