Devon residents living in the shadow of the biggest on-shore wind farm in the UK now have proof they are being subjected to higher-than-permitted noise levels
Tests have revealed that the giant array of 22 turbines at Fullabrook, is exceeding set guidelines.
A third of the dozen locations fitted with sound monitoring equipment registered readings above those set out in the planning permission.
North Devon Council is awaiting the full test results tomorrow before it decides wether to take action.
Site operator Electricity Supply Board (ESB) believes the problems are a result of a tonal fault with the turbines and is in discussion with manufacturers.
Merlin Hyman, chief executive of the green energy group Regen South West, said wind was a "very mature and proven" technology but must be made to work to set levels.
He added: "It is the responsibility of the developer to meet planning conditions – these are fairly sizeable and the fact they have problems which still need ironing out must come as a huge surprise.
"There is a vociferous anti-wind lobby, but they are a minority – most people recognise there is no perfect solution and wind has a role to play in the right place.
"Any development will have requirements and these issues will come up and need to be addressed."
The 110m (360ft) turbines are said to be capable of producing 66MW – enough electricity to meet the needs of about 30,000 homes in North Devon.
But ever since the turbines began turning, people living nearby have complained of droning motors and the "whooshing" of the giant blades.
Locals have told the Western Morning News they have been unable to open their windows and are "stewing" inside on warm summer days.
Some have now called on the company to scale-down the blades.
Nick Williams, who lives at Fullabrook, said the site should be closed down immediately. "We knew it was too noisy and they should close it down – they have breached their planning regulations," he said.
Local MP Nick Harvey said he was "disappointed" and "surprised" by the preliminary results, announced yesterday. "Judging by the level of complaints I have received I would be surprised if there was not a problem with Fullabrook wind farm," he added. "Noise, flicker and vibration have all been an issue for some residents living in the shadow of the turbines.
"I doubt the residents near the 12 sites chosen will be greatly reassured by these results and I wait with interest to see what steps ESB propose to take to address their concerns."
The council did not put an exact figure on the excessive noise, describing it as "a very small fraction".
A spokesman added: "We are awaiting the full report and until such time as we have had the opportunity to scrutinise it and seek the advice of our expert, no further decisions will be taken.
"North Devon Council has not required that any of the turbines are shut down."
An ESB spokesman said: "At eight of the 12 sites the noise levels resulting from the movement of the turbine blades fall within the levels permitted under the conditions of the planning consent.
"At the other four, the levels are marginally above permitted levels, but we already have an agreed plan in place and these remaining issues should be resolved within the next two weeks.
"The results of the 'tonal noise' assessment – the noise made by the mechanics within the turbines themselves – show that tonal noise from the wind farm is audible at times.
"We are in discussions with the manufacturer of the turbines to address any issues."