Solar thermal power plants

Heliostats are mirrors that bundle sunlight in solar tower power plants and direct it to the central receiver. This is situated at the top of the solar tower. Engineers have now developed a new geometric shape for heliostats with a pentagonal mirror. These are controlled by new software. Five of these new heliostats are currently undergoing practical testing on a test field in Jülich. Read more

A key component for the future energy supply system is provided by high-temperature heat storage systems. In power plants, these enable a more flexible drive system and make it easier to store process heat in industrial production. Molten salts, for example, are used as the heat transfer media in these storage systems. Scientists from the German Aerospace Center (DLR) have developed a new storage unit for temperatures up to 560 °C. The construction of the test facility started in summer 2016. Read more

Oils were previously circulated in the receiver pipes of parabolic trough power plants as the heat transfer medium. Scientists from the German Aerospace Center (DLR) are now testing a new concept at the research platform in Almeria, Spain. Here water vapour is directly used in the pipes as the heat transfer medium. This enables higher operating temperatures to be achieved and the absence of an intermediate heat transfer medium eliminates a source of losses. This direct steam generation improves the efficiency of parabolic trough power stations. Read more

The performance capability of receivers in parabolic trough plants is described by two properties: the optical efficiency and the thermal losses. These properties are measured in non-destructive tests on laboratory test stands in the DLR’s QUARZ Centre. To measure thermal losses, the receiver is heated to different operating temperatures. Read more

Air-based measurement systems help when optically examining entire solar arrays. QFly is a measurement system consisting of a flying drone that can carry either a CCD or infrared camera. Depending on the assignment, QFly flies over the solar array using different routes and takes photographs in the visible or infrared range of the spectrum. Read more