Coloured photovoltaics have long occupied an uneasy middle ground between aesthetics and output. At the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany, that balance may now be shifting, with an approach that enables greater treatment of the module surface as a medium for design.
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The method, developed under the name “ShadeCut”, uses coloured films with precisely cut openings to create patterns that resemble conventional building materials. Roof tiles, masonry and other textures can be imitated without fully covering the active cell area, allowing light to reach the cells beneath. The approach builds on MorphoColor® technology, which generates colour through microstructured interference rather than pigments, reducing optical losses.
Design meets output
In performance terms, independent measurements indicate that modules using the coating achieve around 95 percent of the output of comparable uncoated products. While still a compromise, it marks a clear improvement on earlier coloured PV approaches and may be acceptable where aesthetics or planning constraints would otherwise rule out installation. Marco Ernst, developer of the technology at Fraunhofer ISE: “Through targeted structuring and cutouts on a colour-producing film, we can integrate colour effects and complex patterns directly into solar modules and façade elements.”
From film to form
The films can be processed using laser or CAD-controlled cutting and applied to standard photovoltaic and solar thermal modules, either as encapsulation layers or as backsheets. Additional layers can be combined to introduce further colours or structural depth, extending the design possibilities beyond simple surface treatments.
Fraunhofer ISE/ Photo Marco Ernst
Applications are likely to centre on building-integrated photovoltaics, where appearance often decides whether projects move ahead at all. “Modules with ShadeCut can look like masonry or roof tiles and blend in closely in terms of colour,” said Martin Heinrich, who leads encapsulation and integration at Fraunhofer ISE, pointing to particular relevance for façades and historic buildings.
Engineered colour
The colour concept borrows from nature rather than pigment. Inspired by the Morpho butterfly, whose wings produce vivid, angle-stable hues through microscopic structures, the Fraunhofer team has recreated a similar effect on module glass using a vacuum process. The result is a durable colour layer that delivers its visual impact with minimal optical loss.
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If aesthetics no longer stand in the way, solar may find its place on many more buildings and in new kinds of spaces. A shift both technical and visual that may allow solar to move beyond compromise and sit more comfortably within the language of architecture. (TF)
