This paper reports experimental results for accelerated ageing test campaigns performed on four different solar receiver coatings applied on T91 and VM12 steel substrates. VM12 tubular samples are exposed at a dish test facility in order to perform thermal cycles under concentrated solar flux. No significant optical degradation could be observed on coated samples after 100 thermal cycles (50 hours at 650 °C), while bare and polished reference substrates oxidized during testing. Three solar receiver coatings achieved a stable solar weighted absorptance αs above 95 % after exposure. A selective coating further showed a thermal emittance of 25 % at 650 °C, instead of 65-75 % for non-selective coatings, thus achieving a thermal efficiency above 90 % at 250 kW/m2, instead of 85 % for non-selective coatings. T91 coated metal coupons were tested in four standard climate test chambers for condensation, damp heat, humidity freeze and neutral salt spray. Two non-selective coatings passed all climate tests without significant optical degradation, while the selective coating did not pass the neutral salt spray test due to severe corrosion.

1.
Raiselife EU project, Horizon
2020
, https://www.raiselife.eu/
2.
D.
Schmidt
,
M.
Galetz
, and
M.
Schütze
, “
Improved oxidation resistance of ferritic-martensitic steels in water vapour containing environments via diffusion coatings
,”
Mater High Temp
, vol.
29
, no.
3
, S.
159
165
,
2012
.
3.
D.
Schmidt
,
M. C.
Galetz
, and
M.
Schütze
, “
Ferritic-martensitic steels: Improvement of the oxidation behavior in steam environments via diffusion coatings
,”
Surf. Coat. Technol.
, vol.
237
, S.
23
29
,
2013
.
4.
C.K.
Ho
 et al, “
Characterization of High-Temperature Solar Receivers
”,
Journal Solar Energy Engineering
,
136
(
2014
), pp.
041502
1
:4.
5.
C.K.
Ho
,
J.
Pacheco
, “
Levelized Cost of Coating (LCOC) for selective absorber materials
”,
Solar Energy
,
108
(
2014
) pp.
315
321
.
6.
A.
Boubault
 et al, “
Durability of solar absorber coatings and their cost-effectiveness
”,
Solar Energy Materials & Solar Cells
,
166
(
2017
), pp.
176
184
.
7.
CIEMAT-DLR joint laboratory for optical characterization at PSA
, “
Solar reflector durability analysis and optical characterization
”, available at: http://www.psa.es/en/laboratorios/ussc/dur_reflectores.php.
8.
S.
Meyen
 et al, “
Parameters and method to evaluate the solar reflectance properties of reflector materials for concentrating solar power technology
”,
SolarPACES Official Reflectance Guideline Version 2.5
, (
2013
), available at: http://www.solarpaces.org/images/pdfs/201306_SolarPACES-Reflectance-Guidelines-V2_5.pdf
9.
ISO 13573, “
Corrosion of metals and alloys - Test method for thermal-cycling exposure testing under high temperature corrosion conditions for metallic materials
”, (
2012
), pp.
1
28
.
10.
ISO 6270-2, “
Paint and varnishes – Determination of resistance to humidity – Part 2: Procedure for exposing test specimens in condensation-water atmospheres
”, (
2016
), pp.
1
14
.
11.
IEC 62108, “
Concentrator Photovoltaic (CPV) modules and assemblies – Design, qualification and type approval; Section 10.7 – Damp heat test & Section 10.8 – Humidity freeze test
” (
2016
), pp.
28
29
.
12.
ISO 9227, “
Corrosion test in artificial atmospheres – Salt spray tests
”, (
2017
) pp
1
18
.
This content is only available via PDF.