Dynamic evaporative and radiative cooling for efficient year-round energy savings

Electricity-free radiative cooling (RC) techniques are gaining ever-increasing attention to decrease energy consumption and carbon dioxide (CO2) emissions. However, the cooling power of RC in summer is severely limited by atmospheric window constraints and its negative effect in winter offsets annual energy savings in four-season regions. This study introduces a dynamic evaporative and radiative cooling (DERC) device to maximize the cooling power in hot summer and achieve year-round dynamic thermal management. Adaptive to changes in environmental temperature, the DERC device demonstrates dynamic regulation of water evaporation, along with notable modulation of solar and thermal radiation (A A _soi = 87%; AeBroadband = 63%). Theoretical and real-time experiments demonstrate that the DERC device is more energy-efficient than cutting-edge dynamic radiative cooling (DRC) techniques. The energy-saving simulations indicate that the DERC device yields over 40% primary energy savings and CO2 emission reduction compared to the DRC device. This DERC device represents a conceptual advancement, paving the way for global energy savings and emission reductions.