The proposed amendments fail to take into account the potentially significant impacts of solar farms on local insect populations beyond those relatively few species considered as threatened or endangered. Many diurnal insects are attracted to or are confused by the polarization of light produced by artificial surfaces, including solar panels. These surfaces have been dubbed by some as “polarized ecological traps” (see Select References below). Aquatic insects in particular are attracted to these surfaces and lay their eggs on them, thus impeding their abilities to mate and reproduce. Unnaturally high concentrations of these and other insects drawn to artificial polarized light are potentially subject to higher rates of predation by birds and bats, too. 

 

Peer-reviewed research articles that analyze the impacts of solar farms on insects and their mitigation are unfortunately few in number, especially in the United States. Much of the literature available in this country is produced by stake holders in solar energy touting solar farms as “win-win” enterprises. It shouldn’t come as a surprise to anyone that planting more flowers on solar farms increases (or concentrates) populations of bees and butterflies, or that artificial pools of water resulting from the establishment of these sites are readily colonized by a few species of dragonflies that may or may not have occupied the site previously. I think the focus on population trends of bees, butterflies, and dragonflies on solar farms is useful, but it is only a small part of the overall picture of environmental health.

 

While scanning the articles referenced below and elsewhere, it is clear that not all solar panels are created equally in terms of reflecting polarized light attractive to insects. I have much to learn about what is currently being done in the Commonwealth and the long range plans for the development of solar farms across Virginia. I visited DCR's Pollinator Smart Solar Site Portal, its associated links, and reviewed the comprehensive manual and other materials. Like most technologies, green or otherwise, there will be winners and losers in terms of the species impacted, including insects. 

 

Going forward, I think Virginia’s stakeholders in solar energy would do well to consider more than just sensitive species and pollinators in their deliberations for developing and monitoring the environmental impacts of solar farms. Specifically, studies on aquatic insect populations should be given equal priority. Protocols for monitoring general insect populations before and after the construction of solar farms should also be established, followed by the regular collection and analysis of insect remains directly associated with solar panels to monitor local population trends once the facilities are online. The establishment and implementation of these protocols would likely present numerous opportunities for collaboration among federal, state, and local agencies, universities, environmental organizations, and citizen science groups.

 

The above statements and opinions are entirely my own and do not reflect those of my employers or institutions with which I am affiliated.

Sincerely, ARTHUR V. EVANS, D.Sc.

 

Selected References

 

Black, T. V., & Robertson, B. A. (2019). How to disguise evolutionary traps created by solar panels. Journal of Insect Conservation, 1-7.

 

Horváth, G., Blaho, M., Egri, A., Kriska, G., Seres, I., & Robertson, B. (2010). Reducing the maladaptive attractiveness of solar panels to polarotactic insects. Conservation Biology, 24(6), 1644-1653.

 

Horváth, G., Kriska, G., & Robertson, B. (2014). Anthropogenic polarization and polarized light pollution inducing polarized ecological traps. In Polarized light and polarization vision in animal sciences (pp. 443-513). Springer, Berlin, Heidelberg.

Száz, D., Mihályi, D., Farkas, A., Egri, Á., Barta, A., Kriska, G., ... & Horváth, G. (2016). Polarized light pollution of matte solar panels: anti-reflective photovoltaics reduce polarized light pollution but benefit only some aquatic insects. Journal of Insect Conservation, 20(4), 663-675.