Bioreplicated coatings for photovoltaic solar panels nearly eliminate light pollution that harms polarotactic insects

PLoS One. 2020 Dec 3;15(12):e0243296. doi: 10.1371/journal.pone.0243296. eCollection 2020.

Abstract

Many insect species rely on the polarization properties of object-reflected light for vital tasks like water or host detection. Unfortunately, typical glass-encapsulated photovoltaic modules, which are expected to cover increasingly large surfaces in the coming years, inadvertently attract various species of water-seeking aquatic insects by the horizontally polarized light they reflect. Such polarized light pollution can be extremely harmful to the entomofauna if polarotactic aquatic insects are trapped by this attractive light signal and perish before reproduction, or if they lay their eggs in unsuitable locations. Textured photovoltaic cover layers are usually engineered to maximize sunlight-harvesting, without taking into consideration their impact on polarized light pollution. The goal of the present study is therefore to experimentally and computationally assess the influence of the cover layer topography on polarized light pollution. By conducting field experiments with polarotactic horseflies (Diptera: Tabanidae) and a mayfly species (Ephemeroptera: Ephemera danica), we demonstrate that bioreplicated cover layers (here obtained by directly copying the surface microtexture of rose petals) were almost unattractive to these species, which is indicative of reduced polarized light pollution. Relative to a planar cover layer, we find that, for the examined aquatic species, the bioreplicated texture can greatly reduce the numbers of landings. This observation is further analyzed and explained by means of imaging polarimetry and ray-tracing simulations. The results pave the way to novel photovoltaic cover layers, the interface of which can be designed to improve sunlight conversion efficiency while minimizing their detrimental influence on the ecology and conservation of polarotactic aquatic insects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diptera*
  • Ephemeroptera*
  • Glass*
  • Sunlight

Grants and funding

This work was supported by the grant NKFIH K-123930 received by Gábor Horváth from the Hungarian National Research, Development and Innovation Office. Ádám Egri was supported by the Hungarian Economic Development and Innovation Operational Programme (GINOP-2.3.2-15-2016-00057), the Hungarian National Research, Development and Innovation Office (grant PD_19-131738) and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. Benjamin Fritz acknowledges the support of the Karlsruhe School of Optics and Photonics (KSOP, www.ksop.idschools.kit.edu). Furthermore, this study was supported by the German Federal Ministry for Economic Affairs and Energy (BMWi) under contract number 0324179 (CISHiTec).