“After several studies, the conclusion for why birds are drawn to the searing beams of the solar field goes like this: Insects are attracted to the bright light of the reflecting mirrors, much as moths are lured to a porch light. Small birds — insect eaters such as finches, swallows and warblers — go after the bugs. In turn, predators such as hawks and falcons pursue the smaller birds.
But once the birds enter the focal field of the mirrors, called the “solar flux,” injury or death can occur in a few seconds. The reflected light from the mirrors is 800 to 1,000 degrees Fahrenheit. Either the birds are incinerated in flight; their feathers are singed, causing them to fall to their deaths; or they are too injured to fly and are killed on the ground by predators, according to a report by the National Fish and Wildlife Forensics Laboratory.”
- David Danelski, Solar: Ivanpah Solar Described as Deadly Trap for Wildlife,” Riverside-Press Enterprise, April 8, 2014.
The slaughter of birds caught in the revolving blades of wind energy turbines has grabbed national attention lately. But even more pernicious is the nearly invisible vaporizing of birds that fly into the new Ivanpah solar mirror project in California’s Mojave Desert seeking to feed on the insects that are drawn to the light of the reflecting mirrors.
Ivanpah is the largest solar thermal mirror project in the world encompassing 4,000 acres of land and 347,000 heliostat mirrors focused on three 450-foot high towers. 377 megawatts of electricity is generated by a conventional steam turbine from concentrated heat from the mirrors. Solar thermal mirror energy plants are actually hybrid solar-natural gas power plants.
Counting bird deaths may be accurate for wind farms. But counting dead birds on the ground from solar mirror projects may be a highly inaccurate way to measure the impacts on the entire ecological food chain. That is because many birds are vaporized in mid air and often there is no trace left of them. Investigators call these “streamers,” referring to the momentary puffs of smoke as birds are vaporized. Here is how it is described:
“The investigators could not identify many burning objects, which they call streamers. We observed many streamer events, the report said. It is claimed that these events represent the combustion of loose debris, or insects. Although some of the events are likely that, there were instances in which the amount of smoke produced by the ignition could only be explained by a larger flammable biomass such as a bird. Indeed, OLE (U.S. Fish and Wildlife Service Office of Law Enforcement) staff observed birds entering the solar flux and igniting, consequently becoming a streamer. OLE staff observed an average of one streamer event every two minutes.”
Two streaming events every two minutes would be 360 such incidents every 12-hour solar day for an unscientific count of 131,400 per year. However, unsurprisingly only 55 actual dead or injured birds were found on the Ivanpah site in March 2014.
Because of the smaller number of actual bird carcasses, Ivanpah spokesperson Jeff Holland minimized the impacts on birds in an Atlantic magazine article, saying the reports were premature and unscientific.
Yucca Moths Led to Flame of Solar Mirrors?
Unlike wind farms that mainly kill birds, solar tower projects could result in impacts to the entire desert ecological food chain:
Mojave Desert Food Chain:
The raptors prey on the small birds; the small birds and reptiles forage on insects; yucca moths and butterflies pollinate yucca trees and other plants; and yucca trees provide habitat and nectar for yucca moths.
Source: Mojave Desert Gazzette
Yucca moths –- shown here – pollinate Joshua Tree yuccas. The yuccas could not live without the moths and vice versa. And moths and other insects are attracted to the brighter lights of the Ivanpah solar towers and mirrors (shown here).
A word search of the Biological Assessment for the Ivanpah Solar Electric Generating Station completed in December 2009 indicates the document does not even contain the words “insect” or “moth.” A map of the Ivanpah site in the Biological Assessment clearly shows a preserved grove of Mojave Yucca inside the one-mile buffer from the arrays of solar mirrors (see Figure 3-2 on page 3-13). The document also reports that Joshua Trees are found on the site although sagebrush is the dominant ground cover.
Additionally, the Ivanpah site is visible from the Mojave National Preserve, the Mesquite Wilderness and the Stateline Wilderness parks. A dense Joshua tree forest exists in the Mojave National Preserve that is pollinated by the Yucca Moth.
Solar thermal tower energy plants are what is called an attractive nuisance in real estate that end up vaporizing birds. Something similar probably occurs with wind farms, especially at night when most wind energy is generated. See the photos of wind turbines at moonlight near Palm Springs, near the Columbia River, and in Oak Creek Pass, Kern County, California. Insects, including pollinating moths and butterflies, are drawn to the shiny blades of wind turbines in the moonlight and bats, nighthawks, and owls chase them or know that insects congregate around wind towers at night. During the day the shiny wind turbine blades probably have the same effect by attracting small birds that chase insects. Where tall transmission line towers are also nearby, birds typically perch on them to look for prey or to forage insects. If wind farms are bird killers, solar thermal mirror energy plants are bird killers on steroids and by stealth methods.
The California Energy Commission is currently considering an even larger solar thermal mirror project in the Mojave Desert by the same developer as Ivanpah– BrightSource Energy. The Palen Solar Thermal Project would be a 500 megawatt power project comprised of two 750-foot high solar towers and would create the same “solar flux” that kills birds and insects at Ivanpah. BrightSource Energy and Abengoa Solar contend they have data showing only 202 bird kills at Ivanpah based merely on body counts, not reported vaporizations. No mention is made of any insect and yucca moth deaths that are part of the food chain for small birds and reptiles. Unlike Ivanpah, however, the Audubon Society is exerting its opposition to the project but apparently based on bird body counts only.
Oddly, the California Water Resources Control Board has mandated that all 19 coastal power plants must convert from seawater cooling to air cooling systems to avoid killing millions of fish larvae that such sucked into intake tubes. Fish larvae is part of the marine food chain for more mature fish just as insects are for desert wildlife.
If a bird is vaporized in a forest of solar panels and no evidence is left behind, did it ever happen? Perhaps those investigating bird losses from solar and wind farms should refocus on moths and butterflies that are the apparent link to the sustainability of the avian and desert ecosystems. Problem is birds and tortoises are prettier and more captivating than insects or yucca moths. But the yucca moths are perhaps sexier.