Farbkollektor – Concepts for Architecturally Adapted Collectors for Existing and New Buildings

The overall objective of the "Farbkollektor" (Colored Collector) project is to develop spectrally selective colored coatings with high color saturation, lower losses and low-cost manufacturability to facilitate the integration of solar collectors into the facades and roofs of aesthetically sensitive buildings. The development is based on the concept of the MorphoColor® coating, which originated at Fraunhofer ISE and for which a patent has been filed. In the further development of the colored coating, particular emphasis is placed on ensuring that the coating is corrosion-resistant. Furthermore, in addition to the color effect in the visible spectrum, the transmittance over the entire solar spectrum (from 300 nm to 2500 nm) is taken into account when optimizing the coating so that the solar collector yield is reduced as little as possible.

For better integration of solar collectors into the facades and roofs of sensitive buildings and ensembles, inconspicuous solar components are often required. For roofs, the focus is on integration in old town centers in general, not just on historic buildings. In the case of facades, new design options are to be opened up for architects. The concept of the MorphoColor® coating, which was developed at Fraunhofer ISE and for which a patent application has been filed, serves as the basis for the development. In the further development of the colored coating, special emphasis is placed on ensuring that the coating is corrosion-resistant, because condensation cannot be ruled out inside collectors. Furthermore, in addition to the color effect in the visible spectrum, the transmittance in the entire solar spectrum (from 300 nm to 2500 nm) is taken into account when optimizing the coating so that the collector yield is reduced as little as possible. The expectation is that the collector efficiency decreases by significantly less than 10% (target < 5%) relative when a colored glass pane is used instead of a conventional collector cover in new collectors. Collector prototypes with the developed colored layers will be integrated into the roof and facade, respectively, in two demonstration systems, and their performance will be analyzed scientifically using monitoring data. Among other approaches, project results will be disseminated by collaboration in IEA-SHC Task 59, "DEEP RENOVATION OF HISTORIC BUILDINGS TOWARDS LOWEST POSSIBLE ENERGY DEMAND AND CO₂ EMISSION (NZEB)", which addresses not only listed buildings but also older buildings in general that are worth preserving.