Experimental analysis of solar desalination system performance with graphene and graphitic carbon nanopaint-coated solar absorbers

Abstract

Improving the efficiency of basin-type solar stills is crucial for ensuring reliable access to clean water in areas facing water scarcity. One effective way to increase water yield production is by applying various coatings to the solar still's absorber plate. Using nanocoatings on solar absorber plates increases solar radiation absorptivity and minimizes reflectivity, which helps improve water production. In this proposed work, Graphene nanoplatelets (GNPs)-based nano paint, graphitic carbon nanoparticles (GCNPs)-dispersed black paint, and conventional black paint were applied to the solar still's absorber plate. According to the study, the GNPs' nano paint resulted in a cumulative solar still productivity that was 48.23 % higher than the GCNPs-dispersed black paint and 10.28 % higher than the conventional black paint. It also revealed that the energy efficiency of solar stills with GCNPs and GNPs nano paint-coated absorbers was 56.96 % and 69.77 %, respectively, while the traditional black paint-coated absorber managed only 39.42 %. The calculated exergy efficiency of these three solar stills was 8.55 % for the conventional black paint, 13.93 % for the GCNPs, and 22.93 % for the GNPs nano paint-coated absorber. This proposed system also has an energy payback period of 1.79 years and contributes to achieving a carbon credit of $994.90 through the market. The cost of distilled water in this system is also 0.016$/L.