A multifunctional curved CIGS photovoltaic/thermal roof system: A numerical and experimental investigation

With the development of building integrated photovoltaic/thermal (BIPV/T), the nonplanar type BIPV/T structure deserves investigation, while related research is rare. To realize multiple functions and adapt to the building's design style, inspired by Chinese regional architecture, a novel multifunctional curved PV/T roof integrated with Copper Indium Gallium Selenide (CIGS) cells were designed and the test rig was established. The system can generate electricity for the full year. For the PV/water-heating mode, the system can meet domestic water demands; for the PV/air-heating mode, the system can heat the air and adjust the indoor air temperature. A coupled optical-electrical-thermal (O-E-T) model is built to describe and predict the system's performance. The experimental results showed that the electrical and thermal efficiency achieved 5.49% and 33.38% in PV/water-heating mode; in PV/air-heating mode, the daily electrical and thermal efficiency were 5.88% and 40.60%, respectively. Based on the model verified by the experimental data, influence of the weather conditions, the working fluid's temperature, and the space between the adjacent channels on the system's performance is analyzed; the annual performance of the system is predicted based on the weather data of typical meteorological year (TMY) in Hefei.