Big Solar and Avian Mortality

The fact that wind turbines cause avian mortality has been long established and is so ingrained in the renewable energy world that federal management agencies now actually issue permits for wind developers to kill a certain number of birds. But what about big solar energy plants? Could they be affecting bird populations?

A Great Blue Heron found dead at the Genesis Solar site in the Chuckwalla Valley of southern California. (Photo courtesy Genesis Solar)

A Great Blue Heron found dead at the Genesis Solar site in the Chuckwalla Valley of southern California. (Photo courtesy Genesis Solar)

It seems almost counterintuitive that something as passive as a solar farm could result in avian mortality. And yet that’s exactly what’s happening, and by two different mechanisms.

Mojave Desert blogger and utility-scale solar expert Chris Clarke first reported in July (on his excellent and must-read ReWire blog) about aquatic birds mistaking the shimmering mirrored desert plains as lakes, and coming in for hard landings on what they thought would be water. Crashing into the mirrors at high speeds, the birds are thus killed. Amongst the dead aquatic birds was the large and elegant Great Blue Heron (pictured here). Perhaps most ominously, the deaths included a highly endangered Yuma Clapper Rail, of which there are fewer than 1,000 left in the U.S. Interestingly, these deaths occurred more than 25 miles from the nearest water sources.

The bird deaths were reported to the California Energy Commission (CEC), released to the public through permit compliance documents, and finally publicized by Clarke’s ReWire blog. The deaths occurred at two large-scale solar facilities in eastern Riverside County in southern California, the 550 MW Desert Sunlight Solar Farm (a PV plant), and the 250 MW Genesis Solar Energy Project (a solar trough CSP plant). Both facilities are in the large Chuckwalla Valley, in the heart of California’s Colorado Desert.

However it’s not only wayward aquatic birds which are dying at solar sites. In a completely different mechanism of death, birds are being fried to a crisp at the U.S.’s prominent solar power tower plant, Ivanpah Solar Energy Generating System. This was a concern long before Ivanpah became operational. The California Energy Commission, in permitting hearings for another facility for BrightSource, requested tests to determine the effect of the solar flux on passing birds. In a now infamous twist, BrightSource requested that the photos of these tests, which were conducted on already euthanized chickens and pigeons, be withheld from the public because they might be “inflammatory,” (no pun intended). Prominent biologist from the Center for Biological Diversity quipped that they, “…might be disturbing for someone who never cooked chicken before.”

At any rate, inflammatory photos or no, dead birds are indeed turning up at Ivanpah. Again reported by ReWire, a peregrine falcon was found on site, which sustained mortal wounds from the concentrated sunlight. And CEC recent compliance reports show that there are avian deaths on site each month, causing concern amongst wildlife advocates in the desert.

No form of energy will ever be immune from environmental consequences. Coal dirties our air, natural gas poisons our water, nuclear generates unmanageable waste. But renewable energy technologies also have environmental externalities, and these are often minimized during the permitting process for these facilities. While concerns about avian mortality were raised during the permitting process for Genesis, Desert Sunlight, and Ivanpah, these were largely swept under the rug and written off as incidental. The evidence is proving otherwise: avian deaths at big solar plants are not incidental but institutional, a part of the operating plan of these facilities. Future big solar plants in the desert should be permitted with this in mind, and suitable precautions should be taken to minimize these fatalities.