Ultra-high electrical efficiency scalable RC-TE devices utilize renewable radiation energy from the sun and cold outer space

Renewable radiant energy is crucial for maintaining Earth's energy balance through incident solar illumination and infrared radiation heat dissipation. Efficient and high-quality utilization of renewable radiant energy, including solar radiation and sky radiation cooling energy, is an urgent issue that needs to be addressed. The integration of radiative cooling (RC) and thermoelectric generation (TEG) technologies offers opportunities for the efficient use of renewable radiant energy. However, current TEG power generation and efficiency are not promising and fall short of the requirements for large-scale application. This shortfall is primarily due to irreversible losses caused by multi-scale factors, ranging from nanostructured materials to macro-sized device systems.In this study, we constructed a highly efficient vacuum concentrator RC-TEG (VC-RC-TEG) system by optimizing multi-scale coupling, reducing irreversible losses, and increasing energy density. The VC-RC-TEG system achieved a maximum temperature difference of 7.5K and a maximum power density of 1824.95 mW/m2, which is more than twice the highest value reported to date. The generated power can light up LEDs and drive low-power devices such as small sensors. This study provides direction for the large-scale application of low-cost passive power generation technology. [Display omitted] •Multi-scale optimized TEG efficiency with maximum power density of 1824.95 mW/m2.•The power generated by this device can drive multiple light-emitting diodes, which has some practical value.•The power generation efficiency of RC-TEG in a vacuum environment was specifically experimented and analyzed.