Advances in central receivers for concentrating solar applications

This paper provides a review of current state-of-the-art commercial central receiver systems and emerging technologies intended to increase the outlet temperature to >700 °C. Research on particle-based, gas-based, and liquid-based receiver designs that can achieve these higher temperatures are discussed. Particle-based technologies include directly irradiated designs (free-falling, obstructed, centrifugal) and enclosed designs (gravity fed, fluidized). New gas-based receivers include micro-channel designs and light-trapping configurations that increase the surface area, heat transfer, and solar absorptance to enable higher fluxes and pressures. Liquid-based receivers and materials that are reviewed include high-temperature halide salts (chlorides and fluorides), carbonate salts, and liquid metals (sodium and lead bismuth). Advantages and challenges associated with each of the technologies and receiver designs are presented.