Guidelines for heliostat testing

Abstract

Power tower or central receiver systems use hundreds to ten thousands of two-axis tracking mirrors, so called heliostats, which reflect and focus the sunlight onto a receiver. The final quality of each individual heliostat and its interaction as a heliostat field determine the performance of a solar tower system. In recent years, the SolarPACES Guideline for Heliostat Performance Testing and prototype characterization has been developed to ensure the quality of individual heliostats. The paper gives a short introduction to the most relevant aspects of the recently published version 1.0 of this guideline. Its content is currently being incorporated into the international standardization activity IEC-TC-117 62862-4-3 (design qualification of heliostats). The total energy provided to the receiver is generated by the interaction of all heliostats acting together as a heliostat field. For this, a second guideline, the Heliostat Field Acceptance Guideline, has been developed in a German national project to be able to measure the performance of the solar field. This national draft guideline will be disseminated and peer reviewed internationally through the SolarPACES task III in end of 2023. In this manuscript, first insights into the new field guideline are given.