Turbulent flow profiles and wind loads on heliostats in an operational concentrating solar thermal plant

This paper reveals insights into the variations of turbulent flow profiles and wind-driven structural load distributions on three heliostats in a full-scale operational heliostat field. Two of these heliostats are located in the outer two rows at the field perimeter and the third heliostat is in the interior of the field. These measurements were made in operating and stow positions during periods of prevailing northerly winds and southerly winds. Three-dimensional turbulent wind profiles were collected on the heliostat adjacent meteorological masts in the operational solar field. Comparison of prevailing northerly and southerly winds shows distinct differences in wind speed, wind direction, vertical velocity skewness, and the resulting magnitude and directionality of load distributions between the field edge and the interior of the field. Maximum lift forces in the interior are reduced in magnitude in operating positions but are increased in magnitude in stow position compared with the field edge, particularly for southerly winds. Maximum hinge moments in operating positions are increased in magnitude in the field interior compared with the field edge, particularly for southerly winds. These first-of-a-kind measurements highlight the gaps in our current level understanding of wind driven loads on heliostats and help develop guidance for designing future heliostats with increased resilience against wind impacts.