The productivity of solar thermal power plants is considerably impaired by soiling of the mirrors. In the “AVUS” research project, the project partners, Fraunhofer ISE, Suntrace GmbH and PSE AG, are therefore developing a device that is designed to automatically record this soiling, while only requiring a low level of maintenance.

The goals of the research project, which will run until May 2018 and which is funded by the Federal Ministry for Economic Affairs and Energy (BMWi) with around one million euros, are the development of the measuring methods behind the device, a prototype, and its use and testing in the field.

A low-cost diode array spectrometer with LED light sources is used to record the degree of soiling. This supports the measurement the measurement of the type and rate of soiling of the mirrors, both when qualifying locations and during operation of the installed power plant. Two generations of prototypes have been developed during the course of the project and tested under real-life conditions in the “Andasol 3” solar power plant in southern Spain.