AliBabaIncorporated
01-31-2004, 02:28 AM
Such as, for example, the golden eagle. All I can say is, three cheers for clean coal and nuclear power :biggrin:
http://www.oaklandtribune.com/Stories/0,1413,82%257E1865%257E1924751,00.html
Oakland Tribune
Study: Wind farms more lethal to birds than first thought
By Matt Carter
STAFF WRITER
Friday, January 30, 2004 - A new study of bird deaths in the wind farms of the Altamont Pass suggests the problem is more serious than previously thought, and raises questions about a 1998 plan to address the problem by replacing aging wind turbines with a smaller number of modern machines.
The study, sponsored by the U.S. Department of Energy, estimates that about 500 birds of prey are killed by wind farms in the Altamont each year, including red-tailed hawks, burrowing owls and golden eagles. Previous estimates, based in part on studies paid for by wind farm operators, put the number at between 160 and 400 raptors a year.
The study also calls into question a plan approved by Alameda County in 1998 that was to pave the way for "repowering" the wind farms in the Altamont Pass. The repowering plan, which remains untested, envisioned replacing 5,400 existing wind turbines with fewer than 900 larger models capable of generating the same amount of energy.
By reducing the total number of wind turbines -- and placing the new machines in areas where birds are less likely to hunt -- it was hoped that repowering would reduce the number of bird deaths. Modern wind turbines also employ tubular steel towers instead of lattice structures that may provide perches for birds to hunt from.
The study found that while repowering would reduce the total number of wind turbines, the modern machines could prove to be more lethal than those they would replace.
Repowering would drastically reduce the number of wind turbines, but result in a slight net increase in the total area "swept" by the larger machines' longer blades. The study concluded that bird deaths are tied more closely to this factor than the total number of turbines -- a finding that contradicts an earlier, industry-sponsored study.
The study also found that existing wind turbines with tubular towers killed birds at a higher rate than models with lattice towers, and that siting new turbines to avoid bird kills may be difficult.
Observers found raptors were attracted to prey such as ground squirrels, gophers and rabbits that make their homes around wind turbines. Different species of raptors employ varied hunting methods, so what helps one bird -- not placing wind turbines on ridge tops, for example -- may harm another, the study said.
"Based on data presented here, it is reasonable to expect that the number of bird fatalities at fewer post-repowering turbines should remain nearly equal to the number of kills reported at the more numerous pre-repowering turbines," the study said. "This hypothesis remains to be tested as the repowering effort proceeds."
Wind farms -- clusters of windmill-like turbines -- are generally viewed as environmentally friendly because they generate electricity without producing smog or greenhouse gases.
But the hilly grazing land in the Altamont Pass is also home to what's believed to be the largest nesting populations of golden eagles in the world. Other raptors found include the American kestrel and great horned owl.
That has presented a problem that appears to be unique to the Altamont Pass: Soon after wind turbines were installed in the 1980s, wildlife regulators realized that raptors were being killed by the wind farms' spinning blades and electrocuted on power lines.
In 1990, responding to pressure from the U.S. Fish and Wildlife Service, Alameda County stopped approving new wind farms in the pass.
To address the problem, in 1998 the county approved a plan that would have allowed several wind farm operators to scrap 1,300 old wind turbines and replace them with about less than 200 modern machines.
The plan capped electricity generation in the Altamont Pass at 580 megawatts. One megawatt of generating capacity in a conventional power plant is enough energy for 750 to 1,000 homes. But because winds are unsteady, on average wind farms generate only one-third or less of their rated capacity.
Some of the birds now being killed in the Altamont Pass, such as the golden eagle, are protected by federal laws, including the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act.
Much of the debate over wind farms in the Altamont has centered around the question of whether wind turbines are depleting golden eagle populations. The study found the impacts of wind farms on another species, the burrowing owl, may be greater.
The study involved surveys of about one-quarter of the wind turbines in the Altamont Pass over the course of nearly two years. During the surveys, which ended in December 2000, researchers found the carcasses of 226 raptors and 213 other birds such as meadowlarks, starlings, ducks and finches.
After discounting birds that might have been killed by predators or died of natural causes, researchers used statistical analysis to estimate the total number of birds killed each year by wind farms in the Altamont Pass -- 1,026.
Half of the birds killed were raptors -- birds of prey. The study calculated that golden eagles were killed at the rate of 24 per year -- less than previous estimates of between 40 and 60 per year.
But the study suggested that burowing owls -- considered a "species of special concern" by the state of California because its numbers may be dwindling -- are killed at the rate of 93 per year. The more common red-tailed hawk is thought to be killed in the greatest numbers, an estimated 244 per year.
"These estimates of total annual fatalities for golden eagles, red-tailed hawks and burrowing owls warrant continued research, monitoring and management programs designed to reduce these rates," the study concluded.
The peer-reviewed study, conducted by Ojai-based BioResource Consultants, was published in December and posted on the Web site of the Department of Energy's National Renewable Energy Laboratory this month. It is available at www.nrel.gov
http://www.oaklandtribune.com/Stories/0,1413,82%257E1865%257E1924751,00.html
Oakland Tribune
Study: Wind farms more lethal to birds than first thought
By Matt Carter
STAFF WRITER
Friday, January 30, 2004 - A new study of bird deaths in the wind farms of the Altamont Pass suggests the problem is more serious than previously thought, and raises questions about a 1998 plan to address the problem by replacing aging wind turbines with a smaller number of modern machines.
The study, sponsored by the U.S. Department of Energy, estimates that about 500 birds of prey are killed by wind farms in the Altamont each year, including red-tailed hawks, burrowing owls and golden eagles. Previous estimates, based in part on studies paid for by wind farm operators, put the number at between 160 and 400 raptors a year.
The study also calls into question a plan approved by Alameda County in 1998 that was to pave the way for "repowering" the wind farms in the Altamont Pass. The repowering plan, which remains untested, envisioned replacing 5,400 existing wind turbines with fewer than 900 larger models capable of generating the same amount of energy.
By reducing the total number of wind turbines -- and placing the new machines in areas where birds are less likely to hunt -- it was hoped that repowering would reduce the number of bird deaths. Modern wind turbines also employ tubular steel towers instead of lattice structures that may provide perches for birds to hunt from.
The study found that while repowering would reduce the total number of wind turbines, the modern machines could prove to be more lethal than those they would replace.
Repowering would drastically reduce the number of wind turbines, but result in a slight net increase in the total area "swept" by the larger machines' longer blades. The study concluded that bird deaths are tied more closely to this factor than the total number of turbines -- a finding that contradicts an earlier, industry-sponsored study.
The study also found that existing wind turbines with tubular towers killed birds at a higher rate than models with lattice towers, and that siting new turbines to avoid bird kills may be difficult.
Observers found raptors were attracted to prey such as ground squirrels, gophers and rabbits that make their homes around wind turbines. Different species of raptors employ varied hunting methods, so what helps one bird -- not placing wind turbines on ridge tops, for example -- may harm another, the study said.
"Based on data presented here, it is reasonable to expect that the number of bird fatalities at fewer post-repowering turbines should remain nearly equal to the number of kills reported at the more numerous pre-repowering turbines," the study said. "This hypothesis remains to be tested as the repowering effort proceeds."
Wind farms -- clusters of windmill-like turbines -- are generally viewed as environmentally friendly because they generate electricity without producing smog or greenhouse gases.
But the hilly grazing land in the Altamont Pass is also home to what's believed to be the largest nesting populations of golden eagles in the world. Other raptors found include the American kestrel and great horned owl.
That has presented a problem that appears to be unique to the Altamont Pass: Soon after wind turbines were installed in the 1980s, wildlife regulators realized that raptors were being killed by the wind farms' spinning blades and electrocuted on power lines.
In 1990, responding to pressure from the U.S. Fish and Wildlife Service, Alameda County stopped approving new wind farms in the pass.
To address the problem, in 1998 the county approved a plan that would have allowed several wind farm operators to scrap 1,300 old wind turbines and replace them with about less than 200 modern machines.
The plan capped electricity generation in the Altamont Pass at 580 megawatts. One megawatt of generating capacity in a conventional power plant is enough energy for 750 to 1,000 homes. But because winds are unsteady, on average wind farms generate only one-third or less of their rated capacity.
Some of the birds now being killed in the Altamont Pass, such as the golden eagle, are protected by federal laws, including the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act.
Much of the debate over wind farms in the Altamont has centered around the question of whether wind turbines are depleting golden eagle populations. The study found the impacts of wind farms on another species, the burrowing owl, may be greater.
The study involved surveys of about one-quarter of the wind turbines in the Altamont Pass over the course of nearly two years. During the surveys, which ended in December 2000, researchers found the carcasses of 226 raptors and 213 other birds such as meadowlarks, starlings, ducks and finches.
After discounting birds that might have been killed by predators or died of natural causes, researchers used statistical analysis to estimate the total number of birds killed each year by wind farms in the Altamont Pass -- 1,026.
Half of the birds killed were raptors -- birds of prey. The study calculated that golden eagles were killed at the rate of 24 per year -- less than previous estimates of between 40 and 60 per year.
But the study suggested that burowing owls -- considered a "species of special concern" by the state of California because its numbers may be dwindling -- are killed at the rate of 93 per year. The more common red-tailed hawk is thought to be killed in the greatest numbers, an estimated 244 per year.
"These estimates of total annual fatalities for golden eagles, red-tailed hawks and burrowing owls warrant continued research, monitoring and management programs designed to reduce these rates," the study concluded.
The peer-reviewed study, conducted by Ojai-based BioResource Consultants, was published in December and posted on the Web site of the Department of Energy's National Renewable Energy Laboratory this month. It is available at www.nrel.gov