Solar concentrator layout and performance analysis for multi-aperture receiver-reactors in high-temperature applications

Promising new receiver-reactor concepts with multiple apertures have been proposed for high temperature solar thermochemical hydrogen production. However, limited information about suitable solar concentrator designs consisting of heliostat fields and secondary concentrators is available so far. The goal of this study is a detailed investigation of the effect of selected solar concentrator design parameters on its performance. For a 10 MW receiver-reactor the number of subfields and corresponding apertures is varied in combination with the receiver height above the ground, the acceptance angle of the secondary concentrator, and the design point flux density. In addition, the performance is analyzed at different power levels. The average annual performance is evaluated as well as the hourly behavior. The latter of which is important to quantify the performance of a plant with an integrated receiver-reactor. For the heliostat field layout the program HFLCAL 1 1 Heliostat Field Layout CALculation software (version dated 4th of July 2024). is used. Solar concentrator designs with annual average efficiencies of over 60% are identified delivering flux densities of up to 5000 suns at design point for 10 MW receivers. Instead of a joint evaluation of the solar concentrator together with a specific receiver-reactor a generic receiver-reactor surrogate model is introduced. With this surrogate model an hourly analysis of the plant performance is conducted and a parametrized correction factor is presented to derive more accurate yearly plant performance estimates. The study provides detailed information on solar concentrators using multiple heliostat subfields and central tower systems with secondary optics, and indicates further optimization potential of solar concentrators for high-temperature receivers. • Large scale solar concentrator design study with high flux densities at 10 MW design point power. • Over 60% annual average efficiencies for design point flux densities of 5000 suns. • Receiver-reactor surrogate model to evaluate plant performance considering hourly flux data. • Provision of correlation for the correction of simplified design point estimates.