BrightSource Energy, the company building the 377-megawatt Ivanpah Solar Electric Generating System near the Mojave National Preserve has released photos of a burned bird found on the site in August, and while the images aren't particularly grisly, they're nonetheless sobering for those concerned about the effect of concentrated solar energy on desert birds.
The bird in question, a northern rough-winged swallow, was found between Ivanpah's Units 1 and 2 on August 13. As ReWire reported last week, the bird was alive when found but died two days later at a rehabilitation center.
The photos show clear evidence that the bird's feathers were exposed to temperatures sufficient to break down the keratin proteins that make up bird feathers. The swallow suffered extensive damage to feathers on its back side, with the barbs on its flight feathers burned away to the shaft, rendering the bird incapable of flight. The smaller downy "covert" feathers on the bird's back were clearly singed to the point of curling.
The Ivanpah project, being built by Bechtel for BrightSource and its partners NRG Energy and Google, occupies about 3,500 acres of public land in the Mojave Desert near Primm, Nevada.
Concentrated solar energy or "solar flux," generated at Ivanpah when operators focus thousands of mirrored heliostats at receivers atop power towers, has been known to pose a potential source of harm to birds since the days of the old Solar One project in Daggett, California in the 1980s. The flux issue has been a point of contention between BrightSource and state and federal agencies for some time. During discussions of the flux issue at BrightSource's proposed Hidden Hills project near Tecopa, an important bird area, the company was recommending a "safe threshold level" for wildlife exposure to solar flux of about 50 kilowatts per square meter, ten times the level the CEC staff was suggesting as a safe level. (Unfiltered, unconcentrated sunlight in the desert maxes out at around one kilowatt per square meter.)
According to the accompanying text in the report, the project's Unit 3 had been generating solar flux daily for more than a week before the swallow was found.
ReWire has heard uncorroborated reports that a peregrine falcon found dead at the project in early September is also said to have shown signs of solar flux injury. That bird was sent to a facility in Oregon for forensic examination.
If Ivanpah solar flux has been injuring birds during the testing phase, then such injuries may well increase when the project begins full-time power generation with all three towers. Unit 1 supplied power to Pacific Gas & Electric for the first time last week in the "proof of concept" test: full operation of the plant is expected to commence sometime this year.
And agencies are expressing serious concern about the flux issue at the proposed Palen Solar Electric Generating System, which BrightSource wants to build with partner Abengoa in Riverside County east of Joshua Tree National Park. In its Preliminary Staff Assessment of that project, the CEC says that solar flux could pose an "unavoidable" threat to wild birds that "may be significant even after implementation of mitigation."
CEC staff is still looking into how significant a risk Palen's solar flux will be. BrightSource is adamant that Palen be approved by the end of the year so that it can meet lenders' deadlines. An in-depth examination of the flux issue by CEC staff could well push that deadline hard, which may be why BrightSource is now willing to release photos of bird injuries from solar flux. The company hasn't always been willing to make such photos public.