Library filed under Shadow Flicker from UK

Neighbouring council to Fenland rejects wind turbine on flicker, ice and intrusiveness grounds

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.
10 Aug 2009

Wind turbines, flicker, and photosensitive epilepsy: Characterizing the flashing that may precipitate seizures and optimizing guidelines to prevent them

186changeappendix3_thumb 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.
12 Apr 2008
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