Development and verification of an airflow-type photovoltaic-integrated shading device on building façades

Photovoltaic (PV)-integrated shading devices (PVSDs) combine solar shading and electricity generation on building façades, effectively harness solar energy, and promote net zero-energy building initiatives. In high-rise buildings, limited rooftop PV capacity necessitates façade integration, yet vertically installed PVSDs reduce power generation. This study proposed and verified the performance of an innovative airflow-type PVSD that integrates PV panels with ventilated solar shading louvers. The system, featuring openings at the top and bottom, allows air to pass through, enabling passive cooling of the solar panels and mitigating the decline in power generation efficiency without additional energy consumption. During cooling periods, the outside air rises through louvers to cool the panels, whereas during heating periods, the indoor air is warmed by the panels and supplied to the rooms. Detailed numerical analysis models and thermal load calculations were employed to assess the annual energy performance of the PVSD, focusing on PV panel efficiency, heat recovery, and changes in building energy consumption. Simulations were based on a single-room model and specific weather data from a Japanese city, with boundary conditions validated by winter outdoor measurements. The key findings indicate improved daily cumulative electricity generation and lower annual net energy consumption for the airflow-type PVSD compared to the non-airflow-type. The study also highlighted that the installation angle significantly impacts the energy performance, whereas modifications to the opening area and installation height have negligible effects. This study provides valuable insight into the implementation of PVSDs in building applications and serves as a foundation for future design endeavors.