Ivanpah Solar Plant Unintended Consequences

The Ivanpah Solar Electric Generating System (ISEGS) not only roasts birds in mid-air, but also seems to be a hazard to aviation. New estimates for the plant, an innovative 2.2 billion solar project says thousands of birds are dying yearly, roasted by the concentrated sun rays from the mirrors. (1)

---

Workers at the plant in the Mojave Desert have a name for birds that fly through the plant's concentrated sun rays--'streamers,' for the smoke plume that comes from birds that ignite in mid-air. (2) Federal wildlife investigators who visited the plant last year and watched as birds burned and fell, reporting an average of one 'streamer' every two minutes, are urging California to halt the operator's application to build a still-bigger version. (2) More than 300,000 mirrors, each the size of a garage door, reflect the solar rays onto three boiler towers each looming up to 40 stories high. The water inside is heated to produce steam, which turns turbines that generate enough electricity for 140,000 homes. (2) It turns out that insects are attracted to the glowing light of the solar towers, followed by smaller birds seeking to feed on the insects, followed by larger predator birds. As the birds fly into the focal field of the mirrors (the solar flux)—estimated at approximately 800 to 1000 F—many are burned. (3) Federal investigators want to halt activities on a future project until the full extent of the deaths can be assessed. Estimates per year now range from a low of about a thousand by plant officials to 28,000 by an expert from the Center for Biological Diversity environmental group. (2)

---

---

The plant is offering $1.8 million in compensation for anticipated bird deaths, proposing the money for programs such as those to spay and neuter domestic cats, which a government study found kills over 1.4 billion birds a year. Opponents say that would do nothing to help the desert birds at the proposed site. As Ellen Knickmeyer and John Locher point out, “The bird kills are the latest instance in which the quest for clean energy sometimes has inadvertent environmental harm. Solar farms have been criticized for their impacts on desert tortoises, and wind farms have killed birds, including numerous raptors.” (2) Another issue relates to sun rays sent up by the field of mirrors that are bright enough to dazzle pilots flying in and out of Las Vegas and Los Angeles. The California Energy commission (CEC) has received numerous pilot and air traffic controller glare-impact reports. The situation is serious because pilots report that they cannot 'scan the sky in that direction to look for other aircraft.' According to an air traffic controller, “Daily during the late-morning and early-afternoon hours, we get complaints from pilots of aircraft flying from the northeast to the southwest about the brightness of this solar farm.” (4) Results of aerial and ground-based surveys conducted by Sandia National Laboratories showed that the intense glare viewed from the airspace above ISEGS was caused by heliostats in standby mode that were aimed to the side of the receiver. Evaluation of the glare showed that the retinal irradiance and subtended source angle of the glare form the heliostats in standby were sufficient to cause significant ocular impact up to a distance of about 6 miles, but the values were below the threshold for permanent eye damage. A Letter to Airmen has been issued by the FAA to notify pilots of the potential glare hazards. Ivanpah operators BrightSouce and NRG are investigating new strategies and algorithms for heliostat standby positions to reduce the irradiance and number of heliostats that can reflect light to an aerial observer. (4) The future project mentioned earlier that concerns the CEC is the application from Oakland-based BrightSource to build a mirror field and a 75-story tower that would reach above the sand dunes and creek washes between Joshua Tree National Park and the California-Arizona border. The proposed plant is on a flight path for birds between the Colorado River and California's Salton Sea- an area experts say, with protected golden eagles and peregrine falcons, and more than 100 other species of birds, that is richer in avian life than the Ivanpah plant region. (2) The CEC's staff estimates the proposed new tower would be almost four times as dangerous to birds as the Ivanpah plant. The agency is expected to decide this autumn on the proposal. While biologists say there is no known feasible way to curb the number of birds killed, the companies behind the projects say they are hoping to find one—studying whether lights, sounds or some other technology would scare them away. (2) One last item: each of Ivanpah's 4,000 acre facility's three units has gas-fired boilers used to warm up the fluid in the turbines in the early morning, to keep that fluid at on optimum temperature through the night, and to boost production during the day when the sun goes behind a cloud. Chris Clarke reports, “The project's managers originally estimated that the plant's main auxiliary boilers would need to run an hour a day, on average, to allow the plant to capture solar energy efficiently. But after a few months of operation, they're now saying they need to burn more gas, with the boilers running an average of five hours a day. To that end, the companies have asked the CEC to change the project's license to allow Ivanpah to burn more than 1.5 billion cubic feet of gas a year, and the plant's operators say that change won't have any environmental impact. If the petition is approved, the plant would be allowed to use a quantity of natural gas that would have been enough to supply about 35,000 typical California households.” (5) Clarke adds, “To be sure, the amount of natural gas ISEGS would be able to burn under the requested amendments to the plant's license is still dwarfed by the amount a typical gas-fired plant burns in its normal course of operations. Still, the boosted gas consumption limits proposed by ISEGS' backers aren't without impact. The plant's total CO2 footprint from burning natural gas would rise to just above 92,200 tons per year, approximately equivalent to the annual greenhouse gas output of 16,500 average passenger cars.” (5) References

1. Anthony Watts, “A birds-eye view of the bird scorching Ivanpah solar electric power plant,” wattsupwiththat.com, August 18, 2014
2. Ellen Knickmeyer and John Locher, “Emerging solar plants scorch birds in mid-air,” The Kansas City Star, August 17, 2014
3. Benjamin Zycher, “California's new solar plant: burning up taxpayer money, land, and wildlife,” The American, May 21, 2014
4. Clifford K. Ho, Cianan A. Sims, and Joshua M. Christian, “Evaluation of glare at the Ivanpah solar electric generating system.” Sandia National Laboratories, SAND2014-15847, July 2014
5. Chris Clarke, “Ivanpah solar plant owners want to burn a lot more natural gas,” kcet.org/news, March 27, 2014

---