Wind wings its way to better bird protection

WORLDWIDE: Wind power turbines threaten protected birds", "Dead birds unintended consequence of wind power development", "Russia's Putin says wind turbines kill birds".

Wind turbines at Tarifa, Spain, kill 146 raptors a year
Wind turbines at Tarifa, Spain, kill 146 raptors a year

This selection of headlines from around the world shows that the impact of the wind industry on birds is still causing controversy 17 years after Windpower Monthly first broke the story of raptor deaths at Tarifa in Spain.

The industry argues that the number of birds killed by wind turbines is relatively small. A 2005 study by US academics found that around 550 million birds a year are killed by collisions with buildings, while cats kill some 100 million. Wind turbines were blamed for only 28,500 deaths a year.

However, in some specific locations, impacts have been significant. The most famous example, the Altamont Pass in the US, is estimated to kill 60 golden eagles and around 4,000 other birds each year. At Tarifa in Spain, there are 65 griffon vulture and 146 raptor deaths a year.

These might be extreme examples. However, they are cited frequently in media reports whenever the issue raises its head. Overall deaths from turbines may be small, but their impact on the wind industry's image is anything but.

"Bird deaths are a problem that hasn't gone away and won't go away, it's causing the industry a black eye," says Shawn Smallwood, an ecologist who has studied the impact of turbines on wildlife in the Altamont Pass for 12 years.

Bird-death hotspots

Spain and the US are still hotspots for this issue. In July, the Supreme Court of Spain's top wind market, Castile and Leon, ordered a provisional freeze on the 21MW Curuena II project. This was the third such order nullifying local-authority wind-project licenses in the area, the result of 12 cases brought by bird conservation group SEO/Birdlife.

Spanish wind association Aeeolica's energy policy director Heikki Willstedt reports that the issue has resurfaced in recent years due to the fact that many of the projects being built now received environmental permits five to seven years ago. In some cases, the parks were approved very close to, or even within, Natura 2000 sites, which are a network of nature areas protected by European law. These designations did not exist at the time the permits were granted.

Willstedt says that environmental-impact assessments (EIAs) were not done well by today's standards as knowledge of the impact of turbines on birds was much lower. Environmental groups are therefore finding it very easy to challenge the permits.

He estimates that up to 50 wind farms in Spain may have to redo their EIAs. "We don't know to what extent this will happen, some permits might need amendments," he says. "Most probably, they (wind-farm owners) will have to take compensatory measures."

Aeeolica has encouraged members to redo their EIAs before being taken to court. It would be much quicker for wind-farm operators to have their permits reapproved this way as it can take five years to receive a definitive judgment from the courts.

Ultimately, the association is seeking a more holistic solution and is establishing a working group with the local government and Spanish bird and nature conservation association SEO/Birdlife, which is responsible for most of the legal cases.

Willstedt is optimistic about resolving the problem, but resents some conservationists who want certain areas to be completely off-limits to wind farms, even though they are not protected areas. "We don't agree with this kind of radicalism," he says.

Octavio Infante, Natura 2000 officer for SEO/Birdlife, complains that consultants undertaking EIAs typically only spend two days out of a one-year assessment in the field - the rest of the work is done from an office. Some wind-farm promoters have been happy to work with the organisation to improve EIAs as they are keen to avoid problems, he reports. SEO/Birdlife recommends that turbines be fitted with deterrent technology produced by Spanish consultancy DTBird. The technology works in real time to detect birds flying towards turbines and calculates the risk of collision. It then either activates a noise to repel the bird or stops the turbine.

Getting better

Over in California's Altamont Pass, the situation is finally looking up. Years of arguing, confusion and stalemate have been superceded by action. US renewables developer NextEra Energy, which owns more than 50% of the turbines in the Altamont Pass, agreed in December to repower its turbines.

Newer turbines kill far fewer birds than older models, for example, as the longer blades mean their rotation is slower. NextEra will also benefit as the newer turbines will have a capacity factor of 30% or more, compared with 12% in some of the older machines.

Renewables firm enXco, which also owns some of the turbines in the pass, is planning to try out a new turbine produced by US-based consultancy Flodesign. This machine has external housing to prevent birds flying into the rotor plane parallel to the rotor axis, which is a major cause of bird fatalities.

Smallwood, who is advising some of the companies who own turbines in the pass, reports that this turbine should be trialled there by the end of 2012. AES Seawest, a US-based renewables developer, has also shown interest in the turbine. It could be a "game changer" if it is proved to reduce bird mortality, says Smallwood.

Not all operators in the pass are repowering. Local firm Altamont Winds Incorporated (AWI), which owns 20% of the turbines in the pass, has to remove its turbines by 2018 under the terms of its permit. AWI did not reply to Windpower Monthly's request for a comment*.

Nevertheless, Smallwood is positive about the situation in California. "I feel like the wind industry is working with me. We had a very adversarial relationship for many years, but we seem to have got past that," he says. "The repowering of the Altamont Pass is a huge victory for wind power and conservation."

In addition, wildlife protection agency the Fish and Wildlife Service (FWS) appears to be taking a harder line than in the past and is investigating the Los Angeles Department of Water and Power's Pine Tree Wind Project in the Tehachapi Mountains for the deaths of six golden eagles, which are protected by federal law.

"It's a big wake-up call for the industry in California that the service possibly means business now," says Smallwood. Around 1,000 turbines have been removed from the Altamont Pass since 2008. Preliminary data from wind-farm owners shows that raptor fatalities could have been reduced by as much as 80%.

Reason for optimism

Once data from last year is processed, the industry will know whether selective turbine removal really has made a difference. Smallwood is hopeful as he visits the area every week and has seen birds use the gaps that have been formed by turbine removal.

Better data and science would ensure that solutions are found more quickly, adds Smallwood. Most wind farms in the US either have no environmental-impact monitoring or data is not made public, he complains.

John Anderson, director of siting policy at the American Wind Energy Association (AWEA), says that it is working on a pilot database to make such information public with the American Wind Wildlife Institute, which comprises representatives from the industry and conservation groups. However, he admits he has no idea when this will be ready. Bird deaths are a violation of the US Migratory Bird Treaty Act and wind-farm owners are reluctant to hand over information that could incriminate them.

Despite this, Anderson is adamant that the industry has learnt from mistakes of the past. "When the Altamont Pass was first developed, we really had no idea that there would be a significant impact with birds," he says. "Wind was an emerging technology."

Initiatives in other countries show that there are grounds for optimism that the conflict between conservationists and the wind industry over birds could ease. South Africa's wind market has not yet taken off in a significant way, but it already has a specialist group on birds which in March published best-practice guidelines for monitoring birds and mitigating the impact of turbines. In Germany, the Ministry of the Environment commissioned a series of studies costing EUR2.4 million to investigate the potential impact of future growth of wind power on populations of the protected bird species.


In recent years, the wind industry has gained notoriety for killing another form of wildlife — bats.

The impact of turbines on bats was first noticed in 2004. Most deaths are not caused by collision but by a phenomenon known as barotrauma, whereby the change in pressure between turbines causes their lungs to explode.

In certain locations, barotrauma has caused the deaths of tens of thousands of bats a year. The Bat and Wind Energy Cooperative, which was formed by Bat Conservation International (BCI), the FWS, AWEA and the US Department of Energy, has raised over $4 million to study the impact of turbines on bats and work out solutions.

Operational changes, such as increasing the speed at which a wind turbine starts generating energy from 3.5-5.5m/s, can reduce bat fatalities by 50-80%.

Preliminary results from studies on acoustic devices, which generate ultra-high-frequency sounds to deter bats from turbines show a reduction in mortality by up to 70%.

Additional information - 11 December

AWI has since informed Windpower Monthly that plans are in place to repower its 920 wind turbines in the Altamont Pass, California, and is in discussion with local planning authorities over permitting.

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