Autonomous Evaporative Cooling of Solar Photovoltaics Panels Achieved by a Bio‐Inspired Fog‐Harvesting Composite for Arid Regions

Solar photovoltaics (PV) are pivotal in the global shift toward sustainable energy, especially in sun-drenched arid regions. Nevertheless, PV panel efficiency and lifespan are compromised by overheating from intense solar irradiation. Although evaporative cooling is an attractive passive approach due to energy-saving and maintenance-free traits, conventional hygroscopic materials perform poorly in arid climates due to dependence on ambient humidity. Inspired by the fog-harvesting adaptation of the Namib Desert beetle, this work presents an integrated, self-sustaining cooling system that operates independently of external water. The design includes two synergistic components: a biomimetic fog collector with a hydrophilic-hydrophobic patterned surface (CuO@PTFE mesh) for atmospheric water capture, and a temperature-sensitive hydrogel loaded with LiCl crystals for on-demand water storage and thermally regulated release. In lab simulations of a desert environment, the system achieved a peak temperature reduction of 20.4°C and a consistent power output improvement of 7.58%. Subsequent ten-day field tests in arid zones of China-Turpan, Ordos, and Chifeng-confirmed operational reliability, with an average daytime temperature drop over 8.0°C. This bio-inspired autonomous configuration offers a viable and sustainable route to boosting energy generation and prolonging the service life of PV installations in water-scarce regions.