The pigment-free colored photovoltaic inspired by butterfly wings

A research team from the Fraunhofer Institute for Solar Energy Systems ISE has devised special modules inspired by the wings of butterflies

He is about to end up run over, his mother saves him

Photovoltaic and solar thermal systems are not always beautiful to look at. To our aid, Nature arrives which in terms of beauty has a lot to teach us. A research team from the Fraunhofer Institute for Solar Energy Systems ISE has devised special modules inspired by the wings of butterflies.

Graceful, colorful animals. Butterflies are often associated with beauty. Inspired by the phenomenon that generates the shimmering shades of blue or green in the wings of the morpho butterfly, scientists have made gods photovoltaic panels for the production of electricity. At the base there is a mechanism that allows the modules to have a bright and uniform color.

Generate electricity from the sun via photovoltaic systems it is a technology that has been in use for some time and all in all at low cost. The appearance has also evolved with advances in technology. They are made by placing numerous solar cells sandwiched between a front glass sheet and a rear sheet of laminated polymer. Since there are gaps between the solar cells, you can see part of the back sheet. Usually the background color is white and emerges between the dark solar cells.

The pigment-free colored photovoltaic inspired by butterfly wings

But we can completely revolutionize their aesthetics, integrating them totally with the surface on which they will be installed. Or we can make them very colorful and a real element of street furniture. And that's what German scientists have been aiming for.

“Whether you want beautiful bright tones or more subdued grays, you can design the color of the solar module to enhance or blend in with the building it will be mounted on,” explain the creators.

Not only beautiful, also efficient

Despite the various improvements, the "look" of photovoltaic modules is still not very popular but it is important to use this technology to produce more and more clean energy and reduce the use of fossil sources. For this, researchers at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg have developed colorful and visually appealing modules that can be integrated almost invisibly into buildings and can even give the finishing touches to more modern buildings.

"The idea behind this development was not to color the protective glass of the modules with pigments, but to imitate the physical effect of butterfly wings",

explains Dr. Thomas Kroyer, head of the coating technologies and systems group. If the glass was coated with pigments, the modules would lose some of their efficiency because the light could no longer penetrate without obstacles. Instead, according to the researchers, about 93 percent of sunlight can penetrate into the special structure of the surface.

All thanks to the blue morpho butterfly

The bright iridescent wing of the blue morpho butterflies (Morpho menelaus) enjoys a very special feature. These insects, native to the tropical rainforest of Central and South America, create the impression of color through an optical effect, not pigments. The wings of this butterfly have an extremely fine surface texture that reflects a narrow range of specific wavelengths, namely a certain color.

Likewise, the experts at the Fraunhofer ISE applied a similar surface structure and coating to the back of the protective glass of the photovoltaic modules. Depending on the customization of the coating, the cover glass can be made, for example, in blue, green or red.

The modules will be exhibited at the BAU fair, which will take place online from 13 to 15 January 2021. Also on display is a solar thermal collector with MorphoColour coating.

"There is a real benefit because both products can be supplied from a single production line," the scientists explain. “In the future it will be possible to have photovoltaic and solar thermal modules of the same color, mounted almost invisibly next to each other on the roof or facade. When the color is matched to the rest of the building, the result is an exterior wall with a perfectly uniform finish and a facade that provides electricity as well as heat. In this sense, future homes can be aesthetically pleasing by providing more energy than they consume ”.

Sources of reference: Fraunhofer