Evaluating cooling and energy-saving potential of Vertical Greenery Systems based on 3D City Models: A case study of three cities

Abstract. Global cities face escalating urban heat stress and energy demands due to rapid vertical growth and densification. Vertical Greenery Systems (VGS), which mitigate urban heat by providing shading and evapotranspiration, offering a promising nature-based solution to enhance environmental sustainability. 3D city models serve as a suitable tool for simulating VGS due to their precise representation of urban environments. However, research leveraging 3D city models in VGS simulations is still limited. To address this challenge, this study evaluates the cooling and energy-saving potential of VGS using 3D city models in Wuhan, Hong Kong, and Singapore. A novel workflow encompassing microclimate simulation, solar irradiation calculation, and view factors computation is developed to assess VGS’s performance over 24 hours on a typical summer day, June 21st. Cooling and energy-saving performance are subsequently estimated. Our study highlights that VGS’s performance strongly correlates with climatic background and urban morphology, offering valuable insights for promoting and optimizing VGS deployment. By pioneering the integration of 3D city models with VGS, this study establishes a foundation for future multi-seasonal and city-scale VGS simulations.