Advances in solar thermal harvesting technology based on surface solar absorption collectors: A review

This study presents a critical review of the major research and development work that has advanced surface solar absorption technology and also discusses the applications of this technology in the last 15 years. In a surface solar absorption collector (SSAC), solar radiation is first absorbed on the surface of the collector and then transferred to the circulating fluid. This article reviews a wide range of studies on different SSAC systems with the aim of identifying research gaps to prepare this technology for commercial availability. Moreover, qualitative and quantitative research information on non-concentrating and concentrating SSACs was collected and evaluated in the context of a performance-based assessment, environmental issues, and sustainability concerns. The performance of these collectors mainly relies on the receiver design and thermal storage tanks with different heat transfer fluids. For high concentration collectors, there is an urgent need for new heat transfer and storage fluids to withstand elevated temperatures to minimize the flow instability. A review of the literature suggests that ongoing high quality research on this technology, especially on medium and high concentration collectors, will soon overcome the existing problems bringing this technology into temperature ranges that will make it commercially available. Finally, the scientific challenges and opportunities relevant to this technology are also discussed.