Ultrafast heliostat metrology

Heliostat fields constitute one of the large-scale concentrating solar power (CSP) options for electricity production and/or thermal storage. In a typical field, several thousand heliostats, each consisting of one or more mirrors, are precisely oriented to track and reflect the sunlight onto a receiver atop a central tower. Any misorientation of the heliostats during operation - due to structural changes, tracking errors, etc. - must be detected and corrected to ensure maximum light collection essential for the economic viability of the plant. A number of metrology techniques for accurate determination of heliostats orientation during operation have been proposed and implemented. These are briefly reviewed in this paper followed by a detailed description of a novel ultrafast technique for the precise measurement and correction of the canting errors in a heliostat field.