Birds, Bats & Wind Turbines, a presentation by Robert Stribley for Professor Kara Allen's class Energy & the Environment for NYU's Global Affairs Certificate program. As presented April 26, 2021.

1. Energy & the Environment
26 April 2021
Birds, Bats & Wind Turbines
Robert Stribley
A trained falcon, equipped with GPS and a very high frequency
tracker, gathers data that helps scientists improve bird
detection technologies at wind facilities. – NREL.gov
Photo: Jason Roadman, NREL

2. Impact
What’s the harm to bird and bats from wind
turbines?
• Deaths caused by contact but also changes in
air pressure (barotrauma), disruption to habitat
• 3 studies using figures from 2012 placed the
number of death in the U.S. at figures
averaging 234,000 to 573,093 that year
• Overall estimate: 366,000 birds killed by wind
turbines in 2012
• Considering megawatt growth in wind energy,
it’s projected that ~681,000 birds are now killed
by wind turbines in the U.S. annually
• However, one study suggests dogs find many
fatalities humans don’t, so numbers may be as
high as 1.7 million per year
• Displacement of birds from grassland habitats
has been argued but not conclusively proven:
Changes may be temporary during
construction and species return afterwards
Photo: Pembina Institute

3. • 2013 Wildlife Society study estimated 888,000 bat
fatalities per year
• Widespread fatalities of hoary bats could reduce
the population by up to 90% within 50 years, 50%
with no new turbines
• Wildlife biologists have determined bat fatalities
highest during autumn migration, nights with low
wind speeds
• Some bats are attracted to wind turbines,
increasing risk of impact to the population
Impact
Photo: Pembina Institute
Dead Hoary Bat Near Wind Turbine
Photo: Michael Schirmacher

4. • Studies in Canada, UK, Poland
and Norway reveal similar figures
• Canadian wildlife groups
estimated wind turbines killed
23,300 bird deaths in 2011
• They estimated this would rise to
233,000 over 10-15 years
• All these preceding figures
presumably increase as wind
turbines become more ubiquitous
• Additional impacts …
• Land use, disturbance, forest
clearing
• Fish and marine wildlife (also
argued they increase fish
populations via reef formation)
• Sound and visual impact to
public health and community
Impact
Photo: David McNew/Getty Images

5. Context
• Bird death figures from the American Bird Conservancy:
• 6.5 million collisions with communications towers
• 25 million collisions with power lines,
• 300 million collisions with windows
• 1.4 to 3.7 billion killed by cats
• Also via habitat loss, pollution and climate change
• Given 20 times more wind turbines, enough to supply the entire
US, the number of birds killed, assuming no design improvements,
would be ~10 million—still far less injurious than most other
causes of bird deaths
• National Wind Coordinating Committee (NWCC) concluded
impacts are relatively low and don’t endanger species populations
• Conservationists, such as the Sierra Club, argue wind remains a
safer alternative than oil, coal and nuclear
The Smoky Hills Wind Farm –
Drenaline, Wikimedia Commons

6. The Mountaineer Wind Energy Center
Case Study
Backbone Mountain, near Thomas, West Virginia, 2003
Owned and operated by Florida Power & Light (FPL)
Biologist Keith Lott hired to look for birds killed by
turbines.
Instead, he found nearly 400 red bats, eastern pipistrelles
and hoary bats.
He and fellow biologists determined this site was killing
1,400 and 4,000 bats a year.
Fish and Wildlife Service had issued siting guidelines the
previous summer: Suggested a wildlife census before the
wind farm was built.
Some biologists believe these studies should last 2 years,
but some energy companies believe that’s too long.
Guidelines are voluntary: F&WS can’t enforce them unless
endangered or threatened animal are killed.
Mountaineer Wind Energy Center
Photo: Gypsy Road Trip

7. Consequently, wildlife advocates became concerned that
another species, the endangered Indiana bat affected at
another FPL property in Meyersdale, PA.
They threatened legal action, saying the appropriate studies
weren’t done before construction began. Industry biologists
agreed, saying the site was a flight path for the bats.
At the time, FPL pushed back at the time, saying they needed
more data.
However, this incident drew significant attention to the issue
of bat deaths and contributed to it being recognized as an
international problem.
In 2007, Biologist Edward Arnett testified before Congress on
the impact of Mountaineer and similar sites, as did the lawyer
Eric Glitzenstein, on behalf of several conservation non-
profits.
Studies by Arnett and others lead to suggest small changes,
which significantly reduced bat deaths (ranging 44%-93%)
with little loss to power generation (~1% annual output).
Mountaineer Wind Energy Center
Photo: Gypsy Road Trip

8. Solutions
How is the issue being addressed?
• Location: Better siting of wind
turbines around bird and bat
habitats
• Pre-development research to
understand the habitat
• For example, fliDAR (Floating
Light Detection and Ranging)
buoys track weather but also
appearance of birds and bats,
noting protected species
• Digital area surveys – Count and
log animals to understand
populations and their sizes
A technician calibrates equipment
on a meteorological buoy
Photo: Avangrid Renewables

9. Solutions
• Curtailment: “Feathering” turbines and raising cut-in
speeds during high-risk periods. Arguably, cost prohibitive,
limits energy generation
• Radar: Detects when birds are approaching
• GPS tracking for larger birds
• Placing marine turbines further out helps reduce damage
as animal density goes down
• Turbines remaining motionless during low winds reduces
bat deaths
• Painting turbines different colors reduces “motion smear”
• 11-year trial in Norway up to July 2020
• After painting one blade black, 4 trial turbines killed 72%
fewer birds
• Audubon called the study promising but cautioned that 4
turbines painted is a very small sample size
Wind turbine at Smøla wind‐power
farm with painted blade
Photo: Roel May

10. Solutions
• Strike detection: Blade slows upon
striking a bird or bat to reduce
additional strikes
• Larger turbines kill fewer raptors
due to their slower rotation
• Ultrasonic microphones can detect
high-pitched bat squeaks and shut
turbines down
• Acoustic deterrents emit high-
frequency sounds to prevent bats
from approaching turbines
• Study showed such deterrents
reduced bat fatalities for two
species by 78% and 54%
Birds fly past Lake Ostrowo Wind Farm
in Poland. Photo: Wind Denmark

11. Solutions
Identi-Flight
System identifies
eagles, shuts down
wind turbines when
they come too close
Study compared the
number of eagle
fatalities at
Converse County
wind farm to a
nearby one without
Identi-Flight
They found deaths
decreased 82%
where Identi-Flight
was used
Photo: Todd Katzner/U.S. Geological Survey

12. Solutions
Alternative Turbine Shapes
No blade turbines
“His 90-foot-tall device could create the same amount of power as a
1.8-megawatt commercial wind tower, but at a third of the height, on
a seventh of the land, and with a turbine more than eight times
smaller in diameter.”
Daryoush Allaei designed
the Invelox

13. Conclusion
• Well-documented, generally agreed-upon issue
• Little debate except for specifics about the long-term impact upon bird and bat habitats
• Still, local opposition in many cases, as well as opposition from some environmentalists and
traditional energy companies
• Incorporating known solutions so far has reduced deaths significantly
• Understanding this and context of damage from traditional energy resources will likely reduce
opposition
Recommendations:
• Adequate time should be given for studies, which may mean delays in development
• But eventual solutions themselves need not be costly
• Simultaneously, we should continue look at technological solutions, which further reduce deaths
• Fortunately, some of these solutions also lead to turbines producing energy more effectively,
having a positive impact upon the broader energy system

14. Bats & Wind Energy
https://www.batcon.org/our-work/research-and-scalable-solutions/wind-energy
Bats and Wind Energy: A Literature Synthesis and Annotated Bibliography
https://pubs.usgs.gov/of/2012/1110/OF12-1110.pdf
Can Painting Wind Turbine Blades Black Really Save Birds?
https://www.audubon.org/news/can-painting-wind-turbine-blades-black-really-save-birds
Can Win Power Be Wildlife Friendly
https://www.smithsonianmag.com/science-nature/can-wind-power-be-wildlife-friendly-
55741932
Comparing Bird and Bat Fatality‐Rate Estimates Among North American Wind‐Energy
Projects
https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/wsb.260
Environmental Impacts and Siting of Wind Projects
https://www.energy.gov/eere/wind/environmental-impacts-and-siting-wind-projects
Environmental Impacts of Wind Power
https://www.ucsusa.org/resources/environmental-impacts-wind-power
Fatalities at Wind Turbines May Threaten Population Viability of a Migratory Bat
https://www.sciencedirect.com/science/article/abs/pii/S0006320716310485
For the Birds (and the Bats): 8 Ways Wind Power Companies Are Trying to Prevent Deadly
Collisions
https://grist.org/climate-energy/for-the-birds-and-the-bats-8-ways-wind-power-
companies-are-trying-to-prevent-deadly-collisions
Hope for Stemming Wind Energy’s Toll on Bats
https://www.nationalgeographic.com/animals/article/100915-energy-wind-bats
Bibliography
How Many Birds Are Killed By Wind Turbines?
https://abcbirds.org/blog21/wind-turbine-mortality
How New Technology Is Making Wind Farms Safer for Birds
https://www.audubon.org/magazine/spring-2018/how-new-technology-making-wind-
farms-safer-birds
Look Ma, No Blades
http://vault.sierraclub.org/sierra/201303/innovate-wind-turbines
New Wind Turbine Technology Prevents Eagle Fatalities
https://www.wyomingpublicmedia.org/post/new-wind-turbine-technology-prevents-
eagle-fatalities
The Power Environment: making wind turbines work for birds and bats
https://www.power-technology.com/features/wind-turbines-birds-bats-fatalities-nature-
protection-conservation-power-environment
Ultrasonic Acoustic Deterrents Significantly Reduce Bat Fatalities at Wind Turbines
https://www.sciencedirect.com/science/article/pii/S2351989420301827
When Blade Meets Bat
https://www.scientificamerican.com/article/when-blade-meets-bat
Wind Turbines and Birds and Bats
https://www.sierraclub.org/michigan/wind-turbines-and-birds-and-bats
Wind Turbine Interactions With Wildlife and Their Habitats
https://www.energy.gov/sites/default/files/2015/03/f20/AWWI-Wind-Wildlife-
Interactions-Factsheet.pdf
Wind Turbines Mean Trouble for Birds, Bats
https://www.oleantimesherald.com/news/wind-turbines-mean-trouble-for-birds-
bats/article_61230044-9a89-53c3-8de4-9ad037328a69.html

15. Thank you