Combined solar concentration and carbon nanotube absorber for high performance solar thermoelectric generators

Solar thermoelectric generators (STEGs) is one of the most important technologies for solar energy conversion. However, the inefficiency due to coupling constraints such like low working temperature and dimensionless figure of merit of the thermoelectric materials, also known as material's ZT value, has been hampering the development of STEGs for a time. Here we demonstrate a high performance STEG system combined with solar concentrators and carbon nanotubes (CNTs) absorber, which can greatly improve the solar-thermal conversion process. The proposed STEG system enables a peak efficiency of 4.3% with solar concentration of 78, and a maximum power of 11.2 W at 106 x suns. The enhanced efficiency is ensured by the optimized system thermodynamics due to the combination of solar concentration devices and CNT based solar absorber. Our design provides a universal prototype of solar thermal energy recovery system for distributed energy harvesting and deep-space explorations.