Transparent Refractory Aerogels for Efficient Spectral Control in High–Temperature Solar Power Generation

Berquist, Zachary J.; Gayle, Andrew J.; Dasgupta, Neil P.; Lenert, Andrej

doi:10.1002/adfm.202108774

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Transparent Refractory Aerogels for Efficient Spectral Control in High–Temperature Solar Power Generation

Berquist, Zachary J.·Gayle, Andrew J.·Dasgupta, Neil P.·Lenert, Andrej

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Abstract

Although spectrally selective materials play a key role in existing and emerging solar thermal technologies, temperature-related degradation currently limits their use to below 700 °C in vacuum and even lower temperatures in air. Here a solar-transparent refractory aerogel that offers stable performance up to 800 °C in air is demonstrated, which is significantly greater than its silica counterpart. This improved stability is attributed to the formation of a refractory aluminum silicate phase, which is synthesized using a conformal single cycle of atomic layer deposition within the high-aspect-ratio pores of silica aerogels. Furthermore, based on direct heat loss measurements, the transparent refractory aerogel achieves a receiver efficiency of 75% at 100 suns and an absorber temperature of 700 °C, which is a 5% improvement over the state of the art. Transparent refractory aerogels may find widespread applicability in solar thermal technologies by enabling the use of lower-cost optical focusing systems and eliminating the need for highly evacuated receivers. In particular, a shift to higher operating temperatures while maintaining a high receiver efficiency can enable the use of advanced supercritical CO 2 power cycles and ultimately translate to an ≈10% (absolute) improvement in solar-to-electrical conversion efficiency relative to existing linear concentrating systems.

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Berquist, Zachary J., Gayle, Andrew J., Dasgupta, Neil P., Lenert, Andrej. 2021-12-03. Transparent Refractory Aerogels for Efficient Spectral Control in High–Temperature Solar Power Generation. https://doi.org/10.1002/adfm.202108774

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