Optical Coatings for Flat Plate Solar Collectors.

摘要

Optical coatings that would enhance the economic feasibility of flat plate solar collectors were investigated. Processes were developed for producing single and double layer antireflection coatings on glass by dipping in a silica saturated fluosilicic acid solution. The three most promising selective absorbing plated coatings and their typical optical properties were:black nickel (nickel-zinc sulfide),alpha = 0.95,epsilon = 0.07;black chrome (chrome oxide),epsilon = 0.10;Selective paint coatings were developed with nominal optical properties of alpha = 0.90and epsilon = 0.30. Materials cost for a typical selective paint were estimated at 0.1cents/sq ft, a factor of at least 10lower than the selective plated coatings investigated. Paint coating thickness and pigment alpha were the key parameters affecting optical performance. Improvements in paint coating optical performance can be expected with further development.