The owner of the Musselroe wind farm in Tasmania is ditching its original bird radar in favour of a new version, after years of disappointing results and four reported wedgetail eagle collisions in the last year.
Woolnorth Renewables wants to install 30 IdentiFlight units on towers in the 168 megawatt (MW) wind farm.
If it receives council approval, works to install the new system should start in 2024 and be operational by September.
It will use cameras to detect and analyse eagle movements and machine vision and artificial intelligence to predict collisions and send a message to turbines to stop.
“To date Woolnorth Renewables have trialled a range of systems and approaches to manage impacts on bird populations, particularly eagles,” says Woolnorth Renewables general manager Giles Rinckes.
“Wind farms are critical to our clean energy transition and new technologies like IdentiFlight are crucial to manage and mitigate potential risks.”
Eagle tracking
The wind farm owner originally began trialling the Dutch technology ‘Robin Radar’ in 2020 for its bird collision system, after wildlife biologist Nick Mooney told the ABC that since the Musselroe wind farm started operating in 2013, there had been 11 wedge-tailed eagle deaths and one white-bellied sea eagle death, due to collisions with turbines.
Woolnorth launched an observer-based turbine shutdown system in 2019, followed by the Robin Radar technology which was operational in October 2020. But after several years of disappointing results – in 2021 the company said a fully automated was “some time away” – it cancelled the trial in the second quarter of 2023.
“The examples highlight intermittent tracking or regular non-tracking and misclassification of eagles often in high-risk areas,” Woolnorth’s latest environmental report said.
The observer program is still running with three to four people stationed around the wind farm daily providing reports of eagle sightings. The environmental report suggests there is an increasing number of wedge tail and sea eagles present at the site.
Switching over
When Musselroe began trialling the Robin Radar however, Goldwind Australia was testing IdentiFlight at its Cattle Hill project in the island state’s central highlands.
Goldwind suggested in a report into the effectiveness at Cattle Hill that informal chats with Robin Radar indicated that it wasn’t as effective in preventing eagle collisions.
Woolnorth signed a contract with Identiflight in June to supply a system that can integrate with the wind turbines and curtail operation when eagles fly close to the blades.
IdentiFlight uses high performance optical systems with machine vision and artificial intelligence software to identify avian species within a one-kilometre range of turbines in wind farms, and then can send a signal to the wind farm to curtail the turbine to avoid a collisiion.
It says it can detect targeted birds 99 per cent of the time and reduce avian fatalities by 85 per cent.
Four eagle collisions
Woolnorth reported four wedge tail eagle collisions in the 2022-23 financial year at Musselroe.
Because of this high number, the Tasmanian EPA is doing an Eagle Impact Review (EIR) to find out whether the wind farm mortalities are impacting on the local wedge-tailed eagle populations in the Musselroe/Cape Portland region.
The total population of wedge tail eagles in the state is no more than 1000 birds, according to statistics cited by the Department of Energy, Environment and Climate Change and Water from 1998. More recent estimates put the number of breeding pairs anywhere between almost 200 and 350.
Large predatory birds are at risk from wind turbines partly because of their breeding cycles – it takes a long time to rear a chick to adulthood – and partly because of their eyesight, some researchers suggest.
Eagles and other birds of prey look down to find their prey, and aren’t expecting an ‘attack’ from above.
