Low-Cost Solar Coatings for Improved Thermal Performance of Components in Concentrating Solar Power Systems

Conventional solar-receiver piping used in solar power systems uses steel pipe, an absorbing coating, and a concentric glass tube separated axially from the pipe by an evacuated space. This conventional pipe design works, but suffers from high manufacturing cost, a lack of environmental robustness, and difficulty of repair in the field. This project will design, develop, and construct prototypes of new, low-cost and energy efficient coatings for the surfaces of the receiver piping used in solar power generation systems. The proposed approach is to use aqueous-solution, spray-based self-assembly processing to form multilayer coatings on the outer surfaces of cylindrical stainless steel receiver piping. In Phase I, a patented multi-layer self-assembly coating production process will be used to fabricate ¿perfect absorber¿ coatings on prototype stainless steel test specimens. Then, the solar spectral absorption and heat transfer efficiencies will be evaluated, and an analysis will be conducted to determine how the coating process can be scaled-up to the large volumes of piping required by large-scale solar power generation systems. Commercial Applications and other Benefits as described by the awardee: The self-assembly process would be expected to create coatings of uniform thickness and properties on receiver piping components, at a per unit length production cost that is significantly lower than that of conventional glass-encapsulated and evacuated pipe sections. The enhanced economics should encourage the broad commercialization of these systems.