14. Quality of life and safety

 

What ‘they’ say

 

“No member of the public has ever been injured by wind energy or wind turbines anywhere in the world, despite the fact that there are now over 68,000 operational wind turbines.” (BWEA website FAQs, March 2006).

 

This is indeed true and so it is perhaps not wise to over-stress the matter of safety except for situations where turbines are very close to homes, vulnerable industry or fire-prone vegetation.

 

Fire-risk has recently been highlighted by an accident to a 0.66 MW turbine at the Nissan motor works in Sunderland (UK). All three 75 foot blades burned through and dropped onto the factory site. There are serious implications for siting of turbines in fire-prone forestry or amongst refinery buildings (Sunderland Today, December 24, 2005)

 

There have been many turbine accidents involving fire, generally because of faults in the transmission train or wind-shaft braking system (Sunderland accident was caused by a loose bolt and frictional heating). It is almost always the case that they have to be allowed to burn out as fire fighting equipment often cannot reach to the top of the tower and there is plenty of fuel, provided by the transmission train oil-baths.

 

Another common cause of accidents has been the shedding of blades or control-surface elements. This may well become more common – these are the world’s largest rotating structures, often in a hostile environment and with relatively little ‘in-service’ testing.

 

A 2.0 MW turbine rotor weights over 30 tonnes so a single blade is a near 10 tonne aerodynamically shaped object which can ‘fly’ in the wind and is akin to a small fighter aircraft crashing. Again this has connotations for future urban and industrial sites as government is promoting the concept of ‘brownfield’ wind ‘farms’ (for example in the Welsh Assembly’s TAN 8 planning document – Section 9).

 

Finally, as with aircraft, the rotor blades are prone to icing in freezing conditions. Icing of the blades causes production losses from wind turbines and heavy icing can close-down turbines. Downtimes of several weeks with a single icing incident have been reported in Southern Germany.

 

Ice thrown off the blade may also pose a safety risk even in areas where icing is infrequent, specifically when the turbines are situated close to a public road, or by skiing resorts, for example. Ice shedding off the tower or the nacelle can also pose a similar though a more limited risk especially for the service personnel and the public. There are also cases when icing of the yaw gear has resulted in the damage of yawing motor (http://virtual.vtt.fi/virtual/arcticwind/index.htm ).

 

In the UK icing is mainly a winter hazard in upland areas and occurs less frequently in the lowlands.

 

Visual effects – flicker

 

In situations where low sun is behind wind turbines near sunrise and sunset the blades cast shadows which may cause serious irritation and in some sensitive individuals, physiological responses. The flicker rate is low – one ‘flash’ every second or two with large turbines, and in hilly areas with large arrays of machines some properties may be exposed to flicker for substantial periods during the day.

 

A less intense flicker is also caused when the observer is between the sun and the turbines, if the blades have glossy reflective surfaces.

 

The likelihood of flicker may be assessed by considering the orientation of turbines to nearby properties and roads, coupled with the known compass bearing and elevation of the sun at different times of day and year (see Manwell et al, 2002).

 

The consequences of shadow and reflective flicker are also apparent at greater distances, making wind turbines much more obtrusive than static structures of similar height. For this reason the industry’s repeated attempts to compare them with transmission towers (‘pylons’) are deceitful – pylons do not move and are of a half or even a third of the height of big turbines.

 

This is well summed-up in a statement by Mr David Sheers, the Inspector at the Public Inquiry into a proposed wind ‘farm’ at Jordanston in Pembrokeshire (2000).

 

“The movement of WTGs [wind turbine generators]… has a discordant effect on the eye. The rotation of the blades of WTGs in a cluster, while in the same direction, is not synchronised and gives a constant restless quality to the overall experience of a landscape. Especially when several overlapping WTGs are in view at one time, this has a highly distracting and discordant effect that detracts from any sense of tranquillity that an area may have.”

 

The loss of tranquillity may be the least of the ills: -

 

“The sudden emergence of a giant blade from behind a hill-slope, or out of a cloud base, triggers that primeval ‘corner of the eye’ fright which saved our distant ancestor from leaping predators. I am not surprised that those who live in sight and sound of the wind-monsters have their tranquillity stolen and their health damaged." Letter from the author to Press and Journal, May 2005

  

Huge numbers of people object to much smaller, 'non-twitching' electricity transmission towers for example the near 18,000 objections to the Scot's Executive over the Beauly to Denny line

 

 Relevant articles, news items, papers, reports