Wind turbines are being turned off during periods of high wind in case they become too loud.
Following complaints about the noise of rotating blades from nearby residents, operators have agreed to switch off the machines or reduce their speed when the wind is blowing too strongly.
The agreements, which mean the turbines generate less electricity, have been revealed in dossiers from local authorities about their investigations into noise pollution complaints.
They show that at Askam wind farm, near Barrow-in Furness, in Cumbria, which comprises seven turbines, a control system was installed to turn off the machines when wind speeds get too high.
After complaints about noise from a 12-turbine wind farm on a former RAF base at Lissett, near Bridlington, East Riding of Yorkshire, environmental health officers found that high winds caused the machines to exceed the noise limits laid down in the scheme’s planning conditions.
So an arrangement was reached whereby some of the turbines were slowed down when the wind was blowing at certain speeds and from certain directions.
Similar action has been taken following complaints over a turbine at Whittlesey, Cambridgeshire, and at another at a wind farm at in Skelmonae, near Ellon, Aberdeenshire.
The dossiers reveal a total of 269 complaints about noise pollution from wind farms in the last three years.
Following 125 of the complaints, the turbine operators concerned took steps to reduce the noise produced by their machines. A further 36 are still being investigated.
Most cases were resolved informally, either by an agreement to reduce the machines’ output or by fixing faults responsible for the noise.
However, one wind farm near Harrogate, North Yorkshire, was so loud that the operator was served with an abatement notice to quieten it.
The dossiers show that a sixth of new large-scale wind farms built in the past three years have attracted official complaints about noise pollution.
Around a quarter of the complaints related to small-scale turbines fitted to schools, hospitals and houses. In several cases, their operators simply switched them off after receiving the complaints.
Some of those living near large wind farms claimed noise pollution could be heard from more than three miles away. Complaints focused particularly on the low-frequency sound, or “infrasound”, emitted by fast-spinning turbines.
Householders complained they could hear booming sounds or a constant hum when indoors, and some even reported having to wear ear defenders when in their gardens.
People living near a new 22-turbine wind farm at Fullabrook, north Devon, describe the noise as like having a tumble dryer on in their homes. One resident said he now has to sleep on a sofa in his front room, where the sound is less.
Details from the dossiers come as a series of new studies conclude that living near to wind turbines can increase levels of sleep disruption and stress-related conditions.
One review of the scientific evidence written by environmental health consultants who work on behalf of the wind energy industry stated that noise from wind turbines was “associated with some reported health effects”.
The report, published in the Journal of Environmental Health, concluded that wind farms could induce heightened levels of annoyance and stress in residents, leading to physical symptoms, but said there was little evidence to support claims that they can cause epileptic fits or damage hearing.
Another study, compiled by anti-wind farm campaigners in Canada and published in the peer-reviewed Bulletin of Science, Technology and Society, surveyed the health of people living near wind farms and found that nearly three-quarters reported increased anxiety and stress since the turbines were installed.
Dr Lee Moroney, planning director of the Renewable Energy Foundation, which is critical of the expansion of wind farms in the UK, said: “The wind industry has been in denial about the misery that turbine noise causes nearby neighbours.
“Separation distances between turbines and dwellings need to be significantly greater than many developers propose, and noise conditions improved to be robust, straightforward and deal with the thumping noise of turbines.”
A spokesman for Renewables UK, the body that represents the wind industry, said: “Wind farm operators strive to be good neighbours and are conscientious in responding to local concerns.
“There is simply no credible scientific evidence to support claims that infrasound from wind farms are a cause of sleep deprivation or any other negative health impacts.”