Near-room-temperature waste heat recovery through radiative cooling for both daytime and nighttime power generation
Journal
Journal of Materials Chemistry A
Date Issued
2023-01-01
Author(s)
Abstract
With the rapid growth in global energy consumption, the recovery of waste heat is becoming an important issue. Nevertheless, the recovery of near-room-temperature waste heat remains challenging because the slight temperature difference with the surroundings leads to extremely low thermoelectric power generation. In this study, we combined a daytime radiative cooling (DRC) technology with a thermoelectric generator (TEG) to efficiently recover near-room-temperature waste heat. We investigated the effects of the thermal radiation and thermal conduction properties of DRC materials on near-room-temperature waste heat recovery (WHR). We designed a hierarchical micro-nano h-BN/ZnO composite (MNHZC) that possessed an outstanding daytime radiative cooling ability and moderate thermal conductivity. With this hierarchical h-BN/ZnO composite, we achieved record-high levels of thermoelectric power generation of 225.3 and 412.3 mW m−2 during the daytime and nighttime, respectively, with enhancements in thermoelectric power of 1030 and 190%, respectively. The attractive power generation ability of the MNHZC/TEG system suggests its great potential in low-grade waste heat recovery and environmental energy harvesting by consistently generating power in both the daytime and nighttime.
SDGs
Type
journal article