Colorful blades and bubble curtains: How to design a wildlife-friendly wind turbine

Wind power is one of the fastest-growing and most affordable sources of electricity in the United States. Last year, the industry set a record for the global installation of new wind capacity. That’s good news for the climate. But what about for nature?



If they are not well planned, wind turbines can have undesirable impacts on wildlife in both the air and the sea. They can disrupt migration, nesting, and roosting patterns; wildlife can collide with turbines; and noise pollution from the equipment can impact animal behavior and communication.



The paradox is that we must transition to cleaner electricity to help prevent the worst impacts of climate change on animals and people alike—but that can’t come at the expense of nature. In fact, preserving biodiversity can provide a defense against climate change, and experts increasingly see climate and biodiversity as two sides of the same coin.



So how can wind power and wildlife coexist? Engineers and designers are figuring out the ways. Here are some inspiring wind industry innovations around birds, bats, bubble curtains, barracuda, and beyond.



Protecting birds and bats from wind turbines



Potential bird strikes are among the more frequently cited concerns about wind power and wildlife, yet it’s important to put the issue in context.



Climate change is a far greater risk, one that endangers two-thirds of America’s bird species. Even more immediate threats include house cats , which kill more than 2.4 billion birds each year, and buildings, which are responsible for up to a billion bird deaths annually . In contrast, turbines are associated with an avian mortality rate of up to 328,000 annually. While that number could rise as more turbines are installed, innovative approaches are reducing the risk.



Environmental impact assessments that include bird behavior and migration patterns can inform where wind farms are located, how they are positioned, and how they operate in order to minimize their impact on animals with wings. Advanced blade designs or vertical axis wind turbines—which look a bit like the paddle attachment for a stand mixer—can reduce bird deaths while generating more energy per foot.



By monitoring migratory patterns, operators can adjust turbine speeds when more birds are in the area. Researchers also have experimented with advanced blade designs that incorporate colors and patterns that are more visible to birds so they can more easily avoid turbines, even when the blades are turning. Patterns on the ground around a wind farm can help, too, since some birds’-eye views look down, not ahead.



Since research suggests noise pollution can be a significant problem for both human and environmental health, designers are also working to make turbines quieter. Some have analyzed how owls fly to come up with ways that may actually make wind farms silent. Owls are renowned for their stealth, and the new FeatherEdge technology , for example, is modeled on the sound-dampening fringe found on the back of their wings. That technology reduces the air turbulence caused by the blades, making them quieter and more efficient. Reduced turbulence also may enable landowners to install more turbines on a given plot than they would otherwise. Early projects are underway in the U.S. and Europe.



With offshore wind growing by the gigawatt, there is also a need to develop water-based warnings for wildlife. Bats, for example, fly over land and water—including salt water, which can offer rich feeding grounds and migration paths. Some bats have been spotted more than 14 kilometers (approximately 8.7 miles) from land.



To figure out how to protect these essential members of the ecosystem, marine teams are positioning sea bat detectors on buoys throughout the North Sea. A custom version of land-based listening boxes tuned to track and record the ultrasound produced by echolocating bats, the devices provide invaluable data on precisely where and when different species of bats are traveling throughout the summer and fall, when they are most likely to fly over water. The data is helpful in a variety of conservation efforts, and can help modulate how current turbines are run and how and where future offshore wind projects are developed. Today more than 70 sea bat detectors are operational around Denmark, with more on the way.



Offshore wind and bubble curtains



While those efforts can help airborne animals, efforts are also underway to protect barracuda, beluga, and other life below the waves.



Sound travels farther on water than land, so the noise from building offshore wind turbines can create significant health concerns for marine life that rely on sound to navigate, communicate, and locate food. There are several ways to reduce the noise involved with installing wind turbines, from opting for floating turbines to relying on suction to secure the tower. Yet those approaches can’t be used everywhere, since floating turbines can be more expensive and suction is less effective in certain seabed and wave conditions.



Instead, engineers are turning to “bubble curtains.” To create a bubble curtain, a large, perforated hose is laid on the seabed, encircling the wind turbine site. When air is pumped through the hose, bubbles rise out of those holes to the surface. The veil of bubbles absorbs and scatters sound waves, buffering noise (particularly at higher frequencies) and reducing the distance it travels.



The big bubble veil was originally designed around the needs of the endangered harbor porpoise in the North and Baltic seas , in order to keep construction noise within levels that research suggests are safe . Bubble curtains can also deter other marine life from getting too close to the site during construction.



Fish, whales, and beyond



North Atlantic right whales have been classified as endangered since 1970. With fewer than 356 remaining, urgent action is needed to address the leading causes of mortality: collision with vessels and entanglements with fishing gear. Greater understanding of right whales also could help with decisions around where and when to install offshore wind.



The Smart Whales initiative is working on a system that uses data to model and even predict the presence, movement, and behavior of right whales. This will provide near-real-time information on the whales and their risk of encountering a vessel or other obstructions so that boats can change speed or course, for example, to help avoid collisions.



Considering a broader range of marine life, the Responsible Offshore Science Alliance (ROSA) is creating the ROSA Fish and Fisheries Offshore Wind Research Database. Also known as Fish FORWRD , the publicly accessible tool provides a platform to search for existing projects and research around offshore wind development and fish and fisheries along the U.S. East Coast.



Fish FORWRD may be the first effort to compile existing insights on whales while also enabling feedback around gaps in the data. The goal is to ensure wind farm development is environmentally responsible and that future research can focus on the most critical unanswered questions.



ROSA has assembled a group of funders from nonprofits, the U.S. federal government, and from each state to regularly use Fish FORWRD to inform funding decisions. The database is currently live on the ROSA website and available for download to help ensure money for fisheries and offshore wind research is spent in efficient, impactful ways. A user-friendly dashboard version of the database is set to be released and available to the public this summer.



Together, these and other efforts can ensure that wind and wildlife can coexist, powering a brighter future for us all.