Experimental study on a hybrid solar photothermic and radiative cooling collector equipped with a rotatable absorber/emitter plate

Taking the frigid outer space as heat sink, a terrestrial body can cool itself to sub-ambient temperature via radiative sky cooling (RC) scheme. However, poor seasonal and regional adaptabilities low power density of RC technology confine its effective applications only in hot seasons regions with RC-friendly ambient conditions. Similarly, solar thermal collector cannot work at night is little value when needless. To tackle these challenges, hybrid photothermic (PT-RC) equipped rotatable absorber/emitter panel proposed experimentally investigated. This dual-mode flexibly switch between PT match specific energy demands different scenarios. The daily efficiency PT-RC system zero-reduced reached 50.4%, typical level flat-plate water heating systems. could not provide during most daytime hours. easily achieve nighttime cooling, decreasing from about 60 50 W/m2 circulated being continuously cooled down around 20 12 °C. average nocturnal ranged 30.5 57.5 multi-night test. offers new strategy deliver coldness renewable environmental-friendly manner shows potential smart management buildings, vehicles, agriculture, etc.