Many of us hope that alternative energies will replace oil consumption before the world collapses in mayhem.
Wind power is highly promising, but of course it presents a significant danger to birds because wind farms are sited in major wind alleys, which more often than not correspond with primary migration routes.
One wind farm in southern Texas (Peñascal Wind Power Project, just south of Kingsville near Baffin Bay) claims it has the technology to protect migrating birds from wind turbines. The system is equipped with radar sensing equipment that can “detect” flocks of birds up to four miles away, pinpointing their altitude and density. When this happens, the turbines are shut off, thereby granting safe passage to the birds.
I first noticed a blurb on this in OnEarth online magazine. Many questions came to mind:
* Is the radar-detection system (hailed as that in use by NASA and the U.S. Air Force) efficient at detecting migrating flocks? What are its limitations?
* What ornithologists were consulted in the planning?
* By golly, will this really work?
So I did some digging and found an older PR document that says extensive wildlife surveys were done prior to construction of the farm. In fact, they say “for three years, third-party wildlife biologists spent more than 4,000 hours in the field studying the site and avian patterns during a wide variety of weather conditions.”
That’s a good start. What did they learn? This 2005 study, called the Peñascal Wind Farm Avian Risk Assessment, was compiled by that avian & wildlife team, which included: zoologist Glenn Perrigo of Texas A&M, Jim Sinclair, president of Texas Environmental Services & Analysis, physicist Robert Bensen, statistician Margaret Land, biologist David Chruhm, and Brush Freeman.
The study concluded that:
* Although the region is a significant wintering area for many ducks, geese, and shorebirds, and 80% of the world’s Redhead population winters in the Laguna Madre, virtually NO Redheads and few ducks and geese were observed in their “wind resource study area.”
* Although the Coastal Bend area is significant for Broad-winged Hawk migration in fall, significant impacts are unlikely. Hawks avoid large bodies of water. No Broad-winged Hawks were seen in the the study area in 2004.
* Although the region is significant for migrating Mississippi Kites, White Pelicans, and Franklin’s Gulls (among other many large, diurnal species), no significant effects are expected because these species tend to avoid migrating over the open prairie.
Well, all this sounded convenient and rosy. So I contacted Glenn Perrigo to see if he could elaborate.
Perrigo said his team has been studying the 250,000-acre site for more than four years. After spending hundreds and hundreds of hours on site, logging 10-15,000 miles groundtruthing the property, and making systematic point counts along transects during all hours of the day and night, Perrigo confidently says that there is “a surprisingly low risk for bird mortality” associated with this wind farm.
What? Isn’t the wind farm placed smack dab in the middle of a migration flight path? Well, yes. This region is in a flyway, but that characteristic is exaggerated for this parcel. First, many migrants are “trans-Gulf,” which means they cross over the open Gulf, perhaps between Galveston and the Yucatan. Those that are “circum-Gulf” migrate along the perimeter and may be of greater concern. But that’s where habitat comes into play.
Migrating birds almost always seek forested stopover sites and flyways rich in forested cover. In this region of Texas, the most favored habitats are stands of Live Oak in the middle of prairie, called “mottes.” Birds, weary from migrating, have been known to “drop straight down” from the sky into these mottes. Protecting mottes and a reasonably sized buffer zone around them is therefore crucial.
However, the area under study is a highly disturbed short-grass prairie with little to no trees. The researchers saw very little migrant activity through the property, and thus, the conclusions of this study were made.*
When the wind farm company began construction of the wind farm in Spring of 2008, “they paid attention to our initial findings when deciding where to site the turbines. To their credit, they avoided areas of high avian risk,” says Perrigo. The turbines began spinning in April of this year.
The avian risk assessment team is contracted to do post-construction surveys to determine if their predictions of little to no avian risk are correct. The data should be available in another year or two.
UPDATE: On June 12, 2010 a flock of 15 American White Pelicans flew towards the wind turbines and the blades did NOT shut off. At least one pelican was killed before a birder’s eyes. You can read that account at birdingonthenet.net. Isolated incident? Or not? [Thanks to reader Noflickster for that bit of information].
As this story broadened, it became less about the bird-sensing radar technology and more about proper turbine siting within a flyway. At first blush, it doesn’t seem this wind farm will give us a proper test of the radar technology because no birds are expected to near its blades.
So as the data comes out, we need to be sure to attribute “little to no avian deaths,” (should that be the case) to its proper cause, which under fuller examination may be proper siting rather than the more intriguing flock-sensing radar technology.
Proper siting within a flyway.
According to this example, with data collected so far, it is possible to erect wind farms in migration flyways AS LONG AS you do extensive bird and wildlife surveys IN ADVANCE of the construction and FOLLOW THEIR RECOMMENDATIONS upon siting the turbines. That in itself is encouraging.
In April, 2009, the same company, Iberdrola, received approval for a 30-MW wind farm project in the Green Mountain National Forest of Vermont. Will they employ the same pre- and post-construction biological surveys? Will they site the turbines in low-risk areas? Will they employ this radar technology? Hopefully the people of Vermont will demand this be so.
Two things I know: we (most readers of this blog) care about birds and the environment. And as environmental advocates, we need to be open to change in the way energy is produced. Whether or not radar technology is a solution to the bird mortality issue is yet to be seen. But if a wind farm is being proposed in your corner of the world, demand that it be properly sited within the flyway, which requires extensive pre-construction studies.
Share your comments and opinions about this project in the comments.
Also, please see the interview with Bill Evans, avian tower kill authority.
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* Perrigo was quick to point out that his conclusions extend only to the wind resource area that his team studied. What’s known as the Kenedy Ranch is actually two contiguous properties: one 250,000-acre belonging to the Kenedy family trust, and one 250,000-acre parcel (Kenedy Foundation Ranch) belonging to the Catholic Dioceses. A wind farm now exists on both properties but the projects were studied, sited, operated, and reported on separately. Perrigo surmises that conclusions for the other property will likely be different. Based on this document, I can see why. The Kenedy Foundation Ranch features varied habitats including over 40,000 acres of oak woodlands. Obviously, the plot thickens and the story ain’t over.
For more information:
PR Fact Sheet prepared by the company, Iberdrola
Short article on the Renewable Energy Development Web site.
The Peñascal Wind Farm Avian Risk Assessment summary (2005)
A cynical view on tax implications of the wind farm offered by the President and CEO of the über-famous million-acre birding hotspot, Jack Hunt of King Ranch (back in 2006).
Hatfields vs. McCoys got nothin’ over King Ranch vs. Kenedy Ranch
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{ 14 comments… read them below or add one }
Interesting post and comment on an issue that is a big one across the developed world and is likely to be a global issue ten years from now. I haven’t read all the background material yet but it’s bookmarked to come back to. This certainly shows that we should all be lobbying for in depth studies pre-siting of wind farms. If the detection radar works then it should become a pre-requisite on any wind farm planning application, a must have rather than an optional add on.
You’re right. Heard some murmurs on Facebook that such radar technology may already be in use in the MIddle East. Will have to check into that.
Another interesting thing about this wind farm is that the private ranch it is sited on is so large, that it gets lost inside the property and one can barely to not at all see it from the road.
Would love to hear from someone closer to the “other” side of Kenedy Ranch about avian risks….
My company is the developer and manufacturer of the bird radar used at the Penascal wind farm (the MERLIN Avian Radar). The technology was developed by a team of avian biologists and radar engineers. The USAF and NASA use the technology essentially as an “air traffic control radar” for birds to prevent bird-aircraft collisions which as a major safety risk for the Air Force (each year costing over $500 million in damages plus the loss of several aircrafts with occasional crew fatalities) and have done extensive validation of the system. The system can reliably detect bird flocks as far out at 10 miles. There are about 54 MERLIN systems operating in the US, Canada, Europe, Africa and New Zealand at present in aircraft-birdstrike avoidance, for wind farm avian survey and for bird control (keep birds from landing on large contaminated industrial waste/product ponds). The technology is used by several universities and research organizations that include Texas A&M Kingsville Texas, the US Geological Survey, the Birtish environmental agency (fera), the Norwegian Institute of Nature Research, the University of Aberdeen, etc.
The Penascal and adjacent Gulf Wind I wind farms in Texas are the first use of the technology at wind farm anywhere in the world s for bird mortality risk mitigation. Up until these wind farms, the system has been used at wind farms to conduct bird and bat surveys to supplement field biologist observations. You can read a technical paper on the curtailment as well as how the system is used for pre-construction survey and risk modeling at http://www.detect-inc.com/wind.html (see the sidebar to the left).
As good as we believe that our technology is, it is not the “silver bullet” and is just another tool in the biologist’s tool box (a very good one in my opinion). It does not replace, but enhances the field biology work allowing the biologist to “see birds” farther, in all directions and continuously (and at night and in rain when the biologists are effectively blind), providing much more detailed datasets to assess the risk posed by a project.
You are right on the mark in saying that “extensive pre-construction studies” are needed for wind farms and in the U.S., this is not always done (we tend to survey for a few weeks in the spring or fall and not year-round … as is done in Europe based on my experience). There is a shift underway however in the US and we are seeing more developers (like Iberdrola and Babcock & Brown did on these Texas projects) commit to extensive field biology with supplemental use of advanced avian radar technologies to better understand the environment and risk.
Gary, thanks for writing.
Obviously, birders are interested in the use of this technology not only for its wind-farm potential, but for “air traffic control” to prevent aircraft collisions. It would be nice to see it put to widespread use on the latter before Bloomberg blows up every Canada Goose on the Eastern seaboard.
I’m curious about how confident you are that the system can both sense an approaching flock and manage to turn the blades off fast enough?
It’s almost too bad that Penascal won’t give us a fair test of this technique. Will we be seeing it in more wind farms? Can it be installed after the wind turbines are constructed?
And then the big question, what needs to happen in order for more companies to invest in these pre-construction studies, studies that will help them avoid the possible future costs associated with mitigating severe avian impacts? Can/should birders be part of this movement? How?
Interesting post about an extremely important subject. I’m glad Gary added so many details and information about MERLIN and promises of radar as a tool available to conservation biologists.
As someone who spends much of the diurnal part of the day studying what migrating birds do at night (by way of acoustics) , that “report,” apparently a Powerpoint presentation turned document, raises a lot of questions for me. Perhaps there was much more meat in the way of numbers presented in the accompanying narration?
A few things I wonder about:
Though radar is a promising tool to warn of incoming masses, is merely stopping the blades in response to a heavy night of migration (which the Texas coast sees more than its fair share of) sufficient? That makes it sound like the only problem is the blades slicing the birds, but that ignores the structure itself. Communication towers don’t move but claim millions of avian lives each year; wouldn’t wind turbines produce the same result?
Based on that report I don’t buy the argument that circum-gulf migrants avoid this area because there isn’t suitable stopover habitat below. That may make sense for birds landing or taking off, but wouldn’t nocturnal migrants that are already aloft stream through the farm regardless of what habitat is below?
They acknowledge that “night traffic is still problematic,” which should be a huge red flag.
With those questions raised I think you emphasized the right key points. We should certainly be investigating as many potential alternative energy sources as possible and wind should certainly be one of them; siting wind farms at suitable locations should be a necessity, and that’s a process that requires intense pre-construction study and equally intense post-construction follow-up. And these studies should, as Gary mentioned, utilize all the tools available.
Speaking of which, I wonder if the formal report is available (I haven’t been able to find it). It would be interesting to find out what they did observe in the area in addition to what they did not see. Of course, I’m also curious in how they handled their acoustic data and arrays. That is not a trivial undertaking and I’d love to know their methods (not to mention the results).
-Mike
I must rely on the experts for the bottom line on each, but I will try to address a few:
Aren’t still turbines are just like cell phone towers in their impact on avian mortality? If I understood Perrigo correctly, he said that studies show that birds migrate at much higher altitudes than the blades (perhaps MERLIN was employed to test this?). Which begs the next question: are cell phone towers much higher than these turbines?
The Powerpoint conclusions: is there a formal report with more meat? That’s what I was hoping to see. I asked Perrigo if there was a final report and he said there wasn’t one available, at least not online or where I could see it. Much of the data is still proprietary. That said, he described the exhaustive surveys that were done by members of the team, using a variety of field and remote techniques, and suggested that it’s his very well-educated opinion that there just are not many birds at risk. If pressed to estimate the # of bird deaths caused by the blades, his educated guess is approximately 3 deaths per turbine per year.
I’m sure Glenn would welcome your interest in the survey techniques. BTW: he told me he was an original founder of the Rochester Birding Assoc. back in the day. I’ve sent my blog link to him and invited his input.
To answer the questions posted …
To Laura’s comments/questions:
- We can stop the turbines within 1-2 minutes if required (emergency shutdown), but an orderly shutdown is better for wear and tear on the turbines and takes 3-5 minutes. The detection range settings can be set in the system and were designed to allow ample time for an orderly shutdown based on the data developed over nearly three years of pre-construction radar data available for these sites (the only year long + 24-7 radar survey done in north America to date to my knowledge).
- Since Iberdrola and B&B announced their commitment to radar-based curtailment there has been a lot of interest from wind farms worldwide. The USFWS has also been briefed at every step in the development of the methodology and is very favorable to the risk mitigation strategy.
- The technology can be added to any wind farm even after construction. we do have to develop data on how the birds are moving in the area in order to define the risk “threshold” levels and other factors that define when curtailment occurs. Ideally we need a full year or 26 months of 24-7 data to fully understand the bird movements and possible responses.
- The stakeholders (birders, et al) were very important in the way these projects were developed as I understand it. Both developers were sensitive to the value of the resource area to birders and committed to extensive studies prior to construction that went so far as to influence where turbines were actually placed. Babcock & Brown purchased the radar in 2006 and collected over two years of pre-construction radar data and committed early on to installing the radar as a risk management system coupled to the wind farm control system. The model both developers used here is more like what we see in our european projects … extensive, detailed, year-round studies in advance.
To Mike’s:
- You are correct in that the stopped turbine does still present an obstacle however the turbines will be stopped to minimize the frontal surface and present the lowest surface area.
- We do use acoustic sensors also in conjunction with our radar and have worked with Cornell, Boston U and other to integrate a variety of sensors. Again, radar is another tool, but alone is not the panacea.
- As far as the other issues you raise or availability of data/reports, we provided on the radar portion of the work so I cannot comment on these.
It’s possible that weather events could force the birds downward, placing them in danger of the turbines (I believe they are 400′ tall). Could red lights help mitigate that?
To your point about birds migrating over the farm in the dark, regardless of the habitat below. I can’t speak for data I haven’t seen, but those involved say the tens of thousands of data points they collected show surprisingly low risk in this area. Hopefully we’ll see more conclusions from this site (and from the adjoining Kenedy Foundation Ranch site–dig, dig, dig).
There seems to be some promising technology and practices here. Obviously, wind power does not pose a NO AVIAN RISK situation. But nothing is risk-free in the energy business. It’s all a matter of degrees.
Bird watchers are an important lobby group on this issue (there’s 48 million of us, right?). We need to be awakened to both the possibilities and the risks associated with wind farms. We need to make ourselves an informed majority. And we need to put pressure on the industry to conduct pre-construction studies.
This also underscores the importance of ongoing citizen monitoring of birds. We never know when the birding data we collect can be used to help demonstrate the ornithological significance of an area, which may be needed to placed added pressure for pre-construction studies.
Get, thee, to eBird…(ebird.org)
I also wonder: why is the US so far behind Europe in these pre-construction studies? Wait, I don’t want to hear the answer…
Awesome article and research, thanks to each poster for the continued discussion. Having done lots of ground monitoring when they were considering a wind turbine on Mt Pleasant Rd, I appreciate how hard it is to assess a site. This new technology sounds really promising, I’m grateful that it is being developed. Wind and solar need to be ramped up as quickly as possible if we are to save our world as we know it!
Before my overarching points get lost:
- I am all for alternative energy development, and I’m encouraged to see the more cautious approach taken (illustrated by this study) that appears to be underway in siting locations and mitigating collisions. As I mentioned, siting the locations properly is paramount to that end. Of course there will be risk, and I’m glad to see efforts underway to minimize it.
- To that end I am excited by the collaboration among scientists, academics, industry and government to address conservation issues around wind farms, and the use of several different tools to achieve them – radar, acoustic technology, etc.
- The study you focused on is admirable in its breadth and depth to assess and minimize potential environmental impacts, something lacking in many earlier studies (e.g., single-season data collection). My only issue is that the presentation seemed a bit light in presenting results and the data that support them. Simply put, I would like to see more numbers that support the conclusions, especially in a heavily traveled migration corridor like the TX coast.
- And as long as you bring up Citizen Science, preach it, sister! It’s not the final say, but it can be an essential first step to uncovering trends and patterns, focusing our questions, and collecting an amount of data no single research group could gather on their own.
- That is all.
-Mike
Laura, great post; thanks! You quoted the report as saying:
“Although the region is significant for Broad-winged Hawk migration in fall, no significant impacts to these hawks are expected because hawks tend to migrate over open water, not land.”
That’s not correct.
Soaring birds (raptors, vultures, storks, etc.) use thermal updrafts for lift during migration, which requires landmass. While some individuals will make large water crossings, most do not. The more than half-a-million Broad-winged hawks and Swainson’s Hawks that migrate right over Corpus Christie (which is just north of the wind farm) each year are circum-Gulf migrants, meaning they follow the coastline from TX into Mexico, and continue south into Central and South America.
I’m not saying that the wind farm would have direct impact, I’m just saying that whoever wrote the conclusions in the report is at best ill informed about hawk ecology, and given the scope of raptor migration through that region, should reconsider whether the project poses a threat to them.
Cheers
David
I appreciate all your comments on this topic.
David, I’m glad you pointed that out — I went back to the original document and see that it was MY interpretive error, not the scientists’. So I eat my words and offer the exact verbiage instead:
Is there a concern about Fall hawk migration in the wind resource area?
• Unlikely. Hawks avoid large bodies of water. NO Broad-winged Hawks were seen in the Wind Resource Area in 2004.
Researchers said that most hawks passed west of the study area and tend to avoid the open prairie.
The issue Noflickster brought up about turbines with still blades being just as dangerous as cell phone towers is a good one. I feel some more research coming on…what are the best practices in this field?
Two quick things (which shouldn’t be quick, but you know . . . ).
- Talk of migrating birds is one thing, what of residents? I can imagine open prairie is suitable habitat for foraging birds (harriers, Barn Owls, kestrels, etc). Were species like these observed foraging in the area? As I mentioned before, a more detailed report would be really desirable to see all of the concerns addressed, or to discover where more research is a priority.
- Interesting research from studies at communication towers is coming out. One that’s applicable looked at tower heights, presence of guy wires, siting of tower, but also lighting regimes – something that can be changed at existing towers. Assuming I’m remembering this correctly, and with everything else being equal, kills were highest at towers with sold, white lights. Blinking red lights saw significantly fewer tower kills. Blinking white and solid red were somewhere in the middle.
I assume findings like these can be implemented in new designs (though I don’t know what FAA regulations may be, and in the case of towers FCC as well).
And a third bonus “quick” point (actually a wonderment): I’m surprised Baffin Bay is a large enough body of water to deter raptors from crossing it. I always assumed that rule of thumb referred to really large bodies (the Caribbean, the Great Lakes). We know hawks get funneled at sites like Cape May and Cape Charles (Delmarva Penninsula), I assume those birds do cross the mouths of the Delaware and Chesapeake Bays and don’t perish or overwinter at these sites. Did the researchers, or have birders in general, noticed hawks changing course so as not to cross Baffin Bay? Perhaps the traditional, more westerly route is preferred but easily changed due to weather conditions. I’m thinking of the Braddock Bay Hawkwatch in Rochester, NY, where there are two lookouts, one near the lakeshore, one father inland. Which one is used depends on the winds because the hawks change their behavior accordingly.
Interesting discussion!
-Mike
Two recent articles I came across on the same day, coincidentally; one sobering, the other jubilant:
Wind farms cause decline in bird population – RSPB
Wind farms can reduce bird numbers by up to half, according to a new study by the Royal Society for the Protection of Birds, that raises questions about the charity’s support of the new technology.
http://www.telegraph.co.uk/earth/earthnews/6231580/Wind-farms-cause-decline-in-bird-population—RSPB.html
Newest Texas Wind Farm Cause for Community Celebration, Brings Energy Industry Leaders to Kenedy County on the Gulf Coast
http://www.reuters.com/article/pressRelease/idUS126743+17-Apr-2009+BW20090417
I will be very interested in seeing the results of the Texas post-construction study. (Actually, I’d be interested to see the pre-construction results, following the usual scientific peer-review standards . . . ).
-Mike
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