In a recent planning application I was asked to comment on shadow flicker for a very small turbine installation. The turbine in question had a rotor diameter of only 1.7 m.

Shadow flicker is caused by the blades of a wind turbine passing in front of the sun and causing an effect similar to driving under a tree canopy. This can be disturbing if it happens often in a home and can be a problem with larger wind turbines. Small turbines have a much smaller blade and a much higher rotational speed when compared to a larger commercial turbine. For shadow the sun needs to be aligned behind the turbine and at a correct angle. This situation is unlikely to impact any property for more than a few minutes at a time and will only occur on a very few days of the year.

If your planning officer asks for an impact statement then you should be able to prepare a simple statement highlighting the minimal impact and if homes are more than 100m away then there should be no noticeable effects.

Photo by dumbledad

About the author: Graham Eastwick is a director of Encraft, and manages renewable energy installations for home owners, community organisations and small businesses across the UK.

Click here to ask an Energy Expert a question, and sign up to RSS feeds, to make sure you don't miss the answer.