Solar absorptance and emittance properties of several solar coatings

Journal Article · Thu Jan 01 04:00:00 EST 1976 · J. Vac. Sci. Technol.; (United States)

DOI:https://doi.org/10.1116/1.569041· OSTI ID:7343863

Pettit, R B; Sowell, R R

Solar absorptance ..cap alpha.. and total hemispherical emittance epsilon properties of two potential solar selective coating systems are reported. The first coating system studied is a semiconductor-pigmented paint which consists of a high-temperature silicone binder mixed with small particles of Ge, Si, or PbS. Although most of the paints have ..cap alpha.. values above 0.90, all the paints suffer from high epsilon values (approximately 0.70 to 0.90), which are shown to be due to the high emittance of the silicone binder itself. The second system studied is electroplated films of ''black nickel'' and a proprietary ''black chrome.'' Both ..cap alpha.. and epsilon values have been obtained as a function of the electroplating time and the substrate surface roughness. Increasing the plating time initially increases both ..cap alpha.. and epsilon; however, for long plating times, there is no improvement in ..cap alpha.., while epsilon continues to increase. By increasing the surface roughness of nickel-plated substrates, the solar absorptance can be increased while maintaining approximately the same total hemispherical emittance. The coatings show minor decreases in solar absorptance at angles of incidence up to 75/sup 0/ from normal (e.g., about 25 percent decrease at 75/sup 0/).

• Research Organization: Sandia Labs., Albuquerque, NM
• OSTI ID: 7343863
• Journal Information: J. Vac. Sci. Technol.; (United States), Journal Name: J. Vac. Sci. Technol.; (United States) Vol. 13:2; ISSN JVSTA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
CHROMIUM
ELEMENTS
METALS
NICKEL
OPTICAL PROPERTIES
PERFORMANCE
PHYSICAL PROPERTIES
SPECTRALLY SELECTIVE SURFACES
SURFACES
TRANSITION ELEMENTS