PROPOSED REPOWERING AND EXTENSION TO LLANDINAM WIND FARM, POWYS, WALES BY CELTPOWER LIMITED PROOF OF EVIDENCE OF DR MATTHEW CAND NOISE

Transcription

1 Mid Wales (Powys) Conjoined Wind Farms Public Inquiry SESSION 1: SSA C PROPOSED REPOWERING AND EXTENSION TO LLANDINAM WIND FARM, POWYS, WALES BY CELTPOWER LIMITED PROOF OF EVIDENCE OF DR MATTHEW CAND ON NOISE ON BEHALF OF CELTPOWER LIMITED REFERENCE: BERR/2008/0003 NOISE - Proof of Evidence of Dr M CAND Page 1 of 24

2 TABLE OF CONTENTS 1 PERSONAL EXPERIENCE INTRODUCTION AND SCOPE OF EVIDENCE POLICY RELATING TO WIND FARM OPERATIONAL NOISE IMPACT ASSESSMENT... 8 General and specific policy... 8 National Policy Statements... 8 Relevant Local Policy... 9 Discussion ASSESSMENT OF WIND FARM OPERATIONAL NOISE IMPACT WIND FARM OPERATION NOISE IMPACT NOISE IMPACTS SPECIFIC ISSUES Powys County Council objections PCC statement of case THIRD PARTY OBJECTIONS CONCLUSIONS NOISE - Proof of Evidence of Dr M CAND Page 2 of 24

3 1 Personal Experience 1.1 I am Matthew Cand. I am an Executive Engineer within Hoare Lea Acoustics, the specialist noise and vibration consultancy division of Hoare Lea & Partners, Europe s longest established firm of Consulting Engineers. Hoare Lea Acoustics has more than 40 years experience in dealing with all types of sound and vibration issues. I specialise in the measurement, prediction and assessment of different types of community and environmental noise. 1.2 I hold a degree in Engineering awarded in 2001 by the Ecole Polytechnique, France. I was then awarded in 2005 a Doctor of Philosophy degree in Mechanical Engineering, by Imperial College London, following research work in which I investigated computational techniques of noise predictions for aircraft engines. 1.3 I have been employed in the field of acoustics and noise control for 8 years. I joined Hoare Lea Consulting Engineer's acoustics team in 2005 following completion of my post-graduate studies. My role was to provide acoustic advice for the design and planning of a wide range of construction projects, including architectural acoustic design, building services noise control, and large-scale industrial and infrastructure projects. I have increasingly focused my work in the field of environmental noise assessment, providing services for the study of numerous large-scale residential, transport, industrial and infrastructure projects across the UK. 1.4 I have personally developed particular expertise in wind farm acoustics, through my involvement in the practical assessment of over 40 wind farm projects. This included the assessment of the proposed Llandinam Wind Farm, from the earliest stages of the project. I provided expert witness evidence during noise hearings for the application for the Brechfa Forest West Wind Farm to the Planning Inspectorate. 1.5 I am a member of the UK Institute of Acoustics, and I have been a member of the working group set up by the Institute in response to a request from the Department of Energy and Climate Change (DECC) to NOISE - Proof of Evidence of Dr M CAND Page 3 of 24

4 provide additional guidance on the assessment of wind turbine noise impact. The resulting Good Practice Guide has been recently published I have also been involved in other practical research studies focused on environmental noise which have been published and presented at European and UK noise conferences 2,3,4. 1 A Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise, M. Cand, R. Davis, C. Jordan, M. Hayes, R. Perkins, Institute of Acoustics, May [CPL-NOI-005] 2 A. Bullmore, J. Adcock, M. Jiggins, M. Cand, Wind Farm Noise Predictions and Comparison with Measurements. Proc. Wind Turbine Noise 2009 Conference, Aalborg Denmark, June Cand M., Adcock J., Jobling B. Comparison of measurements of aircraft noise levels and their variability with model results. Proceedings of EURONOISE 2009, Edinburgh October Wind Turbine Amplitude Modulation: Research to Improve Understanding as to its Cause & Effect. A. Bullmore, M. Jiggins, M. Cand, Malcolm Smith, Sabine Von- Hunerbein. Proc. Fourth International Meeting on Wind Turbine Noise, Rome, Italy, April NOISE - Proof of Evidence of Dr M CAND Page 4 of 24

5 2 Introduction and Scope of Evidence 2.1 This Inquiry concerns the Llandinam Wind Farm ( the Development ), a development of thirty-four wind turbines which Celtpower Limited propose to construct and operate on land south-west of Newtown in Powys. This proof of evidence deals with the issues related to noise and vibration from the proposed site during construction and operation. 2.2 The Development originally comprised the replacement of 102 existing turbines with 42 new turbines. An assessment of the potential noise impact of this Development was undertaken by Hoare Lea Acoustics during , the outcome results of which were contained in Chapter 11 of the Llandinam Repowering and Extension Environmental Statement, submitted in support of a section 36 application dated May 2008 (ref: BERR/2008/0003), which, for simplicity, I refer to hereafter in my evidence as the Original ES 5. I was personally involved in this assessment. The Original ES considered the results of a background noise survey undertaken in consultation with Powys County Council (PCC). 2.3 Subsequent to this, Supplementary Environmental Information (SEI) was prepared in 2011 and submitted in January 2012 ("the 2011 SEI"). This followed the reduction of the scheme to 39 turbines, by the omission of Turbines T22, T23 and T24. This SEI comprised an updated noise assessment, which I undertook. 2.4 The assessment followed the methodology set out in ETSU-R-97, The Assessment and Rating of Noise from Wind Farms, dated September The ETSU-R-97 report was prepared by The Working Group on Noise from Wind Turbines convened by the Energy Technology Support Unit of the UK DTI. This report is hereafter generally referred to in my evidence as ETSU-R-97. By reference to the advice contained in 5 Llandinam Repowering and Extension Environmental Statement, April ETSU-R-97, The assessment and Rating of Noise from Wind Turbines [CPL-NOI- 001] NOISE - Proof of Evidence of Dr M CAND Page 5 of 24

6 TAN 8 Planning for Renewable Energy 7 and the National Policy Statement for Renewable Energy Infrastructure (EN-3) the use of the noise impact assessment methodology contained in ETSU-R-97 is the appropriate methodology for the assessment and rating of noise from Wind Energy Developments. This was the position at the time of the noise impact assessment reported in the Original ES, and it remains the case now. 2.5 On 25 September 2012 PCC decided to object to the application and I will make reference to the reasons given for that objection ( The Objection ). 2.6 An additional SEI, submitted in April 2013 ("the 2013 SEI"), included an updated noise assessment following the omission from the application of turbines T19, T20, T21, T25 and T26, resulting in a total of 34 turbines. I also undertook this assessment. 2.7 In undertaking a review of the assessment contained within the Original ES and subsequent SEIs, I conclude it can be satisfactorily demonstrated that the Llandinam Wind Farm can be constructed and operated within noise limits derived according to current best practice, as specified in the relevant planning policy and advice documents, including: Technical Advice Note (Wales) 11: Noise (TAN11) 8 ; Technical Advice Note 8 (TAN8): Planning for Renewable Energy. Overarching National Policy Statement (NPS) for Energy 9 National Policy Statement (NPS) on Renewable Energy Infrastructure Planning Policy Wales Technical Advice Note 8: Planning for Renewable Energy, National Assembly for Wales, 2005 [CD/COM/016] 8 Planning Policy Wales, Technical Advice Note (Wales) 11: Noise (TAN11), 1997 [CPL-PLA-012] 9 Overarching National Policy Statement (NPS) for Energy (EN-1), DECC, July 2011 [CD/COM/001] 10 National Policy Statement for Renewable Energy Infrastructure (EN-3), DECC, July 2011 [CD/COM/002] NOISE - Proof of Evidence of Dr M CAND Page 6 of 24

7 2.8 Specifically, for the operational phase of the development, the assessment methodology set out in ETSU-R-97 The Assessment and Rating of Noise from Wind Farms was followed, as recommended in TAN 8 as well as the NPS on Renewable Energy Infrastructure document. 2.9 My evidence is divided into a number of parts set out as follows: in Chapter 3 I present a review of existing national and regional planning policies and any other relevant guidance relating to the assessment of noisy developments in existing noise sensitive areas, including consideration of wind farm construction and operational noise; in Chapter 4 and Appendix A I present an overview of the specific approach to environmental noise impact assessment of operational noise from wind farms; in Chapter 5 I discuss the issues which pertain to noise from the Development, mainly in relation to operational noise impacts; in Chapter 6 I consider the previous Objection and statement of case of PCC; in Chapter 7 I address the specific concerns over noise raised by third parties in so far as these issues are set out in the available documentation. I will deal as appropriate with any subsequent outstanding matters on the subject of noise by way of rebuttal; in Chapter 8 I summarise the findings of my investigations The evidence which I have prepared and provide for this application reference BERR/2008/0003 in this proof of evidence is true and has been prepared and is given in accordance with the guidance of my professional institution and I confirm that the opinions expressed are my true and professional opinions. NOISE - Proof of Evidence of Dr M CAND Page 7 of 24

8 3 Policy Relating to Wind Farm Operational Noise Impact Assessment 3.1 There is now a well-established approach to assessing and controlling the impact of wind farm operational noise. It is described in the report prepared by ETSU for the Department of Trade and Industry entitled The Assessment and Rating of Noise from Wind Farms (ETSU-R-97). ETSU-R-97 seeks to achieve an appropriate balance between the noise levels associated with this form of renewable energy generation whilst providing adequate protection of residential amenity, thereby reflecting general Government policy on noise control. The ETSU-R-97 methodology has been and remains current Government policy. General and specific policy 3.2 The assessment of noise in general was considered in Appendix 11-A of the Original ES. The current Welsh Assembly planning advice to Local Authorities in Wales concerning takes two forms. General guidance on noise is provided by Planning Guidance (Wales): Planning Policy [CD/COM/008]. This guidance document is then supplemented by Technical Advice Note (Wales) 11: Noise (TAN11) [CPL-PLA-012]. 3.3 General guidance on renewable energy developments is provided in TAN 8 Planning for Renewable Energy [CD/COM/016]. TAN 8 in particular makes clear reference to the use of the ETSU-R-97 methodology as relevant guidance on good practice. National Policy Statements 3.4 The overarching National Policy Statement (NPS) for Energy (EN-1) outlines general considerations on the control of noise from energy developments and makes reference to the specific guidance contained in the National Policy Statement (NPS) on Renewable Energy Infrastructure (EN-3). 3.5 The EN-3 document provides the primary basis for decisions by the National Infrastructure Directorate (NID), which replaces the former Infrastructure Planning Commission (IPC). It sets out national policy NOISE - Proof of Evidence of Dr M CAND Page 8 of 24

9 for large developments in excess of 50 MW; as identified by Mr Frampton and others, the proposed Llandinam Wind Farm, though over 50 MW, predates the procedures under the Planning Act It includes specific guidance on noise impact assessment for onshore wind farm developments. It states that: Mitigation should be inherent in good design of a wind farm so that increases in ambient noise levels around developments are kept to acceptable levels in relation to existing background noise. 3.6 EN-3 advises that the ETSU-R-97 methodology, in accordance with latest industry good practice which should reflect any updated guidance issued in relation to ETSU-R-97 and accepted by Government, should be used to assess whether the noise from the operation of the wind turbines is within acceptable levels, and that: Where the correct methodology has been followed and a wind farm is shown to comply with ETSU-R-97 it should be reasonable for the IPC to conclude that it may give little or no weight to adverse noise impacts from the operation of the wind turbines 3.7 This confirms that ETSU-R-97 represents current government policy. Relevant Local Policy 3.8 This includes Policy E3 (Wind Power) of the Powys County Council Core Strategy which requires in particular that applicants demonstrate that such developments will not unacceptably adversely affect users of sensitive properties, and this will include noise impacts. In the absence of specific criteria, the general policy guidance set out above can be referenced in this respect. Discussion 3.9 In conclusion, ETSU-R-97 seeks to achieve an appropriate balance between some increase in noise levels (accepted by Government Policy as a necessary consequence of wind energy development) and providing adequate protection of residential amenity. Based on the policy, guidance and advice under the planning system, as described NOISE - Proof of Evidence of Dr M CAND Page 9 of 24

10 above, ETSU-R-97 defines noise levels at nearby noise sensitive receptor locations which in planning terms are deemed to be acceptable The test is not one of audibility. Notwithstanding any personal preference of any one person not to be subjected to such audible sound, compliance with ETSU-R-97 means that effects on amenity are considered to be within reasonable and acceptable bounds, having balanced these effects against the benefits from renewable energy generation In the circumstances, the conclusion of unacceptable loss of amenity can only be sustained if the noise levels 'in planning terms' were unacceptable. It is my view that noise levels which meet, and are restricted to, limits derived according to ETSU-R-97 would not be unacceptably high (in planning terms) as they meet the requirements of ETSU-R-97, which remains current government policy, as reiterated as recently as July A wind farm which can operate within noise limits which have been derived according to ETSU-R-97 would, therefore, not be considered to have an unacceptable impact on existing communities in planning terms and will therefore accord with the requirements of both national and local planning policy. NOISE - Proof of Evidence of Dr M CAND Page 10 of 24

11 4 Assessment of Wind Farm Operational Noise Impact 4.1 An overview of the general approach to environmental noise impact assessment was set out in Appendix 11A of the Original ES. In the case of wind farm noise, as set out above, ETSU-R-97 is the relevant methodology to be adopted. 4.2 In summary, the ETSU-R-97 assessment procedure specifies noise limits as a combination of fixed and relative limits. Absolute lower limits, different for day-time and night-time, are designed to provide reasonable protection while not unduly restricting the development. 4.3 ETSU-R-97 also specifies how noise limits can be increased when windrelated background noise levels are sufficiently high to provide some degree of masking of the wind turbine noise, reflecting the variation in both turbine source noise and background noise with wind speed. 4.4 To undertake the assessment of noise impact in accordance with the ETSU-R-97 methodology, the following steps are required: measure the background noise levels, as a function of site wind speed, at the nearest noise-sensitive neighbours to the proposed wind farm, or at least at a representative sample of these dwellings; determine the appropriate day-time and night-time noise-limits; calculate the noise immission levels due to the operation of the wind turbines, as a function of site wind speed, at the nearest neighbours, based on the noise emission characteristics of the wind turbines; compare the calculated wind farm noise immission levels with the derived noise limits. 4.5 Robust noise conditions can then be set out in line with the derived day time and night time noise limits. This methodology was described in the Original ES and is considered in further detail in Appendix A. NOISE - Proof of Evidence of Dr M CAND Page 11 of 24

12 5 WIND FARM OPERATION NOISE IMPACT Overview 5.1. Chapter 11 of the Original ES and subsequent SEI have considered the operational noise impacts of the proposed Llandinam Wind Farm In summary, the assessment of noise impact presented in these documents was performed in accordance with the guidance in ETSU-R- 97. It has therefore fully accounted for the relevant Planning Policy on both a National and Regional level, as set out in section The Original ES included details of measured baseline noise levels at locations determined in consultation with PCC. More conservative criteria based on the fixed absolute limits specified in ETSU-R-97 were used to derive appropriate limits, as considered in paragraphs 5.6 to Operational noise predictions are then considered in paragraphs 5.13 to The calculated noise levels associated with the operation of the Wind Farm were based on the use of a candidate Siemens 2.3 MW VS82m wind turbine These predicted noise immission levels are then compared with the noise limits derived for each location. These comparisons show that compliance with the derived noise levels can be achieved at all locations. The cumulative operational noise from other wind farms in the area is then considered, and compliance remains predicted at all locations. This is considered in paragraphs 5.26 to I then consider other aspects of the assessment in the remainder of this section. NOISE - Proof of Evidence of Dr M CAND Page 12 of 24

13 Baseline noise measurements and noise limits 5.7. The baseline monitoring process undertaken was described in the Original ES. ETSU-R-97 clearly specifies that existing windfarms should not be included within the prevailing background noise for the purpose of deriving noise limits, in order to prevent creeping cumulative increases. The operation of the existing Llandinam windfarm therefore represented a key factor for consideration In consultation with PCC and Celtpower, background noise levels were measured by Hoare Lea Acoustics at six locations (described in Table 11-2 of the Original ES), in combination with some periods of shutdown of the existing wind turbines. This resulted in derivation of an appropriate baseline background noise environment More conservative noise limits, based on fixed absolute limit values of 40 db(a) and 43 db(a) for day-time and night-time respectively, were used at all locations. The Original ES details why these limits are considered suitable for the Development in line with the guidance set out in ETSU-R It is widely recognised that wind speed varies with height above the ground. This effect is commonly termed wind shear. Given the conservative nature of the noise limits proposed for the Development, set at a fixed level which does not increase with wind speed, there is no need to further account for such wind shear effects When considering cumulative impact, and in particular the properties situated in the vicinity of the proposed Llaithddu development, the 2011 SEI additionally considered the noise limits derived in the Environmental Statement for the Llaithddu scheme. For the properties of Pabyllwyd and South of Pabyllwyd, these noise limits were referenced and are set out in Table 11-8 of the 2011 SEI for the Development It is also noted that wind shear effects have been accounted for in the limits which were derived in the ES for the Llaithddu scheme, by incorporating a correction to account for the potential for increased levels of wind shear to occur during night-time periods. This correction NOISE - Proof of Evidence of Dr M CAND Page 13 of 24

14 was applied to the background noise curves from which the resultant ETSU-R-97 noise limits are obtained. These limits were referenced in the SEIs for the properties located in Garn Fach forest area, in proximity to the Llaithddu proposal This approach is consistent with current good practice and ETSU-R-97. Appendix A contains a more detailed discussion of the issues concerning site specific wind shear effects and how they can be dealt with when undertaking a wind farm noise assessment. Prediction of Noise from Operating Wind Turbines ETSU-R-97 does not explicitly specify the type of noise emission data to consider or the method to calculate the propagation from source to receptor. For both of these considerations, examined in turn below, reference can be made to best practice in the field, based on relevant research work and practical experience at a number of operational wind farm sites It is common practice that developers cannot secure a preferred turbine supplier until a planning consent has been secured. Furthermore, due to the time involved in the planning process, there is no guarantee that the same turbine would still be commercially available by the time the wind farm is built. When demonstrating to the determining authority that it will be possible to build a wind farm capable of operating within the derived noise limits, it is therefore standard practice to select for this purpose a typical candidate turbine, typical of those that may be considered for installation at the site In this respect, the noise emission characteristics of modern turbines have improved rapidly with technological improvements in nacelle insulation and blade design and control. The type of turbines to be used at the site will employ variable speed control mechanisms which regulate the pitch of the blades, ultimately leading to relatively similar emissions characteristics for the different makes of turbines which could be used at the site. Notwithstanding these considerations, turbine emissions can vary slightly. Nonetheless, even if the final NOISE - Proof of Evidence of Dr M CAND Page 14 of 24

15 turbine selected differs from the candidate turbine considered at the earlier stage, any developer is still bound by the noise limits fixed by condition on any consent granted The candidate turbine used for the Original ES is the Siemens 2.3 MW VS82m machine. It was selected in the Original ES and retained in the subsequent SEIs as being representative of the typical emissions for the type of turbine being considered at the site More often than not, a manufacturer will warrant the sound power output level of their turbine to not exceed a level greater than the certification test measured level plus the stated uncertainty associated with the measurement. It is common practice for wind farm developers to account for this uncertainty/warranty margin when designing wind farm layouts, as this is the level of noise that is guaranteed not to be exceeded. This adoption of conservative sound power levels has been adopted throughout the assessment of operational noise impact arising from Llandinam Wind Farm The at source noise emission levels for all the candidate turbines are based on manufacturer s data which include a margin to account for measurement uncertainties, all in accordance with current best practice. These levels and spectral data assumed for the Siemens 2.3 MW VS82m turbine were presented in Table 11-1 in section of the 2011 SEI A number of empirical or semi-empirical noise propagation models are currently in common use. The model utilised in both the Original ES and herein is based on ISO which is the International Standard applicable to noise propagation predictions Importantly, the ISO method has mainly been derived to calculate the noise level expected under conditions favourable to the propagation of sound from the source to the receiver, such as those obtained when downwind of the source (which the Standard defines as 11 International Organisation for Standardisation (ISO), Acoustics Attenuation of Sound During Propagation Outdoors, Part 2: A General Method of Calculation, ISO :1996 [CPL-NOI-004] NOISE - Proof of Evidence of Dr M CAND Page 15 of 24

16 a wind direction within an angle of 45 degrees of the direction connecting the source to the receiver). Under other conditions, the received noise level can be significantly lower than that calculated using the ISO procedure. In particular it has been demonstrated that, under upwind propagation conditions, received noise levels are commonly more than 10 db(a) to 15 db(a) less than the ISO calculated levels In order to clarify some of the potential issues that have historically resulted from the use of ISO for the calculation of noise propagation from wind farms, a summary set of best practice guidelines 12 was published by a group of acousticians having an interest in wind farm noise. Subsequently this was followed by the publication in May 2013 of the aforementioned Institute of Acoustics Good Practice Guide 1. Where the use of ISO allows a user selectable choice of certain parameters (e.g. temperature, humidity, ground factor, receiver height) this guidance recommends the values most appropriate to the assessment of wind farm noise propagation. This was based on research in the area of outdoor sound propagation, both for noise sources in general and from operational wind farms specifically. All results presented the Original ES and SEIs follow these best practice recommendations, and represent realistic estimates of the levels of noise likely to be experienced when receptor locations are downwind of the turbines The most up-to-date predictions of noise from the Development are shown in the 2013 SEI (Table 11-5), based on the layout of 34 turbines The same 2013 SEI also considers cumulative operational noise predictions for other wind farms in the area In the original ES and 2011 SEI, the impact of the Llanbadarn Ffynydd, Garreg Lwyd Hill, Bryn Titli and Waun Garno wind farms was assessed and was found to be effectively negligible. For other wind farms which 12 Bowdler et. al., IOA Bulletin article, 2009 [CPL-NOI-002] NOISE - Proof of Evidence of Dr M CAND Page 16 of 24

17 are proposed or existing in the area but situated even further away, the additional operational noise contribution is also negligible. Smallerscale or single-turbine developments are considered to produce a relatively low noise contribution outside of their immediate surroundings, and are situated in such a way that their relative effect at the properties considered in the assessment undertaken in the assessment would also be negligible The cumulative operational noise assessment in the 2013 SEI therefore considered the Development along with the proposed Llaithddu, Neuadd Goch, and Hirddywel windfarms, as all the other developments considered were determined to have negligible effects. Section 11.8 of the 2013 SEI presented noise predictions from each of these individual wind farms, as well as cumulative predictions from all turbines in Table These calculations assume simultaneous downwind propagation for all turbines, which represents a conservative assumption. Assessment of Noise Impact at Receptors The assessments shown in the 2013 SEI, which is the most up-to-date, compared predicted noise immission levels with the noise limits derived for each location. The predictions for the Development with all turbines operating unconstrained comply with the derived limits at all locations and all wind speeds In addition, the assessment of tables 11.9 and of the 2013 SEI demonstrates that the cumulative noise predictions remain below the relevant noise limits at all wind speeds and for all properties Satisfactory control of cumulative noise immission levels would be achieved through enforcement of the individual consent limits for each of the individual windfarms, through the application of suitable planning conditions. Partial noise limits, which would apply to the Llandinam wind farm in isolation, were shown in Table 11-3 of the 2013 SEI. For dwellings in the vicinity of the Llaithddu wind farm, they were obtained through the apportionment of the total ETSU-R-97 limit. These partial limits are such that compliance of the Development with these noise limits would maintain the conclusion of the cumulative NOISE - Proof of Evidence of Dr M CAND Page 17 of 24

18 assessment and result in cumulative levels which do not exceed the derived ETSU-R-97 noise criteria and therefore remain acceptable It is therefore possible to construct conditions to control operational noise from the proposed Llandinam Wind Farm to the noise limits derived in the Original ES/SEI, all in line with the guidance of ETSU-R- 97 and current best practice. A Condition wording to control operational noise from the turbines is included in the proposed set of draft conditions. The wording is considered robust and standard, having been developed over a number of years and accepted in a similar form for previous developments (see [CPL-INS-012] for example). The wording is based on the example provided in Annex B of the Institute of Acoustics 2013 Good Practice Guide document For the reasons outlined above, it is standard practice to consider a candidate turbine at the application stage. However, other turbine models are available which would enable same noise limits to be achieved. It is for the wind farm operator to determine how best to comply with these noise limits. The selection of the final turbine to be installed at the Development would be made on the basis of enabling the relevant partial noise limits to be achieved at the surrounding properties ETSU-R-97 specifies a penalty to be applied for the presence of tonal components in the noise emitted by the turbines. The potential for this characteristic to be emitted is best controlled by way of a penalty applied to overall noise levels and incorporated into the methodology for demonstrating compliance. This is included within the proposed noise condition (guidance note 3 attached to the operational noise condition) in order to provide a robust control of noise levels from the development. Micro-siting The proposed 50 m micro-siting tolerance for turbines would correspond to potential differences in the wind turbine noise level of less than 1 db(a) at any given property. A level change of this order would be unlikely to alter the preceding findings with respect to NOISE - Proof of Evidence of Dr M CAND Page 18 of 24

19 construction and operational noise. The proposed micro-siting of turbines 10, 13, 32 and 14 proposed in 2013 would correspond to a predicted negligible change of 0.1dB or less. Irrespective of the degree of micro-siting actually employed, noise immissions from the wind farm will still be required to meet the derived noise limits. Low Frequency Noise, Infrasound and Ground-borne vibration Vibration levels and infrasound noise levels at all noise sensitive receptors will be well below the thresholds of perception Potentially audible low frequency noise (20 to 200Hz) is adequately accounted for within the assessment of overall A-weighted noise levels presented within the Original ES and SEIs (see Appendix A for details). Amplitude/Aerodynamic Modulation (AM) ETSU-R-97 suggests that a certain level of amplitude/aerodynamic modulation (AM) should be considered typical of the characteristics of wind turbine noise. The methodology formulated in ETSU-R-97 therefore does not propose any additional penalty for the presence of AM. The mechanisms/circumstances that may give rise to increased levels of AM is not well understood and the potential for increased levels of AM to be present cannot be predicted, but the likelihood is low based on the experience of other operating wind farms (see Appendix A for details) It is not appropriate or possible to formulate an effective condition to control the potential for increased levels of AM based on the current state of knowledge. The most appropriate way of dealing with the potential for increased levels of AM, should it occur, is by way of nuisance action; this separate regime affords appropriate protection. Construction and Decommissioning Noise The Original ES and subsequent SEIs presented an assessment of the impact of the noise associated with the construction and decommissioning activities of the Development, including construction traffic and the potential for cumulative effects in this respect. NOISE - Proof of Evidence of Dr M CAND Page 19 of 24

20 5.39. Based on this assessment, noise during construction and decommissioning of the Llandinam Wind Farm is not predicted to cause significant impacts and is most appropriately dealt with by way of planning conditions restricting the hours when significant noise generating activities may take place. In addition to existing powers under the Control of Pollution Act 1974, one of the proposed conditions would secure a Construction Method Statement which would detail working practices used to control noise emissions during construction, with reference to BS 5228:2009. In addition, another proposed condition would restrict the hours of work and of traffic movements. I consider that this represents the mitigation required in this instance. NOISE - Proof of Evidence of Dr M CAND Page 20 of 24

21 6 Noise Impacts Specific Issues Powys County Council objections 6.1 PCC s decision (dated 25 September 2012) cites noise as one of the objections: There is insufficient information to demonstrate that there will not be unacceptable adverse noise impact. 6.2 Prior to this, in early September, a representative from the Environmental Health Department of PCC had expressed his strong recommendation that joint discussions between applicants (or their appointed consultants) for the Llandinam and Llaithddu developments take place. The aim of these discussions being to agree a suitable apportionment of the total noise limits between the two applicants, at relevant properties, because of the relative proximity of both developments. 6.3 These discussions took place and the resulting agreed conditions were confirmed to PCC on the 24/09/2012, which I understand was too late to be considered for the decision taken the next day. The reference to insufficient information therefore likely relates to the then outstanding joint agreement on suitable noise conditions. 6.4 PCC also reserved the right to raise further issues including health implications, however this was not considered further. PCC statement of case 6.5 PCC now acknowledges that the necessary information had been provided. In its final statement of case for Session 1 of the inquiry, for the Llandinam Development, PCC state that they are satisfied in principle that noise can be managed within acceptable levels through appropriately worded conditions. 6.6 The wording of the condition on operational noise for the Development is based on that set out as an example in the Institute of Acoustics Good Practice Guide (Annex B), which PCC recommended NOISE - Proof of Evidence of Dr M CAND Page 21 of 24

22 (correspondence 15/07/2013). It is therefore expected that significant common ground is likely to be reached with PCC. 6.7 The statement of case does not make reference to health implications of the Development. NOISE - Proof of Evidence of Dr M CAND Page 22 of 24

23 7 Third Party Objections 7.1. Concern has been raised by some objectors regarding the levels of noise generated by the proposed wind farm. As stated in section 3 and detailed in Appendix A, the ETSU-R-97 method provides the appropriate balance between the impact of operational noise from wind farms on residential amenity and the provision of renewable energy generation, under current UK planning policy Section 5 of my proof presents the results of operational noise predictions for the Llandinam Wind Farm. All of the predictions indicate that the acceptable noise limits derived in accordance with ETSU-R-97 can be achieved at all of the properties considered. As such, whilst noise from the proposed turbines may be audible under certain weather conditions, the predicted impact of noise on residential amenity in the local area would be considered acceptable under current planning guidelines Another concern that has been raised is that of the potential health effects of noise from wind farms. This subject was considered in Appendix 11-A of the Original ES with further considerations in Appendix A of this proof. There is no scientific evidence that noise of the character and level of that produced by wind farms will cause any direct health effects. NOISE - Proof of Evidence of Dr M CAND Page 23 of 24

24 8 Conclusions 8.1 This evidence has reviewed the adequacy of the assessment of noise from the proposed Llandinam Wind Farm, in terms of the assessment contained in the Original ES and subsequent SEIs. This evidence has covered the potential impact of the decommissioning, construction and operational noise arising from the wind farm development. 8.2 Through my evidence, and by reference to the information contained in the aforementioned documents, it is my view that sufficient information has been presented to establish that the wind farm can be constructed and operated fully in accordance with all relevant procedures, as specified in relevant planning policies, relevant Standards and other relevant guidance documents such as the recently published Institute of Acoustics Good Practice Guide. 8.3 For wind farm operational noise, the accepted noise criteria derived in accordance with ETSU-R-97 have been applied. The methodology set out in ETSU-R-97 is recommended as relevant good practice for the assessment of wind farm noise in TAN 8. The ETSU-R-97 derived noise criteria applicable to both day-time and night-time periods will be achieved at all residential dwellings in the vicinity of the proposed wind farm at all wind speeds. This remained the case when considering the cumulative impact of neighbouring wind farms. 8.4 As a result of my investigations, I conclude there is no cause to consider noise as a reason for refusal of the application relating to the proposed Llandinam Wind Farm. Matthew Cand PhD MIOA 01 August 2013 NOISE - Proof of Evidence of Dr M CAND Page 24 of 24