You may soon be able to choose the colour of your solar panels
By imprinting solar panels with silicon nanopatterns that scatter green light back towards the observer, researchers at the Netherlands’ AMOLF Institute have moved closer to being able to produce solar modules in any colour. The panels have about 10% less power because of the loss of absorbed green light. “The new method is attractive as an architectural design element and has the potential to widen their use", said Verena Neder, a researcher at AMOLF. Once imprints are created for red and blue solar cells, the institute will have the primary colours and so will be able to produce any colours.
LEFT: The nanopatterned module appears green, independent of the angle. RIGHT: Schematic of silicon nanoscatterer arrays on top of a sapphire cover slide, integrated into a commonly used solar panel design.

By stamping dense arrays of crystalline silicon nanocylinders onto solar modules, researchers in the Netherlands have managed to give green energy a green color.

A new study published this week in Applied Physics Letters demonstrates photovoltaic modules with a bright green color, based on silicon heterojunction solar cells integrated with arrays of light scattering dielectric nanoscatterers. The panels show only around a 10% power reduction due to the loss of absorbed green light, paving the way to designing efficient colorful or white building-integrated photovoltaics.

“Some people say ‘why would you make solar cells less efficient?’ But we can make solar cells beautiful without losing too much efficiency,” said Verena Neder, a researcher at AMOLF and lead author of the paper. “The new method to change the color of the panels is not only easy to apply but also attractive as an architectural design element and has the potential to widen their use.”

Unlike existing colored solar panels, the nanopatterns give a consistent appearance from different angles, so the panels appear green even from a wide angle.

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Next, the researchers are designing imprints to create red and blue solar cells. Once they master these three colors, the primary colors of light, they can create any color, potentially even white.

“You have to combine different nanoparticles, and if they get very close to each other they can interact and that will affect the color,” said Albert Polman, a scientific group leader at AMOLF and senior author on the paper. “Going to white is a really big step.”

While most research to date has focused on increasing efficiency and reducing cost, the latest invention combines efficiency with aesthetics. Among other notable achievements in the field of aesthetic photovoltaic solutions are full-black solar modules and panels with integrated high-definition images.