Wind Power: Green and Deadly

An average US citizen or corporate entity who kills an endangered animal can be in big trouble with the law. Birds, eagles in particular, are zealously protected by nature lovers in America and around the world. Yet a July 2008 study of the wind farm at Altamont Pass, California, estimated that an average of 80 golden eagles were killed there by wind turbines each year. The study, funded by the Alameda County Community Development Agency, estimated that about 10,000 other protected birds were being killed along with the eagles every year at Altamont. Where is the outrage over this slaughter? It would seem ecologists have a blind spot when it comes to the wind energy industry. As a result, the carnage caused by wind turbines, the “Cuisinarts of the Air,” is getting greenwashed. And birds are not the only creatures wind turbines kill—they kill bats and people as well.

In the US, birds are protected by the Migratory Bird Treaty Act, which dates back to 1918. Over the past two decades, the federal government has brought hundreds of cases against energy companies for killing wild birds in the operation of their businesses. For example, in July 2009, the Oregon based electric utility PacifiCorp paid $1.4 million in fines for killing 232 eagles in Wyoming over a period of two years. The birds were electrocuted by poorly-designed power lines. At the same time, wind-powered turbines are killing a vast number of birds each year yet their owners are not being prosecuted.

While the total number of birds killed in the US each year fluctuates, Michael Fry of the American Bird Conservancy estimates that US wind turbines kill between 75,000 and 275,000 birds per year. Yet the Justice Department is not bringing cases against wind companies. “Somebody has given the wind industry a get-out-of-jail-free card,” Fry said, in an interview with the Wall Street Journal. “If there were even one prosecution,” he added, the wind industry would be forced to take the issue seriously (see “Windmills Are Killing Our Birds”).


A dead white-tailed eagle killed in the Smøla wind-farm, off the Norwegian coast. Photo Espen Lie Dahl.

According to the American Wind Energy Association, each megawatt of installed wind-power results in the killing of between one and six birds each year. If environmentalists, lobby groups and some government officials have their way, the U.S. will be producing 20% of its electricity from wind by 2030. Meeting that goal will require about 300,000 megawatts of wind capacity, a 12-fold increase over 2008 levels, according to the DOE. If that target is achieved, at least 300,000 birds will be killed each year by wind turbines. Even so, wildlife enforcement officials do not expect to see any prosecutions of the politically correct wind industry.

America isn't alone in creating avian carnage, people across Europe have started to take notice of the true cost of “environmentally friendly” wind power. An energy company has admitted that endangered Red Kites are at significant risk from its planned new wind farm complex in South Wales. Other reports place the kestrel and plover in danger from wind turbines as well.

Martina Carrete, and colleagues from the Doñana Biological Station in Seville, recorded the number of Egyptian vulture carcasses with collision injuries found around 675 wind turbines in southern Spain between 2004 and 2008. Using a computer model containing information about turbine locations and nesting sites, the researchers estimate the rare Egyptian vulture will go extinct ten years sooner than expected, even if no more wind farms are built in Spain. The Spanish conservation group, Gurelur, places the current yearly damage at 409 vultures, 432 birds of prey, 671 bats and 6152 other bird species.

While some experts have downplayed the danger to birds it seems that bats are taking a greater hit—often in a literal sense. Bats, being a rather unloved species compared to birds, do not seem to carry as much weight with the eco-conscious. Two separate sets of researchers have reported two different ways that wind farms, with their rotating turbine blades, are dangerous, even deadly to bats. One report shows that bats, with their amazing flying and hunting abilities, are none the less being struck down by slashing turbine blades.

It is hard to believe that these adept, acoustic radar-equipped flying mammals simply fly into the blades, but a surprising number of bats are being killed by wind turbine farms. A study was prompted by recent finding that forest-dwelling bats are often found dead beneath operating wind turbines at wind energy facilities. Thermal infrared video cameras were used to record the flight behavior of bats at night near these turbines in an attempt to understand the cause of these fatalities. Quoting from the study report:

We observed bats actively foraging near operating turbines, rather than simply passing through turbine sites. Our results indicate that bats: 1) approached both rotating and non-rotating blades, 2) followed or were trapped in blade-tip vortices, 3) investigated the various parts of the turbine with repeated fly-bys, and 4) were struck directly by rotating blades. Blade rotational speed was a significant negative predictor of collisions with turbine blades, suggesting that bats may be at higher risk of fatality on nights with low wind speeds.

This followed previous research that showed that bats can have their lungs ruptured from the sudden low pressure of passing turbine blades: the bats are actually drowning in mid-air. It is not necessary for the bats to collide with the turbines, bats don't even need to come in physical contact with the turbine blades. A blade passing close by is enough to be fatal—an unexpected hazard that was previously unsuspected. For more on the bat deaths, including infrared video footage, see “Wind Turbines Spread While Bats Take Beating.”

Earlier this year, Judge Roger W. Titus of the US District Court of Maryland has “reluctantly” enjoined construction of a West Virginia wind farm under the Endangered Species Act (ESA) to protect the Indiana bat. “Like death and taxes, there is a virtual certainty that Indiana bats will be harmed, wounded, or killed imminently by the Beech Ridge Project,” Titus wrote in a 74-page opinion. “The development of wind energy can and should be encouraged, but wind turbines must be good neighbors.”


The threatened Indiana bat halted construction of a wind farm.

Wind power projects in a large part of the US may now need to add Fish and Wildlife Service permits to development financing and cost estimates. Greens may be about to do to wind power what they have previously done to the nuclear industry, creating red tape and legal barriers to green energy deployment. It seems that some greens oppose any energy project supporting the “unsustainable” Western lifestyle.

Wind power, like every other source of power, has its hazards and negative effects on nature. There is no free lunch, ecologically speaking. Every action by man—or any other species for that matter—affects the environment in some way. We are all for wind power where it is appropriate and can operate economically. If appropriate means not along known bird migration routes, near nesting sites or areas with a lot of bat activity the potential for wind power may be a lot smaller than even moderate estimates.

It may, however, be impossible to avoid the impact widespread use of wind power could have on the environment. Analysis from MIT researchers suggests generating electricity from large-scale wind farms could influence climate—and not necessarily in the desired way. Scientists have discovered that directly interfering with wind on a sufficiently large scale affects the climate of the atmosphere.

In a paper published online February 22, 2010, in Atmospheric Chemistry and Physics, MIT researchers Chien Wang and Ronald Prinn suggest that using wind turbines to meet 10% of global energy demand in 2100 could cause temperatures to rise by 1°C in regions where land based wind farms are installed, with a smaller increase in surrounding areas. Their analysis indicates the opposite result for wind turbines installed in water: a drop in temperatures by 1°C over those regions. According to the paper:

Temperature increase occurs because the wind turbines affect two processes that play critical roles in determining surface temperature and atmospheric circulation: vertical turbulent motion and horizontal heat transport. Turbulent motion refers to the process by which heat and moisture are transferred from the land or ocean surface to the lower atmosphere. Horizontal heat transport is the process by which steady large-scale winds transport excessive heat away from warm regions, generally in a horizontal direction, and redistribute it to cooler regions. This process is critical for large-scale heat redistribution, whereas the effects of turbulent motion are generally more localized.

What the true impact of widespread, large scale wind turbine deployment will be is uncertain. What is certain is that the environment will be affected. The MIT researchers also suggest that the intermittency of wind power could require significant and costly backup options, such as natural gas-fired power plants. For more information about the reliability of wind power and the costs associated with its intermittency, see my previous post, “Energy Answer Not Blowin' In The Wind.”

An Ill Breeze

In January 2008, two giant Vestas wind turbines in the UK collapsed within weeks of each other. An executive from Vestas Wind Systems gave reassurances after it emerged that one of its turbines had fallen in Scotland just weeks before an incident near Caldbeck in Cumbria. The global manufacturer has produced about 35,000 turbines since being formed in the 1970s. These were the first such incidents in the 29-year history of wind energy in the UK, and have prompted safety fears to be raised by anti-windfarm campaigners.

This, and similar incidents around the world have raised questions regarding the safety and durability of wind turbines. Wind power is usually thought of as being totally safe and benign, not a source of industrial accidents or even death. The truth is rather startling: since the 1970s there have been 482 reported accidents resulting in 49 deaths.

Of the known deaths, 35 were wind industry workers—installers, maintenance engineers, etc—and one farmer attempting to maintain his own turbine. The most common cause is falling from turbines. Working on wind turbines is a dangerous profession. It begins with a climb up the supporting tower, as much as 300 ft (90 m) straight up. A fit maintenance worker can make the climb from ground to turbine in perhaps five minutes.


Wind turbine failure in Cumbria, UK. Source CLOUD.

At the top awaits a room the size of a small bus, filled with a large generator, motors, gears and electronics. A typical turbine contains 8,000 parts, and the largest models can generate 3 MW of electricity. The turbine technician works in a cramped space, filled with complicated machinery and high voltage circuitry. A gentle wind at ground level can be a near gale 27 stories above the surface. Like a ship at sea, the top of a wind turbine can sway from side to side, with the generator housing constantly shifting to keep its blades facing into the wind. Under strong winds, technicians have been known to vomit. In all, not a job for the weak or faint of heart.

Outside of wind industry workers, there were 14 public fatalities reported over the past four decades, three of which were from road accidents attributed by police to drivers being distracted by the turbines. One was from a road accident collision with a turbine transporter in which a driver was killed, while in another, the road collapsed and a transport driver drowned.

Among the stranger circumstances was an aircraft accident where a pilot flew into a new, unmarked anemometer (a device used for measuring wind speed) that was mounted atop a turbine. Four people died in another aircraft accident when a plane collided with a turbine in fog. A 16-year old boy strangled after his necktie became tangled around an unprotected turbine shaft and a farmer killed himself because of public opposition to his proposed wind turbines. Perhaps the strangest incident of all was when a German skydiver drifted into an operating wind turbine on her first unassisted jump. In doing so she became the first woman killed by wind energy.

A further nineteen accidents resulting in human injury are documented. Thirteen accidents involved wind industry or construction workers, and a further five involved members of the public: one lost a leg in a transport accident, one was hit by thrown ice, one suffered spinal injuries from a falling turbine part, one fell from 100 m tower during an accompanied visit, and another flew his aircraft into a wind farm site. One 2003 accident resulted in two industry workers receiving appalling burns.

By far the largest number of incidents are due to blade failure. Blade failure can arise from a number of possible sources, and results in either whole blades or pieces of blade being thrown from the turbine. A total of 122 separate incidents have been documented. Pieces of blade are known to have landed over 1300 feet (400 m) from the turbine. Most of these were from older turbines that are much smaller than those being built today.


Short circuits, friction or lightening strikes can cause wind turbines to go up in flames. Photo Der Spiegel/DPA.

In Germany, blade pieces have gone through the roofs and walls of nearby buildings. Safety experts believe that there should be a minimum distance of at least 3000 ft (1 km) between turbines and occupied housing. European countries mandate at least 6500 ft (2 km) in order to address other problems such as noise.

Surprisingly, fire is the second most common accident cause in incidents found. Fire can arise from a number of sources and some turbine types seem more prone to fire than others. The biggest problem with turbine fires is that, because of the turbine height, the fire brigade can do little but watch it burn itself out. While this may be acceptable in reasonably still conditions, in a storm it means burning debris being scattered over a wide area, with obvious consequences. In dry weather there is obviously a wider-area fire risk, especially for those constructed in or close to forest areas and/or close to housing. A total of 104 fire incidents have been reported.

Structural failure, like the incident in Cumbria, is the third most common accident cause, with 58 reported instances. Structural failure implies major component failure under conditions which the turbine should be designed to withstand. This mainly occurs during storms, which can damage turbines and even cause tower collapse. Dramatic footage was captured of a Danish wind turbine collapsing during a storm in February, 2008. The blades and generator housing practically exploded under the strain.

While structural failure is far more damaging than blade failure, the accident consequences and risks to human health are most likely lower, as risks are confined to within a relatively short distance from the turbine. However, as smaller turbines are now being placed on and around buildings, including schools, the accident frequency is expected to rise. A related type of incident is ice being thrown from the rotating blades, with distances of up to 450 ft (140 m) being reported.


Aftermath of Danish wind turbine structural failure.

The wind power industry is fond of showing tranquil scenes with contented cows munching grass underneath soaring turbine blades in a wind park. Little did we know that the cows were in such danger. Being an engineer as well as a scientist, I accept that humans will have an impact on nature and other living things. What I cannot abide are those sanctimonious, greener-than-thou conservationists who are mindlessly devoted to “green power” while becoming apoplectic at the mention of building new nuclear power plants.

I am all for clean energy, but only if it is safe energy. So let's be realistic here, birds and bats do not get hacked from the air by nuke plants. And I know from personal experience, living on Chesapeake Bay near the Calvert Cliffs Nuclear Power Plant, that fish love the warm water outlets from such installations. Over the past 40 years there have been more deaths attributed to wind power than to nuclear power, yet nuclear power is the one always called “unsafe” by conservationists. It's time to grow up children—if you want to save the birds, the bats and the humans, embrace the power of the atom.

Be safe, enjoy the interglacial and stay skeptical.


Green energy done right, the Calvert Cliffs Nuclear Power Plant.

[ Note: most of the information presented in this post was taken directly from our new book, The Energy Gap. Look for The Energy Gap on Amazon later in May, 2010. ]