Toward Net-Zero Energy Cooling: Dynamic Radiative Coolers with Near-Zero Energy Input

Radiative cooling (RC) has emerged as a promising passive thermal management strategy with zero energy consumption. However, conventional RC systems operate continuously regardless of environmental conditions or user demand, often resulting in performance mismatches. To address this challenge, near-zero-energy dynamic radiative cooling (NZ-DRC) technologies have been developed, enabling reversible modulation of radiative properties without continuous external power. This review places particular emphasis on energy-autonomous switching strategies that leverage intrinsically responsive materials or one-time activation processes. NZ-DRC systems are systematically categorized into five types based on their switching mechanisms: fluid-mediated, thermal, mechanical, electrical, and wavelength-selective. Their operational principles, energy independence, and material adaptability are critically examined. The potential applications of NZ-DRCs in building materials, textiles, vehicles, and spacecraft are explored, highlighting their relevance across diverse sectors. Furthermore, key considerations such as long-term durability, environmental compatibility, and scalability are discussed to assess their feasibility for real-world deployment. This perspective aims to provide a conceptual and practical framework for guiding the development of next-generation radiative cooling technologies that are both adaptive and energy-resilient.