By Louise Gray, Environment Correspondent, The Telegraph, www.telegraph.co.uk 17 March 2011
The misery of shadow flicker, which blights the lives of people living near some wind turbines, could soon be over.
The flickering is caused when rotating turbine blades periodically cast shadows through openings, such as windows.
A report commissioned by the Department for Energy and Climate Change recommended that turbines should be built no closer than 10 rotor diameters from the nearest home.
This means that if the blade had an 80metre (262ft) diameter, it should be at least 800 metres, or half a mile away.
Shadow flicker is worse when the sun is low in the sky in winter, when the wind can also be strong.
Studies cited in the report said that, over the long term, it could cause “a significant nuisance”.
It was also a risk for a small number of people with epilepsy.
Although the report concluded that flicker was not a “significant health risk”, protesters insist the issue can cause headaches and stress–related problems.
Lynn Harlock, who lives almost half a mile from Redtile wind farm in Cambridgeshire, said she was “sick to death” of flicker.
“You cannot sit in any rooms when the sun is setting at certain times of year,” she said.
“It is like flashing strobe lighting. It is quite upsetting not being able to sit in your own home.
“People think you are barmy. They think you are after compensation. But all we want is our home back.”
The report recommended that homes and offices within 500 meters, or a third of a mile, of a turbine should not suffer flicker for more than 30 minutes a day or 30 hours a year.
Developers applying for planning permission where there could be a flicker should put in place measures to stop significant nuisance, it added.
In many cases, problems could be solved by shutting a turbine down for short periods of the year, changing the position slightly or planting vegetation and trees.
The Coalition wants to build up to 6,000 wind turbines onshore over the next 10 years.
Charles Hendry, minister for energy and climate change, welcomed the report. He said new planning laws would ensure turbines were sited where there was plenty of wind rather than near residential areas where they might cause protests. Planning guidance would stick to the “10 diameter rule”.
Lee Moroney, a wind energy expert with the Renewable Energy Foundation, said the rules were not strong enough and wind turbines should not be built within a mile of residential areas.
Birds are not so eagle–eyed after all, according to a study that found that some species crash into wind turbines and power lines because they do not look where they are going.
Professor Graham Martin at the University of Birmingham said large birds of prey and sea birds were particularly vulnerable to crashing into man–made structures. In a study published in the journal Ibis, he suggested the reason was because birds had evolved to look for movement either side and potential prey on the ground rather than straight ahead.
He suggested that wind farms or other structures should have decoys on the ground to try to distract birds, or emit sound to alert them to the danger.
URL to article: https://www.wind-watch.org/news/2011/03/17/flicker-of-hope-for-the-wind-turbine-victims/