High temperature stability of transparent silica aerogels for solar thermal applications
Solar thermal energy systems combined with low-cost thermal storage provide a sustainable, dispatchable source of renewable energy. One approach to increase the attractiveness of these systems is to use high-performing solar transparent, thermally insulating silica aerogel to significantly increase...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing
2020
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| Online Access: | https://hdl.handle.net/1721.1/127188 |
| _version_ | 1826217583568748544 |
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| author | Strobach, Elise M. Bhatia, Bikramjit S Yang, Sungwoo Zhao, Lin Wang, Evelyn |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Strobach, Elise M. Bhatia, Bikramjit S Yang, Sungwoo Zhao, Lin Wang, Evelyn |
| author_sort | Strobach, Elise M. |
| collection | MIT |
| description | Solar thermal energy systems combined with low-cost thermal storage provide a sustainable, dispatchable source of renewable energy. One approach to increase the attractiveness of these systems is to use high-performing solar transparent, thermally insulating silica aerogel to significantly increase efficiency. Several past works have proposed using these ultra-nanoporous materials to reduce thermal losses in the receiver, but only recently have aerogels reached the high solar transparency necessary to be considered for concentrated solar applications (>97%). However, the durability and stability of optically transparent silica aerogels at the operating conditions of solar-thermal receivers has not been examined. Here, we investigate the high temperature stability of transparent silica aerogel for use in concentrated solar thermal energy applications. Transparent samples (visible transmission >95% at 4 mm thickness) were annealed for several months at 400, 600, and 800 °C to investigate the relative change in nanostructure, solar transparency, and effective thermal conductivity. Results showed that at 400 and 600 °C, the temperature-dependent changes reach a plateau within 30 days of continuous annealing, but at 800 °C, samples are structurally unstable. A simple receiver efficiency model was used to show stable performance at 400 and 600 °C temperatures, even after months of exposure. This work validates that transparent silica aerogels can be used in solar thermal receivers below 800 °C, yielding appreciable increases in efficiency for solar energy harvesting operation. |
| first_indexed | 2024-09-23T17:05:39Z |
| format | Article |
| id | mit-1721.1/127188 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T17:05:39Z |
| publishDate | 2020 |
| publisher | AIP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1271882022-09-29T23:39:50Z High temperature stability of transparent silica aerogels for solar thermal applications Strobach, Elise M. Bhatia, Bikramjit S Yang, Sungwoo Zhao, Lin Wang, Evelyn Massachusetts Institute of Technology. Department of Mechanical Engineering Solar thermal energy systems combined with low-cost thermal storage provide a sustainable, dispatchable source of renewable energy. One approach to increase the attractiveness of these systems is to use high-performing solar transparent, thermally insulating silica aerogel to significantly increase efficiency. Several past works have proposed using these ultra-nanoporous materials to reduce thermal losses in the receiver, but only recently have aerogels reached the high solar transparency necessary to be considered for concentrated solar applications (>97%). However, the durability and stability of optically transparent silica aerogels at the operating conditions of solar-thermal receivers has not been examined. Here, we investigate the high temperature stability of transparent silica aerogel for use in concentrated solar thermal energy applications. Transparent samples (visible transmission >95% at 4 mm thickness) were annealed for several months at 400, 600, and 800 °C to investigate the relative change in nanostructure, solar transparency, and effective thermal conductivity. Results showed that at 400 and 600 °C, the temperature-dependent changes reach a plateau within 30 days of continuous annealing, but at 800 °C, samples are structurally unstable. A simple receiver efficiency model was used to show stable performance at 400 and 600 °C temperatures, even after months of exposure. This work validates that transparent silica aerogels can be used in solar thermal receivers below 800 °C, yielding appreciable increases in efficiency for solar energy harvesting operation. National Science Foundation (Grant 1122374) 2020-09-04T20:25:26Z 2020-09-04T20:25:26Z 2019-08 2019-05 2020-08-12T16:50:45Z Article http://purl.org/eprint/type/JournalArticle 2166-532X https://hdl.handle.net/1721.1/127188 Strobach, Elise M. et al. "High temperature stability of transparent silica aerogels for solar thermal applications." APL Materials 7, 8 (August 2019): 081104 © 2019 Author(s) en http://dx.doi.org/10.1063/1.5109433 APL Materials Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf AIP Publishing American Institute of Physics (AIP) |
| spellingShingle | Strobach, Elise M. Bhatia, Bikramjit S Yang, Sungwoo Zhao, Lin Wang, Evelyn High temperature stability of transparent silica aerogels for solar thermal applications |
| title | High temperature stability of transparent silica aerogels for solar thermal applications |
| title_full | High temperature stability of transparent silica aerogels for solar thermal applications |
| title_fullStr | High temperature stability of transparent silica aerogels for solar thermal applications |
| title_full_unstemmed | High temperature stability of transparent silica aerogels for solar thermal applications |
| title_short | High temperature stability of transparent silica aerogels for solar thermal applications |
| title_sort | high temperature stability of transparent silica aerogels for solar thermal applications |
| url | https://hdl.handle.net/1721.1/127188 |
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