Publication Type Journal Article
Title Degradation of selective solar absorber surfaces in solar thermal collectors - An EIS study
Authors JCS Fernandes Ana Nunes M. Joao Carvalho Teresa C. Diamantino
Groups CSSE
Journal SOLAR ENERGY MATERIALS AND SOLAR CELLS
Year 2017
Month February
Volume 160
Number
Pages 149-163
Abstract The selective solar absorber surface is a fundamental part of a solar thermal collector, as it is responsible for the solar radiation absorption and for reduction of radiation heat losses. The most common absorbers are nowadays produced by vacuum deposition, presenting disadvantages, such as lower durability, lower resistance to corrosion, higher cost and complex production techniques. Spectrally selective paints are a potential alternative for absorbing surfaces in low temperature applications, with attractive features such as ease of processing, durability and commercial availability with low cost. Thus, two PVD coatings and three organic coatings obtained by projection on aluminium substrates were studied. Electrochemical impedance spectroscopy (EIS) allows for the assessment of mechanistic information on the degradation processes, especially if equivalent circuits are used, providing quantitative data that can easily relate to the kinetic parameters of the system. EIS measures were carried out in NaCl and Na2SO4 solutions at different immersion times up to 4 weeks. The performance of the coatings, based on coupons as-received and exposed to atmosphere, is discussed and a ranking is proposed.
DOI http://dx.doi.org/10.1016/j.solmat.2016.10.015
ISBN
Publisher ELSEVIER SCIENCE BV
Book Title
ISSN 0927-0248
EISSN 1879-3398
Conference Name
Bibtex ID ISI:000390072700020
Observations
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