Quantifying Arboreal Shading Efficacy on Southern Vertical Surfaces: A Parametric Analysis of Vegetation-Driven Solar Mitigation in Urban Built Environments

Abstract

Urban greening, particularly through vegetation, has been recognized for its role in regulating building microclimates and enhancing energy performance. Among greening elements, trees significantly affect the solar radiation received by south-facing facades, thereby influencing thermal gains and photovoltaic (PV) power generation. However, the scientific planning of tree configurations to control facade solar exposure remains underexplored. In this study, a parametric framework was developed by integrating parametric modeling with solar radiation simulation. The spatiotemporal effects of tree parameters—including trunk-to-façade distance(TFD), the radius of the tree crown(RTC), tree height(TH), tree spacing(TS) and crown transmittance(CT)—were quantitatively evaluated. Tree layouts were optimized to maximize net power generation, defined as PV output minus cooling energy demand. Significant spatial and temporal heterogeneity was observed in radiation attenuation across facades. Daily attenuation rates exceeded 15% in summer and 6% in winter. Influential parameters varied notably by floor level. With optimized tree configurations and facade-integrated photovoltaics, net power generation was increased by up to 14.83%. These findings provide a technical pathway for integrating vegetation design with building energy systems, contributing to the coordinated advancement of energy efficiency and renewable energy utilization in urban environments.

Keywords: Tree, Solar radiation, Parametric modeling, Seasonal transmissivity, Photovoltaic potential, Optimize the layout of trees.