Proposed erection and operation of 4 wind turbines and associated access tracks, hardstanding and sub-station building.

Approved in accordance with the case officer’s recommendation subject to conditions 13 and 20 being amended as outlined in the update sheet. The final detailed wording of the conditions to be delegated to officers.

The Chairman advised members that the case officer had produced a detailed list of updates which should be noted prior to the application being discussed. Members were therefore given suitable time to read the update sheet. In response to a question, the Development Manager advised that the updates could not be circulated 5 days before the meeting as the Council’s constitution required any information received before 12 noon the day before the meeting to be reported to the Committee. The update sheet is attached as an appendix to these minutes.

 

The Development Manager gave a detailed presentation on the report. He advised Members of a number of details, including:

 

·         The application had been submitted in 2008.

·         In 2009 the Planning Committee had effectively granted planning permission subject to conditions.

·         The Planning Committee had visited the site as well as visiting a working wind farm.

·         The site was located in north-west Herefordshire and that the nearest settlements were Norton, Knighton and Presteigne.

·         Some parts of the access would require planning permission from Powys County Council.

·         The proposed turbines were 105m in height to the top of the blade tip, and 70m to the top of the hub.

·         The secretary of state had not called in the 2009 decision however it had been bought back to Committee as some further clarification had been required following regulation 19 requests by the Council regarding wind shear and other noise data, the landscape enhancement fund, the methodology used in the visual impact assessment and hydrology/hydrogeology matters.

·         Once the information had been received in 2010 it was decided that a further consultation exercise should be undertaken.

·         There had been minor changes to national policies but there had been no changes to the Council’s Unitary Development Plan in respect of wind turbines.

·         Further advice needed to be given in respect of Shobdon Airfield.

In summing up the Development Manager advised the Committee that there were four recommendations in the report and that these had been subject to a minor amendment as detailed in the updates sheet. He also requested that if the Committee were minded to approve the application it would be beneficial to delegate the final wording of the conditions to Officers as some of the conditions may require minor amendments.

 

In accordance with the criteria for public speaking Mr Andrews, representing Knighton Town Council, and Mrs Bywater and Dr Hugh-Jones, representing the Stonewall Hill Conservation Group, spoke in objection to the application and Sir Gourlay and Mr Corker, on behalf of the applicants, spoke in support.

 

In accordance with paragraph 4.8.2.2 of the Council’s Constitution, Councillor LO Barnett, the local ward member, commented on a number of issues, including:

 

·         The application was controversial and had divided the community.

·         There had been 38 letters of objection since the re-consultation.

·         As local ward member she had a duty to represent the people who had made representations; those who had written in previously; and the local residents who had not written in.

·         Mrs Bywater, who was thanked for attending, had raised the concerns of the neighbouring residents in her submission.

·         Stonewall Hill was a beautiful area of great landscape value.

·         The concerns raised in the various letters and emails received included the following; the turbines were not energy efficient; the turbines would be a blot on the landscape; there would be no local benefit; tourism would suffer; the detrimental impact on wildlife.

·         The local residents and Dr Hugh-Jones and his wife had remained courteous and polite throughout the application process.

·         She had not been put under any pressure from the applicants, officers, fellow councillors or any member of the community and that there had been no communication from the developers.

·         There had been a considerable amount of detailed technical information circulated throughout the application process which she had attempted to digest and understand.

·         That she cared deeply for the people she served from within her ward.

·         The local ward member wished it to be noted that her comments were taken from the emails that she had received. [note: amended at the meeting of Planning Committee on 12 October 2011]

·         It was noted that the committee were only decided on conditions. [note: amended at the meeting of Planning Committee on 12 October 2011]

·         She was well aware of national and local policies on renewable energy. [note: amended at the meeting of Planning Committee on 12 October 2011]

The debate was opened with a member of the committee commenting that in the 15 years that he had been involved in planning the application being discussed had caused the most public interest. He added that the Committee had visited the site as well as a working wind farm in South Wales and that the members who also served on the previous Planning Committee had also visited a working wind farm in North Wales. It was noted that the key considerations appeared to be in respect of noise, visual impact, and the potential output of the turbines. The application was moved subject to the revised conditions detailed in the update sheet.

 

In response to a question, the Development Manager advised the Committee that the proposed Section 106 Agreement required the applicant to be in receipt of planning permission for the areas of the site that fell within the remit of Powys County Council prior to any development being commenced.

 

The local concerns in respect of the application were noted, however a member of the committee who had attended the recent site visit noted that the turbines produced very low levels of noise and that in her opinion the turbines would not have an adverse effect on tourism in the County.

 

Another Member of the committee had reservations in respect of the application. Concern was expressed in respect of the national guidance regarding wind farms. It was noted that the proposal would benefit from a substantial government subsidy and the question was asked as to whether the application would have been forthcoming without the subsidy. It was also noted that the applicants had requested a 25 year permission, the question was asked as to whether this was based on the government subsidy or as a result of the lifespan of the turbines.

 

In response to a question regarding the reason for a 25 year permission, the Senior Planning Officer advised that the period was as requested by the applicants. Additionally the Assistant Director - Economic, Environment & Cultural Services, advised that this was in keeping with national policies as well as being based on government subsidies. He added that the financial viability of the proposal was a matter of consideration for the operator and land owner and not a material planning consideration. It was also noted that there was a considerable capital investment being made by the applicant and that a 25 year permission reflected this. Finally he advised members that the conditions recommended would ensure that any landscape impact could be reversed.

 

In response to a question regarding overhead cables, the Senior Planning Officer advised members that this matter did not form part of the application but that the applicant had indicated that turbines would be linked to the national grid via underground cables.

 

In response to the comments made by the committee, the Assistant Director - Economic, Environment & Cultural Services, advised them that they were required to make a judgement in respect of the application based on all the key issues that had been raised. He drew their attention to PPS22 which gave advice in respect of material planning considerations, which included the landscape concerns and the technical findings. In summing up he advised members that the case officer was satisfied with the technical details and also that the committee could give weight to the landscape and noise issues in making a judgement.

 

The Committee noted the concerns of the local residents and felt that the issue of flicker needed to be addressed, they therefore requested further clarification from the case officer in respect of this issue.

 

Members continued to discuss the application and noted a number of issues. They noted that the environmental statement submitted with the application indicated that the magnitude of change in the landscape was judged to be high. Some members had concerns in respect of wind turbines but noted that the technology was available and ready for installation. They noted that other forms of renewable energy production may come forth in the future and felt that this was where a 25 year permission would be beneficial. The educational facility on the site was also welcomed.

 

In response to a number of questions raised by the committee, the Senior Planning Officer advised members of the following points:

 

·         There were 15 dwellings within 1000 metres of the site. He added that the health issues were addressed on paragraph 6.1 of the report.

·         The issue regarding the mitigation of shadow flicker had been addressed in the previous report at page 81.

·         The depth of the base of the turbine was 2m, conditions required 1m to be removed if the turbines either became redundant or at the end of the 25 year permission.

·         No bridleways or footpaths would be affected and the public rights of way officer had not objected to the application.

 

Councillor LO Barnett was given the opportunity to close the debate. She reiterated her opening remarks and made the following additional comments:

 

·         The policy issues and the need for renewable energy were accepted but did not reflect the views of the local residents.

·         That she was representing the views of those local residents who had contacted her in respect of the application.

·         Members needed to consider the views of the local community before voting.

 

RESOLVED

 

THAT:

 

A)        It be recorded that the Environmental Statement, including the additional information received as a result of the Regulation 19 Notices, has been taken into account in making this decision

 

B)        Subject to the completion of a Section 106 Agreement in accordance with the Heads of Terms (as attached and dated 29 January 2009, and

 

C)        Subject to the applicant supplying a Unilateral Undertaking for the purposes as set out in the Environmental Statement for the creation of a Community Fund, that

 

D)        Planning Permission is granted subject to the following conditions:

 

1.         The development shall be carried out strictly in accordance with the particulars of the development, plans, specifications constructed in accordance with the following plans:

 

Reason:  In the interests of the visual amenity of the surrounding area and to comply with Policies DR1 and DR4 of the Herefordshire Unitary Development Plan.

 

2.         The development to which this permission relates shall be begun not later than the expiration of 3 years beginning with the date of this permission.

 

Reason:  Required to be imposed by Section 91 of the Town and Country Planning Act 1990.

 

3.         The operational period of the turbines hereby permitted shall expire 25 years following the first generation of electricity to the local electricity supply. The Local Planning Authority will be informed by the developer/operator in writing within 28 days of the date of the first generation of electricity to the local electricity supply.

 

Reason: In order to protect the amenity of the surrounding area and to comply with Policies DR4 and CF4 of the Herefordshire Unitary Development Plan.

 

4.         All the above ground elements of the development and the turbine bases to a depth of 1 metre below ground level shall be removed from the site within 6 months immediately following the expiry of the operational period of the turbines referred to in condition number 3 of these conditions. The land shall be reinstated in accordance with a scheme to be approved in writing by the local planning authority. The scheme for reinstatement shall be submitted for the approval of the local planning authority not later than 20 years from the date of the first generation of electricity to the local electricity supply.

 

Reason:  In order to protect the amenity of the surrounding area once the site has ceased producing electricity and to comply with policy LA2 of the Herefordshire Unitary Development Plan.

 

5.         Notice of the date of commencement of the development shall be given by the developer/operator in writing to the local planning authority before any works commence on the site.

 

Reason:  In order to comply with condition 3 and to comply with Policy CF4 & DR4 of the Herefordshire Unitary Development Plan.

 

6.         Before the development is commenced a scheme to secure the investigation and alleviation of any interference to any form of electromagnetic transmission which may be caused by the operation of the wind turbines shall be submitted by the developer/operator to the local planning authority and approved in writing by the local planning authority.  The scheme shall be implemented as approved.

 

Reason: To protect the amenity of the surrounding area and to comply with Policy S11 of the Herefordshire Unitary Development Plan.

 

7.         All the turbine blades shall rotate in the same direction.

 

Reason: In the interests of the visual amenity of the surrounding area and to comply with Policies DR1 and DR4 of the Herefordshire Unitary Development Plan.

 

8.         The turbines shall be located in the positions shown on the approved plans unless otherwise agreed in writing by the Local Planning Authority.

 

Reason: In the interests of the visual amenity of the surrounding area and to comply with Policies DR1 and DR4 of the Herefordshire Unitary Development Plan.

 

9.         If a wind turbine fails to produce electricity for supply to the grid for a continuous period of 12 months, all of its above ground elements and the turbine bases to a depth of 1 metre below ground level shall be removed at the request in writing of the local planning authority within a period of six months from the end of the 12 month period.  Within the ensuing 12 months the land shall be reinstated in accordance with a scheme that has been submitted by the developer/operator to the local planning authority and approved in writing by the local planning authority.  The scheme shall be submitted within two months of a request in writing by the local planning authority under this condition.

 

Reason: In order to protect the amenity of the surrounding areas and to comply with Policies DR4 and CF4 of the Herefordshire Unitary Development Plan.

 

10.       There shall be no external lighting of the turbines hereby permitted. Before commencement of the development details of any other floodlighting/external lighting during the construction phase shall be submitted by the developer/operator to the Local Planning Authority for written approval. Development shall be carried out in accordance with the approved details and there shall be no other external illumination of the development.

 

Reason: To protect the amenity of the surrounding area and to comply with Policies DR4 of the Herefordshire Unitary Development Plan.

 

11.       Any facilities for the storage of oils, fuels or chemicals shall be sited on impervious bases and surrounded by impervious bund walls. The volume of the bunded compound shall be at least equivalent to the capacity of the tank plus 10%. If there is multiple tankage, the compound shall be at least equivalent to the capacity of the largest tank, vessel or the combined capacity of interconnected tanks or vessels plus 10%. All filling points, associated pipework, vents, gauges and sight glasses must be located within the bund or have separate secondary containment. The drainage system of the bund shall be sealed with no discharge to any watercourse, land or underground strata. Associated pipework shall be located above ground and protected from accidental damage. All filling points and tank/vessels overflow pipe outlets shall be detailed to discharge downwards into the bund.

 

Reason: To prevent pollution of the water environment and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

12.       All foul drainage shall be contained within a sealed and water tight cesspool, fitted with a level warning device to indicate when the tank needs emptying.

 

Reason: To prevent pollution of the water environment and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

13.       Development shall not commence until a Private Water Supply Protection Plan has been submitted by the operator to the local planning authority and approved in writing by the local planning authority. The submitted details shall include the following:-

 

a.         the identification of appropriate water features (including but not limited to springs, boreholes and wells ) and location of water features to be monitored including the proposed observation boreholes adjacent to each turbine foundation, that are to be used for the monitoring of water flows and water quality;

b.         the  method and nature of monitoring with subsequent provision of baseline data to adequately characterize the flow regime and quality and quantity of water provided by any private water supply that might be affected by the development;

c.         the mitigation measures for the protection of such  water features;

d.            the system to ensure that upon notification to the developer of a concern about a possible deterioration in water quality or quantity arising from the development, that immediate provision of alternative suitable and sufficient water supplies takes place (whether on a temporary or permanent basis) in the event of any interruption or adverse change caused by the development in the quantity or quality of water previously enjoyed;

e.            the arrangements for undertaking sampling, measurement and analysis of private water supplies before, during and following construction, (a period of up to 6 months, or as otherwise agreed as part of the Private Water Supply Protection Plan).

The above measures under the Private Water Supply Protection Plan, as approved, shall thereafter be implemented at the developers/operators own expense at all times whilst the development hereby approved remains operational. 

Reason: In order to protect the water environment which includes natural water supplies and to comply with Policy DR6 of the Herefordshire Unitary Development Plan.

 

14.       Before development is commenced a detailed plan for a surface water and ground water management plan to include details of associated drainage and sediment control shall be submitted by the developer/operator to the Local Planning Authority and approved in writing by the Local Planning Authority. The scheme shall be implemented as approved.

 

Reason: To prevent impact on the groundwater environment and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

15.       An appropriately qualified and experienced ecological clerk of works will be appointed (or consultant engaged in that capacity) to oversee the ecological monitoring, mitigation and enhancement work.

 

Reason:  To ensure an appropriate level of protection for all species protected under the Wildlife and Countryside Act 1981 (as amended), the Conservation of Habitats and Species Regulations 2010 and policies NC1, NC6 and NC7 within Herefordshire Unitary Development Plan 2007.

 

To ensure that nesting birds are not disturbed as they are protected under the Wildlife and Countryside Act 1981 (as amended) and policies NC1, NC6 and NC7 within the Herefordshire Unitary Development Plan 2007.

 

To conserve and enhance biodiversity and comply with Herefordshire Unitary Development Plan 2007 Policies NC1, NC6, NC7, NC8 and NC9 in relation to Nature Conservation and Biodiversity and to meet the requirements of PPS9 Biodiversity and Geological Conservation and the NERC Act 2006.

 

16.       Before development is commenced, full working method statements and strategies for protected species (including bats, birds and great crested newts) based upon the recommendations in the Environmental Statement (May 2008) and the Supplementary Environmental Report (October 2008 & October 2010) shall be submitted by the developer/operator to the Local Planning Authority for written approval. These shall be implemented as approved.

 

Reason:  To ensure an appropriate level of protection for all species protected under the Wildlife and Countryside Act 1981 (as amended), the Conservation of Habitats and Species Regulations 2010 and policies NC1, NC6 and NC7 within Herefordshire Unitary Development Plan 2007.

 

To ensure that nesting birds are not disturbed as they are protected under the Wildlife and Countryside Act 1981 (as amended) and policies NC1, NC6 and NC7 within the Herefordshire Unitary Development Plan 2007.

 

To conserve and enhance biodiversity and comply with Herefordshire Unitary Development Plan 2007 Policies NC1, NC6, NC7, NC8 and NC9 in relation to Nature Conservation and Biodiversity and to meet the requirements of PPS9 Biodiversity and Geological Conservation and the NERC Act 2006.

 

17.       Before development is commenced, schemes for long-term monitoring of the impact of the wind turbines upon protected and/or notable species (including bats, birds and great crested newts) shall be submitted by the developer/operator to the Local Planning Authority for written approval. The monitoring schemes shall be implemented as approved and the results submitted annually to the Local Planning Authority.

Reason:  To ensure an appropriate level of protection for all species protected under the Wildlife and Countryside Act 1981 (as amended), the Conservation of Habitats and Species Regulations 2010 and policies NC1, NC6 and NC7 within Herefordshire Unitary Development Plan 2007.To conserve and enhance biodiversity and comply with Herefordshire Unitary Development Plan 2007 Policies NC1, NC6, NC7, NC8 and NC9 in relation to Nature Conservation and Biodiversity and to meet the requirements of PPS9 Biodiversity and Geological Conservation and the NERC Act 2006.

 

18.       Before development is commenced, a full habitat enhancement and management scheme based upon the recommendations in the Environmental Statement (May 2008) and the Supplementary Environmental Reports (October 2008 & October 2010) shall be submitted by the developer/operator to the Local Planning Authority for written approval. This shall be implemented as approved and maintained thereafter.

 

Reason:  To ensure an appropriate level of protection for all species protected under the Wildlife and Countryside Act 1981 (as amended), the Conservation of Habitats and Species Regulations 2010 and policies NC1, NC6 and NC7 within Herefordshire Unitary Development Plan 2007.

 

To ensure that nesting birds are not disturbed as they are protected under the Wildlife and Countryside Act 1981 (as amended) and policies NC1, NC6 and NC7 within the Herefordshire Unitary Development Plan 2007.

 

To conserve and enhance biodiversity and comply with Herefordshire Unitary Development Plan 2007 Policies NC1, NC6, NC7, NC8 and NC9 in relation to Nature Conservation and Biodiversity and to meet the requirements of PPS9 Biodiversity and Geological Conservation and the NERC Act 2006.

 

19.       H03 - Visibility splays

 

Reason: In the interests of highway safety and to conform to the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

20.       H05 - Access gates

 

Reason: In the interests of highway safety and to conform to the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

21.       H06 - Vehicular access construction

 

Reason: In the interests of highway safety and to conform to the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

22.       H13 - Access, turning area and parking

 

Reason: In the interests of highway safety and to ensure the free flow of traffic using the adjoining highway and to conform to the requirements of Policy T11 of Herefordshire Unitary Development Plan.

 

23.       H21 - Wheel washing

 

Reason: To ensure that the wheels of vehicles are cleaned before leaving the site in the interests of highway safety and to conform with the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

24.       H27 - Parking for site operatives

 

Reason: To prevent indiscriminate parking in the interests of highway safety -and to conform to the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

25.       H30 - Travel plans

 

Reason: In order to ensure that the development is carried out in combination with a scheme aimed at promoting the use of a range of sustainable transport initiatives and to conform with the requirements of Policy DR3 of Herefordshire Unitary Development Plan.

 

26.       Prior to the commencement of site works, full details of the turbines including their make, model, design, colour, finish, hub height, blade measurements and power rating shall be submitted to and approved by the Local Planning Authority.

 

Reason: In consideration of the amenity of the surrounding area and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

27.       Prior to the erection of the wind turbines or installation of the transformer units, any wind turbine generator not of the make, model and characteristics considered in the Noise Assessment Chapter of the Environment Statement for the development must first be agreed with the Local Planning Authority.  The following information should be submitted:

 

a)    An acoustic emissions report for the selected wind turbine generator.  The report shall be in accordance with BS En 61400-11, Wind Turbine Generator Systems Part 11:  Acoustic noise measurement techniques and shall include the A weighted sound power levels, spectra and tonality at integer wind speeds from 6 to10 m/s.

 

b)   A Noise prediction report from a suitably qualified and competent acoustic consultant that demonstrates the sound levels from the wind farm will not exceed those conditions set out in Condition 33 below. This should include measurements or calculations that take into account wind shear.  The modes of operations and the type of turbine must be specified.

 

Reason: In consideration of the amenity of the surrounding area and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

28.       During the construction phase the hours during which working may take place shall be restricted to 08:00 to 18:00 Mondays to Fridays and 08:00 to 13:00 on Saturdays. There shall be no such working on Sundays, Bank or Public Holidays.

 

Reason: In order to protect the amenity of occupiers of nearby properties so as to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

29.       Before development is commenced, a scheme to avoid the incidence of any shadow flicker at Folly Farm, The Gutters, Tipton Farm and Willey House or any other dwelling considered reasonable by the Local Planning Authority, shall be submitted to and approved by the Local Planning Authority. The scheme shall include details of the sighting of the photocells and measures to control or shut down the turbine. Unless otherwise agreed in writing, if shadow flicker during the operational period is being caused at a dwelling, the turbine shall be shut down and the blades remain stationary until the conditions causing such effects have passed. The above scheme shall be implemented as approved for the duration of the authorised use.

 

Reason: In the interest of the amenity of nearby properties and to comply with Policy DR4 of the Herefordshire Unitary Development Plan.

 

30.       At the request of the Local Planning Authority, upon receipt of a complaint considered reasonable by the Local Planning Authority relating to noise from the turbines, the operator of the development shall, at its expense, employ an independent consultant approved by the Local Planning Authority to measure and assess the level of noise emissions from the wind turbines.   The noise assessment must be undertaken whilst operational conditions are representative of those appertaining to the periods of operation giving rise to noise complaints.  The noise assessment shall take place within 60 days of a written request by the Local Planning Authority and shall be undertaken following the procedures described in the Guidance Notes annexed to this decision.  Findings shall be reported to the Local Planning Authority within 30 days of the completion of monitoring being undertaken.

 

Reason:  In the interest of the residential amenity of the surrounding area and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

31.       At the request of the Local Planning Authority the developer and/or site operator shall carry out measurements to determine whether the turbines exhibit any tonality.  Tonality measurements shall take place within 30 days of a written request by the Local Planning Authority and shall be undertaken in accordance with procedures described in the Guidance Notes annexed to this decision.

 

Reason: In consideration of the amenity of the surrounding environment and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

32.       The rating level of noise emissions from the combined effects of the wind turbines when measured and calculated in accordance with the Guidance Notes annexed to this decision shall not exceed the values set out in Tables 1 and 2 below.  Where a property is not listed, the rating of noise emissions shall not exceed the lowest value shown for the relevant standardised wind speed.

 

Reason: In the interest of the amenity of surrounding dwellings and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

Night Time Rating Values

23:00 – 07:00

TABLE 1

 

	Standardised 10m agl wind speed (m/s)
	4	5	6	7	8	9	10	11	12
Carter's Farm	38	38	38	38	38	39.8	44.2	48.1	48.1
Cook's House	38	38	38	38	38	39.7	43.8	43.8	43.8
Gutters / Folly Farm	38	38	38	38	38	38.6	38	39.1	39.1
Hill House Farm	38	38	38	38	38	38.3	42.1	45.7	45.7
Maryvale	38	38	38	38	40.4	42.7	43.9	44.2	44.2
The Colony	38	38	38	38	38	39.6	42.8	46	46
The Warren	38	38	38	38	39.9	42.9	45.2	46.5	46.5
Tipton Farmhouse	38	38	38	38	41.2	45.1	48.4	50.5	50.5
Willey House	38	38	38	38	38	38.6	41	42.7	42.7

 

 

Day Time Rating Values

07:00 – 23:00

TABLE 2

 

	Standardised 10m agl wind speed (m/s)
	4	5	6	7	8	9	10	11	12
Carter's Farm	35	35	35	37.4	41	44.2	44.2	44.2	44.2
Cook's House	35	35	35	36	38.7	41.7	44.4	44.4	44.4
Gutters / Folly Farm	35	35	35	36.7	39.8	42.3	42.3	42.3	42.3
Hill House Farm	35	35	35	37.3	41.6	45.1	45.1	45.1	45.1
Maryvale	35	35.3	39.4	43.2	46.1	47.6	47.6	47.6	47.6
The Colony	35	35	35.7	38.5	41.1	43.3	43.3	43.3	43.3
The Warren	35	35	37.5	41	44.4	47.7	47.7	47.7	47.7
Tipton Farmhouse	35	35	37.5	41.3	45.4	48.7	48.7	48.7	48.7
Willey House	35	35	35	37.7	41.3	44.4	44.4	44.4	44.4

 

33.         Upon notification in writing of an established breach of the noise limits as referred to in Condition 32 above, the development operator shall within 30 days submit a scheme for approval to the Local Planning to remedy the breach to prevent future occurrence.

 

Reason:  In the interests of the amenity of the surrounding area and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

34.         From the date of commencement of the operation of the wind farm the operator shall continuously log wind speed, wind direction and power generation data for each wind turbine.  The data shall be continuously recorded throughout the period of operation of the wind farm and made available to the Local Planning Authority within 30 days of their written request.  The wind data shall include the wind speed in metres per second (ms -1) at 10 metres in height and the wind direction in degrees from north for each ten minute period.  Where wind speed is measured at a height other than 10m, the wind speed data shall be converted to 10m height, accounting for wind shear and with the associated methodology for this conversion also provided to the Local Planning Authority.  The data shall be retained for a period of not less than 12 months.

 

Reason: In the interest of surrounding amenity and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

35.         Prior to the commencement of operation of the wind turbines a scheme shall be submitted and approved by the Local Planning Authority for monitoring noise levels at no fewer than 5 selected residential boundary locations during the 6 months following connection to the electricity grid and with the site fully operational.  The duration of such monitoring shall be sufficient to provide comprehensive information on noise levels in a representative range of wind speeds and wind directions with all turbines operating.  Monitoring sites shall be agreed with the Local Planning Authority and monitoring shall be carried out in accordance with the agreed scheme.

 

Reason:  In the interests of residential amenity and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

36.         A revised noise management scheme shall be submitted and agreed in writing with the Local Planning Authority prior to commencement of use of the turbines.  The monitoring and management of low frequency noise, blade swish, amplitude modulation, mechanical defect noise, tonal noise, infrasound, vibration, day and night-time noise levels should be included in the scheme.  The scheme shall be in use for 2 years from the date of agreement.  A new scheme should be agreed every two years by the Local Planning Authority prior to the expiry of the previous scheme.  A scheme shall remain in force for the duration of the authorised use.

 

Reason: In the interest of the amenity of the surrounding environment and to comply with Policy DR13 of the Herefordshire Unitary Development Plan.

 

37.         Before development is commenced details of a nominated representative for the development to act as a point of contact for Local Authority Officers and local residents in relation to noise and nuisance issues shall have been submitted in writing for approval by the local planning authority.  Information shall also be provided detailing the arrangements for notification of any change to the nominated representative.  The nominated representative shall have responsibility for dealing with any noise complaints made during the construction, operation and decommissioning of the wind farm and liaison with the Local Planning Authority.

 

Reason: In consideration of the amenity of the surrounding environment and to comply with Policies DR4 and DR13 of the Herefordshire Unitary Development Plan.

 

38.       The approved

 

Informatives

 

1.         N15 – Reason(s) for the Grant of Planning Permission

The development.

The application proposes four turbines and associated access tracks, hard standing and sub-station building for  a period of 25 years, covering an area of approx. 3.81 hectares on land at Reeves Hill, Reeves Lane, Nr. Knighton,  (Known locally as Stonewall Hill).

The application proposes four three bladed turbines with a total tip height of 105 metres and the maximum length of the blades is 40 metres. Each turbine would have a generating capacity of up to 2.3 megawatts. The site would have the potential of generating up to 9.2 megawatts of electricity, which the Environmental Statement indicates would meet the potential energy requirements of approximately 5,144 homes.

Site location.

The site lies on the English/ Welsh border, and is typical of the surrounding area, being semi-improved agricultural land, mainly used for the grazing of livestock or corn growing. The site forms part of a ridge line running north-south and peaks at a height of just over 400 metres, encapsulating elements of two landscape character types, namely 'Enclosed Moors and Commons' and ' Principle Wooded Hills' , as referred to in the Council’s Landscape Character Assessment, and does not form part of any specific landscape designations. There are approximately 16 dwellings within 1 km of the site.

The nearest landscape designations to the site are the Shropshire Hills Area of Outstanding Natural Beauty, located approximately 3.5 km to the north of the site, and Offa's Dyke National Trail, located approximately 3km to the west of the site. Also slightly further from the site in a westerly direction is another national trail known as Glyndwr's Way. Within 1 km of the application site is a dwelling, Tipton Farm House, which is a grade two Listed Building. There are no other listed buildings within close proximity to the application site.

Environmental Statement.

The application was accompanied by an Environmental Statement as the result of a Scoping Opinion request by the applicants under Environmental Impact Regulations 1999, to which the Scoping Opinion identified the development as EIA development under Schedule 2 - 3i DETR Circular 02/99 - Annex A (15). Further Supplementary Information was submitted in support of the application under Regulation 19 of the Town and Country Planning (Environmental Impacts etc) Regulations 1999 as a result of two separate requests from the Council dated 30th November 2009 and 5th August 2010.

Development Plan Policies.

The relevant development plan is Herefordshire Unitary Development Plan. The key policy is Policy CF4: Renewable Energy. This policy encourages development proposals for renewable energy provided that they do not adversely affect the integrity of sites of international importance for nature conservation and that the objectives of the designation of nationally important sites and areas such as Sites of Special Scientific Interest, National Nature Reserves, Areas of Outstanding Natural Beauty, Scheduled Ancient Monuments or sites of other national archaeological remains will not be compromised and any significant adverse effects on the qualities of the area are clearly outweighed by the environmental social and economic benefits. The Policy also emphasises that outside of nationally designated sites and areas there should be no significant detrimental effect upon the character of the particular landscape and no significant impact upon the amenity of neighbouring residents and that regard will also be given to the wider environmental, social and economic benefits to be gained from the use of renewable energy sources.

Other key Herefordshire Unitary Development Plan Policies are Policy LA2: Landscape areas and areas least resilient to change which indicates that proposals that would adversely affect either the overall character of the landscape and its key features will not be permitted and where appropriate developers will be encouraged to restore degraded or despoiled landscapes to their inherent character.  Policy HBA4: Setting of Listed Buildings indicates that development proposals which would adversely affect the setting of a listed building will not be permitted. Policy ARCH3: Scheduled Ancient Monuments indicates that development proposals and works which may adversely affect the integrity, character or setting of Scheduled Ancient Monuments will not be permitted. Policy NC1: Biodiversity and Development indicates that in determining all development proposals, the effects upon biodiversity and features of geological interest will be taken fully into consideration. Policy DR13: Noise, states developments with the potential for generating significant levels of noise or for exposing a noise sensitive use to an existing noise source will be required to include appropriate measures within the proposal to mitigate the noise impact to an acceptable level or otherwise the development will not be permitted. Policy DR2: Land Use and Activity, refers to sustainable forms of travel and protection to amenity of adjoining land and buildings with no prejudice on surrounding areas. Policy DR3: Movement, refers to a safe and acceptable means of public highway access into and out of the site with consideration to surrounding public highways. Policy S1: Sustainable Development: promotes development and land use change which in terms of its level, form and design contributes to the achievement of sustainable development.

The decision to grant planning permission also had regard to the provisions of National Planning Policy and in particular Planning Policy Statement 22: Renewable Energy; which promotes sustainable forms of renewable energy. Also of consideration, (although scheduled to be abolished),  was Regional Government Advice in the form of the West Midland Regional Spatial Strategy; this encapsulates both the national and Local Plan policies. In addition, nationally it remains a Government objective to provide 15% of all energy consumption from renewable sources by 2020. The proposal is in accordance with National Policy Energy Statements, approved by Parliament in July 2011.

Landscape consideration.

In reaching the decision, the Council were mindful of the particular circumstances of the case, and in particular the key issues of impact of the proposed turbines on the surrounding visual and historic landscape, including Offa’s Dyke and surrounding public rights of way as well as impact on amenity of the surrounding environment, which includes residential amenity and landscape characteristics, most notably the Shropshire Hills Area of Outstanding Natural Beauty. Public Highway access to the site was also given consideration.

Landscape impact was a significant issue as the proposed development is considered to have an impact on the surrounding landscape visually. The Environmental Statement indicates that any landscape impacts will be moderate, depending on the distance from the site and after the application's lifespan of 25 years any detrimental impacts will be reversed. The Council consider the impact is one of a temporary nature (Lifespan of the planning permission). The site itself is within no landscape designations and it is considered that the proposed development will not have any significant detrimental impact on surrounding landscape designations such as the Shropshire Hills Area of Outstanding Natural Beauty due to separation distance. Any impact on Offa's Dyke is considered very localised and there will be no significant detrimental impacts on surrounding historic parks, also in consideration of separation distance, the nearest being Stanage Park and  Brampton Bryan Park neither will there be significant impacts on the Glyndwrs Way.

Biodiversity.

Impacts on biodiversity are considered to be of a low impact as the Environmental Statement indicates the application site has little significant natural cover or remaining habitat, the application site being mainly semi-improved grassland or land used for corn production. The Environment Statement indicates that fauna is diverse but low in number and that the proposed development will result in very little land take and loss of scrub, and therefore little loss in breeding or foraging habitat. Protected species are known to use the site such as Great Crested Newts and Bats. However survey work concluded that there will be very minimal impacts on low numbers of species present and that any impacts can be mitigated with enhancement. A landscape/biodiversity enhancement fund as offered by the applicants will help towards reducing impacts. The Council consider there are not likely to be significant  impacts on biodiversity issues, and  land take for the proposed development is minimal with very little impact on vegetation, or loss of suitable scrub/tree vegetation. Impacts on protected species and nesting birds are considered very minimal. Any concerns as a result of the proposed development on ecological issues can be mitigated by means of appropriate conditions attached to any decision notice issued, as well as the said biodiversity fund.

Hydrology and Hydrogeology.

The Environmental Statement and additional information received acknowledges that water features on site provide water to livestock on the land as well as to surrounding dwellings to the application site. Whilst the additional information in support of the application reclassified the aquifer classification from a non aquifer to a secondary (A) aquifer, in the context of the ground water resource potential the Supplementary information as having a 'high importance' compared to a previously 'low importance', the degree of risk to the wider ground water system remains relatively minor, given the scale of the proposed development. Within the surrounding area are isolated dwellings that have private water supplies, which are fed from the surrounding land including the application site. Whilst it is acknowledged that any likely impacts on water features is minimal, the mitigation as put forward by the applicants is considered acceptable as no precise impacts on water supplies can be established prior to development on site. However the application indicates micrositing for the proposed turbines and with adequate conditions attached to any decision notice to ensure adequate on site monitoring and mitigation it is considered that water features will be adequately protected as advised by the Environment Agency and the Council's Environmental Health Manager in response to the application.

The Environmental Statement and additional information received indicate there will be little impact on surface water drainage. The Council concur with the findings of the information and consider that any issues of concern can be adequately addressed by means of appropriate conditions to any decision notice issued with regard to surface water drainage and on site pollution such as oil spills etc.

Noise.

The applicants by means of the Environmental Statement and additional information have indicated that the predicted noise from turbines on site will be to an acceptable level and fully complies with the industry's ETSU-R-97 guidance as well as that of advice as contained in an  Acoustic Bulletin published in March/April 2009.

In support of the application the applicants as a result of a Regulation 19 request from the Council provided further background noise measurements from nine separate locations neighbouring the proposed wind farm and these locations were approved prior to the background noise testing by Environmental Health Officers of both Herefordshire and Powys County Councils.  The conclusion drawn by both Herefordshire and Powys Council Council’s, is that the additional noise information meets the criteria of ETSUR-97 and with appropriate conditions attached to any decision notice, noise issues are not considered a reason for refusing the application.  In consideration of concerns as raised by the public and in particular the Stonewall Hill Conservation Group, the Council, (Herefordshire), sought the expert advice of noise specialists, (Enviros SKM), who also concluded that the noise data gathered was to an acceptable level, complying with the industry’s guidelines and that the application could be supported with appropriate conditions attached to any decision notice in order to protect surrounding residential amenity.

 

Road and traffic issues.

 

The application was accompanied by a traffic impact assessment which in particular assessed the relationship to abnormal load vehicles, which will approach the site from a northerly direction travelling along the A49 from the north until the junction of the A4113, from where they will travel in a westerly direction to Knighton, (Powys) and then towards the site (along a proposed new stretch of roadway), onto Llanshay Lane towards the application site.

 

Highway issues have been subject to negotiation and discussions between the applicants, police and representative of Shropshire, Powys and Herefordshire Councils Transportation teams and all three councils concluded that transportation issues can be addressed in a satisfactory manner subject to a Section 106 agreement under the Town and Country Planning Act 1990, to which all three councils are party too, to which the applicants accept the proposals as put forward.

 

The last stretch of the access road to the site is along Llanshay Lane which is in the sole control of Powys County Council.  The applicants have made a separate application to Powys County Council for Highway improvements in order to enable the development.  A letter from Powys County Council confirms that this is an acceptable process and therefore the Section 106 agreement on transportation issues under the Town and Country Planning Act 1990 includes details restricting construction of the turbines on site until a satisfactory means of access to the site has been obtained in the form of a planning approval from Powys County Council.

 

Shadow Flicker.

 

The Environmental Statement considered the issue of Shadow Flicker and residential amenity. (Shadow Flicker occurs when the sun passes behind a moving blade and casts a shadow on the window of a neighbouring property). The Environmental Statement indicates that the type of turbine proposed on site will have built in capacity to shut down the relevant turbine when shadow flicker is to occur.  The Council have concluded that the justification put forward by the applicants is acceptable and that an appropriate condition attached to any decision notice will give adequate protection in relation to shadow flicker.

 

Electromagnetic interference.

 

The Environmental Statement considers electromagnetic interference and in the safeguarding assessment, indicates the applicants are willing to undertake an evaluation of any possible effects to local transmitters and introduce suitable mitigation measures that may be required.  The Council consider that a suitable condition attached to any decision notice, addresses this issue satisfactorily.

 

Icing.

 

The Environmental Statement indicates that modern wind turbines don’t have an issue with regard to icing on turbines, (build up of ice on turbine blades).  Turbines are fitted with vibration sensors which identify ice build up in order to close turbine operation and thus avoiding any potential incident in relation to ice thaw.  The Council are satisfied with the applicant’s consideration to this issue.

 

Tourism.

 

Many objections from members of the public were received in relation to impacts of the proposed development on tourism.  Tourism is an important factor in relation to the local economy and in particular in relation to farm diversification.   The Environmental Statement acknowledges tourism has a part to play in the local economy.  There is no substantial evidence to indicate that wind farms are detrimental to tourism and the Council consider that impacts on tourism are not a basis on which to consider refusal of the application.

 

Airfield.

 

The proposed wind farm is some 11km to the north west of Shobdon Airfield.  Herefordshire Gliding Club is also based on this airfield.  The proposed wind farm is not considered an obstacle to the operation of the airport which receives its license to operate from the Civil Aviation Authority and who along with all the other statutory consultees on flight safety raised no objections to the proposed development.  (The manager of Shobdon Airport did object, in consideration of flight safety).

 

None of the published procedures in relation to the Shobdon Airfield illustrate any requirement for aircraft using the airfield to fly in close proximity to the site for the proposed turbines.  The site itself is not on any flight path and furthermore the proposed turbines are under 150 metres high and therefore do not require aeronautical lighting as they do not infringe on any physical safeguarding criteria.

 

Within close proximity to the site is the Powys Spaceguard Centre (Observatory). No objections have been received from the Spaceguard Centre in relation to the proposal.

 

Consultation

 

The Council consulted all the necessary consultees in accordance with EIA regulation requirements and received responses from various consultees to the initial ES as well as the additional information received as a result of the Council's Regulation 19 request.

 

Natural England initially recommended refusal to the application but later withdrew their objection subject to the completion of a legal agreement under Section 106 of the Town and Country Planning Act for a landscape/biodiversity fund for landscape biodiversity enhancement/mitigation in the surrounding area.  The applicants offered this fund and a copy of the Draft Heads of Terms is attached to the report.

 

English Heritage, The Countryside Council for Wales, EON Central Networks, CAA, NATS, MOD OFCOM, The Joint Radio Company Limited, Atkins Windfarm Support, Highways Agency, Severn Trent Water, West Midlands Regional Assembly, Shropshire Hills Area of Outstanding Natural Beauty, RSPB, all responded  raising no objections to the proposed development.

 

The Environment Agency also raise no objections, subject to appropriate consideration to either conditions and/or a legal agreement being attached to any decision notice issued, The Council concluded in conjunction with its Environmental Health and Land Drainage teams that satisfactory conditions could be attached to any decision notice issued.

 

Objections received from Statutory consultees included:  The National Trust, Cadw, The British Horse Society, Hereford and Worcester Gardens Trust, The Georgian Group, The Garden History Society, The Welsh Historic Gardens Trust, The Ramblers Association, (incl Herefordshire Mortimer Group). Many of these objected to the proposed development in consideration of its impacts on the surrounding landscape in relation to its historic context, visual and amenity issues, rights of way etc. All objections were taken into consideration and the Council concluded that concern raised could be addressed by either mitigation or were considered not to be substantial enough in order to recommend refusal to the application having regard to the relevant policy context on sustainable development and renewable energy and the fact that any perceived damage to the environment could be considered temporary and reversed after the life span of the development (25 years).

 

Internal council consultees who raised no objections included: The Environmental Health Manager, (subject to appropriate conditions attached to any approval notice).  Economic Development, the Planning Ecologist, (also subject to appropriate conditions attached to any decision notice)l The Conservation Manager, (Built Environment), Land Drainage Manager, The Forward Planning Manager, Public Rights of Way Manager, Building Control Manager, The Tourism Manager, Minerals and Waste Manager and Transportation Manager, (subject to satisfactory conditions and legal undertaking attached to any decision notice).

 

The County Archaeologist recommended refusal to the application in consideration of the negative impact the proposal would have on Offa’s Dyke within the vicinity of the application site.  The Council concluded that impacts of the proposal on the Dyke were well set out and carefully considered in the Environmental Statement and that any impacts were of a temporary nature and would not have any significant permanent unacceptable impact  on the setting of the Dyke given its distance from the site for the turbine development.

 

Representations.

 

Representations were also received from surrounding Local Parish Council’s both in England and Wales as well as from organisations such as Herefordshire Campaign to Protect Rural England, Herefordshire Wildlife Trust, South Shropshire Campaign for Protection of Rural England, ‘Visit Herefordshire’, Offa’s Dyke Association, The Radnorshire Society, Radnorshire Branch of Campaign to Protect Rural England, West Midlands Friends of the Earth and Herefordshire Friends of the Earth.  Also many letters from the public in support to the application as well as objections, which included: The Stonewall Hill Conservation Group, (a local group set up to oppose the proposed development).

 

Neighbouring Councils

 

Shropshire County Council raised no objections. Powys County Council responded objecting in consideration of concerns about the detrimental impact on the surrounding landscape from a visual, cultural and historic perspective. Concerns were also raised about lack of information on ecological issues, applicants’ noise impact assessment and impacts in relation to hydrological issues. No response was received from Powys County Council with regards to Herefordshire Council's consultation in respect of the additional information received subject to the Regulation 19 request, other than a response from Powys County Council's Environmental Health, raising no objections on noise issues in respect of the Regulation 19 request specifically on noise issues.

 

All representations were carefully considered (as outlined in both committee reports) and the Council concluded that the proposed was considered acceptable with appropriate conditions attached to any decision notice issued and legal agreement between the applicants and the council when assessed against relevant local, regional and national planning policies in consideration of policy criteria on sustainable renewable energy, impacts on the major issues such as landscape, visual, historic, cultural, ecological, noise, residential amenity and highway issues, and the fact that the proposal is temporary in nature and  reversible in relationship to the turbine development after 25 years.

 

Conclusions

 

The application raised many issues and divided opinion both from the public and various consultees.

 

The Council consider the application is in accordance with the principles as set out in PPS 22, as well as development plan policy and in particular Policy CF2 on renewable energy, regional planning policy was also shown consideration.

 

The Council acknowledge the proposed turbines will have a degree of detrimental impact on the surrounding landscape from both a visual and historic context, the fact is that the application site is not in any landscape designation and impacts on the nearby Area of Outstanding Natural Beauty and Offa’s Dyke were considered minimal and any adverse effects will be temporary and reversible, as the application is for a 25 year duration.

 

The proposal is for a source of renewable energy in accordance with Government advice on renewable energy and the application is accompanied by an Environmental Statement that sets out the scale and significance of the likely environmental impacts of the proposal if granted planning permission.

Note - The Community fund is a financial contribution offered by the applicants for the benefit of the local community. This is not a material planning consideration in respect of the application. However to ensure that it is delivered as promised, the applicants have agreed to a Unilateral Undertaking to ensure the financial benefits are delivered as set out in the Environmental Statement.

Relevant Policies considered in the Herefordshire Unitary Development Plan 2007:

· Policy S1 Sustainable development

· Policy S2 Development requirements

· Policy S7 Natural and historic heritage

· Policy DR1 Design

· Policy DR2 Land use and activity

· Policy DR3 Movement

· Policy DR4 Environment

· Policy DR5 Planning obligations

· Policy DR13 Noise

· Policy HBA4 Setting of listed buildings

· Policy LA2 Landscape character and areas least resilient to change

· Policy LA3 Setting of settlements

· Policy LA4 Protection of historic parks and gardens

· Policy NC1 Biodiversity and development

· Policy NC7 Compensation for loss of biodiversity

· Policy NC8 Habitat creation, restoration and enhancement

· Policy NC9 Management of features of the landscape important for fauna and flora

· Policy ARCH 1 Archaeological assessments and field evaluations

· Policy ARCH 3 Scheduled ancient monuments

· Policy CF4 Renewable energy

 

2.      HN01 - Mud on highway

 

3.      HN04 - Private apparatus within highway

 

4.      HN05 - Works within the highway

 

5.      HN07 - Section 278 Agreement

 

6.      HN10 - No drainage to discharge to highway

 

7.      HN24 - Drainage other than via highway system

 

8.      HN25 - Travel plans

 

9.      HN28 - Highways Design Guide and Specification

 

10.    The applicants or successors in title are reminded to advise Defence Estates, DE Operators North, Safeguarding Wind Energy, Kingston Road, Sutton Coldfield, B75 7RL, tel: 0121 311 3714 of the date when construction starts in order for the turbines to be plotted on flying charts.

 

11.  The applicants or successors in title are reminded that permission is required from Powys County Council with regards to the shared access from the adjacent public highway to turbine numbers 1 and 2 and the access from the public highway to turbine number 4 as indicated on the ‘Proposed red line boundary map.

 

GUIDANCE NOTES

 

The following notes are based on the Supplementary Guidance Notes to the Planning Obligation contained in The Assessment and Rating of Noise from Wind Farms (ETSU-R-97) published by ETSU for the Department of Trade and Industry (DTI), page 99.  It has been adapted in the light of experience of actual compliance measurements.

 

NOTE 1

Values of the LA90, 10-minute noise statistic should be measured at the affected property using a sound level meter of at least IEC 651 Type 1 quality.  This should be fitted with a ½” diameter microphone and calibrated in accordance with the procedure specified in BS4142: 1990.  The microphone should be mounted on a tripod at 1.2 – 1.5m above ground level, fitted with a two layer windshield or suitable equivalent, and placed in the vicinity of and external to the property.  The intention is that as far as possible, the measurements should be made in ‘free-field’ conditions.  To achieve this, the microphone should be placed at least 3.5m away from the building façade or any reflecting surface except the ground.

 

The LA90, 10-minute measurements should be synchronised with measurements of the 10-minute arithmetic mean average wind speed, power generation and operational data from the turbine control systems of the wind farm.

 

The wind farm operator shall continuously log arithmetic mean wind speed and arithmetic mean wind direction data in 10 minute periodsfrom the hub height anemometer located on the site meteorological mast unless otherwise agreed with the Local Planning Authority, to enable compliance with the conditions to be evaluated. The mean wind speed data shall be ‘standardised’ to a reference height of 10 metres as described in ETSU-R-97 at page 120 using a reference roughness length of 0.05 metres. It is this standardised 10m height wind speed data which is correlated with the noise measurement in the manner described in Note 2 below. 

 

NOTE 2

The noise measurements should be made over a period of time sufficient to provide not less than 40 valid points.  Measurements should also be made over a sufficient period to provide valid data points throughout the range of wind speeds considered by the Local Authority to be critical and during periods/times at which the noise is considered to be a problem by the complainant.  Valid data points are those that remain after the following data has been excluded:

 

• All periods of rainfall
• All periods during which the wind direction is more than 45 degrees from every line from each of the turbines and the measurement position
• All periods during which turbine operation was not normal

 

A ‘best fit’ curve should be fitted to the data points.  Measurements detailing the complete data set including invalid removed data points shall be retained and submitted to the Local Authority upon request.

 

NOTE 3

Where, in the opinion of the Local Authority, the noise emitted from the turbines contains a tonal component, the following rating procedure should be used.  This is based on the repeated application of a tonal assessment methodology.

 

For each 10-minute interval for which LA90, 10-minute data has been obtained, a tonal assessment is performed on noise emission during 2 minutes of the 10 minute period.  The 2 minute periods should be regularly spaced at 10 minute intervals provided that uninterrupted clean data has been obtained.  Where clean data is not available, the first available uninterrupted clean 2 minute period out of the affected overall 10 minute period shall be submitted.  Any deviations from the standard procedure shall be reported.

 

For each of the 2 minute samples, the margin above or below the audibility criterion of the tone level difference, ?Ltm, is calculated by comparison with the criteria given in section 2.1 on page 104 of ETSU-R-97.  The margin of audibility is plotted against wind speed for each of the 2 minute samples.  For samples where the tones were inaudible or no tone was identified, substitute a value of zero audibility.

 

A Linear regression shall then be performed to establish the margin above audibility at the assessed wind speed for each integer wind speed.  If there is no apparent trend with wind speed then a simple arithmetic average will be used.

 

The tonal penalty is derived from the margin above audibility of the tone according to figure 17 on page 104 of ETSU-R-97.

 

The rating level at each wind speed is the arithmetic sum of the wind farm noise level, as determined from the best fit curve described in Note 2, and the penalty for tonal noise.

 

The rating level shall be determined for each wind speed.  If the values lie below the maximum values of turbine noise indicated by the table in the conditions, then no further action is necessary.

 

NOTE 4

If the rating level is above the limit, a correction for the influence of background noise should be made.  This may be achieved by repeating the steps in Note 2 with the wind farm switched off and determining the background noise at the assessed wind speed (Lb).  The wind farm noise at this speed (Lw) is then calculated as follows where La is the measure level with turbines running but without the addition any tonal penalty:

 

 

Lw = 10 log (10^La/10 – 10^Lb/10)

 

 

The rating level is then recalculated by adding the tonal penalty (if any) to the wind farm noise.   If the rating level is below the values indicated in the table in the conditions then no further action is necessary.

 

If the rating level exceeds any of the turbine noise levels in the table, the development fails to comply with condition 32.