

Even though photovoltaics is a key technology for the energy supply of the future, even this environmentally friendly technology sometimes poses challenges: one little-known phenomenon concerns the reflection of light from solar modules. Sunlight, which is actually unpolarized, is polarized when reflected – which can mislead aquatic insects.
Why do solar modules look like water surfaces to insects?
The smooth surfaces of solar modules, usually made of glass, reflect polarized light. For many aquatic insects, such as dragonflies and certain beetles, solar modules therefore appear similar to a water surface. This causes the insects to land on the modules, lay eggs there or die due to the high temperatures of the surface. This problem was first scientifically investigated back in 2009 [1].
A growing challenge for nature conservation
With the rapid expansion of solar energy – in Germany alone, solar systems with a total output of 14 gigawatts were installed last year, which corresponds to an area of around 70 square kilometers – this “polarized light pollution” (PLP) is becoming increasingly relevant. Particularly in protected areas, this phenomenon should no longer be ignored when planning ground-mounted solar installations in the future.
An innovative solution: microtextured surfaces
Initial scientific studies have shown that microstructured surfaces can provide a remedy, as they have a different polarization signature of the reflected light. For example, it was shown that solar modules with the surface texture of rose petals were less attractive to insects [2].
Our contribution to the solution
Phytonics is working on innovative coatings that effectively reduce the polarized light pollution caused by solar modules. Our aim is not only to protect insects, but also to promote the sustainable expansion of solar energy. Together, we are helping to preserve biodiversity and create a greener future.
[1] Horváth, Gábor, et al. “Polarized light pollution: a new kind of ecological photopollution.” Frontiers in Ecology and the Environment 7.6 (2009): 317-325. https://doi.org/10.1890/080129
[2] Fritz, Benjamin, et al. “Bioreplicated coatings for photovoltaic solar panels nearly eliminate light pollution that harms polarotactic insects.” PLoS One 15.12 (2020): e0243296. https://doi.org/10.1371/journal.pone.0243296