Session: 05-02: Concentrating Solar Power I -- Heliostats and Trough Receivers

Paper Number: 138565

138565 - Techno-Economic Performance of Linear Aerogel Receivers Based on Experimental Characterization at an Industry Relevant Scale 

Abstract: 

The use of linear concentrating systems for generating solar industrial process heat and baseload electricity is an attractive prospect owing to their high optical efficiency and reduced capital costs when compared to solar towers. However, linear concentrators face challenges related to low solar-to-thermal conversion at high operating temperatures due to their significant thermal losses. Degradation of efficient selective absorber coatings limits their use to  To address this issue, silica aerogels can be integrated into the design of the linear receiver to improve the performance of parabolic trough collectors (PTC). It is possible to use broadband absorbers while leveraging the greenhouse effect of silica aerogels to suppress the emitted radiation, thereby enhancing the receiver selectivity.

In previous work, we characterized the optical and thermal properties of alumina-coated silica aerogels, demonstrating the potential for record-high solar receiver efficiencies in high-temperature environments (550-800°C).¹ The alumina coating, performed using a single cycle of atomic layer deposition (ALD), is necessary to mitigate the sintering experienced by silica aerogels at these elevated temperatures while preserving their high solar transmission.²

In this work, we characterize the efficiency of a prototype aerogel receiver and determine the economic viability of this technology based on experimentally validated models. The suppression of heat losses achieved by the introduction of silica aerogels is demonstrated through direct power loss testing up to 700°C on an industrial relevant scale prototype receiever. Optical colorimetry techniques are developed to map out temperature profiles across the absorber surface and monitor the transmittance of the aerogel segments in operando.  The results indicate that the aerogel receiver requires substantially less input power compared to the setup without aerogels.

Furthermore, utilizing a validated heat transfer model to estimate heat losses within the solar receiver, we optimized the design of the aerogels operated at three different temperatures (400°C, 550°C, and 700°C). We then estimated annualized plant efficiencies and energy costs for aerogel-based receivers based on these parameters. Our calculations show promising results, particularly in regions with high solar irradiance. We observed notable enhancements in predicted plant efficiency at 550°C compared to a 400°C commercial baseline case and energy cost estimates below 6 cents/kWh.

References

1.       Berquist, Z. J., Gayle, A. J., Dasgupta, N. P. & Lenert, A. Transparent Refractory Aerogels for Efficient Spectral Control in High-Temperature Solar Power Generation. Adv Funct Mater (2021) doi:10.1002/adfm.202108774.

2.       Gayle, A. J. et al. Tunable Atomic Layer Deposition into Ultra-High-Aspect-Ratio (>60000:1) Aerogel Monoliths Enabled by Transport Modeling. Chemistry of Materials 33, 5572–5583 (2021).

Presenting Author: Andres Miranda Manon University of Michigan

Presenting Author Biography: Andres Miranda Manon is a Ph.D. student and graduate student research assistant in the Department of Chemical Engineering at the University of Michigan - Ann Arbor.

Authors:

Andres Miranda Manon University of Michigan
Yiwei Gao University of Michigan
Ethan Moran University of Michigan
Katie Watson University of Michigan
Victor Vogt University of Michigan
Vishnu Ramasawmy Aeroshield Materials, Inc
Kyle Wilke Aeroshield Materials, Inc
Neil Dasgupta University of Michigan
Andrej Lenert University of Michigan