Polarized Light Pollution from Solar Panel Reflections Affects Wildlife Behavior: It Can Trick Migrating Birds, Bats, and Insects: Results are Mixed, but Solar Farms Can Be Designed for Positive Wildlife Impacts

     New research suggests that grid-scale solar farms have mixed effects on wildlife, some positive and some decidedly negative. The abstract of the paper notes that the authors studied wildlife impacts at both solar PV and concentrated solar power (CSP) facilities. CSP utilizes mirrors that attract large amounts of flying insects and birds that hunt them. Both kinds of solar facilities attract water birds. The abstract notes:

“Solar facilities impact fauna through habitat loss and fragmentation, altered microclimate, and creation of novel habitat. Evidence suggests increases in insect, bird and bat species richness and abundance around solar facilitates built over degraded landscapes, likely due to introduction of novel habitat and presence of generalist species, but a decrease when comparison is made with intact reference landscapes.”

     According to the paper’s author, ecologist Professor Trish Fleming:

"The reflective glare from solar panels mimics the appearance of water bodies, confusing migrating birds and leading them off course.”

"This phenomenon, known as polarized light pollution, can also attract insects, inadvertently creating new feeding grounds for birds and bats.”

"While this may seem beneficial, it can alter natural foraging behaviors and increase collision risks."   

     The study noted that evaporation ponds used to catch water after washing the dust off of panels also attract wildlife. These can also collect metals from the panels in potentially high enough concentrations to affect wildlife.

     As noted, a major wildlife impact issue is due to polarized light “pollution,” or the glint and glare from panels, which wildlife often mistakes for water surfaces, which can draw migrating birds off course. 

     Below are some graphics from the paper, including a global map of solar radiation and solar facilities by output size, data on fatalities, and examples of sensitive species accommodation. 

 

Solar Farms Can Be Designed for Positive Wildlife Impacts

     There are several things that can be done to reduce negative wildlife impacts, including technological solutions.

"Nano-coating solar panels to reduce polarized light pollution is one change that could help prevent birds from mistaking panels for water," Professor Fleming said.

"These coatings alter the way light is reflected, making the panels less visually disruptive to wildlife."

     Another thing that can be done is to keep the facilities accessible to local wildlife. Accommodation for local Mojave Desert tortoises is shown below. Preserving natural washes and natural vegetation can also be beneficial.

     In Minnesota, the creation of ‘solar meadows’ with solar panels intermingled with pollinator plants, mostly wildflowers, has resulted in an increase in pollinators and less mowing maintenance requirements for the facilities.

     A May 2023 study by the Renewable Energy Wildlife Institute focused on the effects of grid-scale PV solar farms on landscapes and wildlife habitat, collision fatalities, and mitigation efforts. Mitigation efforts include designing sites for positive impacts to increase ecosystem services, such as pollination, to counteract the negative effects on wildlife.  

"PV facilities have biotic and abiotic components that interact within the footprint and the surrounding landscape — a basic tenet of the ecosystem concept (Tansley 1935), and these facilities alter these biotic and abiotic conditions and their interactions due to construction, operation, and infrastructure relative to natural ecosystems (Hobbs et al. 2006; 2009). There is value in an ecosystem framework to guide and synthesize research because PV facilities are already viewed within the ecosystem concept, in terms of ecosystem function and service. Furthermore, pollinator-friendly solar, other on-site habitat mitigation, and even turfgrass, which could enhance ecosystem function and services relative to pre-construction land-use (if sited on disturbed lands), can create suitable habitats that attract and support wildlife to these ecosystems."

     Grid-scale solar PV facilities disturb and disrupt the local soils, which can reduce vegetation, increase erosion, and destroy habitat. They can create microclimates with both positive and negative effects. The disturbance of the facilities can also lead to fragmentation, where landscape continuity is separated by the facility.

     Impacts also vary by region and regional climate. For example, desert regions have different concerns than wet temperate regions. Avoiding the building of facilities in more sensitive areas with more potentially negative wildlife impacts is a strategy that can minimize impacts.

“Minimization will come in two forms — on-site habitat restoration and fatality reduction. On-site habitat restoration has garnered much attention in the PV solar industry in the form of pollinator-friendly solar or native grassland restoration to minimize habitat loss within the footprint. The benefits of vegetation restoration in solar facilities include enhanced wildlife habitat and ecosystem function, and a variety of ecosystem services, such as pollinator services, agrivoltaics, and soil and water retention. However, native vegetation restoration at PV facilities is a relatively new practice, and more research on the degree and magnitude of habitat quality and ecosystem function outcomes related to the various vegetation management strategies (e.g., grazing, mowing, seed mixes) is needed by region.”

     On-site vegetation management is an important way to minimize risks, or rather to optimize positive impacts. The paper also calls for more study of the wildlife impacts of solar farms.  

 

    

References:

 

Scientists raise alarm over unexpected wildlife behavior around solar farms: 'Leading them off course'. Calvin Caffee. The Cool Down. August 12, 2025. Scientists raise alarm over unexpected wildlife behavior around solar farms: 'Leading them off course'

All that glitters – Review of solar facility impacts on fauna. P.A. Fleming. Renewable and Sustainable Energy Reviews. Volume 224, December 2025. All that glitters – Review of solar facility impacts on fauna - ScienceDirect

Experts uncover incredible side effects of traditional solar panels: 'We have to address both challenges at the same exact time'. Leslie Sattler. October 1, 2024. The Cool Down. Experts uncover incredible side effects of traditional solar panels: 'We have to address both challenges at the same exact time'

How Solar Farms Can Power the Grid Without Derailing Wildlife. Charles Mitchell. Modern Engineering Marvels. August 14, 2025. How Solar Farms Can Power the Grid Without Derailing Wildlife

Solar farms look like lakes to birds—and it's messing with their migrations.by Murdoch University. edited by Lisa Lock, reviewed by Andrew Zinin. Phys.org. July 17, 2025. Scientists raise alarm over unexpected wildlife behavior around solar farms: 'Leading them off course'

Solar Energy Interactions with Wildlife and Their Habitats: A Summary of Research Results and Priority Questions. Renewable Energy Wildlife Institute. May 2023. REWI-Solar-Energy-Wildlife-Interactions-Summary-2023.pdf