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 (CO 2 ) 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 (Δ A sol = 87%; Δε Broadband = 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 CO 2 emission reduction compared to the DRC device. This DERC device represents a conceptual advancement, paving the way for global energy savings and emission reductions.