Study of the errors influencing heliostats for calibration and control system design

Abstract

“Power tower” or central receivers are a type of solar thermal energy system in which many heliostats, or movable planar mirrors, are used to focus sunlight onto a central receiver located on top of a tower. To design a control and calibration system for power tower systems, a thorough understanding of the numerous errors which can be present is essential. In this work, the various and different types of errors that present themselves in heliostat based solar energy systems are identified, categorized and assessed based on their potential impact and level of difficulty of resolution. The results of this work can be used to aid in designing a control system for heliostats in which the greatest amount of error can be corrected with the least difficulty.