Floating Absorber Integrated with Compound Parabolic Concentrator for Effective Solar Water Desalination

Abstract

Accessibility to clean water is one of the most important challenges currently being faced by humanity. More than 780 million people in the world do not have access to clean water. Though earth has plenty of water, 97% of it is saltwater in oceans which needs appropriate treatment technologies to convert this to potable water. The current technologies of water desalination such as reverse osmosis consume a significant amount of energy, leading to the water-energy conundrum. To overcome this limitation, recently, several technologies based on nanoparticle-enhanced steam generation have been explored demonstrating extremely high conversion efficiencies (>40%) in the laboratory scale. These methods effectively utilize the plasmonic resonances of nanoparticles to increase the absorption cross section for the sunlight. However, they typically need to be operated under high concentration (>10X) requiring continuous tracking which results in increased system cost and complexity. Here, a novel solar-powered desalination system is proposed using CPC-based concentrator (with concentration ratio 2) combined with a low-cost absorber. The system demonstrates huge potential with an efficiency of 39% achieved at 2X concentration.