Solar-based nighttime electric power generator based on radiative cooling

Abstract

This study focuses on developing and investigating a hybrid nighttime electric power generator that integrates photovoltaic (PV) cells with thermoelectric generators (TEG) to provide continuous power generation during both day and night. During the day, PV cells efficiently capture solar energy and convert it into electricity. At night, radiative cooling lowers the surface temperature of the PV panels, creating a temperature differential between the ambient air and the cooled panels. This temperature difference drives the TEG modules, which generate electricity based on the Seebeck effect. The experimental results reveal that the size and configuration of TEG modules significantly affect power output. A single 3 cm×3 cm TEG produced up to 0.9 mW of power with a 55°C temperature difference, while a larger 4 cm×4 cm TEG generated up to 3.8 mW. Furthermore, connecting two 4 cm×4 cm TEGs in series resulted in a peak output of 7.7 mW, nearly double that of the single TEG setup. This hybrid system demonstrates potential for moderate nighttime power generation, suitable for small household applications such as LED lights, laptops, phone chargers, and wireless routers. The ability to generate power both during the day and night enhances the efficiency and reliability of renewable energy systems, offering a continuous, sustainable power supply that mitigates the limitations of conventional solar panels. The results underscore the feasibility of scaling up TEG modules to achieve higher power outputs, making this system a promising solution for addressing nighttime energy demands in off-grid and low-power applications.