Cooling energy savings from passive daytime radiative cooling in Europe: A comparative analysis with and without population weighting from open-source data, with additional comparisons to Chinese cities
Yujie Yang, Guoqiang Zhang, Li Rong
Abstract
Passive Daytime Radiative Cooling is a promising technology to reduce surface temperatures below ambient levels even under direct sunlight, potentially helping Europe counteract increasing cooling demands due to frequent heatwaves. This research focuses on mapping possible cooling energy saving of PDRC across Europe utilizing a wavelength-dependent PDRC model, taking into account temperature, total column water vapor, and cloud cover. Moreover, a comparison of cities at analogous latitudes in Europe and China is undertaken. Our results reveal that regions around the Mediterranean Sea have the highest cooling potential, exceeding 180 kWh/m2 annually. For the conditions with and without considering the population, PDRC exhibits the highest possible cooling energy saving in Malta. Besides, possible cooling energy saving of PDRC in Europe decreases from south to north, reaching its lowest in Iceland. However, the northern European regions typically experience summer temperatures below 18 °C. Therefore, northern European regions present limited suitability for PDRC. Notably, while cities at equivalent latitudes in Europe and China exhibit similar annual cooling potentials, the harsh winter conditions in northern China diminish the practicality of PDRC. Thus, European cities demonstrate a more favorable environment for PDRC implementation than their Chinese counterparts at matching latitudes.