The FLAP Heliostat

A Novel Low-Cost Heliostat Design Featuring a Mirror Protection Mechanism Based on Dual-Use of the Elevation Drive




Heliostat, Foldable Reflector, Desert Environment, Mirror Degradation, Anti-Soiling, Concentrating Solar Power, Central Receiver, Power Tower


Heliostats represent a major cost share of concentrating solar power (CSP) plants with central receiver. They are essential for system efficiency and strongly influence maintenance cost and service life. Since CSP facilities require direct solar radiation, suitable installation sites can eminently be found in desert regions. However, dusty conditions may greatly reduce the performance of the plant due to soiling of the heliostat’s reflective surface and / or irreversible degradation caused by abrasive sand particles. A novel heliostat called FLAP, developed specifically for desert environments, is presented in this paper. It was designed with an emphasis on maximum manufacturing and maintenance cost reduction, yet improved service life in mind. The essential innovation of the FLAP heliostat is the patented foldable reflector support structure consisting of two panel sections that are oriented face-to-face when being in lay-down stow position. Folding of the panels is accomplished by means of a mechanism comprising a simple yet effective 4-bar linkage. To avoid costs for additional drives, the device is actuated by the one single central linear actuator that is also used for elevation tracking. Furthermore, wind loads are minimized due to the low profile of the heliostat structure in stow position, resulting in material and hence overall cost savings.


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How to Cite

Preßmair, R., & Buchroithner, A. (2023). The FLAP Heliostat: A Novel Low-Cost Heliostat Design Featuring a Mirror Protection Mechanism Based on Dual-Use of the Elevation Drive. SolarPACES Conference Proceedings, 1.

Conference Proceedings Volume


Receivers and Heat Transfer Media and Transport: Point Focus Systems