The pilot installation consists of 224 solar modules with a so-called morpho-colour coating, which were installed on both east and west facing roof surfaces. In the PV Hide research project, Fraunhofer ISE together with the module manufacturer Axsun Solar, Interpane Entwicklungs- und Beratungsgesellschaft and the town of Eppingen installed a brick-red BIPV system directly into the roof of the gymnasium. In order for buildings to be able to produce solar electricity inconspicuously, photovoltaic modules in matching colours that can be integrated into building envelopes are needed - for example in listed buildings.

Improved understanding of optics and angular stability

The aim of the research project was to develop scalable concepts for cost-effective, invisible BIPV. To this end, Fraunhofer ISE developed the next generation of its patented Morpho Color structure for the coloured design of the cover glass of modules or even solar thermal collectors. Interpane implemented the module glass coating on industrial equipment and Axsun built coloured modules from it.

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The developments have now been put into practice with the installation of the BIPV system in a historic building. "The completion of the pilot plant is an important step forward for the large-scale implementation of the Morpho-Color coating. Since producing the coloured glass panes, we have been able to significantly improve our understanding of the optics and the angular stability of the colours," says Thomas Kroyer, project manager at Fraunhofer ISE.

Solar for listed old buildings

The next coated modules always show the intense colour, no matter from where the sun shines on them. "For us, this is an important step towards the aesthetic integration of BIPV systems into the time-honoured stock of our half-timbered town," says Thomas Frey, architect and head of the building construction department of the town of Eppingen. Even particularly energy-intensive listed old buildings can thus be equipped with colour-matched solar systems. (nhp/mfo)