Image: Howard Ignatius/Flickr
Two months ago, 34 birds were found dead or injured on the site of the Ivanpah solar plant owned by BrightSource Energy in east San Bernardino County, California. Almost half suffered from singed feathers after running afoul of the plant’s reflected beams of sunlight, according to a report from The Desert Sun. This was not an isolated incident: another 19 were found dead at the 500-megawatt Desert Sunlight plant, which is also located in California.
So what’s going on here? Why are birds dropping like their winged-brethren, flies, around these plants and what can we do?
The Californian desert has become a popular place to build solar energy plants because of the abundant space and, of course, the sun. However, the region also serves as one of the four major north-to-south trajectories for migratory birds: the Pacific Flyway. So while it seems like an ideal locale, birds who fly over these structures face some new and unusual hazards.
When it comes to death by solar farm, birds typically die in one of two ways. In the first, the glimmering sheer of solar panels might trick birds into thinking they are actually part of a body of water. And so the birds, especially waterfowl in this scenario, dive towards the panels, looking for moisture and food, only to find themselves, bones broken, dying in the middle of the arid California sand.
Blunt force trauma aside, others feel the wrath of the harnessed sunlight. At the right (or really, wrong) angle, the potent radiation bouncing off solar mirror’s are enough to burn a bird’s fragile wings, abruptly sending the creature downward towards the ground and impending death. They’re like tragic avian Icaruses, except without an easily digestible moral lesson behind their fatal crashes.
Anthropogenic threats to birds are everywhere, but they vary according to the environment. In cities, the seeming invisibility of windows confuse the animals, who smash into the impenetrable glass barriers headfirst, an accident that can either stun or kill. Statistics differ: the American Bird Conservancy cites the annual number of bird deaths via window strikes at 300 million to one billion birds whereas the US Fish and Wildlife Service says its anywhere from as low as 97 million upwards to 972 million.
Whatever the actual number, it’s clear window strikes are a major concern, even causing some urban planners and architects, like those in Portland, to reconsider building methods. Will massive solar projects become the desert’s equivalent, inadvertently perplexing birds and luring them to their doom?
Since solar technology is still a neophyte in the world of energy solutions, we can’t yet know. So far, the numbers at single sites are comparatively low. But numbers only tell a part of the story: some of the victims are endangered or otherwise protected by the federal government under the Migratory Bird Treaty Act. That should undoubtedly factor into future discussions on this issue.
In the future, scientists will need to undertake studies of the interactions between migratory birds, their travel patterns, and humanity’s quest for solar energy. Answers will not be quick to obtain. Much more research has been conducted on how wind power and birds mix, and the scant research covering bird mortality and solar plants is based on plants much smaller than the projects being built today.
As Eric Davis of the US Fish and Wildlife Service told The Desert Sun, “Bird migration studies have to wait for bird migrations… This is going to be months and years of trying to better understand the problem and then make better management decisions as we gain more scientific understanding.”
Ultimately, when the research is complete, sorting out this scenario will involve an unpleasant and morbid calculus. What can be done to minimize migratory bird mortality? And since no solution will likely ever be perfect, how many birds might we “permit” to die? Thankfully, the current impact is quite low, but questions like these serve as a necessary reminder that even green projects have an impact on their surrounding environment.