The global wind energy industry is rapidly expanding, with more turbines installed in different parts of the world.
Unfortunately, one major issue associated with this development relates to bird collisions caused by turbine blades.
Migratory birds are particularly vulnerable due to their long-distance flights; thus, we must understand why these accidents occur to develop effective strategies for avoiding them.
Investigating the contributing factors leading up to a bird colliding with a wind turbine can be instrumental in preventing future incidents from taking place.
Here are a few contributing factors to be considered:
1. Attraction to Turbines as a Source of Food
Wind turbines have been observed to attract birds due to the presence of insects, such as bats.
The environment created by wind turbines is favorable for insect growth and can thus provide a source of food for avian species.
Studies suggest that an increased number of insects around turbine sites corresponds with an elevated risk of bird collision incidents at these locations.
2. Attraction to Turbines as a Source of Habitat
The American Bird Conservancy (ABC) conducted a study that determined that wind turbines attract birds due to the presence of suitable habitats.
These structures mimic natural features such as trees or cliffs, making them desirable locations for bird habitation and increasing their risk of collisions with the turbine blades.
The findings suggest that areas in shortage of suitable habitats are more prone to higher rates of bird-turbine interactions.
3. Confusion Caused by Lighting on the Turbines
Wind turbines may attract birds due to confusion caused by lighting.
Avian species, especially nocturnal ones such as bats that rely on light cues for navigation, can mistake the lights on wind turbines for stars or other natural illumination sources and consequently fly into the turbine blades.
A study revealed that bird collisions with wind turbines are more likely at night when they’re lit up by artificial lighting than during daylight hours.
Migratory Routes and Weather Conditions: Key Factors in Wind Turbine Bird Collisions
Wind turbines present a risk of bird collisions, which can cause injury or death.
Migratory species are particularly vulnerable due to their extensive flight ranges and may be more likely to collide with wind turbine blades.
To reduce the effect on avian species, we must comprehend two critical elements:
1. Migratory Routes
Migratory routes substantially impact the likelihood of collisions between wind turbines and birds.
Birds that migrate long distances are more vulnerable to colliding with wind turbines due to their reliance on established migratory paths.
A prominent example is the eastern North American flyway, which numerous bird species use for spring and fall migration, but also encompasses many existing wind energy facilities.
Consequently, avian populations utilizing this route are significantly exposed to collision risk from nearby turbine structures.
2. Weather Conditions
The weather can have a significant impact on bird collisions with wind turbines. poor visibility, such as fog or low cloud cover, decreases birds’ ability to detect the turbine blades and avoid them.
Furthermore, strong winds may push birds into the path of spinning blades.
This is especially worrisome for migratory species that traverse long distances since they are more at risk of colliding with turbines during their journeys.
A study by NREL in the Great Lakes region revealed an increased probability of bird strikes when conditions included impaired visibility (fog/low clouds) and high-speed winds, respectively.
Preventing Wind Turbine Bird Collisions: Efforts Being Made to Protect Avian Populations
It is essential to analyze existing protective measures implemented and evaluate their effectiveness. Potential strategies for decreasing bird-turbine interactions include:
1. Shut Off Protocols During Migration Seasons
The U.S. Fish and Wildlife Service (FWS) has recommended that wind energy developers implement shut-off protocols during migration seasons to prevent bird collisions.
This strategy involves shutting down the turbines at certain times of the year when bird activity is most likely, such as morning and evening hours during spring or fall migrations seen across the Great Lakes region.
The FWS also provides guidelines for minimizing impacts on birds by avoiding the construction of turbine sites near high concentrations of conservation concern species or other important avian areas.
2. Use Radar Technology
Wind energy companies are incorporating radar technology to detect birds in the vicinity of wind turbines and thus reduce bird collisions.
The utilization of such systems allows for shutdown protocols when nearby birds are detected, minimizing potential risks associated with a collision.
Additionally, combining these detection systems alongside shut-off procedures further increases safety measures against any possible harm to avian species.
3. Implement Insect Management Strategies
We should implement an effective insect management strategy to reduce birds’ attraction to wind turbines.
This can include using pesticides or installing bat-friendly turbines that deter insects from gathering around them.
These measures could effectively minimize bird visits and optimize turbine operations in the long run.
4. Providing Alternative Sources of Habitat
Alternative habitats must be considered when selecting suitable turbine sites to minimize the likelihood of bird collisions with wind turbines.
We can help divert birds away from hazardous areas and potential threats by offering appropriate environments close to such infrastructure.
5. Using Motion Activated Lighting Systems
Finally, wind turbine operators can reduce confusion caused by lighting on turbines at night by implementing bird-safe, motion-activated systems.
These specialized lights use red or amber colors, which are less visible to birds and only turn on when necessary.
This effectively minimizes the potential for avian disruption and ensures a safe environment for all involved.
The efficacy of current methods for mitigating bird collisions with wind turbines is a subject of debate.
A study by the National Renewable Energy Laboratory (NREL) indicated that shutting down turbines during migration seasons in the Great Lakes region did not lead to statistically significant reductions in bird collision events.
Contrarily, research conducted by the American Bird Conservancy (ABC) found that implementing shut-off protocols during migratory periods resulted in a notable decline in such incidents compared to data from before implementation.
Additionally, further improvements were observed when combining this measure with radar technology designed to detect birds near turbine blades.
Proposals for further measures, such as retrofitting existing structures with deterrents and designing new models less likely to cause harm, have been made.
However, until now, there has yet to be any conclusive evidence that these approaches would effectively prevent bird impacts on large-scale installations.
Consequently, additional studies are required to advance our understanding of this issue and develop solutions applicable across multiple projects within renewable energy industries worldwide through standardized metrics used for measuring and reporting incidences involving migrating fauna impacted by wind power operations.
Reference:
- Can wind turbines and migrating birds coexist? | Phys ORG – https://phys.org/news/2022-04-turbines-migrating-birds-coexist.html
- Julie Craves explains why so many birds fly into wind-turbine blades – Bird Watching Daily – https://www.birdwatchingdaily.com/beginners/birding-faq/julie-craves-explains-why-so-many-birds-fly-into-wind-turbine-blades/
