Planning the installation of building-integrated photovoltaic shading devices: A GIS-based spatiotemporal analysis and optimization approach

Building-integrated photovoltaics (BIPV) can produce power while occupying little urban space. Photovoltaic-integrated shading devices (PVSDs) are a key component of BIPV that can generate electricity while blocking excess daylight. However, previous studies have lacked a systematic design of PVSDs that accurately estimates the trade-offs between indoor sunshade duration and electricity generation. This study proposes a multi-objective optimization framework for maximizing PV potential, minimizing PV area, and enabling proper sunshade duration in complex urban surfaces. A GIS-based spatiotemporal analysis and optimization approach was applied to three PVSD planning scenarios: (i) parallel to the horizontal land surface, (ii) inclined at an angle equal to the local latitude, and (iii) rotated in real-time to keep the PV surface perpendicular to the solar radiation. It was found that 2978 units of PVSDs with a surface area of 0.8×1.0 m2 can generate 0.644 GWh of electricity annually in Hong Kong. In the static inclined scenario, some units can generate up to 241 kWh of electricity per year, which is competitive with rooftop PV efficiency. Hybrid installation scenarios are suggested to account for shading from upper floor PVSDs and surrounding buildings. This study can facilitate solar farming in global cities and contribute to renewable energy penetration.