Scientific Publication: Laboratory intercomparison of solar absorptance and thermal emittance measurements at room temperature

DLR, CIEMAT-PSA, Fraunhofer ISE, CNRS-PROMES and University of Almería published a scientific publication about SFERA-III in the international research journal, Solar Energy Materials and Solar Cells. The paper is available in open access.

Abstract

Solar thermal absorber coatings play an important role in the opto-thermal efficiency of receivers in Concen-
trated Solar Power (CSP). Two standard figures of merit are the solar absorptance αsol and thermal emittance εth,
derived from spectral directional hemispherical reflectance measurements at room temperature. These two
figures of merit allow comparing coating formulations in terms of performance and durability.

In this study, a black coating and a solar selective coating are optically characterized by different laboratories
to compare spectral datasets, solar absorptance αsol and thermal emittance εth calculations. The comparison
includes various benchtop spectrophotometers operating in the UV-VIS-NIR and Infrared spectral ranges as well
as three commercial portable reflectometers/emissometers.

A good agreement is found between the nine parties participating in this intercomparison campaign. The black
coating αsol value is 96.6 ± 0.2%, while the solar selective coating αsol value is 94.5 ± 0.4%. For the thermal
emittance, spectral data is concatenated and integrated from 0.3 to 16 μm. The black coating εth value calculated
at 650 ◦C is 80.8 ± 3.8%, while the solar selective coating εth value calculated at 650 ◦C is 25.0 ± 0.5%.

References

Title Laboratory intercomparison of solar absorptance and thermal emittance measurements at room temperature

Authors Simon Caron, Leslie Herding, Yaniv Binyamin, Mubeen Baidossi, Yelena Vinetsky, Angel Morales, Christina Hildebrandt, Reine Reoyo-Prats, Olivier Faugeroux, Alina Agüero, Sergio Rodriguez, Florian Sutter, Marc Röger, Francisco Manzano-Agugliaro

Cite as Simon Caron, Leslie Herding, Yaniv Binyamin, Mubeen Baidossi, Yelena Vinetsky, Angel Morales, Christina Hildebrandt, Reine Reoyo-Prats, Olivier Faugeroux, Alina Agüero, Sergio Rodriguez, Florian Sutter, Marc Röger, Francisco Manzano-Agugliaro, Laboratory intercomparison of solar absorptance and thermal emittance measurements at room temperature, Solar Energy Materials and Solar Cells, Volume 238, 2022, 111579, ISSN 0927-0248, https://doi.org/10.1016/j.solmat.2022.111579.