Researchers from Tel Aviv University and Haifa University tested the effectiveness of a dedicated device mounted on a drone, designed to keep bats away from the wind turbines that kill them en masse, and allow the turbines to operate efficiently and continuously
The world is moving towards the use of renewable energies, which is great, but it is a little more difficult for the animals to get used to the presence of systems that utilize the energies offered by nature. The wind turbines, for example, kill many winged animals, including bats, which fly many kilometers every night at the height where the blades of the facilities operate. Some of the turbines in Israel have a mechanism installed that stops their activity when it detects the approach of an animal, but this is only a partial solution, which also slows down the energy production activity. Researchers from Tel Aviv University and Haifa University tested the effectiveness of a dedicated device mounted on a drone, designed to keep bats away from the wind turbines that kill them en masse, and allow the turbines to operate efficiently and continuously. The device, which emits a combination of ultrasonic signals and lights, deters bats and causes them to fly higher, out of the danger zone.
Make handlers fly higher
The research was led by doctoral student Yuval Verber from the Department of Evolutionary and Environmental Biology at the University of Haifa, and his two supervisors: Prof. Yossi Yuval from the School of Zoology at the George S. Wise Faculty of Life Sciences, and Prof. Nir Sapir from Haifa University. The article was published in the journal Remote Sensing in Ecology and Conservation.
"Wind turbines are considered a promising technology in the field of renewable energy, but their operation involves a variety of biological challenges. Among other things, they kill large numbers of flying animals that come across the rotors of the turbine, including millions of bats, which are killed in this way every year around the world. Today, the only answer to the killing of bats is to stop the turbine activity at times when a lot of their activity is expected, but such interruptions harm the efficiency of the turbine and reduce the amount of energy that can be produced from it. In this study, we tested a new possible solution: a device mounted on a drone, which transmits a combination of visual and acoustic signals designed specifically for bats. The advantage of the drone is that it is in motion: when the signals are stationary and constant, the animals tend to get used to them and ignore them," explains Prof. Yuval.
Flying hundreds of kilometers at night, and flying exactly at the height of the blades of the wind turbines. take care of
"The research, which is part of my doctoral thesis, was conducted in the Emek Hula area, a place where there is a lot of bat activity," explains Yuval Verber and expands: "We operated the drone at a height of 100 m, which is the average height of the center of the wind turbines, and in motion along a path of About 100 m, there and back. To monitor the activity of the bats, we used the radar located on the ground, which allows tracking at a height of 100 m and above, and we added a device of the lidar type - a laser-based radar that is mostly used as a warning device in vehicles, for tracking at a lower height."
"At the same time, we made acoustic recordings of the bats in flight, using receivers placed at three different heights: one meter, 150 m and 300 m. To raise the shelters to a height we used zeppelins. It is important to note that our research was the first in the world to apply these technologies - radar, lidar, and zeppelins - to track bats."
An effective and life-saving environmental solution
Using a variety of monitoring methods, the researchers compared the bats' normal activity with their activity in the presence of the drone carrying a repellent device. The findings were unequivocal: the device does keep bats away. In its presence, the activity of bats under the drone decreased by about 40%, and at a distance of up to about 500 meters from it. On the other hand, the activity increased above an altitude of 100 m, and especially at a high altitude of up to 800 m.
"The device seems to be effective in keeping bats away from its immediate environment. The bats sense the visual and ultrasonic signals it emits and choose to fly over it, as we had hoped. We hypothesize that if the device is activated near a turbine it will cause the bats to raise a chicken and fly over the turbine, out of harm's way. This is an effective and applicable solution that costs a reasonable amount, with great benefit to all parties: on the one hand, preventing the killing of bats, and on the other hand, the possibility to operate the turbine and produce green energy in a safe, continuous and efficient manner. We intend to carry out a follow-up experiment on the site of wind turbines, in order to test the efficiency of the facility under real conditions", Prof. Yuval concludes.
