Optical Properties Working Group

General Coordination: Aránzazu Fernández-García, CIEMAT-PSA, Spain (arantxa.fernandez@psa.es)

Objective

Define and improve the measurement methods and protocols of optical properties of solar materials (including reflectors –clean and soiled-, receiver particles, etc.), both in laboratory conditions and in solar fields, and translate the results into official standardization bodies.

Partners

R&D Centers: CIEMAT, DLR, ENEA, FRAUNHOFER ISE, UNIV. ZARAGOZA, NREL, SANDIA, CENER, CEA, CNRS, UNIV. BARCELONA, IMDEA, ANU 

Industries: RIOGLASS, TSK, ABENGOA, BRIGHTSOURCE, AGC, Alanod

Activity lines

1. Standard reflectance measurement under laboratory conditions

Coordinator: Aránzazu Fernández-García, CIEMAT-PSA, Spain (arantxa.fernandez@psa.es)

Current status:

2. Advanced reflectance measurement under laboratory conditions

Coordinators: Cristina Pelayo, University of Zaragoza, Spain (cpelayo@unizar.es)
Florian Sutter, DLR, Germany (florian.sutter@dlr.de)

Current status:

  • Several advanced instruments and configurable measurement setups are available in different R&D labs to fully characterize reflectance properties of solar mirrors with a wide range of parameters (wavelength, incidence angle and acceptance angle).

3. Reflectance measurement on soiled mirrors

Coordinator: Florian Sutter, DLR, Germany (florian.sutter@dlr.de)
Gregor Bern, Fraunhofer ISE, Germany (gregor.bern@ise.fraunhofer.de)

Current status:

4. Receiver particle measurement

Coordinator: Florian Sutter, DLR, Germany (florian.sutter@dlr.de)

Current status:

5. Advanced optical modeling

Coordinator: Marco Montecchi, ENEA, Italy (marco.motecchi@enea.it)

Current status:

List of projects

The following table includes the list of projects funded by SolarPACES that have supported the activity of this working group during the last years.

Title

Partners

Duration

Budget (€)

Development of guidelines for standards for CSP components

DLR, NREL, CIEMAT

Jan 2010 – Dec 2011

72,000

Advance in the development of the reflectance guideline

CIEMAT, DLR, ENEA, FRAUNHOFER ISE, CEA, CENER, CNRS

Jan 2015- Dec 2016

30,000

Measuring and modelling near-specular solar reflectance at different incidence angles

DLR, CIEMAT, ENEA, FRAUNHOFER ISE, UNIV. ZARAGOZA

Jul 2017 – Dec 2018

104,756

Soiling measurement of solar reflectors 

CIEMAT, DLR, ENEA, FRAUNHOFER ISE, UNIV. ZARAGOZA, NREL, RIOGLASS, TSK, ABENGOA, BRIGHTSOURCE

Oct 2019 – Mar 2022

123,000

Characterization of optical properties of particles for CSP

DLR, CIEMAT, ENEA, UNIV. BARCELONA, NREL, SANDIA

Oct 2021 – Sept 2022

59,952

Other projects that have addressed or are currently focusing on activities related to reflectance measurement are listed below:

  • SFERA-III, WP10. 

List of publications

Journal papers

Buendía-Martínez F, Fernández-García A, Sutter F, Martínez-Arcos L, Reche-Navarro TJ, García-Segura A, Valenzuela L. Uncertainty Study of Reflectance Measurements for Concentrating Solar Reflectors. IEEE Transactions on Instrumentation and Measurement. 2020;69(9):7218-7232. DOI: 10.1109/TIM.2020.2975387.

Sutter F, Montecchi M, Von Dahlen H, Fernández-García A, Röger M. The effect of incidence angle on the reflectance of solar mirrors. Sol Energy Mater Sol Cells. 2018;176:119-133. DOI: 10.1016/j.solmat.2017.11.029.

Fernández-García A, Sutter F, Martínez-Arcos L, Sansom C, Wolfertstetter F, Delord C. Equipment and methods for measuring reflectance of concentrating solar reflector materials. Sol Energy Mater Sol Cells. 2017;167:28-52.

Sansom C, Fernández-García A, King P, Sutter F, Garcia Segura A. Reflectometer comparison for assessment of back-silvered glass solar mirrors. Sol Energy. 2017;155:496-505. DOI: 10.1016/j.solener.2017.06.053.

Montecchi M. Approximated method for modelling hemispherical reflectance and evaluating near-specular reflectance of CSP mirrors. Solar Energy 2013;92:280-287. DOI: 10.1016/j.solener.2013.03.014

Conference papers

Sutter F, Fernández-García A, Montecchi M. Indirect Method to Determine Near-Normal Sun-Conic Reflectance. 25th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Daegu, South Korea. October 1-4, 2019. Oral. In: AIP Conference Proceedings 2303, 100007 (2020); https://doi.org/10.1063/5.0028749

Wolfertstetter F, Hanrieder N, Bellmann P, Ghennioui A, Wette J, Fernández-García A. Parallel Soiling Measurements for 4 Mirror Samples during Outdoor Exposure with TraCS. 25th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Daegu, South Korea. October 1-4, 2019. Oral. In: AIP Conference Proceedings 2303, 100009 (2020); https://doi.org/10.1063/5.0028969

Montecchi M, Sutter F, Fernández-García A, Heimsath A, Torres F, Pelayo C. Enhanced Equivalent Model Algorithm for Solar Mirrors. 25th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Daegu, South Korea. October 1-4, 2019. Oral. In: AIP Conference Proceedings 2303, 100005 (2020); https://doi.org/10.1063/5.0028768

Wolfertstetter F, Wilbert S, Bellmann P, Gonzales Rodriguez S, Reche-Navarro TJ, Keller L, Fernández-García, A. T-TraCS – an Automated Method to Measure Soiling Losses at Parabolic Trough Receiver Tubes. 25th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Daegu, South Korea. October 1-4, 2019. Oral. In: AIP Conference Proceedings 2303, 210006 (2020); https://doi.org/10.1063/5.0029685.

Sutter F, Fernández-García A, Heimsath A, Montecchi M, Pelayo C. Advanced Measurement Techniques to Characterize the Near-Specular Reflectance of Solar Mirrors. 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Casablanca, Morocco. October 2-5, 2018. Oral. In: AIP Conference Proceedings 2019:2126; 110003. DOI: 10.1063/1.5117618.

Wolfertstetter F, Wilbert S, Terhag F, Hanrieder N, Fernández-García A, Sansom C, et al. Modelling the soiling rate: dependencies on meteorological parameters. 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Casablanca, Morocco. October 2-5, 2018. Oral. In: AIP Conference Proceedings 2019:2126;190018. DOI: 10.1063/1.5117715.

Heimsath A, Pino A, Wolferstetter F, Fernández-García A, Nitz P. Towards Comparative Soiling Measurements for Tracked Collectors. 23th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems. Santiago de Chile, Chile. September 26-29, 2017. Poster.

Fernández-García A, Sutter F, Heimsath A, Montecchi M, Sallaberry F, Peña-Lapuente A, et al. Simplified Analysis of Solar-Weighted Specular Reflectance for Mirrors with High Specularity. 21st SolarPACES, International Conference on Concentrating Solar Power and Chemical Energy Systems. Cape Town, South Africa. October 13-16, 2015. Oral. In: AIP Conference Proceedings 2016;1734:130006. DOI: 10.1063/1.4949216.

Montecchi M, Delord C, Raccurt O, Disdier A, Sallaberry F, García de Jalón A, Fernández-García A, et al. Hemispherical Reflectance Results of the SolarPACES Reflectance Round Robin. 20th SolarPACES, International Conference on Concentrating Solar Power and Chemical Energy Systems. Beijing, China. September 16-19, 2014. Oral. In: Energy Procedia 2015;69:1904-1910. DOI: 10.1016/j.egypro.2015.03.174.

Fernández-García A, Cantos-Soto ME, Meyen S, Martínez-Arcos L. Measurement method to obtain accurate solar-weighted specular reflectance of solar reflectors. 18th SolarPACES, International Conference on Concentrating Solar Power and Chemical Energy Systems. Marrakech, Morocco. September 11-14, 2012. Oral.

Meyen S, Fernández-García A, Kennedy C, Lüpfert E. Standardization of solar mirror reflectance measurements – Round Robin Test. 16th SolarPACES, International Conference on electricity, fuels and clean water powered by the Sun. Perpignan, France. September 21-24, 2010. Poster.

Montecchi M. Upgrading of ENEA Solar Mirror Qualification Set-up. Energy Procedia 2014;49:2154-2161. DOI:10.1016/j.egypro.2014.03.228.

Montecchi M. Proposal of a New Parameter for the Comprehensive Qualification of Solar Mirrors for CSP Applications. AIP Conference Proceedings 2016;1734:130014. DOI: 10.1063/1.4949224.