Protecting Birds and Bats from Wind Turbines

Scientists are seeking to expand wind energy production while also better protecting birds and bats. To achieve this goal, researchers at the University of Siegen are working with partners on a novel detection system for wind turbines.

As part of the European Green Deal, the European Union has set itself the goal of becoming climate neutral by 2050. For this to happen, renewable energy sources must be further expanded, with wind energy playing a starring role. One significant concern is wildlife protection: Birds and bats can be hurt or killed by the spinning turbines, leading to frequent rejection of approval for wind generation stations in sensitive locations. Existing wind turbines are also routinely ordered to shut down fully during certain crucial times. To resolve this “green-on-green dilemma” (climate protection vs. wildlife protection), researchers at the University of Siegen have joined with several partners to develop and test a novel detection system for birds and bats in the vicinity of wind turbines. The "SENSE2SAVE” project is funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK).

It brings together partners from research and business to develop what is known as a radar acoustic sounding system: Using millimeter-wave radar technology and microphones, it identifies and classifies birds and bats approaching wind turbines. Radar signals provide information about the position and flight elevation of individual animals. Body size, flight direction and velocity can also be derived from the reflected signals. The microphones also record the animals’ calls, to help better identify them. If the birds are from an endangered species, such as the red kite or white-tailed eagle, then the speed of the rotors is automatically reduced or the station can even be brought to a full standstill to prevent harm to the creatures.

“Our system works around the clock and in almost any weather conditions. It can identify birds and bats even in the dark or in fog. That is a clear advantage over the camera-based detection systems that are currently in their pilot phases,” says Project Director Dr. Jochen Moll from the Teaching Chair for Mechanical Engineering with a focus on Damage Monitoring (Dr. Peter Kraemer) and the Center for System Systems (ZESS) at the University of Siegen. An efficient and practical system would allow for more green energy to be produced from wind power, Moll believes: “Wind turbines would then only need to be powered down where there was pressing need, meaning when animals were actually in the danger zone. This would eliminate the need for blocks of down time as is currently the practice.”

The project partners are investigating novel methods for installing radar antenna and microphones on the wind turbines. Their plans call for the development of a special film with the technology integrated inside, to then be simply glued onto the wind turbines. “This kind of foil would truly allow us to make a technological leap forward. It can be printed out by the meter and then applied to the station,” Moll says, although also noting that the idea is still in the development stage: “We just can’t be sure yet whether we’ll actually be able to implement the very fine structures needed for this to work using existing film technology.” Preliminary experiments have shown promising results, he says. But should the film technology fail to produce the expected results, then the team can instead opt for existing antenna technology.

An initial field study was launched in July in the Swabian Alb region. The project partners have been tasked with applying the technology to wind turbines on the WINSENT research test field — initially using existing radar technologies. “We're looking to build up the infrastructure under real conditions for testing during a bat season,” explains Jochen Moll. At the same time, other partners will continue developing the film technology and improvements to the radar systems. The systems should be capable of looking out as “far” as possible and delivering a high density of information. The collected data is analyzed in real time, in part using artificial intelligence.

“Our goal is to use millimeter-wave radar technology and microphones to capture high-quality data for collation and real-time assessment. If we succeed, it will truly represent a major contribution to the expansion of wind power while also protecting nature and wildlife,” Moll says.

Background:

SENSE2SAVE, a project dedicated to “Acoustic and Radar Sensory Technology to Identify Bats and Birds Near Wind Turbines,” was launched in late 2023, with a three-year mandate. It receives support from the BMWK under the funding code 03EE3099F. The project partners include the Teaching Chair for Mechanical Engineering at the University of Siegen, JUWI GmbH from Wörrstadt (associate), IMST GmbH from Kamp-Lintfort, the Institute for Animal Ecology and Natural Education from Gonterskirchen, and the Center for Solar Energy and Hydrogen Research of Baden-Württemberg (ZSW). The project is centrally coordinated by Flexoo GmbH of Heidelberg.

Contact:
Dr.-Ing. Jochen Moll (Teaching Chair for Mechanical Engineering with a Focus of Damage Monitoring and the ZESS at the University of Siegen)
Email: jochen.moll@uni-siegen.de
Tel.: +49 271 740-4943