Mr Edward Romaine Land at Troed-y-Bryn, Tregaron ... 8 noise assessme… · MLM Acoustics TEL:...

MLM Acoustics TEL: 01872 672010

Trevissome Park, Blackwater, Truro, Cornwall, TR4 8UN

Mr Edward Romaine

Land at Troed-y-Bryn, Tregaron, Ceredigion, Cymru, SY25 6QF

Technical Report

Document Ref: AB/100504/R1 Prepared: Antony Best BSc (Hons) MIOA

Revision: 0 Principal Acoustic Consultant

Date: 28 August 2014

Land at Troed-y-Bryn Wind Turbine © MLM Consulting Engineers Ltd Technical Report

N:100504/R1 2

Table of Contents

1 Introduction .............................................................................................. 3

2 Scope and Limitations ................................................................................ 3

3 Relevant Standards and References ............................................................. 3

4 Site Description ......................................................................................... 4

5 Assessment Criteria.................................................................................... 5

6 Calculations............................................................................................... 5

7 Assessment............................................................................................. 16

8 Conclusion .............................................................................................. 17

Appendices

Appendix A – Definition of Terms ..................................................................... 20

Appendix B – Summary of Manufacturers’ Noise Data......................................... 22


N:100504/R1 3

1 INTRODUCTION

MLM Acoustics has been commissioned by Mr Edward Romaine, to undertake an

environmental noise assessment for the proposed wind turbine on land associated

with Troed-y-Bryn, Llwnygroes, Tregaron, Ceredigion, Cymru, SY25 6QF, in

accordance with the guidance given in ETSU-R-97.

This environmental noise assessment considers noise as a result of the proposed

Endurance X-29 wind turbine. This report details the calculation and assessment of

the impact of the proposed wind turbine at the nearest noise sensitive receptors.

Objectives and Aims

The objective of this report is to:

• Assess the likelihood of the proposed wind turbines impacting adversely on the

nearest noise sensitive receptors;

• Assess, by calculation, the noise impact on the noise sensitive receptors in

accordance with nationally recognised standards.

The aim of this report is to:

• Be used as part of a planning application made to the Local Planning Authority.

2 SCOPE AND LIMITATIONS

This environmental noise assessment has the following limitations:

• The assessment relates to the effect of noise on the nearest noise sensitive

receptors, resultant from the proposed wind turbine;

• The distance between the wind turbines and the nearest noise sensitive premises

has been calculated to the curtilage of that receptor;

• The noise data relating to the wind turbine was provided by the manufacturer;

and

• The degree of detail presented within the report is limited by the information

available to the writer at the time of this assessment.

3 RELEVANT STANDARDS AND REFERENCES

The assessment will be made in accordance with the following references and

standards, whose relevance will be explained in the assessment text:

• ISO9613-1:1993 Acoustics – Attenuation of sound during propagation outdoors –

Part 1: Calculation of the absorption of sound by the atmosphere.

• ISO9613-2:1996 Acoustics – Attenuation of sound during propagation outdoors –

Part 2: General method of calculation.

• ETSU-R-97 The Assessment & Rating of Noise from Wind Farms.


N:100504/R1 4

4 SITE DESCRIPTION

The proposed Endurance X-29 wind turbine is located on land associated with Troed-

y-Bryn. The Endurance X-29 is a 225 kW wind turbine, with a hub height of 30.0 m

supporting a 30.0 m diameter rotor blade assembly, with the overall height of the

turbine being 45.0 m. This is not a candidate wind turbine.

The proposed Endurance X-29 (WT1) is located at E:261829 N:258717.

A summary of the distances between the non-financially involved residential noise

receptors and WT1 can be seen below in Table 1.

TABLE 1: NON-FINANCIALLY INVOLVED RESIDENTIAL RECEPTORS (WT1)

Receptor ID Easting Northing Distance from WT (m) Valley Penalty?

Glynissa R1 261813 259296 579 N

Cefn-y-Garn R2 262201 258987 460 N

Tynyrhos Bungalow R3 262627 258834 807 N

Tynyrhos Farm R4 262701 258777 874 N

Tynyrhos Uchaf R5 262543 258644 718 N

Cae-glas R6 262240 258499 465 N

Penlan R7 261973 258232 506 N

Cefnfaes R8 261387 258331 587 N

Cilrhyg R9 260983 259131 942 Y

Glan-dwr R10 261206 259350 888 Y

Fron-heulog R11 261252 259355 860 Y

Llysywawr R12 261284 259511 963 Y

A summary of the distances between the financially involved residential noise

receptors and WT1 can be seen below in Table 2.

TABLE 2: FINANCIALLY INVOLVED RESIDENTIAL RECEPTORS (WT1)

Receptor ID Easting Northing Distance from WT (m) Valley Penalty?

Goyallt F1 261598 259047 403 N

Troed-y-Bryn F2 261645 259072 400 N


N:100504/R1 5

5 ASSESSMENT CRITERIA

When assessing the noise impact on non-financially involved receptors, Clause 25 of

the ETSU-R-97 guidance states the following:

“For single turbines or wind farms with very large separation distances between the

turbines and the nearest noise sensitive receptors a simplified noise condition may

be suitable. We are of the opinion that, if the noise is limited to an LA90,10min of

35 dB(A) up to wind speeds of 10 ms-1 at 10 m height, then this condition alone

would offer sufficient protection of amenity, and background noise surveys would be

unnecessary. We feel that, even in sheltered areas when the wind speed exceeds

10 ms-1 on the wind farm site, some additional background noise will be generated

which will increase background levels at the receptor”.

In addition to this, the noise impact on financially involved receptors shall be

assessed against a maximum noise level of LA90 45 dB(A) up to wind speeds of

10 ms-1 at 10 m height.

6 CALCULATIONS

Assumptions

Background Information

Calculations were carried out in accordance with guidance given in ISO9613-1:1993

and ISO9613-2:1996. The calculation parameters calculate the equivalent continuous

downwind sound pressure level at each noise sensitive receptor, in accordance with

Equation 3 and Equation 5 in Clause 6 set out in ISO9613-2:1996. As such, any

meteorological correction, Cmet, which is used to calculate the equivalent continuous

long term sound pressure level, as set out in Clause 8 of ISO9613-2:1996, has been

ignored.

The wind turbine noise level has been calculated in full accordance with the guidance

given in the Institute of Acoustics’ A Good Practice Guide to the Application of ETSU-

R-97 for the Assessment and Rating of Wind Turbine Noise.

It is stated that G=0.5 should be used together with the vendor’s warranted sound

power levels or with measured turbine sound power levels plus an allowance for

measurement uncertainty. It is recommended that when using a Ground Factor of

0.5, the source height should the hub height of the specific wind turbine, with the

receiver height set to 4 m above ground level. It is recommended that the calculated

LAeq should be converted into LA90 by applying a correction 1.5-2.5 dB(A).

A correction of 2.0 dB has been applied to all subsequent calculations, in accordance

with the guidance given by the Institute of Acoustics.

In order to calculate atmospheric absorption, absorption coefficients at a

temperature of 10 °C and relative humidity of 70% have been used.


N:100504/R1 6

Endurance X-29 Emission Data

The calculations are based on the apparent sound power levels for the Endurance

X-29 wind turbine, as given by the manufacturers. The apparent sound power levels

for the Endurance X-29 wind turbine can be seen below in Table 3.

TABLE 3: APPARENT SOUND POWER LEVELS FOR ENDURANCE X-29

10m height wind speed (ms-1) 4 5 6 7 8 9 10

Apparent sound power level, LWA,k (dB) 92.5 93.6 94.7 95.8 97.0 98.1 99.2

The octave band noise spectrum used for predictions was taken from the octave

band sound power level data given for 10 ms-1 in the manufacturer’s data and

normalised to the overall sound power level for all effective sound power levels

shown above in Table 3 and can be seen below in Table 4.

TABLE 4: A-WEIGHTED OCTAVE BAND SPECTRUM FOR ENDURANCE X-29

Octave band centre frequency (Hz) 63 125 250 500 1k 2k 4k

Octave band sound power level (dBA) 83.4 90.1 92.7 94.2 91.4 89.8 84.5

In the absence of the measurement uncertainty, a correction of 2 dB has been

applied to all calculations, in accordance with the guidance given by the

manufacturer.

A summary of the manufacturers’ noise data can be seen in Appendix B – Summary

of Manufacturers’ Noise Data.


N:100504/R1 7

Noise Map

The noise emissions associated with the proposed wind turbines have been calculated and plotted onto a map of the surrounding area, using Brüel & Kjær

Predictor v6.2.

The resultant noise map can be seen overleaf in Figure 1. It should be noted that a

detailed breakdown of the calculated noise emissions, at each of the receptors, has

been presented later on in this section.


N:100504/R1 8

FIGURE 1: NOISE EMISSIONS FROM PROPOSED WIND TURBINE


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Non Financially Involved Receptors

Glynissa

The calculations for the sound pressure level at Glynissa from WT1 can be seen

below in Table 5.

TABLE 5: GLYNISSA CALCULATIONS FROM WT1

Octave band centre frequencies, Hz (dB) Element

63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5

Distance attenuation -66.3 -66.3 -66.3 -66.3 -66.3 -66.3 -66.3

Atmospheric attenuation -0.1 -0.2 -0.6 -1.1 -2.1 -5.6 -19.0

Ground absorption 3.0 -0.2 0.5 1.5 1.5 1.5 1.5

Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 22.1 25.3 28.4 30.3 26.5 21.4 2.8

The total A-weighted broadband sound pressure level is LAeq 34.5 dB. As such, the

calculated LA90 at Glynissa is 32.5 dB at a wind speed of 10 ms-1 from WT1.

Cefn-y-Garn

The calculations for the sound pressure level at Cefn-y-Garn from WT1 can be seen

below in Table 6.

TABLE 6: CEFN-Y-GARN CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5


Atmospheric attenuation 0.0 -0.2 -0.5 -0.9 -1.7 -4.5 -15.1


Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 24.1 27.5 30.5 32.5 28.9 24.6 8.7


calculated LA90 at Cefn-y-Garn is 34.8 dB at a wind speed of 10 ms-1 from WT1.


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Tynyrhos Bungalow

The calculations for the sound pressure level at Tynyrhos Bungalow from WT1 can be

seen below in Table 7.

TABLE 7: TYNYRHOS BUNGALOW CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 19.2 22.2 25.3 27.0 22.8 16.3 -7.6


calculated LA90 at Tynyrhos Bungalow is 29.2 dB at a wind speed of 10 ms-1 from

WT1.

Tynyrhos Farm

The calculations for the sound pressure level at Tynyrhos Farm from WT1 can be


TABLE 8: TYNYRHOS FARM CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 18.5 21.5 24.5 26.2 21.8 15.0 -10.5


calculated LA90 at Tynyrhos Farm is 28.4 dB at a wind speed of 10 ms-1 from WT1.


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Tynyrhos Uchaf

The calculations for the sound pressure level at Tynyrhos Uchaf from WT1 can be


TABLE 9: TYNYRHOS UCHAF CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 20.2 23.3 26.4 28.2 24.1 18.2 -3.7


calculated LA90 at Tynyrhos Uchaf is 30.4 dB at a wind speed of 10 ms-1 from WT1.

Cae-glas

The calculations for the sound pressure level at Cae-glas from WT1 can be seen

below in Table 10.

TABLE 10: CAE-GLAS CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 24.0 27.4 30.4 32.4 28.8 24.4 8.4


calculated LA90 at Cae-glas is 34.7 dB at a wind speed of 10 ms-1 from WT1.


N:100504/R1 12

Penlan

The calculations for the sound pressure level at Penlan from WT1 can be seen below

in Table 11.

TABLE 11: PENLAN CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 23.2 26.6 29.6 31.6 27.9 23.3 6.3


calculated LA90 at Penlan is 33.9 dB at a wind speed of 10 ms-1 from WT1.

Cefnfaes

The calculations for the sound pressure level at Cefnfaes from WT1 can be seen

below in Table 12.

TABLE 12: CEFNFAES CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 22.0 25.2 28.3 30.2 26.3 21.2 2.4


calculated LA90 at Cefnfaes is 32.4 dB at a wind speed of 10 ms-1 from WT1.


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Cilrhyg

The calculations for the sound pressure level at Cilrhyg from WT1 can be seen below

in Table 13.

TABLE 13: CILRHYG CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 17.8 20.8 23.8 25.4 20.9 13.7 -13.4


calculated LA90 at Cilrhyg is 27.6 dB at a wind speed of 10 ms-1 from WT1. Including

the valley penalty, as identified in Table 1, the overall wind turbine noise level

Cilrhyg, from WT1, is LA90 30.7 dB.

Glan-dwr

The calculations for the sound pressure level at Glan-dwr from WT1 can be seen

below in Table 14.

TABLE 14: GLAN-DWR CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 18.3 21.3 24.4 26.0 21.6 14.7 -11.1


calculated LA90 at Glan-dwr is 28.2 dB at a wind speed of 10 ms-1 from WT1.

Including the valley penalty, as identified in Table 1, the overall wind turbine noise

level Glan-dwr, from WT1, is LA90 31.2 dB.


N:100504/R1 14

Fron-heulog

The calculations for the sound pressure level at Fron-heulog from WT1 can be seen

below in Table 15.

TABLE 15: FRON-HEULOG CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 18.6 21.6 24.7 26.3 22.0 15.2 -9.9


calculated LA90 at Fron-heulog is 28.5 dB at a wind speed of 10 ms-1 from WT1.


level Fron-heulog, from WT1, is LA90 31.5 dB.

Llyswawr

The calculations for the sound pressure level at Llyswawr from WT1 can be seen

below in Table 16.

TABLE 16: LLYSWAWR CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 17.6 20.5 23.6 25.1 20.6 13.3 -14.3


calculated LA90 at Llyswawr is 27.4 dB at a wind speed of 10 ms-1 from WT1.


level Llyswawr, from WT1, is LA90 30.4 dB.


N:100504/R1 15

Financially Involved Receptors

Goyallt

The calculations for the sound pressure level at Goyallt from WT1 can be seen below

in Table 17.

TABLE 17: GOYALLT CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 25.2 28.7 31.7 33.8 30.3 26.3 11.7


calculated LA90 at Goyallt is 36.1 dB at a wind speed of 10 ms-1 from WT1.

Troed-y-Bryn

The calculations for the sound pressure level at Troed-y-Bryn from WT1 can be seen

below in Table 17.

TABLE 18: TROED-Y-BRYN CALCULATIONS FROM WT1


63 125 250 500 1k 2k 4k

Wind turbine sound

power level 83.4 90.1 92.7 94.2 91.4 89.8 84.5




Uncertainty 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Lp 25.3 28.8 31.8 33.9 30.4 26.3 11.8


calculated LA90 at Troed-y-Bryn is 36.2 dB at a wind speed of 10 ms-1 from WT1.


N:100504/R1 16

7 ASSESSMENT

It was stated in Section 5 that the calculated sound pressure level of the proposed

wind turbine should not exceed LA90 35.0 dB at the non-financially involved

receptors.

The assessment for the non-financially involved receptors can be seen below in

Table 19.

TABLE 19: ASSESSMENT OF NON-FINANCIALLY INVOLVED RECEPTORS

Receptor Wind turbine noise

level, LA90 (dB) Criteria, LA90 (dB) Difference (dB)

Glynissa 32.5 35.0 -2.5

Cefn-y-Garn 34.8 35.0 -0.2

Tynyrhos Bungalow 29.2 35.0 -5.8

Tynyrhos Farm 28.4 35.0 -6.6

Tynyrhos Uchaf 30.4 35.0 -4.6

Cae-glas 34.7 35.0 -0.3

Penlan 33.9 35.0 -1.1

Cefnfaes 32.4 35.0 -2.6

Cilrhyg 30.7 35.0 -4.3

Glan-dwr 31.2 35.0 -3.8

Fron-heulog 31.5 35.0 -3.5

Llysywawr 30.4 35.0 -4.6

It can be seen that the criteria has been met at all of the nearest non-financially

involved residential receptors.

It was stated in Section 5 that the calculated sound pressure level of the proposed

wind turbine should not exceed LA90 45.0 dB at the financially involved receptors.

The assessment for the financially involved receptors can be seen below in Table 20.

TABLE 20: ASSESSMENT OF FINANCIALLY INVOLVED RECEPTORS

Receptor Wind turbine noise

level, LA90 (dB) Criteria, LA90 (dB) Difference (dB)

Goyallt 36.1 45.0 -8.9

Troed-y-Bryn 36.2 45.0 -8.8

It can be seen that the criteria has been met at all of the nearest financially involved

residential receptors.


N:100504/R1 17

8 CONCLUSION

The assessment has been carried out according to ETSU-R-97. Predictions of the

turbine noise have been carried out according to the agreed calculation method, ISO

9613-2, based on an Endurance X-29 wind turbine.

ETSU-R-97 states that "if the noise is limited to an LA90,10min of 35dB(A) up to wind

speeds of 10m/s at 10m height, then this condition alone would offer sufficient

protection of amenity". Predicted noise levels from the wind turbine do not exceed

this level at any dwelling.

Therefore noise from the proposed wind turbine complies with all relevant guidance

on noise and there is no material reason to refuse this application on grounds of

noise.


N:100504/R1 18

Appendices

Appendix A – Definition of Terms

Appendix B – Summary of Manufacturers’ Noise Data


N:100504/R1 19

Appendix A


N:100504/R1 20

APPENDIX A – DEFINITION OF TERMS

Nearest Noise Sensitive Receptor

The nearest receptor that by its nature will be sensitive to any increase in the level

or character of the ambient noise. Such receptors will comprise dwellings, hospitals,

schools, etc.

A-weighted sound pressure level – LpA or LA

The sound pressure level that has been adjusted, by calculation or by measurement

using a sound level meter, to conform to the frequency sensitivity of the human ear.

Equivalent Continuous A-weighted Sound Pressure Level – LAeq

The value of the A-weighted sound pressure level of a continuous sound that, within

a specified time interval T, has the same mean square sound pressure as the sound

under consideration whose level varies with time. This is to say that it has the same

mean sound energy as the sound under consideration, expressed in dB.

Wind Turbine Noise Level - LAF90

The A-weighted sound pressure level over a time period T that is exceeded for 90%

of that time period. This defines the lower levels of the residual noise conditions.

Rating Level

The noise level, as calculated or measured by a defined method, after corrections

have been made for any tonal element.


N:100504/R1 21

Appendix B


N:100504/R1 22

APPENDIX B – SUMMARY OF MANUFACTURERS’ NOISE DATA

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