Exclusive: Energy department commissions review into disturbance from turbine noise in order to decide when annoyance becomes unacceptable
Noisy wind farms that disturb local communities could be banned, after ministers launched an unprecedented review into the annoyance they cause.
In the first official admission that wind turbine noise can adversely affect local residents, the Department of Energy and Climate Change (DECC) has commissioned an independent investigation to assess the levels of sound wind farms produce and the extent of disturbance caused as a result.
Experts from the Institute of Acoustics will conduct the research next year, the Telegraph has learnt, and ministers across Government will then use the data to decide at which point the annoyance officially becomes “unacceptable”.
The review is likely to lead to tighter planning guidance for new wind farms and could force existing wind farm operators to restrict their turbines’ operation to stay within the limits.
It is also likely to open the door to claims for compensation by residents subjected to noise above the official nuisance threshold.
Many residents living near wind farms have complained of noise disturbance, while studies have linked wind turbine noise to poor sleep and mental health.
As well as the routine “swishing” noise of the blades spinning, turbines can sometimes produce “thumping” noises when sudden variations in the wind speed cause the blades to stall.
Current planning guidance limits the swishing noise to 43 decibels at night-time for the nearest property but does not deal with the thumping noises, which are a deeper pitch and can be heard at 40 decibels a kilometre away from the turbine.
Residents near some wind farms have likened the noise to a cement-mixer or a shoe stuck in a tumble-dryer.
A source said the new review would consider all types of turbine noise. “Everything is on the table,” they said.
Developers could be forced to use software to adjust the angle of the blades to prevent the thumping being caused at an unacceptably annoying level.
A spokesman for the DECC said: “This review should empower local people to stop disruptive wind farms and make sure local authorities have all the information they need before giving a planning application the green light.”
The review is expected to be completed by June. While the Institute of Acoustics will independently draw up the index of noise annoyance, the decision over what will be deemed an acceptable threshold will be a political decision for the next Government.
The Conservatives have already pledged an effective ban on new onshore wind farms if they win the election, by ending subsidies for those projects that do not already have planning permission. They have also pledged that all future onshore wind farm planning decisions would be determined by local authorities, instead of large projects being deemed nationally significant.
Matthew Hancock, the Conservative energy minister, said: “It’s important that we maximise the potential of domestic energy resources but we must do this in a responsible way. We cannot jeopardise our green and pleasant land.”
Ed Davey, the Lib Dem energy secretary, has heavily criticised the Conservative plan to ban onshore wind, arguing it would push up consumer bills by forcing the UK to build more expensive types of renewable technologies such as offshore turbines to hit green targets.
Wind industry body Renewable UK said it had already conducted extensive research into the extent of the thumping problem – known as Other Amplitude Modulation – and had devised the ways of tackling it.
Independent research published by the lobby group late last year had helped “to pinpoint when, where and how this sound varies”, Gemma Grimes, the group’s Director of Onshore Renewables said.
“We found that this can be addressed by using computer software to adjust the way turbines operate, changing the angle of the blades to minimise the sound levels.
"We’re hoping that this will now be incorporated within the Institute of Acoustics’ existing Good Practice Guidance document," she said.
But she said she did not believe the existing guidance on swishing noises would or should be changed. “In this [Institute of Acoustics] guidance, which they published last summer, there was no question of changing the current noise limits, which are rightly very stringent, so we wouldn’t expect any alteration in that when they update the current document,” she said.