Complaints about noise disturbance can range from the steady swishing noise from the blade to a louder thump which can sometimes occur, the review said. But, it added, the annoyance is not just limited to the thunderous sound a wind farm can create. Flickering shadows can similarly irk those who live near one.
Library filed under Shadow Flicker from UK
The blight of shadow flicker from turbine blades could soon be a thing of the past for those living near wind farms. The government has recommended strict guidelines for developers to relieve householders of the annoying strobe-like effect.
A North Lincolnshire wind farm plan has been rejected because of the "serious effect" it would have on eight-year-old autistic twin boys living nearby. Anita and Trevor Glathorne, who have one wind farm overlooking their Burton upon Stather home, said the rotating blades affected their sons' behaviour.
A long-running campaign to build a wind turbine at the Queen Elizabeth Hospital in King's Lynn has been dealt another blow by councillors. The latest application to build an 80m turbine in the hospital grounds has been refused by West Norfolk's development control board ...This is the second planning application for the turbine which has been turned down.
Wind turbines are known to produce shadow flicker by interruption of sunlight by the turbine blades. Known parameters of the seizure provoking effect of flicker, i.e., contrast, frequency, mark-space ratio, retinal area stimulated and percentage of visual cortex involved were applied to wind turbine features. The proportion of patients affected by viewing wind turbines expressed as distance in multiples of the hub height of the turbine showed that seizure risk does not decrease significantly until the distance exceeds 100 times the hub height. Since risk does not diminish with viewing distance, flash frequency is therefore the critical factor and should be kept to a maximum of three per second, i.e., sixty revolutions per minute for a three-bladed turbine. On wind farms the shadows cast by one turbine on another should not be viewable by the public if the cumulative flash rate exceeds three per second. Turbine blades should not be reflective.