Concentrating solar thermoelectric generators with a peak efficiency of 7.4%

• Main Authors: Jie, Qing (Author), Cao, Feng (Author), Liu, Weishu (Author), Ren, Zhifeng (Author), Kraemer, Daniel (Contributor), McEnaney, Kenneth (Contributor), Weinstein, Lee Adragon (Contributor), Loomis III, Robert James (Contributor), Chen, Gang (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor)
• Format: Article
• Language: English
• Published: 2017-05-26T13:55:47Z.
• Subjects: Article
• Online Access: Get fulltext

Concentrating solar power normally employs mechanical heat engines and is thus only used in large-scale power plants; however, it is compatible with inexpensive thermal storage, enabling electricity dispatchability. Concentrating solar thermoelectric generators (STEGs) have the advantage of replacing the mechanical power block with a solid-state heat engine based on the Seebeck effect, simplifying the system. The highest reported efficiency of STEGs so far is 5.2%. Here, we report experimental measurements of STEGs with a peak efficiency of 9.6% at an optically concentrated normal solar irradiance of 211 kW m⁻², and a system efficiency of 7.4% after considering optical concentration losses. The performance improvement is achieved by the use of segmented thermoelectric legs, a high-temperature spectrally selective solar absorber enabling stable vacuum operation with absorber temperatures up to 600 °C, and combining optical and thermal concentration. Our work suggests that concentrating STEGs have the potential to become a promising alternative solar energy technology.
United States. Department of Energy (DE-EE0005806)
Solid-State Solar-Thermal Energy Conversion Center (DE-SC0001299)
Solid-State Solar-Thermal Energy Conversion Center (DE-FG02-09ER46577)