Wednesday, 28 November 2012

Response by PfR re Thorington Wind Turbines

PfR have asked that I show their response to residents concerns as per my previous posts. I am happy to do that as I think it is only fair to see all sides.
Please feel free to add your own comments after this piece in the area shown or contact me direct.
Also please remember there is a meeting tonight Wed 28th November 2012 at Belstead village 7.30pm with the developers. See you there!

Dear Mr and Mrs Daynes, 

Thank you for your email. We have addressed your comments and concerns in detail below, however, we would be happy to discuss the predicted effects with you in due course when we have a final design and can undertake the detailed assessment. At that point we will also be scheduling some community surgeries locally which we hope you will be able to attend, these will be advertised both on our website and in the local press.

I would like to reassure you that we completely understand your concerns and that as a responsible developer we will be fully addressing issues such as noise and shadow flicker as part of our environmental impact assessment (EIA) prior to submission of any planning application for the project. An EIA is the process by which assessments of all the varying receptors are assessed for significant impacts, for example birds and other wildlife, levels of noise, shadow flicker, archaeology, landscape and visual effects etc. 
In addition, as with any new development, the Local Planning Authority (Babergh District Council) has a duty to ensure that the proposal does not have an unacceptable effect on the living conditions of local residents. It is absolutely standard for any successfully consented planning application to have various planning conditions attached to protect the interests of the local community, covering both noise and shadow flicker. 

Shadow Flicker
As part of our EIA, we routinely assess the potential for "shadow flicker" effects. Shadow flicker is when the shadow of the rotating turbine blades is cast onto a building, or a given location, and viewed through a narrow gap such as a window. Shadow effects outside buildings are far less noticeable compared to those seen inside through a window, due to the higher levels of ambient light outside.
We can predict the potential for shadow flicker because it requires a combination of predictable conditions to coincide for it to take place. The occurrence of shadow flicker is dependent on the time of day, location of the sun in the sky and how clear or cloudy the sky is. The orientation of nearby residential properties and their windows are then assessed and an assessment is made of all the days and times when shadow flicker could occur at each location.  

The calculation of the potential shadow flicker at is carried out as follows. The position of the sun relative to the turbines and the resulting shadow they would cast is calculated in steps of 1 minute throughout the year. If the shadows of the turbine rotors at any time casts a shadow on any window (or solar panel), then this will be recorded as 1 minute of potential shadow impact.

The following information is used: 
.             The position of the turbines (x, y, z coordinates) 
.             The hub height and rotor diameter of the turbines 
.             The position of the house or shadow receptor (x, y, z coordinates) 
.             The size of the windows (and solar panels in this case), their orientation, both direction and tilt (angle to the horizontal). 
.             The geographic position (latitude and longitude) together with time zone and daylight saving time information. 
.             A simulation model of the sun's position in the sky

It is important to make clear that these simulations are worst-case scenarios (i.e. calculations which are solely based on the positions of the sun relative to the turbine and the window). If the weather is overcast (reducing shadows) or calm (i.e. the turbines are not rotating), or if the wind direction forces the rotor plane of the wind turbine to stand side-on to the window, the turbine will not produce a shadow although the impact will still be assumed to occur in the simulation.  
A calendar can be produced for any specific point of observation, which indicates the exact days, and time periods throughout the year where shadow impact may occur.
As we do not yet have the final positions for the turbines, only a preliminary assessment has been completed to date. The final assessment will be undertaken during the EIA process and the results will be included in the planning application. 
We will ensure that any potential wind turbine development at the Thorington Barn site is designed to avoid any reduction of residential amenity through shadow flicker, including the use of mitigation measures if needed which can avoid shadow flicker occurrence completely. The predictability and infrequency makes shadow flicker a very manageable problem; effects can be curtailed by many mitigation measures for example creating screening features or programming the turbines to cease operation for the short time during which dwellings are affected.
Importantly, at distances beyond about 1km (10 rotor diameters) from the turbines, the effect of shadows will be very limited indeed, due to the distance over which the shadow is cast. This is widely agreed as the limit of potential for shadow flicker effects inside a building (as stated above, shadow effects being more noticeable inside buildings with a window than outside), and outside where the light levels are higher shadow effects would be barely noticeable.

Well-designed and well-sited modern wind turbines can be quiet enough to cause no disturbance to people living only a few hundred metres away from them. There are also strict environmental health guidelines and noise limits set out in Government guidelines ('The Assessment and Rating of Noise from Wind Farms' 1996, DTI, ETSU, recently supplemented by additional guidance and confirmed by the Department for Business Enterprise and Regulatory Reform (DBERR) more recently (2007), to be the guidance that Local Planning Authorities should continue to use) and the development will need to operate within these to gain consent.

We have carried out a detailed background noise survey to inform our design and to ensure that any future proposal for the Thorington Barn site minimises any potential noise effects for local residents and complies with the strict noise limits, which would be enforceable by planning conditions if we were to obtain planning permission.
In order to accurately gain an understanding of any potential noise effects, we undertook a detailed background noise survey using noise monitoring equipment placed at various nearby houses, following consultation with the local Environmental Health Officer. We monitored the background noise levels for 24 hours a day for two to five weeks (in excess of the required survey period, in order to obtain a robust dataset). By correlating this background noise data with the predicted noise levels of the proposed wind turbines at various wind speeds, we are able to gain an accurate understanding of the potential noise associated with the turbines.

The results recorded a relatively high background noise regime at each property so we are fully confident that the noise emitted by the turbines would be well within the acceptable noise limits set out in the noise guidelines. For most of the time the noise levels from the turbines are likely to be similar to or lower than existing background noise levels. Once we have finalised our design we will update the noise assessment and confirm that the proposal will indeed meet the noise guidelines. The data and the results of these studies will be included in the environmental statement and will be assessed by the planning officer and the Environmental Health Officer. 

Turbine Locations
There will be a maximum of to turbines on the site. There are three locations shown on diagrams as we have yet to define the exact locations and we have been assessing many potential designs. However, only two locations will be selected for the final design.

Once a layout for the site has been selected, photomontages will be created. These will be put onto the website and also be displayed at public exhibitions and community surgeries.

House Values
There is no strong evidence that confirms that the presence of wind turbines has a long term impact on nearby house prices. A report by RICS in 2007  stated that "proximity to a wind farm was simply not an issue". ( A temporary negative impact on property prices can sometimes occur when a wind farm is in planning and construction based upon anticipated negative impact of the turbines, but this quickly readjusts when these anticipated negative impacts fail to materialise.
Finally, if you wish to read  some additional information can I suggest a review of the following document (  I look forward to the opportunity to speak with you at the upcoming consultation events (TBC).

I do hope this address all the points made in your email. However, we are happy to discuss the predicted effects with you when we have a final design. Please do feel free to give me a call if you have any further questions or queries.
Kind regards
Alice Gill
Communications Manager
Partnerships for Renewables Development Company Limited
Station House, 12 Melcombe Place, London NW1 6JJ 

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