How solar systems can become a problem for insects

Although photovoltaics is a key technology for the energy supply of the future, this actually environmentally friendly technology sometimes also brings challenges: A little-known phenomenon concerns the reflection of light on solar modules. The actually unpolarized sunlight becomes polarized upon reflection – which can mislead water-loving insects.

Why do solar modules appear like water surfaces to insects?

The smooth surfaces of solar modules, mostly made of glass, reflect polarized light. For numerous water-loving 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 perish due to the high temperatures of the surface. This problem was first scientifically investigated in 2009 [1].

A growing challenge for nature conservation

With the rapid expansion of solar energy – in Germany alone, solar systems with a total capacity of 14 gigawatts were installed last year, corresponding to an area of about 70 square kilometers – this "polarized light pollution" is becoming increasingly relevant. Especially in protected areas, this phenomenon should no longer be overlooked in the planning of ground-mounted solar systems in the future.

An innovative solution approach: Microstructured surfaces

Initial scientific studies show that microstructured surfaces can provide relief because they have a different polarization signature of the reflected light. For example, it has been shown that solar modules equipped 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 polarized reflection on solar modules. With this, we aim not only to protect insects but also to promote the sustainable expansion of solar energy. Together, we contribute to preserving biodiversity and creating 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