In this episode of The Top 3 by E3, Ginger Elbaum, E3's Managing Director, interviews Carol Ho, an E3 Senior Director and environmental engineer, about the impact that wind turbines have on wildlife. Carol provides an overview of the top three ways developers are attempting to minimize harm to wildlife, including:
Carol's article on this topic is available by going to Wind Power and Its Impact on Wildlife: A Look at Current Efforts to Minimize Harm - E3 Consulting. If you are interested in learning more about this subject or would like to discuss mitigation strategies with Carol, please contact her at carol.ho@e3co.com.
In this episode of The Top 3 by E3, Ginger Elbaum, E3's Managing Director, interviews Carol Ho, an E3 Senior Director and environmental engineer, about the impact that wind turbines have on wildlife. Carol provides an overview of the top three ways developers are attempting to minimize harm to wildlife, including:
Carol's article on this topic is available by going to Wind Power and Its Impact on Wildlife: A Look at Current Efforts to Minimize Harm - E3 Consulting. If you are interested in learning more about this subject or would like to discuss mitigation strategies with Carol, please contact her at carol.ho@e3co.com.
Ginger Elbaum (10s):
Welcome to the top three by E3, a monthly podcast about the intersection between engineering energy and project finance. We know that the energy transition from fossil fuel based to renewable energy will help STEM the tide of climate change and benefit all species on the planet. But what happens when renewable energy has a negative impact on certain species, wind turbines harness the free energy of wind, but there are impacts to songbirds Raptors, other birds and bats. This concern grows with the increasing wind energy development that we are seeing across the globe. Today, we are talking with Carol Ho, environmental engineer, about ways to reduce the impacts of wind turbines on wildlife. Welcome Carol.
Carol Ho (47s):
Thank you, Ginger. I wanted to start off by addressing a comment. We often hear if you are so worried about bird deaths, aren't a wind turbines so much less harmful compared to other dangers such as being killed by cats vehicles or flying into windows of buildings. The answer is yes. And while this is true, no owner of a wind farm wants to sacrifice birds and bats for their project, regardless of how many are killed elsewhere. And while the number may be low compared to other dangerous now, as wind farms are built and especially if they are built with no regard for mitigating impacts, those numbers will increase from our experience with clients, project owners and operators who do not want their technology to harm birds and are looking for practical ways to address this issue.
Ginger Elbaum (1m 31s):
So, Carol, what are the most practical ways that have been found so far?
Carol Ho (1m 35s):
Well, in the past lattice towers like transmission towers were used on wind farms, and many of these are now being replaced with the modern monopoles that we are all familiar with. Now, lattice towers attracted birds by offering perching space. So the monopoles are better, but it hasn't solved the problem. The simplest way to minimize impacts to birds when you are designing your wind farm is to site or locate the individual wind turbines properly. Biological surveys are done sometimes for several years prior to development to provide data, to know where there may be sensitive habitat, nesting location and migration routes, and just simply having a biologist study the landscape and point out risks that may not be obvious to the engineers also of importance is to be aware of how operations impact these species and whether there can be minor changes in operations that can significantly reduce risk.
Carol Ho (2m 30s):
For example, that's preferred to fly in low wind. So raising the wind speed when a wind, when a turbine system allows the blades to begin turning called the cut-in speed has resulted in significant reduction in that impacts without sacrificing a lot of electrical production.
Ginger Elbaum (2m 47s):
So once you've cited properly and have your operations optimized as much as possible, what else can be done?
Carol Ho (2m 54s):
Well, companies and researchers have invested significant resources in finding new ways or new to lessen impacts. And that brings us to the first subject, if our top three by <inaudible> for today. First of all, the use of radar to detect approaching birds is tried and true. It has been used for over 10 years now on wind farms and has been largely voluntary. Radar is good at detecting large flocks of migrating birds. Wind farms on the Texas coast were I believe the first to apply this use of radar to wind farms located along migration routes that see thousands of birds each season, it is less accurate at detecting individual, large birds.
Carol Ho (3m 34s):
However, they are becoming more sophisticated and newer systems have seen success with detecting large individuals or smaller flocks of large or small birds. The first systems required a human to respond to the information, meaning someone would need to turn off one or a group of turbines when birds are approaching within a certain distance. Current radar systems can be connected directly to the wind turbine controls to turn them off or on automatically some high-tech products are able to map flight paths and then display it on a 3d maps such as Google earth on a much larger scale software is being developed to identify biological targets versus other flying objects, such as planes from large scale established, whether surveillance radar, this approach could provide significant information by being able to track movements across the large areas.
Carol Ho (4m 28s):
The data could be used to produce models that would help with finding new good locations for wind farms or to improve curtailment protocols at existing wind farms.
Ginger Elbaum (4m 37s):
So, Carol, can you give us an example from work that E3 has been involved in?
Carol Ho (4m 43s):
Sure. In California the California condor has presented a challenge to wind farms in the to Tihachipee Region, which is North of LA. The California condor was near extinction in the 1980s. And at one point there were only 27 left in the world for conservation. The last few individuals were brought into captivity for a breeding program. Some Condors were hand raised until ready for release into the wild. Their repopulation has been successful and their range is expanding. So now there is starting to be some overlap into the wind farm areas. On the plus side, not only our California condor is a very large, most were tagged over the years with a very high frequency or VHF radar or GPS device for tracking this enabled wind farm biologists to be alerted to the approach of a California condor and monitor their movements, curtailing turbines as needed as more Condors are born in the wild though, of course they will not all have GPS wind farms in this location still rely on biologists in surveillance towers to observe and respond to condor and Eagles.
Ginger Elbaum (5m 52s):
Really interesting. So, you know, this does sound like there's still a lot of human involvement in the day-to-day operations. What kind of new technology is the industry seeing?
Carol Ho (6m 3s):
So new technology brings us to our second subject of the top three by <inaudible>. There are several exciting new ideas that are being used around the world that I wanted to share. First, a bird deterrent technology called DT bird was developed in Spain and is being used at about 50 sites worldwide. According to their website, they look like speakers strapped to the monopole towers, aimed up toward the blade swept area. The system detects birds, and then can either make a warning sound or can curtail the turbine. It is designed to distinguish between species and the responding sound can be targeted at specific species. If the birds can be deterred from entering the area, you don't have to curtail and reduce energy production.
Carol Ho (6m 46s):
The issue with the sound is disturbance of non-targeted wildlife and people. If you are near a populated area, a study done on turbines in California, found some challenges with false positives and you don't want extra noise due to a false alarm, but this technology has been used for over 10 years in Europe. So it's improving other researchers are working on directional sound to address the noise issue, directing sound in a narrow beam like light. This is called audio spotlight technology and a product called audio lighthouse is being studied for use at wind firms. Another new technology called identify flight uses cameras on top of their own towers, not the wind towers combined with artificial intelligence software to identify species of birds and curtail turbines as needed.
Carol Ho (7m 34s):
Let's say you're interested in detecting golden Eagles. This system uses a database of millions of images of golden Eagles to match the characteristics of an observed bird to the images along with adding images in real time to further refine its intelligence, the technology can see one kilometer away and respond by curtailing turbines in the same way that radar can. The main advantage of identify flight is its ability to identify individual protected species. It is in commercial use in the U S and over 50 sites worldwide
Ginger Elbaum (8m 6s):
Because those ideas are really high tech. Are there also some more simple ideas like regarding tower design that could also have positive effects or, you know, what about tower height or different color paints?
Carol Ho (8m 18s):
Yes. There are also studies regarding basic design. Researchers are studying different paint colors since light colors, attract insects, yellow, white, and gray were the most attractive and darker colors, less. So a recent study in Norway found reduced bird fatalities by painting one of the three turbine blades black, but darker colors may have other issues such as heat thinking beyond the pinwheel spinning blades that we are all familiar with, which are called a horizontal axis, wind turbines engineers have been experimenting with new designs. One that is teardrop shape, for example, and spins on a vertical axis. But these designs have not had the decades of field experience and improvements.
Carol Ho (8m 59s):
And so it's hard to know their impacts on wildlife. And then what affected turbine tower, height and blade length have on wildlife? Some studies have shown that a higher hub height and smaller blade lengths have reduced impacts on birds. Although other studies have not found this to be the case.
Ginger Elbaum (9m 17s):
So Carol circling back to the intro, you mentioned bats are the same technologies for birds going to prevent impacts to bats as well.
Carol Ho (9m 27s):
That's require a different approach for study and protection. And this brings us to our third topic for today regarding sighting it's been found through experience that biological surveys prior to development may not identify risks locations that did not show a lot of bat activity. Prior to construction have been found to have increased activity. Once the turbines are in place, it appears that bats are attracted to the turbines. For some reason, it's been speculated that that's mistake the monopoles for trees and come looking for food. It's also possible that the multiples actually do attract insects, that the bats come looking for. That's used sound waves for identifying objects and navigation called echolocation.
Carol Ho (10m 9s):
And it has been hypothesized that their sense of echolocation may not detect the moving blades. Once they're in close proximity to the spinning blades, the sudden and extreme change in air pressure could burst air pockets in the body. This is called Baro trauma. A study in 2008, found that more than 50% of the dead bats had internal borrow trauma without any signs of impact at a particular site. But a later study by NRL was not as conclusive and indicated that bats are in fact being struck by the blades. In either case, the challenge is keeping bats away from the turbines. The company that developed DT bird also is developing DT bat.
Carol Ho (10m 50s):
The system identifies the presence of bats by recognizing their ultrasound then can curtail the turbines to prevent impacts researchers at various organizations and private companies have developed technology to deter bats from approaching wind turbines, using what we know about echolocation, the systems, the emit and ultrasonic acoustic field in the same range as bats, natural frequencies, but louder. This effectively jams the airwaves and the bat's ability to hear its own echoes. The goal is to discourage bats from entering the airspaces being treated with these unnatural sound waves. A study in Texas used such a product to buy energy systems and found reductions in bat deaths from 50 to 80%, depending on the species of bat, based on the success of the study, the wind farm owner decided to install the systems on 255 of its turbines at that <inaudible> wind farm the first commercial scale installation in the continental us.
Ginger Elbaum (11m 50s):
Interesting Carol, thank you. There is so much here.
Carol Ho (11m 54s):
More information than what I've touched on here. And for people who are interested to learn more, you can check out the Department of Energy's Wind Energy Technologies Office website. They summarize the many studies being done to develop innovative technologies and lower costs to accelerate the deployment of wind energy throughout the country, check out the category called environmental impacts and siting of wind projects. The DOE invest toward these goals through cooperative agreements with companies, universities, laboratories, and other organizations. Looking through the current projects these days, you will notice that the focus has really shifted to offshore wind development. I'm sure we will see some of the technologies discussed here applied to offshore wind farms.
Ginger Elbaum (12m 37s):
Carol, thank you so much again for the topic. I think it's, it's fascinating and thank you all for listening and we hope you enjoy today's topic. If you have any questions for Carol regarding mitigation measures or other environmental topics, please reach out to us at e3@e3co.com. Okay.