Status update of the SolarPACES heliostat testing activities

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 on top of a tower during the day. As basis for a well performing heliostat field, a single heliostat has to perform "correctly". In order to describe and measure the performance of a single heliostat, the SolarPACES Guideline for Heliostat Performance Testing has been developed by a group of R&D and industry experts during the last years. However, at the end, the performance of the whole field, which means the superposition and interaction of all heliostats determines the energy collected in the aperture of a solar central receiver. For that reason, a second guideline is currently outlined, the SolarPACES Guideline for Heliostat Field Performance Testing. Both guidelines aim to be commonly agreed protocols between R&D centers and industry in the field of heliostat performance testing. Recently, a third guideline activity has been started to improve and unify heliostat wind load design methods. The once finalized guidelines (or their concepts) should be included in international standards (e.g. IEC) and used by national organizations like DKE, AENOR, ASME, ASTM. This paper gives an update of the state of the three guidelines being developed in the SolarPACES task III-heliostat working group.