The story of solar energy is often told in idealistic terms, as a means of harmlessly using the energy of the sun to power human activities. But though its advantages over its carbon-based predecessors are evident, solar isn’t perfectly innocuous. Like any technology, it has environmental consequences too.
A small but growing body of literature indicates that solar farms—both photovoltaic and concentrating solar power installations—may pose serious risks to birdlife. And efforts to mitigate the problem remain largely theoretical, Richard Pallardy writes for Corporate Knights.
In the United States, there are now around 5,700 large-scale solar farms operating, according to data collected by the U.S. Geological Survey. Globally, there are more than 75,000. While the harm to wildlife inflicted by the petroleum industry has generated reams of research, the ecological effects of solar are poorly studied.
While comprehensive impact studies are lacking, it is clear that both migratory and resident birds are commonly killed or stunned by these novel features in their environment. One hypothesis suggests that the shimmering arrays of photovoltaic panels that most people envision when they think of a solar farm read as bodies of water to birds from the air.
Because of the so-called lake effect, birds may attempt to land on the panels or drink from them, either dying on impact or perishing on the ground after colliding with what appears to be a liquid surface. This is particularly concerning for migratory waterbirds passing over photovoltaic facilities, which could appear as tempting oases and not the fields of unyielding glass and silicon they really are.
Small, ground-dwelling birds may be disoriented by the panels as well, crashing into them as they forage the swarms of invertebrates attracted to the polarized light that they reflect.
Impacts on Bird Habitats
“Habitat loss is the greatest potential impact, obviously correlated to the size of a single project, and the cumulative effects of neighbouring projects,” says Andrew Jenkins, owner of Avisense Consulting, a South African firm that conducts birdlife impact assessments for energy installations, in an email.
It often takes several years to get a solar installation up and running. Aside from regular human activity, vegetation is frequently shorn or removed entirely to create space for the structures, resulting in habitat destruction. “Utility-scale installations often replace native habitats such as grasslands, deserts or wetlands, disrupting breeding, foraging and nesting areas,” says Crystal Anderson, a wildlife biologist with the James C. Kennedy Waterfowl and Wetlands Conservation Center, in Georgetown, South Carolina, in an email. “This is particularly damaging for ground-nesting birds and area-sensitive species that require large, contiguous habitats.”
Non-native bird species and native species well adapted to man-made environments may move into the vacuums created by solar farms – though they too sometimes meet their ends cruising into glittering solar arrays. Both native house finches and non-native Eurasian collared doves quickly dominated the Macho Springs Solar Facility established in New Mexico in 2012, for example. These species are known for their adaptability to human disturbance.
Solutions Are Still Being Developed
A variety of bird deterrents have been proposed: chemical substances that create aversive scents or tastes, recorded predator sounds, flashing lights and objects to prevent birds from landing.
“Incorporating bird-friendly design features such as non-reflective panel coatings, reduced artificial lighting and buffers or corridors of native vegetation can mitigate some of the most pressing risks to avian species,” Anderson says.
“The disturbance impacts of construction are probably unavoidable, except by minimizing the durations of the construction period, timing the construction to avoid sensitive seasons and working to minimize noise and activity-related disturbance,” Jenkins adds.
Situating new solar plants on “brownfields” – sites such as former mines, landfills and fossil fuel facilities – may also be a way to avoid damage to vulnerable habitats. These sites are already wastelands. Placing solar plants there obviates the harms of development.
Special Challenges at Concentrating Solar Power Sites
While photovoltaic systems are dominant in solar, another related technology is once again making inroads after years of skepticism. Concentrating solar power (CSP) sites use mirrors to direct solar energy toward towers that contain various substances that then generate electricity. Despite its high costs, CSP has the advantage of being able to store power overnight, helping it stage a comeback. Last year, for example, Botswana announced that it would build a 200-megawatt concentrated solar-thermal power plant.
In 2014, the Associated Press published an alarming account of birds going up in smoke as they passed through beams of concentrated sunlight at a CSP facility in the Mojave Desert. These “streamers,” as they were called, plummeted to the ground after igniting. Later research suggested that the phenomenon was more likely attributable to insects passing through the beams rather than birds, though some observers contest this.
Surveys of similar CSP farms have turned up numerous dead birds with singed feathers. Birds may not be incinerated mid-air as the original report suggested, but they certainly get burned.
These beams may reach 1,000°C. “This can cause severe injuries or death, particularly among high-flying birds like raptors,” Anderson says.
Reducing the solar flux – the amount of solar energy reaching a certain location – for solar thermal energy systems has proven helpful in several cases. Both the Ivanpah and Crescent Dunes projects in California have reduced solar flux and seen reduced bird deaths.
Solar Installations Increase Biodiversity, and Some Birds Benefit
While solar facilities may pose a danger to birds, they can also be beneficial to other wildlife and even some types of birds.
Several studies have found increased species diversity at solar sites in comparison to nearby arable land, likely due to the way in which solar farms contribute to more diverse plant species and structures for shelter. These increases favour birds that forage on the ground and eat insects. Conversely, birds with more specific habitat requirements will be negatively affected. “Endangered species may suffer population-level consequences from even localized disturbances,” Anderson says.
As solar energy deployment grows – it will account for a majority of renewable growth capacity in the remainder of the decade per the International Energy Agency – examination of its unintended negative effects on wildlife will be crucial.
Richard Pallardy is a freelance writer based in Chicago. He has written for such publications as Science, Discover, Live Science and National Geographic.
This post originally appeared on Corporate Knights August 14, 2025, and is posted here with permission.
