Work

Tunable All-Day Thermoelectric Generator Driven by Solar Heating and Radiative Cooling

Year: 2026

Type: article

Abstract: The complementary utilization of solar heating and radiative cooling offers a promising approach for all-day thermoelectric energy harvesting. In this work, a tunable all-day thermoelectric generator (TAD-TEG) integrating a solar absorber, an optical filter, an IST-based phase-change radiative cooler, and a thermoelectric generator is proposed, and its optical, thermal, and power-generation performance is numerically investigated using a steady-state coupled thermal–electrical model. The optimized solar absorber achieves an AM1.5-weighted solar absorptance of 0.961, while the assembled cold-side system exhibits an emissivity of 0.980 in the 8–13 μm atmospheric window in the cooling-mode “on” state and 0.007 in the “off” state, enabling pronounced radiative modulation. Under representative baseline environmental conditions, the average power densities in the “on” state reach 12.80 W/m 2 during the daytime and 0.114 W/m 2 at night, markedly higher than the corresponding values of 7.45 and 0.011 W/m 2 in the “off” state. The corresponding 24-h electrical energy yields are 167.66 and 96.99 Wh/m 2 , respectively, indicating that radiative-state switching can effectively regulate the all-day thermoelectric output. Further analysis shows that the system exhibits tunable thermoelectric responses under different environmental conditions and TEG parameters, together with favorable power-generation performance across different seasons and geographical locations. These results indicate that the proposed TAD-TEG enables the synergistic utilization of solar heating and radiative cooling through cold-side radiative modulation, providing a promising tunable strategy for all-day thermoelectric energy harvesting under diverse climatic conditions.

Source: Renewable Energy

DOI: 10.1016/j.renene.2026.126410