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.
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This material is partially based upon work supported as part of the Sunshot Initiative funded by the US Department of Energy, Office of Energy Efficiency & Renewable Energy under Award Number: DE-EE0005806 (for device engineering) and based upon work supported as part of the Solid State Solar-Thermal Energy Conversion Center (S3TEC), an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number: DE-SC0001299/DE-FG02-09ER46577 (for materials).
The authors declare no competing financial interests.
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Kraemer, D., Jie, Q., McEnaney, K. et al. Concentrating solar thermoelectric generators with a peak efficiency of 7.4%. Nat Energy 1, 16153 (2016). https://doi.org/10.1038/nenergy.2016.153
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