Urban-scale radiative cooling potential and spatial heterogeneity: A study based on urban building energy modeling (UBEM)

Radiative cooling materials (RCMs) dissipate heat to outer space through long-wave radiation and have recently been explored for building surfaces owing to their ability to significantly lower surface temperatures. Assessing the energy-saving potential of RCMs at the urban scale is challenging due to the dynamic performance of RCMs and complex shading effects among buildings. In this study,an integrated simulation framework for RCM performance and urban building energy models (UBEMs) is proposed,considering the actual urban building form and shading relationships. The energy-saving potential and its spatial heterogeneity were analyzed in a case study of 158,497 buildings in Guangzhou,China. The results showed that installing radiative cooling materials on roofs will achieve a 0.5 TWh electricity (5.2%) reduction in annual cooling electricity consumption and a 0.3 GWe (4.1%) reduction in peak cooling electricity loads. When applied to both the roofs and facades,the electricity reductions increase to 1.3 TWh (13.4%) in annual consumption and 0.8 GW (11.0%) in peak load. The proposed approach enables the assessment of radiative cooling potential in complex urban environments,supporting the optimal placement of RCMs and the development of effective deployment strategies.