Wind turbines 'could trigger fits'

Wind turbines which rotate quickly could cause seizures, a new study has said.

Blades should not spin more than 60 times a minute, according to researchers at the Universities of Essex and Aston.

They said people who were photosensitive could be in danger if they were too close to fast-spinning turbine blades.

Professor Arnold Wilkins, who works in the University of Essex's psychology department, and his colleagues analysed the effect of "shadow flicker" on photosensitive people.

"Turbines that rotate faster or have more blades will produce unacceptable levels of flicker," said a spokeswoman for the research team.

"Smaller variable-speed turbines range between 30 and 300 revolutions a minute and some have more than three blades, so their flicker is within the range for which seizures are likely.

"In addition, photosensitive people would need to be at least four kilometres away to significantly reduce the possibility of seizures, a distance approximately 100 times the height of an average turbine."

The spokeswoman added: "They were looking to identify what type of flicker from wind turbines could bring on seizures and as a result have come up with guidelines to minimise impact.

"Planning permission for wind farms often consider flicker, but current guidelines relate to annoyance and are based on physical or engineering considerations rather than the danger to people who may be photosensitive."

Three years ago an energy firm started switching off a wind turbine near a top-security prison during the early morning because the flickering shadows it created annoyed inmates. Longhill Energy agreed to halt the turbine outside Whitemoor Prison near March, Cambridgeshire, because of possible "security problems" if prisoners became upset.