Making Wind Turbines Bat-Proof: Researchers to Create 3D Printed Echolocation Whistles

Cashing in on the pros of wind energy sure sounds like a great idea up front, but before you go erecting a wind turbine in the expanse of your back yard, there are some things to consider.

As with all ‘pros,’ there are unfortunately usually cons to balance everything out. Many find wind energy to be a fascinating subject, as it is often touted as a way to set us free from worry about non-renewable resources.

Some of the benefits of wind energy are that it is basically a free and native fuel that does not have to be processed or transported, turbines can be placed in farmland as well as bringing profit to rural areas, and it is a pollution free way to make energy.

On the other hand, when there’s no wind–there’s no energy. Like the solar industry, that’s something we can’t control. Turbines are large pieces of equipment that can cause erosion where they are placed as well. But their biggest problem is how they can affect wildlife. While it’s the law of the jungle (and the concrete one as well) that the strong survive–and adapt–issues like losing 600,000 to 900,000 bats per year are a major concern.

Pencil drawing of a Brazilian free-tailed bat by researcher Grace Smarsh (Credit: Grace Smarsh)

While many environmental groups give the thumbs up to wind turbines due to their massive benefits, researchers and many concerned individuals still want to find a way to keep bats from being hit by surprise when flying at night armored only with echolocation for navigating their way through the dark evening air.

Now, biologists at Texas A&M University are collaborating with scientists at the University of Massachusetts Amherst to save the bats from wind turbine danger; not only that, they have federal funding to back a project which involves dealing with the use of ultrasonics for the bats, since even though they are not blind, they can’t see well in the dark, and they rely on their specialized and heightened sense of echolocation. Before anyone installs the devices, the researchers will be testing them in their lab first.

“Bats are very vocal animals, and the parts of their brain that control their voice are much larger proportionally, relative to other animals,” Smotherman said. “Ultimately in my lab, we want to learn how specific brain circuits are interpreting and producing their communication sounds. Understanding these functions has important medical purposes for us.”

Since putting blinking neon lights wouldn’t be quite as effective–or attractive to anyone involved–researchers developed an unobtrusive whistle that is 3D printed and can be placed on the turbine blades as warning devices.

Not only is this a smart design, but with 3D printing it’s an affordable and durable design, meaning they can make lots of these whistles, which will also help other wildlife veer away from the blades. The project, headed up by Michael Smotherman, an associate professor in the Department of Biology at Texas A&M University, has received $312,500 in funding from both the US Department of Energy and the Massachusetts Clean Energy Center. This grant and project serve as part of the Office of Energy and Efficiency initiative to protect wildlife at wind energy plants.

“We hope that by developing and refining this technology we can promote the development of sustainable wind energy while mitigating these important negative impacts on North American bat populations,” stated Smotherman, an expert in bat behavior.

Michael Smotherman discusses research with Grace C. Smarsh ’14, a Ph.D. candidate and member of the Smotherman Laboratory (Photo: Texas A&M)

The whole idea is incredibly streamlined and simple, but makes complete sense. The tiny 3D printed devices are lightweight enough to be mounted on the turbines without causing any dysfunction, but are still able to glean power from the air pressure generated by their movement. The greater the speed of the spinning blades, the faster and louder the whistles become.

The research team anticipates the possibility of designing 3D printed whistles for a wide range of species should this program prove successful with the free-tailed bats they have designed the whistles for initially. A variety of whistles would be needed just for other types of bats due to the number of different bat larynges they would need to imitate.

“The point is to establish whether or not the whistle noises can effectively alter the bats’ flight paths,” Smotherman said. “There is definitely some concern that the whistles might accidentally attract bats to windmills, since sometimes bats interpret the sounds of other bats as an indication that another bat has found food nearby and will fly there. So, the behavioral tests are critical to deciding whether or not we go forward with testing the whistles on actual windmills.”

Because they are such vocal animals, focusing on that sense should prove to help with the large numbers being affected by the wind turbines, but only time–and testing–will tell. Once printed, all of the whistles will be delivered to Smotherman’s lab sometime this fall so they can begin evaluating how well they function with Mexican free-tailed bats. If all goes well, the project should be in its final testing phases by summer of next year.

“I think it’s a great opportunity to highlight this positive interface between biology and engineering,” he said. “It is important for people to know about this project because it shows that results emerging from our prior studies of bat biosonar and communications can have very tangible translational benefits to society.”

And whether you have a liking for bats or not, it’s a larger ecological concern, as these tiny winged mammals are responsible for doing their own particular and unique job in the environment in terms of controlling insects as well as helping with pollination. A number of types of bats are already extinct due to loss of habitat and other factors.

Do you think this is a good idea for re-routing bats? Do you have any other ideas for a similar 3D printed device? Discuss in the 3D Printed Echolocation Whistles for Bats forum thread over at 3DPB.com.

A wall of bats (Credit: Texas A&M, Smotherman Lab)