Experimental and numerical investigation on a radiative cooling driving thermoelectric generator system

Abstract

Thermoelectric (TE) technology and radiative sky cooling (RSC) technology have proven to be a promising and green way to harvest energy from the environment. Combining RSC technology with Thermoelectric generator (TEG) device for passive power generation at night is meaningful and remains a challenge. Here, a radiative sky cooling driving thermoelectric generator (RSC-TE) system integrated by a doped modified TiO2/PMMA radiative cooling film, a commercial TEG, and an aluminum heat sink is developed, with a simple structure, low cost and high efficiency. The thermal-electrical performance of the RSC-TE system was evaluated through a consecutive nighttime experiment. Experimental results show that the temperature of the cold side of the TEG in contact with the radiative cooler is 2.7–4.2 °C lower than the ambient temperature, and the temperature difference between the hot and cold sides of TEG is 2.3–3.2 °C. The temperature difference at 00:00 can reach 2.5 °C, which corresponds to an open circuit voltage of 87 mV. Furthermore, a 3D model has been established by COMSOL software to investigate the effects of different environmental parameters and component-related parameters on system performance, which has guiding significance for the improvement and optimization of the experimental setup. This study can provide a new thinking and some practical guidelines for the design and application of the RSC-TE system.