What happens when wind farms meet birds?

As demand for renewable energy rises, wind farms are rapidly scaling up globally. According to Bernstein Research, wind power has a carbon footprint 99 percent less than coal-fired power plants and even 75 percent less than solar. However, this "green energy" often garners scrutiny as its turbines sometimes kill birds.

It is estimated that 1.17 million birds are killed by wind turbines in the United States each year, according to the American Bird Conservancy. That is a huge number, but it is still significantly lower than the 5-6.8 million birds killed each year by communication towers or the 365 million to one billion birds killed by cats each year in the U.S., according to a 2012 study published in Nature.

Considering the wind power's threat to birds, experts are looking for ways to make birds live in harmony with wind farms. 

At the Cattle Hill wind farm in Tasmania, Australia, owned by Power Construction Corporation of China and Goldwind Capital Australia, an aerial monitoring and detection system called IndentiFlight was employed to protect local endangered birds like the Tasmanian wedge-tailed eagle and the white-bellied sea eagle. 

The 16 optical sensors scattered across the wind farm can detect flying objects and use algorithms to see whether they are eagles. If their speed and flight trajectory are on a collision path with a wind turbine, the system will send a signal to shut that turbine down. 

"On average, we're seeing about 400 curtailment signals sent to a turbine daily within the wind farm, with each shutdown averaging slightly more than two minutes, or about 14.5 hours daily on average across the 48 turbines," said Leigh Walters, the Goldwind project director.

The project won the Clean Energy Council's Innovation Award for 2021 because it greatly decreased the eagle deaths at the wind farm. According to the wind farm's annual environmental review, two wedge-tailed eagle mortalities were recorded in 2022 and five in 2023. Staff are still working on how to improve the system and make a balance between energy generation efficiency and bird protection.

(Cover image via CFP)