Wind Energy & Infrasound Myth Debunked By Court

Wind Energy & Infrasound Myth Debunked By Court

OPED by David Waterworth for Clean Technica 7/28/24

In a testament to the longevity of FUD (Fear, Uncertainty, and Doubt) and the ability of the internet to encourage stupidity, a legal action against the building of the Tilt Renewables Palmer Wind Farm in South Australia has gone all the way to the South Australian Supreme Court and lost. It was claimed that infrasound from wind turbines made the locals sick. A quick search of CleanTechnica reveals that this issue was dealt with ten years ago. Here we go again.

Although claiming that infrasound produced by wind turbines would make people unwell — subjective non-specific symptoms included annoyance, sleep disturbance, headaches, and nausea — no medical evidence was presented to the court. The argument was also tendered that infrasound would confuse the sheep dogs working on the farming properties. Anyone heard of confused sheep dogs herding sheep around and around a wind turbine? And perhaps tripping over the piles of dead birds killed by said turbines? Now, that would make a great Facebook post. Dog whistling taken to an extreme. FUDster heaven! Waterfalls and waves also produce infrasound, but no one is complaining about them. Their sound is deemed relaxing!

The Tilt Renewables Palmer Wind Farm will now go ahead, and is expected to start construction in 2025 after fighting for 12 years with an absentee landlord who spearheaded the local opposition. Over those years, much has improved in the engineering of wind turbines. Tilt Renewables will produce almost as much power (288 MW) with the 40 turbines in the updated proposal that it would have done with the original 103 proposed. Construction is expected to be completed in 2028.

Tilt Renewables describes itself as a “leading renewable energy business and the largest owner of wind and solar generation in Australia. We tilt with the wind, and towards the sun to rebalance the electricity generation mix towards a lower carbon outcome. We tilt for good. We tilt for the future.” According to its website, Tilt Renewables has solar and wind farms already generating up to 1300 MW of power, with projects with a generating capacity of 500 MW under construction and projects with 3500 MW capacity in development.

As originally proposed: “The Palmer Wind Farm would produce enough clean energy to power about 144,000 homes. Every year it will avoid 305,000 tonnes of greenhouse gas emissions, the same as taking 144,000 cars off the road. The Palmer Wind Farm would create approximately 250 jobs during construction. This is in addition to the flow on jobs that would be created by regional procurement.”

The knowledge around infrasound has also changed since the Tilt project was proposed. A 2001 literature search found: “Among the more consistent findings in humans were changes in blood pressure, respiratory rate, and balance. These effects occurred after exposures to infrasound at levels generally above 110 dB. Physical damage to the ear or some loss of hearing has been found in humans and/or animals at levels above 140 dB.” This has now been debunked.

A 2006 UK study into noise complaints about 3 wind farms found that infrasound could be measured on some occasions, but the noise level was below the threshold of human hearing. “This study also noted that at all the measurement sites the low frequency sound from the traffic on local roads was greater than that from the wind farms. This study made an important finding that the common cause of complaint regarding sound from wind farms was not associated with low frequency noise, but the occasional audible modulation of aerodynamic noise, especially at night.”

A paper presented at the 159th Meeting of the Acoustical Society of America outlines the results of sound measurements from Siemens SWT-2.3 MW-93 turbines: “… at more than 1000 feet (305 metres) the turbine model does not pose a low frequency noise or infrasound problem as it meets standards published by the American National Standards Institute (ANSI)… ‘Low frequency sound’ is the term used to describe sound energy in the region below about 200Hz. The rumble of thunder and the throb of a diesel engine are both examples of sounds with most of their energy in this low frequency range. Infrasound describes sound energy below 20Hz.”

Yet no one is calling for the ban of diesel motors? In fact, I would expect that most of the properties in the affected area of the Palmer Wind Farm would have diesel backup generators to run their equipment.

There was some genuine concern about low frequency noise from wind turbines due to the early turbine designs, “where the blades were down wind of (or behind) the turbine tower. This design caused a strong low frequency pulse, which also had significant levels of energy in the infrasound range, when the blades passed behind the tower.” So, there may be a grain of truth behind the FUD — but, like most FUD, now totally debunked and out of date.

“Most modern wind turbines are designed with the blades upwind of the tower, and have an increased distance between blades and the tower to minimise any residual possibility that the blades may interact with disturbed airflow upwind of the tower. These design developments have dramatically reduced the intensity of low frequency sound created by wind turbines.”

Australia needs wind power, especially in the evening peak time, to remove expensive gas peakers from the grid. At the moment, on a sunny morning in Brisbane, the east coast grid is 38% renewable, with South Australia and Queensland the only two states using a combined 475 MW of gas-fired electricity. Over 2 GW (out of a total of 30 GW) of electricity is being generated by wind and fed into the east coast grid. Today, most of the energy generation is coming from black and brown coal. Large and small solar is contributing almost 7 GW. Wind power averages out at one third of the cost of gas, and over the past twelve months has provided over 12% of Australia’s electricity generation. Thanks to John Baldwin for this link with the stats.

Tilt Renewables thanked the court, the local supporters, and stakeholders for their patience. Now let the work begin as we tilt towards a brighter and cheaper electrical future for Australia powered by renewable wind and solar