An interesting comment on the wildlife impacts of concentrating solar technology comes to us via ReWire reader Brandon Hill in Fresno County, in the form of a local news report from two years back on a BrightSource Energy project in Coalinga.
Unlike BrightSource's much larger Ivanpah Solar Electric Generating System now nearing completion in the Mojave Desert, the Coalinga project --- built in partnership with the oil company Chevron -- doesn't generate electricity. Both the Coalinga and Ivanpah projects focus sunlight on a boiler with fields of mirrored heliostats, but where the Ivanpah plant will use that steam to drive electrical generating turbines, the Coalinga plant injects the steam into Chevron's Coalinga oil wells to make it easier to pump the heavy crude out of the ground.
When a school group went on a guided tour of the plant in Fresno County soon after the plant opened in late 2011, reporter Gene Haagenson tagged along to cover the event for local ABC affiliate KFSN. Haagenson caught a very interesting, notably frank exchange between a fifth-grade student and the Chevron engineer leading the tour.
Here's Haagenson's piece, which aired October 3, 2011. The exchange that caught our notice takes place one minute and 30 seconds in:
A transcript of the exchange:
Jaden Johnson, local 5th grader: "Is it true right now that if a bird flies through that right now it will catch on fire?"
Unidentified Chevron engineer: "Yeah! If a bird were to fly through that it would catch on fire."
The Coalinga plant, completed in 2011 after significant cost overruns, uses 8,000 mirrored heliostats on 100 acres of land to generate the equivalent of 29 megawatts' worth of thermal energy atop a 350-foot tower. That's quite a bit smaller than either the Ivanpah plant, which uses seven times as many heliostats to generate more than four times as much power per tower, or the proposed Palen project, which would use more than ten times as many heliostats for each of its two towers as Coalinga, and would generate almost nine times as much power atop those towers.
Which means that in theory, both Ivanpah and Palen would pose a substantially larger threat to flying wildlife than Coalinga. While BrightSource has always acknowledged that its projects' concentrated solar flux can't be called safe for birds and other wildlife that might fly through it, the company has spent a great deal of time and effort in the last two years attempting to reassure regulators that that flux doesn't pose a significant risk to wildlife. Among the company's claims has been that moderate levels of solar flux would cause only minimal damage to the protein in birds' feathers.
And yet two years ago, a representative of one of BrightSource's closest business partners blithely confirmed that a relatively small plant's relatively small solar flux output would cause birds flying through that to "catch on fire."
Of course, that unidentified Chevron engineer tour guide may have been caught by surprise by the question, and explaining the nuances of solar flux levels in kilowatts per square meter, thermal absorption, and denaturing of keratin would be lost on the vast majority of fifth-graders. That tour guide was certainly playing to his audience, and there are a lot of fifth graders who might quietly find the prospect of birds bursting into flame to be exciting.
Still, it boils down to this: a proponent of and user of BrightSource's technology readily admitted on the public record that birds flying through the solar flux from a relatively small power tower project would burst into flame.
It's hard not to find that interesting.