BERRIMAL WIND FARM Noise Assessment Rp001 R04 2012437ML · 2017. 8. 15. · Reports produced by Marshall Day Acoustics Pty Ltd are prepared based on the Client’s objective and are

BERRIMAL WIND FARM

Noise Assessment

Rp001 R04 2012437ML

29 November 2013

6 Gipps Street

Collingwood 3066 Victoria Australia

T: +613 9416 1855 F: +613 9416 1231

A.C.N. 006 675 403

www.marshallday.com

Project: BERRIMAL WIND FARM Noise Assessment

Prepared for: ACCIONA Energy Oceania Level 12 2 Southbank Boulevard Southbank VIC 3006

Attention: Jamie McGilp

Report No.: Rp001 R04 2012437ML

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Document control

Status: Rev: Comments Date: Author: Reviewer:

Draft - 13/12/2012 C. Delaire D Griffin

Draft 01 06/09/2013 C Delaire D Griffin

Issued 02 20/09/2013 C Delaire D Griffin

Issued 03 31/10/2013 C Delaire R Leo & D Griffin

Final 04 29/11/2013 C Delaire R Leo & D Griffin

Rp001 R04 2012437ML Berrimal Wind Farm Noise Assessment Page 3 of 60

TABLE OF CONTENTS

1.0 INTRODUCTION ........................................................................................................................ 5

2.0 PROJECT DESCRIPTION ............................................................................................................ 5

2.1 Wind turbines ........................................................................................................................... 6

2.1.1 Turbine type .............................................................................................................................. 6

2.1.2 Sound power levels .................................................................................................................. 6

2.1.3 Tonality ...................................................................................................................................... 8

2.2 Residential properties .............................................................................................................. 9

3.0 NOISE LIMIT CRITERIA ............................................................................................................ 10

3.1 Victorian Guidelines ............................................................................................................... 10

3.2 NZS6808:2010 ........................................................................................................................ 10

3.2.1 Objectives ............................................................................................................................... 10

3.2.2 Noise limit ............................................................................................................................... 11

3.2.3 High amenity areas ................................................................................................................. 11

3.2.4 Special audible characteristics ............................................................................................... 12

3.2.5 Cumulative assessment ......................................................................................................... 12

4.0 NOISE ASSESSMENT METHODOLOGY .................................................................................. 13

5.0 NOISE SENSITIVE LOCATIONS ................................................................................................ 13

5.1 Preliminary noise predictions ................................................................................................ 14

6.0 MEASUREMENTS .................................................................................................................... 14

6.1 Background noise monitoring ............................................................................................... 14

6.2 Wind speed monitoring ......................................................................................................... 15

6.3 Rainfall data ............................................................................................................................ 15

7.0 NOISE LIMITS .......................................................................................................................... 16

7.1 High amenity areas ................................................................................................................. 16

7.2 Applicable noise limits ........................................................................................................... 16

8.0 NOISE PREDICTIONS ............................................................................................................... 18

8.1 Special audible characteristics ............................................................................................... 19

9.0 CUMULATIVE ASSESSMENT ................................................................................................... 20

9.1 Coonooer Bridge Wind Farm ................................................................................................. 20

9.1.1 Wind farm details ................................................................................................................... 20

9.1.2 Noise limits.............................................................................................................................. 22

9.2 Predicted wind farm noise levels .......................................................................................... 22

9.2.1 Approach ................................................................................................................................. 22

9.2.2 Results ..................................................................................................................................... 22

10.0 CONCLUSION .......................................................................................................................... 24

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11.0 SUMMARY OF PARAMETERS ................................................................................................. 24

APPENDIX A ACOUSTIC TERMINOLOGY ......................................................................................... 25

APPENDIX B BERRIMAL WIND FARM LAYOUT .............................................................................. 26

APPENDIX C ZONING MAP .............................................................................................................. 30

APPENDIX D BACKGROUND NOISE MONITORING RESULTS ........................................................ 31

APPENDIX E THIRD-OCTAVE BAND ANALYSIS ............................................................................... 36

APPENDIX F NOISE LIMITS .............................................................................................................. 43

APPENDIX G NOISE PREDICTION MODEL ....................................................................................... 49

APPENDIX H NOISE CONTOUR MAP ............................................................................................... 52

APPENDIX I COONOOER BRIDGE WIND FARM INFORMATION .................................................. 53

APPENDIX J AW125/3000 NOISE ASSESSMENT ........................................................................... 54

APPENDIX K DOCUMENTATION ..................................................................................................... 59


1.0 INTRODUCTION

This report, commissioned by ACCIONA Energy Oceania Pty Ltd (AEO), details the results of a noise assessment for the Berrimal Wind Farm which is proposed to be located between the Victorian townships of St Arnaud, Wedderburn and Charlton.

The proposed wind farm comprises twenty-four (24) 3MW wind turbines. This assessment has been undertaken in accordance with the New Zealand Standard NZS6808:2010 Acoustics – Wind farm noise as required by the Victorian Government's Policy and planning guidelines for development of wind energy facilities in Victoria dated July 2012.

Acoustic terminology used throughout this report is presented in Appendix A.

2.0 PROJECT DESCRIPTION

On 13 June 2007, Planning Permit No. 71/06 (the Planning Permit) was issued by the Buloke Shire Council for the development of the Berrimal Wind Farm which, at the time, comprised sixteen (16) 1.5MW turbines.

AEO has revised the proposed Berrimal Wind Farm layout which now comprises twenty-four (24) 3MW wind turbines. The noise impact assessment of this revised layout, relating to the Planning Permit variation to accommodate the turbine layout change, is presented herein.

A plan of the proposed wind farm is presented in Appendix B together with GPS coordinates for the wind turbines.


2.1 Wind turbines

2.1.1 Turbine type

The candidate turbine for this project is an ACCIONA Windpower AW116/3000 turbine with a rated power of 3MW and a rotor diameter of 116m. Details for this turbine model are provided in Table 1 below.

Table 1: WTG manufacturer specifications

Details

Make ACCIONA Windpower

Model AW116/3000

Rotor Diameter (m) 116

Hub Height (m) Up to 120

Orientation Upwind

Nominal rotor speed (rpm) +

12.3

Cut-in Wind Speed (hub height, m/s)+ 3

Rated Wind Speed (hub height, m/s) +

10.6

Cut-out Wind Speed (hub height, m/s) +

25

Sound Power LWA at 10.3m/s (hub height, dB) 108*

Tonality audibility (La,k>0dB) No

* See Section 2.1.2 +

Sourced fro http://www.acciona-energia.com/media/315814/AW3000_brochure.pdf, viewed on 30 October 2013.

A secondary candidate turbine, the ACCIONA Windpower AW125/3000 has also been assessed for informative purposes. This assessment is detailed in Appendix J.

2.1.2 Sound power levels

Sound power data for the ACCIONA Windpower AW116/3000 turbine has been provided by ACCIONA Windpower in an extract from CENER test report number 21.2679.0AN dated 20 November 2012. The provided document presents measured sound power levels as well as associated uncertainties (Uc). This noise impact assessment references ‘measured + uncertainty’ sound power level data to quantify expected sound levels from the proposed AW116 turbines.

The profile of A-weighted sound power levels per wind speed is presented in Figure 1 below, referenced to hub height wind speeds1 in the range 8.8m/s – 14.7m/s. The levels reported in Figure 1 are measured levels plus uncertainty (Uc).

1 Corresponding to a wind speed range of 6-10m/s at 10m above ground level with a roughness length

z0=0.05, as per the convention of standardised wind speeds detailed in IEC 61400-11 Second Edition Wind turbine generator systems – Part 11: Acoustic noise measurement techniques

http://www.acciona-energia.com/media/315814/AW3000_brochure.pdf


Figure 1: Provided sound power level + uncertainty for the AW116/3000

Tabular values are also presented in Table 2.

Table 2: Provided sound power levels for the AW116/3000

Hub height wind speed (m/s)

8.8 10.3 11.8 13.2 14.7

LWA (dB) 105.3 106.5 106.4 105.7 106.1

LWA + Uc (dB) 106.8 108.0 107.9 107.2 107.5

A reference A-weighted octave band sound power spectrum is presented in Figure 2. The spectral data has been sourced from ACCIONA document DG200266 Rev C dated 20 November 2012 and has been scaled to match the highest provided level presented in Figure 1 above, namely 108 dB LAeq at the hub height wind speed of 10.3 m/s.

106.8

108.0 107.9

107.2

107.5

100

102

104

106

108

110

112

8 9 10 11 12 13 14 15 16

Soun

d po

wer

lev

el (d

BA

)

Wind speed, standardised 10m AGL Z0 = 0.05m

Wind turbine sound power levels vs wind speed

AW300 116


Figure 2: A-weighted octave band sound power level spectra for the AW116/3000,


Table 3: Reference A-weighted octave band sound power level spectra for the AW116/3000

Octave Band Centre Frequency (Hz)

63 125 250 500 1000 2000 4000 8000

LWA (dB) 84.9 94.3 100.8 103.4 102.9 97.8 87.2 80.9

2.1.3 Tonality

CENER test report number 21.2679.0AN presents tonal audibility results as shown in Table 4.



8.8 10.3 11.8 13.2 14.7

∆La,k (dB) * -2.08 -0.75 -1.31/-2.41 -2.61

Tone frequency (Hz) * 711 1533 707/1537 708

* No significant tones detected

84.9

94.3

100.8103.4 102.9

97.8

87.2

80.9

0

20

40

60

80

100

120

63 125 250 500 1000 2000 4000 8000

Soun

d po

wer

lev

el (d

B L

Aeq

)

Octave band centre frequency (Hz)

Octave band sound power level spectra

AW300 116


2.2 Residential properties

Six (6) residential properties have been identified by AEO within 3km of the proposed wind farm. These properties are presented in Table 5.

Table 5: Residential properties within 3km of the Berrimal Wind Farm

House Nearest turbine

Distance (m) Direction (o) Turbine

H17 2015 61 23

H18 2364 92 7

H19 2477 66 2

H20 2253 93 2

H21 2449 136 1

H22 2663 189 1

GPS coordinates for the identified residential properties are presented in Appendix B.


3.0 NOISE LIMIT CRITERIA

The assessment of wind farm noise which supported the 2007 Planning Permit was carried out using the New Zealand Standard 6808:1998 Acoustics – The Assessment and Measurement of Sound from Wind Turbine Generators (NZS6808:1998) as required by the Victorian Government's Policy and planning guidelines for development of wind energy facilities in Victoria dated 1stJuly 2012 which were applicable at the time.

In 2010, the Planning Permit was extended for three (3) years until June 2013.

Since the time of the Planning Permit extension, AEO has revised the proposed Berrimal Wind Farm layout which now comprises twenty-four (24) 3MW wind turbines. AEO are seeking an amendment to the Planning Permit to accommodate the revised wind farm layout.

The requirements for wind farm noise assessment in Victoria have been revised since the issue of the Planning Permit. The current Victorian Government's Policy and planning guidelines for development of wind energy facilities in Victoria dated July 2012 (Victorian Guidelines) requires that assessments be carried out using a revised version of the New Zealand Standard, 6808:2010 Acoustics – Wind farm noise (NZS6808:2010). It is this revised standard that therefore forms the basis of this noise impact assessment.

3.1 Victorian Guidelines

Section 4.3.b of the Victorian Guidelines requires the following:

an assessment of the noise impact of the proposal prepared in accordance with the New Zealand Standard NZS 6808:2010, Acoustics – Wind Farm Noise (the Standard), including an assessment of whether a high amenity noise limit is applicable, as assessed under Section 5.3 of the Standard

Furthermore, the Victorian Guidelines also states:

[…] no plans will be endorsed by the responsible authority, and no variation to the endorsed plans will be approved by the responsible authority, which allow a turbine to be located within 2kms of an existing dwelling (measured from closest point of the turbine to closest point of the dwelling) unless evidence has been provided to the satisfaction of the responsible authority that the owner of the dwelling has consented in writing to the location of the turbine.

3.2 NZS6808:2010

3.2.1 Objectives

Section C1.1 of NZS6808:2010 discusses the intent of the standard, which is:

[...] to avoid adverse noise effects on people caused by the operation of wind farms while enabling sustainable management of natural wind resources.

The Outcome Statement of NZS6808:2010 reads as follows:

This Standard provides suitable methods for the prediction, measurement, and assessment of sound from wind turbines. In the context of the Resource Management Act, application of this Standard will provide reasonable protection of health and amenity at noise sensitive locations.

To deliver on this objective the standard specifies noise criteria which are used to assess wind farm noise.


3.2.2 Noise limit

Section 5.2 Noise limit of NZS6808:2010 defines acceptable noise limits as follows:

As a guide to the limits of acceptability at a noise sensitive location, at any wind speed wind farm sound levels (LA90(10 min)) should not exceed the background sound level by more than 5dB, or a level of 40dB LA90(10 min), whichever is the greater.

This arrangement of noise limits requires the noise associated with wind farms to be restricted to a permissible level above background noise, except in instances when both the background and source noise levels are low. In this respect, the criteria indicate that it is not necessary to continue to adhere to a margin above background when the background values are below the range of 30-35dB.

Compliance with the criteria may result in wind turbine noise being audible at some locations for some of the time. The forwarding comments of NZS 6808:2010 note that:

Wind farm sound may be audible at times at noise sensitive locations, and this Standard does not set limits that provide absolute protection for residents from audible wind farm sound. Guidance is provided on noise limits that are considered reasonable for protecting sleep and amenity from wind farm sound received at noise sensitive locations.

3.2.3 High amenity areas

Section 5.3.1 of NZS6808:2010 states that the baseline noise limit of 40dB LA90 detailed in Section 5.2 is “appropriate for protection of sleep, health, and amenity of residents at most noise sensitive locations.” It goes on to note that high amenity areas may require additional consideration:

[…] In special circumstances at some noise sensitive locations a more stringent noise limit may be justified to afford a greater degree of protection of amenity during evening and night-time. A high amenity noise limit should be considered where a plan promotes a higher degree of protection of amenity related to the sound environment of a particular area, for example where evening and night-time noise limits in the plan for general sound sources are more stringent than 40 dB LAeq(15 min) or 40 dBA L10. A high amenity noise limit should not be applied in any location where background sound levels, assessed in accordance with section 7, are already affected by other specific sources, such as road traffic sound.

The definition of a high amenity area provided in NZS6808:2010 is specific to New Zealand planning legislation and guidelines. A degree of interpretation is therefore required when determining how to apply the concept of high amenity in Victoria.

Section 5.3 of NZS6808:2010 provides details of high amenity noise limits, requiring that where a residential property is deemed to be located within a high amenity area as defined in Sections 5.3.1 and 5.3.2 of NZS6808:2010, wind farm noise levels (LA90) during evening and nigh-time periods should not exceed the background noise level (LA90) by more than 5dB or 35dB LA90, whichever is the greater, for wind speeds below 6m/s at hub height. High amenity noise limits are not applicable during the daytime period.


3.2.4 Special audible characteristics

Section 5.4.2 of NZS6808:2010 requires the following:

Wind turbine sound levels with special audible characteristics (such as tonality, impulsiveness and amplitude modulation) shall be adjusted by arithmetically adding up to +6dB to the measured level at the noise sensitive location.

Notwithstanding this, the standard requires that wind farms be designed with no special audible characteristics at nearby residential properties while concurrently noting in Section 5.4.1 that:

[…] as special audible characteristics cannot always be predicted, consideration shall be given to whether there are any special audible characteristics of the wind farm sound when comparing measured levels with noise limits.

While the standard emphasises assessment of special audible characteristics during the post-construction measurement phase of a project, an assessment of tonality can be carried out pre-construction, as discussed below.

Tonality

Section B2.3 of Appendix B of NZS6808:2010 references ISO 1996-2:20072 as an appropriate method for assessment of tonality at noise sensitive locations around a wind farm. Annex C of the ISO standard, in turn, provides a detailed methodology for narrow band assessment of tones and proposes a sliding penalty scale with the following features:

For tonal audibility levels greater than 10dB, a penalty of 6dB applies.

For tonal audibility levels less than 4dB a penalty of 0dB applies (that is, no penalty shall apply)

3.2.5 Cumulative assessment

NZS6808:2010 requires that a unique noise limit apply at each noise sensitive location for cumulative impact from all affecting wind farms, as stated in Section 5.6.1:

The noise limits [defined in Section 5.2 above] should apply to the cumulative sound level of all wind farms affecting any noise sensitive location.

2 ISO 1996-2: 2007 Acoustics – Description, assessment and measurement of environmental noise


4.0 NOISE ASSESSMENT METHODOLOGY

There are several key stages involved in a noise assessment undertaken in accordance with NZS6808:2010.

Firstly, preliminary wind farm noise predictions are carried out for all identified residential properties around the wind farm. The results of the preliminary analysis are used for the following:

Identification of noise sensitive locations, where predicted wind farm noise levels exceed 35dB LA90

Identification of selected noise sensitive locations where background noise monitoring should be undertaken

The background noise surveys allow quantification of the existing ambient noise environment around the proposed site. Section 7.1.4 of NZS6808:2010 notes the following:

If there are no noise sensitive locations within the 35dB LA90(10 min) predicted wind farm sound level contour then background sound level measurements are not required.

Having identified noise sensitive locations and carried out any background noise monitoring that may be required, applicable limits for wind farm noise may be determined including any adjustment of the limits to account for background noise levels.

Once noise limits have been established, further wind farm predictions are carried out. Compliance is assessed by comparing the predicted wind farm noise levels with the noise limits over a range of wind speeds.

Where required, alteration of the turbine layout or a noise management plan can be considered to achieve compliance with noise limits.

5.0 NOISE SENSITIVE LOCATIONS

NZS6808:2010 defines noise sensitive locations as follows:

The location of a noise sensitive activity, associated with a habitable space or education space in a building not on the wind farm site.

Noise sensitive locations include residential dwellings, schools and hotels located outside the wind farm site. As stakeholder properties are located within the wind farm site, they are not considered as noise sensitive locations as part of an assessment in accordance with NZS6808:2010. However, they have been considered as part of this assessment for informative purpose.

NZS6808:2010 requires that the noise assessment be undertaken at all noise sensitive locations in the vicinity of the proposed wind farm where predicted wind farm noise levels exceed 35dB LA90.


5.1 Preliminary noise predictions

Preliminary noise predictions have been undertaken at the six (6) residential properties identified within 3km of the wind farm using the methodology detailed in Section 8.0.

The preliminary noise predictions corresponding to the highest sound power level, at a hub height wind speed of 10.3m/s, are presented in Table 6.

Table 6: Berrimal Wind Farm preliminary noise predictions3

Nearest turbine

House Turbine Distance (m) LAeq (dB)

17 23 2011 35.2

18 7 2361 33.4

19 2 2474 32.6

20 2 2250 32.2

21 1 2446 30.8

22 1 2661 30.4

* MGA94 Z54

It can be seen from Table 6 that predicted noise levels at five (5) of the six (6) identified residential properties within 3km of the proposed wind farm are below 35dB LAeq.

At House 17, predicted operational wind farm noise is marginally greater than 35dB LAeq.

6.0 MEASUREMENTS

6.1 Background noise monitoring

According to Section 7.1 of NZS6808:2010, background noise monitoring should be carried out at locations where predicted noise levels are greater than 35dB LAeq. For the current assessment one receiver location, House 17, is therefore identified for background noise monitoring.

However, AEO requested that background noise monitoring be undertaken at an additional four (4) residential properties.

Details of the measurement campaign are provided in Table 7. Photographs of the monitoring positions and a time history plot of measured noise levels in provided in Appendix D for each monitoring location.

3 Refer to Section 9.0 for an assessment of cumulative noise from more than one wind farm.


Table 7: Background noise monitoring locations

House Required monitoring location?

Monitoring period

17 Yes 25 January to 22 February 2013

19 - 1 December 2012 to 4 January 2013

20 - 22 January to 22 February 2013



As Houses 18 is in comparatively close proximity to House 19, background noise monitoring collected at House 19 has been deemed representative of the noise environment at House 18.

01dB DUO Class 1 noise loggers have been used to measure the background noise levels, recording sound levels across continuous 10 minute intervals. The noise loggers were calibrated before and after placement at site, with no significant drift observed at the end of the monitoring periods.

6.2 Wind speed monitoring

Wind speed and direction data has been collected at a met mast on the proposed wind farm site throughout the noise monitoring period.

The location of two (2) met masts installed on site is presented in Table 8.

Table 8: Met mast locations

Met mast Easting Northing Height

Berrimal 1 719,137 5,961,206 45m

Berrimal 2 716,696 5,964,891 106m

Wind speed and direction data has been collected from the Berrimal 2 mast at 106m AGL, whilst the proposed turbine hub height is up to 120m. The measured wind speed data has

been extrapolated to hub height using a wind shear factor of =0.15.

Wind data collected at the met masts has been provided to us by AEO and has been used for correlations with noise data.

6.3 Rainfall data

Where it is considered likely that rainfall has occurred at the monitoring locations, associated noise and wind speed data points must be removed from regression analysis.

Rain intensity was measured using a Vaisala WXT520 weather station connected to the 01dB DUO noise logger at Houses 17 and 20.

Photographs of the weather station position are presented in Section D1 of Appendix D.


7.0 NOISE LIMITS

7.1 High amenity areas

The area surrounding the proposed wind farm is zoned Farming Zone as per the planning map shown in Appendix C.

The Victoria Planning Provisions Practice Note prepared by the Department of Sustainability and Environment entitled Applying the rural zones and dated March 2007 states the following:

The Farming Zone is designed to encourage diverse farming practices, some of which can have significant off-site impacts. For this reason, the level of amenity that can be expected in this zone will usually not be compatible with sensitive uses, particularly housing.

Based on the above, it is our understanding that the high amenity noise limit is not generally applicable for residential properties located within a Farming Zone. On this basis, the high amenity noise limit has not been applied in this assessment.

7.2 Applicable noise limits

Wind speed dependant noise limits have been derived at each of the noise monitoring locations in accordance with NZS6808:2010, as detailed in Section 3.2 above.

A regression analysis has been undertaken by correlating the measured background noise levels with hub height wind speeds. Where rainfall was detected during a given measurement interval noise data for that period has been removed from regression analysis.

To complement the analysis of A-weighted noise levels in accordance with NZS 6808:2010, a sensitivity analysis of the measured one-third octave band noise level data has also been carried out to identify any potential anomalies or atypical periods during the monitoring. The results of this analysis are presented in Appendix E.

A summary of collected data points and regression information is presented in Table 9 and Table 10.


Table 9: Summary of collected data points and regression information – 24 hour

House Number of data points Regression information

Measured Removed Analysed Equation (where x is the hub height wind speed)

R2

17 4035 19 4016 -0.00694x3 +0.2607x

2 -0.9814x +23.48 0.56

19 4801 580 4221 0.002558x3 -0.02555x

2 +0.7336x +27.8 0.17

20 4451 19 4432 0.00698x3 -0.1241x

2 +1.527x +21.16 0.37

21 7398 1354 3745 0.001995x3 +0.02471x

2 +0.1437x +28.77 0.26

22 7466 1480 5986 -0.001639x3 +0.07831x

2 +0.4765x +22.98 0.42

Table 10: Summary of collected data points and regression information – night-time

House Number of data points Regression information

Measured Removed Analysed Equation (where x is the hub height wind speed)

R2

17 1512 8 1504 -0.01571x3 +0.589x

2 -4.37x +28.91 0.61

19 1794 496 1298 -0.01776x3 +0.5778x

2 -4.318x +30.67 0.33

20 1674 8 1666 -0.0004086x3 +0.1765x

2 -1.641x +24.43 0.68

21 2754 875 1879 -0.0116x3 +0.5063x

2 -4.3595x +31.951 0.50

22 2754 908 1846 -0.01703x3 +0.6288x

2 -5.04x +32.65 0.53

Section C7.2.1 of NZS6808:2010 recommends that a minimum of 1,440 data points be collected in order to capture a suitable range of data. It can be seen from Table 9 that the minimum 1,440 data points are included in the analysis for all monitored locations.

Regression analysis and derived noise limits, based on filtered data where relevant, are presented in Appendix F for all monitored locations, showing the following:

Analysed background noise levels versus hub height wind speeds (blue points)

Removed background noise levels versus hub height wind speeds (light grey points)

Fitted background noise regression line (blue line)

Derived NZS6808:2010 noise limits (black line)


8.0 NOISE PREDICTIONS

Noise from the Berrimal Wind Farm has been predicted using ISO9613-2:1996 Acoustics – Attenuation of sound during propagation outdoors Part 2: General method of calculation (ISO9613-2:1996) as implemented in version 7.1 of SoundPLAN. Predictions have been carried out using the sound power level data presented in Section 2.1.2.

Calculations have been performed using octave band data from 63Hz to 8kHz and each wind turbine has been modelled as a point source with a hub height of 120m. All noise predictions use a receiver height of 1.5m above ground level. Atmospheric attenuation has been modelled using a temperature of 10°C and 70% humidity as recommended by NZS6808:2010.

The hardness of the ground between the sources and the receivers needs to be defined in accordance with ISO9613-2:1996. 100% hard ground (G=0) is considered to be fully reflective as would occur with concrete or asphalt, while 100% soft ground (G=1) would be considered to absorptive and be appropriate for fields and grass. Our experience is that, in rural areas, it is appropriate to assume that the ground is 50% hard/50% soft (G=0.5). A ground factor (G) of 0.5 has been used in the predictions.

Further details regarding the use of ISO9613-2 for wind farm nose predictions and the use of G=0.5 is presented in Appendix G.

Possible screening effects from the landscape are considered using 10m elevation contour information provided by the proponent. Attenuation due to screening effects has been limited to a maximum value of 2dB, based on barrier effects calculated between the receiver and the maximum tip height of the turbine. This approach is consistent with the recommendations of the Joule Report4. Refer to Appendix G for further details.

Specifically, in instances where the ground falls away significantly between the source and receiver, such as valleys, an adjustment of 3dB should be added to the calculated sound pressure level. For the assessed properties, the largest adjustment for this affect is 1.0dB (House 17).

Predicted noise levels from the proposed wind farm at all residential properties identified in Table 6 of Section 5.1 are presented in Table 11 for each available wind speed.

Predicted noise levels are compared with the applicable NZS6808:2010 noise limits detailed in Appendix F.

4 Bass, Bullmore and Sloth - Development of a wind farm noise propagation prediction model;

Contract JOR3-CT95-0051, Final Report, January 1996 to May 1998 (commonly referred to as the Joule Report)


Table 11: Predicted noise from the Berrimal Wind Farm5, LAeq dB

Hub height wind speed (m/s) Compliance with

noise limits? House 8.8 10.3 11.8 13.2 14.7

H17 34.0 35.2 35.1 34.3 34.7

H18 32.1 33.3 33.2 32.5 32.8

H19 31.3 32.5 32.4 31.7 32.0

H20 31.0 32.2 32.1 31.3 31.7

H21 29.6 30.8 30.7 29.9 30.3

H22 29.2 30.4 30.3 29.5 29.9

It can be seen from Table 11 that predicted noise levels from the proposed wind farm comply with the applicable noise limits at all six (6) assessed receivers within the range of assessed wind speeds.

Predicted noise levels at all six (6) assessed receivers also comply with the lowest possible NZS6808:2010 noise limit of 40dB LA90 at all wind speeds by at least 4dB.

Wind farm noise at all residential properties further from the wind farm will be lower than 30dB LAeq and therefore comply with the lowest possible NZS6808:2010 noise limit at all wind speeds.

A noise contour map is presented in Appendix H for the hub height wind speed of 10.3m/s. It should be noted that the noise contour maps generated by SoundPlan are not able to reflect the Joule Report adjustments directly. Therefore, the noise contour maps are provided for informational purposes only.

An assessment of predicted operational wind farm noise levels for a secondary candidate turbine, the ACCIONA Windpower AW125/3000 are presented in Appendix J for information.

5 Sound levels in environmental assessment work are typically reported to the nearest integer to reflect the practical use of measurement and prediction data. In the case of wind farm layout design however, significant layout modifications may only give rise to fractional changes in the predicted noise level. This is a result of the relatively large number of sources influencing the total predicted noise level, as well as the typical separating distances between the turbine locations and surrounding assessment positions. It is therefore necessary to consider the predicted noise levels at a finer resolution than can be perceived or measured in practice. It is for this reason that the presented levels are reported to one decimal place.


8.1 Special audible characteristics

The specification for the proposed AW116-3000 turbine, as detailed in Section 2.1, states

that tonal audibility levels (La,k) are expected to be less than 0dB as assessed in accordance with IEC 61400-11:2006, at locations within 100-200m from the turbine.

IEC61400-11 requires the reporting of identified tones where the tonal audibility, ∆La,k ≥ -3.0dB. It is important to note that the reporting requirements of IEC61400-11 do not necessarily reflect the expected levels of audibility or annoyance from the assessed tones. We understand that work by Zwicker and Fastl6 indicates that:

La,k = -2dB to 0dB is the approximate region of the audibility threshold for a tone

La,k < 0dB the tone, while perhaps audible, is generally not likely to cause significant issues

On the basis of the above we consider that, where La,k < 0dB, identified tones are unlikely to be problematic at the IEC61400-11 assessment location. Levels of tonal audibility generally decrease with increasing separation distance away from a source and are therefore anticipated to be lower at the six (6) identified receiver locations. .

On this basis, a penalty for special audible characteristics (tonality) has not been applied in this assessment.

9.0 CUMULATIVE ASSESSMENT

We understand there is one other wind farm currently proposed in the general vicinity of the Berrimal Wind Farm: Coonooer Bridge Wind Farm.

9.1 Coonooer Bridge Wind Farm

9.1.1 Wind farm details

The Coonooer Bridge Wind Farm is proposed to be located to the west of Berrimal Wind Farm and is being developed by Windlab Developments. The relative locations of the two proposed schemes are shown in Figure 3. The nearest turbines from each proposed development are approximately 4.3 km apart from each other.

6 Fastl, H, Zwicker, E, (2007) Psycho-acoustics, Berlin, Springer


Figure 3: Location of the Berrimal Wind Farm in relation to the Coonooer Bridge Wind Farm

Marshall Day Acoustics prepared a noise impact assessment report 001 2012420ML titled Coonooer Bridge Wind Farm – Noise Impact Assessment and dated 14 December 2012 (MDA Coonooer Bridge Wind Farm Report). This assessment was based on a wind farm layout comprising six (6) Alstom ECO110 wind turbines with a hub height of 90m.

Planning permit 488/13 was granted by the Buloke Shire Council on 12 June 2013 for the construction of five (5) turbines, leaving to the developer the choice of which five (5) of the six (6) proposed turbines to construct.

An assessment of cumulative noise from the proposed Berrimal and Coonooer Bridge Wind Farms is presented herein. Information relating to the Coonooer Bridge Wind Farm for the assessment has been sourced from the MDA Coonooer Bridge Wind Farm Report. In particular, noise levels from the Coonooer Bridge Wind Farm are predicted using the six (6) turbine layout which presents a conservative assessment given that only five (5) turbines are actually to be constructed.

Sound power level data for the Coonooer Bridge Wind Farm candidate turbine (Alstom ECO110) is presented in Table 12. The approved turbine layout is provided in Appendix I.

Table 12: Alstom ECO110 sound power level spectrum, LWA dB


Overall 63 125 250 500 1000 2000 4000 8000

LWA at 11.3m/s (@90m AGL) 106.3 83.4 94.2 100.6 101.1 100.2 96.2 88.6 73.4

Coonooer Bridge

Berrimal


9.1.2 Noise limits

Planning Permit 488/13 for the Coonooer Bridge Wind Farm details the use of a 40dB LA90 baseline noise limit. Condition 12 of the proposed planning permit is provided below with added emphasis.

The operation of the wind energy facility must comply with the New Zealand Standard ‘Acoustics – The Assessment and Measurement of Wind Farm Noise’ (NZ 6808:2010) (the ‘New Zealand Standard’), in relation to any dwelling existing at the date of approval of this document to the satisfaction of the Responsible Authority. In determining compliance with the New Zealand Standard, the following apply:

(a) The sound level from the wind energy facility, when measured outdoors within 10 metres of a dwelling at any relevant nominated wind speed, should not exceed the background level (L95) by more than 5dBA or a level of 40dBA L95 (sic), whichever is the greater.

(b) When sound has a special audible characteristic, the measured sound level of the source shall have a 5dBA penalty applied.

(c) Compliance at night must be separately assessed with regard to night time data. For these purposes the night is defined as 10.00pm to 7.00am. For sleep protection purposes, a breach of the standard set out at Condition 12(a), for 10% of the night, amounts to a breach of the condition.

9.2 Predicted wind farm noise levels

9.2.1 Approach

A 30dB LAeq wind farm noise contour has been predicted for each proposed wind farm, using the prediction method described in Section 8.0 and the maximum sound power level for the respective turbines.

We consider that any noise sensitive locations which are situated in the region of intersection of the two contours require detailed assessment.

For locations outside of the intersecting region, the combined level of wind farm noise from both proposed sites is predicted to be less than 40dB LA90. The combined predicted wind farm noise level will therefore satisfy the 40dB LA90 base noise limit applicable to each development.

9.2.2 Results

30dB LAeq noise contours have been calculated for each proposed wind farm and are shown together in Figure 4. It should be noted that the noise contour maps generated by SoundPlan are not able reflect the Joule Report adjustments directly. Therefore, the noise contour maps are provided for informational purposes only.


Figure 4: Indicative 30dB LAeq noise contours for the Coonooer Bridge Wind Farm and the Berrimal Wind Farm

It can be seen that there are three (3) residential properties located in the region of intersection for the two 30dB LAeq contours.

Table 13 below presents the predicted cumulative level of wind farm noise for these three (3) noise sensitive locations.

Table 13: Cumulative predicted noise levels, LAeq dB

Distance to nearest Berrimal wind turbine (m)

Distance to nearest Coonooer Bridge wind turbine (m)

Predicted noise level, LAeq dB

House Berrimal Wind Farm

Coonooer Bridge Wind Farm

Cumulative

H18 2364 1449 33.3 32.3 35.9

H19 2477 1237 32.5 33.8 36.2

H20 2253 1800 32.2 31.6 34.9


It can be seen from Table 13 that the predicted noise contribution of the approved Coonooer Bridge Wind Farm to the predicted level of noise from Berrimal Wind Farm at the identified dwellings is up to 4dB across the considered noise sensitive locations. Predicted cumulative noise levels from the Berrimal and Coonooer Bridge wind farms comply with the lowest possible NZS6808:2010 noise limit of 40dB LA90, at all assessed wind speeds, at all assessed noise sensitive locations.

An assessment of cumulative noise based on installation of AW125/3000 turbines at Berrimal Wind Farm is provided in Appendix J for informative purposes.

10.0 CONCLUSION

The Berrimal Wind Farm is proposed to consist of twenty-four (24) ACCIONA Windpower AW116/3000 3MW wind turbines with a hub height of up to 120m.

An assessment has been undertaken in accordance with NZS6808:2010 as required by the Victorian Guidelines at six (6) residential properties identified by AEO within 3km of the proposed wind farm.

Predicted noise levels have been calculated at all six (6) identified properties using the ISO9613-2:1996 algorithm with the available range of wind speeds.

It has been found that predicted wind farm noise complies with the applicable NZS6808:2010 noise limits and the lowest possible NZS6808:2010 noise limit of 40dB LA90 at all six (6) identified properties.

The proposed Berrimal Wind Farm is located approximately 4.3km to the west of the approved Coonooer Bridge Wind Farm.

Predicted cumulative noise levels from both the Berrimal and Coonooer Bridge Wind Farms comply with the lowest possible NZS6808:2010 noise limit of 40dB LA90 at all wind speeds at all assessed residential properties in the vicinity of the proposed Berrimal Wind Farm.

If the turbine selection and/or layout are to be changed, compliance with the relevant noise limits will need to be reassessed.

11.0 SUMMARY OF PARAMETERS

Documentation of relevant parameters as required by NZS6808:2010 is contained in Appendix K.


APPENDIX A ACOUSTIC TERMINOLOGY

Ambient The ambient noise level is the noise level measured in the absence of the

intrusive noise or the noise requiring control. Ambient noise levels are frequently measured to determine the situation prior to the addition of a new noise source.

dB Decibel. The unit of sound level. Frequency Sound can occur over a range of frequencies extending from the very low, such

as the rumble of thunder, up to the very high such as the crash of cymbals. Sound is generally described over the frequency range from 63Hz to 8000Hz (8kHz). This is roughly equal to the range of frequencies on a piano.

Octave band Sound, which can occur over a range of frequencies, may be divided into octave

bands for analysis. The audible frequency range is generally divided into eight (8) octave bands. The octave band frequencies are 63Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz and 8kHz.

Noise is often not steady. Traffic noise, music noise and the barking of dogs are all examples of noises that vary over time. When such noises are measured, the noise level can be expressed as an average level, or as a statistical measure, such as the level exceeded for 90% of the time.

LA90 The A-weighted noise level exceeded for 90% of the measurement period. This is

commonly referred to as the background noise level. LAeq The A-weighted equivalent continuous sound level. This is commonly referred to

as the average noise level.


APPENDIX B BERRIMAL WIND FARM LAYOUT

B1 Site plan


B2 Turbine coordinates (MGA94 Z54)

Turbine ID Easting Northing Turbine ID Easting Northing

1 715724 5966459 13 717468 5965350

2 715655 5966256 14 717075 5964446

3 715996 5966287 15 717338 5964254

4 716125 5965969 16 717591 5964054

5 716240 5965670 17 717849 5963867

6 716329 5965356 18 718076 5963601

7 715978 5964923 19 718283 5963335

8 716365 5964916 20 718451 5963046

9 716701 5964879 21 718807 5962919

10 717056 5964867 22 718533 5962600

11 717284 5965095 23 718328 5962401

12 717179 5965361 24 718697 5962307

B3 Receiver coordinates (MGA94 Z54)

Property ID Easting Northing Property ID Easting Northing

H1 708296 5968833 H68 723042 5944833

H2 709116 5970222 H69 723329 5944745

H3 709249 5966359 H70 723210 5944572

H4 708164 5966941 H71 722775 5944234

H6 710742 5960483 H72 723668 5943083

H7 707734 5960837 H73 723667 5942830

H8 707750 5960608 H74 723603 5955644

H9 707613 5960666 H75 723572 5956222

H10 710595 5959413 H76 722804 5957377

H11 712261 5959200 H77 724094 5954370

H12 712815 5956153 H78 725493 5950641

H13 716311 5958073 H79 725544 5951441

H14 715952 5958406 H80 726444 5951914

H15 717802 5955901 H81 726327 5952436

H16 716293 5953156 H82 724446 5956429

H17 716562 5961438 H83 728256 5954121

H18 713619 5965020 H84 729081 5955246



H19 713400 5965238 H85 728837 5955503

H20 713409 5966393 H86 728767 5957159

H21 714035 5968228 H87 728164 5959074

H22 716126 5969089 H88 726354 5960358

H24 723311 5965954 H89 726329 5960719

H25 722933 5964782 H90 724719 5962677

H26 723527 5964617 H91 716427 5948134

H27 723294 5964404 H92 723739 5945879

H28 722739 5964247 H93 715449 5948156

H29 721276 5959482 H94 729910 5958117

H30 722150 5958655 H95 734104 5957119

H31 721455 5958463 H96 735302 5955666

H32 719812 5957710 H97 732844 5957241

H33 721643 5955942 H98 732515 5956511

H34 721150 5953928 H99 736028 5962061

H35 720346 5954637 H100 713954 5971533

H36 719330 5954277 H101 712962 5972607

H37 719192 5954118 H102 715348 5971871

H38 716833 5952836 H103 728348 5950846

H40 712966 5968824 H104 711839 5972347

H41 708687 5963762 H105 716454 5971841

H42 706506 5964603 H106 716768 5972296

H43 706576 5964422 H107 717722 5971180

H44 707535 5960850 H108 720626 5971118

H45 711259 5959937 H109 719047 5952825

H47 724758 5966394 H110 722173 5947654

H48 724817 5966144 H111 722270 5946342

H49 720517 5968787 H113 723994 5959548

H50 719013 5969795 H114 733970 5962728

H51 726059 5966383 H115 734556 5961984

H52 727377 5970437 H116 736631 5964311

H53 728652 5966925 H117 736044 5963546

H54 731965 5968755 H118 736401 5963315



H55 725172 5947606 H119 736767 5963158

H56 724868 5948969 H120 736694 5962812

H57 712577 5953939 H121 736495 5962613

H58 715866 5952170 H121 736422 5962320

H59 713753 5954249 H122 736851 5962634

H60 716477 5950719 H123 736967 5962896

H61 721447 5951216 H124 741353 5959336

H62 722907 5951338 H126 722753 5962160

H63 723394 5949584

H64 722006 5947183

H65 722260 5946432

H66 720708 5944921

H67 721270 5944774


APPENDIX C ZONING MAP


APPENDIX D BACKGROUND NOISE MONITORING RESULTS

D1 House H17

Looking North Looking East

Looking South Looking West

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LA90

Wind Speed @ 120m AGL

Correlation Coefficient = 0.74

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Wind Speed measured at Berrimal 2 @109m AGL extrapolated to 120m AGL using =0.15


D2 House H19



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D3 House H20



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D4 House H21



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D5 House H22



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Background noise levels and wind speeds vs timeHouse H22 filtered - December 2012

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APPENDIX E THIRD-OCTAVE BAND ANALYSIS

The noise measurement methods detailed in NZS 6808:2010 are based on measuring broadband A-weighted noise levels. Extraneous noise sources such as insects, birds and frogs can at times significantly affect measured A-weighted noise levels. This can introduce uncertainty regarding the extent to which data can be relied upon to represent noise levels at other times of year when such noise sources may be less prevalent. Identifying these types of seasonal influences using A-weighted noise levels alone can be difficult and failure to identify these effects may result in corrupted and unusable background noise data

Noise from insects, birds and frogs can typically be characterised by its discrete high frequency noise content. Collecting one-third octave band noise level data can therefore provide a means to identify periods where such extraneous noise may be occurring.

To complement the analysis of A-weighted noise levels in accordance with NZS 6808:2010, we have carried out a sensitivity analysis of measured one-third octave band noise levels to identify any potential anomalies or atypical periods during the monitoring surveys. This analysis comprises the following:

review of one-third octave band noise levels to identify periods affected by discrete high frequency noise

a listening study of a sample of the available audio data to confirm the source of extraneous noise

a sensitivity study to estimate the affects of any anomalous periods on the correlation of background noise levels with wind speeds

Table 14 provides a summary of the percentage of measurement periods influenced by high frequency noise7.

Table 14: Occurrence rate for high frequency noise events during background noise monitoring surveys

One-third octave Band Centre Frequency (Hz)

House 2kHz 2.5kHz 3.15kHz 4kHz 5kHz 6.3kHz 8kHz 10kHz

H17 - - - 2% - - - -

H19 - - - 12% - - - -

H20 - - - - - - - -

H21 - - - 15% 4% 3% - -

H22 - - - 13% 6% 4% - -

Note: “-“ indicates a percentage lower than 2%, which is not investigated further

It can be seen that significant periods of time are influenced by high frequency noise at three (3) of the five (5) noise monitoring locations. Samples of the audio data recorded during the identified affected periods have been reviewed. Insect noise was clearly audible throughout the reviewed samples and we consider that it is the controlling source of the identified high frequency noise events.

7 Where the one-third octave band A-weighted noise level is within 5dB of the broadband A-weighted noise level and

where the one-third octave band A-weighted noise level is greater than 20dB.


As presented in Figures 5 to 10 below, a filtering study has been performed to assess the influence of these high frequency noise events on the larger data set. It can be seen that there is a small change in the background noise regression curve for Houses H19, H21 and H22 monitoring locations when the high frequency noise events are excluded. The filtered data sets have therefore been used to derive the noise limits at these properties, a method which is considered conservative. The non-filtered data sets have been used to determine noise limits for Houses H17 and H20.


Figure 5: House 17 - 24hr Filtered data set

Figure 6: House 17 - night Filtered data set

y = -0.0048x3 + 0.1924x2 - 0.2781x + 21.123R² = 0.5841

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Background noise levels vs wind speeds: Filtered data setHouse H17 (24hr)

NZS6808:2010 noise limit:Filtered Background noise levels: Filtered

Background noise regression line of best fit NZS6808:2010 noise limit

Background noise regression line of best fit TrendLine: Background noise levels: Filtered


y = -0.0147x3 + 0.5451x2 - 3.7219x + 25.653R² = 0.6589

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Background noise levels vs wind speeds: Filtered data setHouse H17 (Night)

Background noise levels: Unfiltered (Night) Background noise levels: Filtered







y = 0.0027x3 - 0.0271x2 + 0.7224x + 27.941R² = 0.1636

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Noise Limit -filtered TrendLine: Background noise levels: Filtered

y = -0.017x3 + 0.5779x2 - 4.3211x + 30.675R² = 0.3344

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Wind Speed measured at Berrimal 2 @109m AGL extrapolated to 120m AGL using z0=0.05




y = 0.0072x3 - 0.1333x2 + 1.6396x + 20.732R² = 0.373

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APPENDIX F NOISE LIMITS

F1 Regression analysis and derived 24hour noise limits – House 17

F2 Regression analysis and derived night-time noise limits – House 17

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Background noise levels vs wind speedsHouse H17 - January 2013

Background noise levels NZS6808:2010 Noise Limit Background noise regression line of best fit

Background noise equation of best fitLA90= -0.00694x3 +0.2607x2 -0.9814x +23.48

where x=wind speed in m/s

R2 = 0.56

(25.01.2013 - 22.02.2013)


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Night-time background noise levels vs wind speedsHouse H17 - January 2013

Night-time background noise levels NZS6808:2010 Noise Limit Night-time background noise regression line of best fit

(25.01.2013 - 22.02.2013)


Night-time background noise equation of best fitLA90= -0.01571x3 +0.589x2 -4.37x +28.91


R2 = 0.61




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Background noise levels vs wind speedsHouse H19 (Filtered) - December 2012


Background noise equation of best fitLA90= 0.002558x3 -0.02555x2 +0.7336x +27.8


R2 = 0.17

(01.12.2012 - 03.01.2013)


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Night-time background noise levels vs wind speedsHouse H19 (Filtered) - December 2012


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Wind Speed measured at Berrimal 2 @109m AGL extrapolated to 120m AGL using z0=0.05



R2 = 0.33




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Background noise levels vs wind speedsHouse H20 - January 2013


Background noise equation of best fitLA90= 0.00698x3 -0.1241x2 +1.527x +21.16


R2 = 0.37

(22.01.2013 - 22.02.2013)


10

15

20

25

30

35

40

45

50

55

60

65

70

10

15

20

25

30

35

40

45

50

55

60

65

70

0 2 4 6 8 10 12 14 16 18 20

So

un

d P

ress

ure

Le

vels

, dB

LA

90


Night-time background noise levels vs wind speedsHouse H20 - January 2013


(22.01.2013 - 22.02.2013)




R2 = 0.68




10

15

20

25

30

35

40

45

50

55

60

65

70

10

15

20

25

30

35

40

45

50

55

60

65

70

0 2 4 6 8 10 12 14 16 18 20

Soun

d Pr

essu

re L

evel

s, d

B L

A90


Background noise levels vs wind speedsHouse H21 filtered - December 2012


Background noise equation of best fitLA90= 0.001995x3 +0.02471x2 +0.1437x +28.77


R2 = 0.26

(01.12.2012 - 22.01.2013)


10

15

20

25

30

35

40

45

50

55

60

65

70

10

15

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25

30

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40

45

50

55

60

65

70

0 2 4 6 8 10 12 14 16 18 20

Soun

d Pr

essu

re L

evel

s, d

B L

A90


Night-time background noise levels vs wind speedsHouse H21 filtered - December 2012


(01.12.2012 - 22.01.2013)




R2 = 0.5




10

15

20

25

30

35

40

45

50

55

60

65

70

10

15

20

25

30

35

40

45

50

55

60

65

70

0 2 4 6 8 10 12 14 16 18 20

Soun

d Pr

essu

re L

evel

s, d

B L

A90


Background noise levels vs wind speedsHouse H22 filtered - December 2012


Background noise equation of best fitLA90= -0.001639x3 +0.07831x2 +0.4765x +22.98


R2 = 0.42

(01.12.2012 - 22.01.2013)


10

15

20

25

30

35

40

45

50

55

60

65

70

10

15

20

25

30

35

40

45

50

55

60

65

70

0 2 4 6 8 10 12 14 16 18 20

Soun

d Pr

essu

re L

evel

s, d

B L

A90


Night-time background noise levels vs wind speedsHouse H22 filtered - December 2012


(01.12.2012 - 22.01.2013)




R2 = 0.53


F11 Summary of NZS 6808:2010 noise limits – 24 hour

Hub height wind speed, m/s

House ≤5 6 7 8 9 10 11 12 13 14 15

H17 40 40 40 40 40 40 40 42 45 47 49

H19 40 40 40 40 40 40 41 42 44 45 47

H20 40 40 40 40 40 40 40 40 40 42 45

H21 40 40 40 40 40 40 41 43 44 46 48

H22 40 40 40 40 40 40 41 42 44 46 47

F12 Summary of NZS 6808:2010 noise limits – night-time

Hub height wind speed, m/s

House ≤5 6 7 8 9 10 11 12 13 14 15

H17 40 40 40 40 40 40 40 40 42 45 48

H19 40 40 40 40 40 40 40 40 40 40 41

H20 40 40 40 40 40 40 40 40 40 40 43

H21 40 40 40 40 40 40 40 40 40 43 46

H22 40 40 40 40 40 40 40 40 41 44 46


APPENDIX G NOISE PREDICTION MODEL

Environmental noise levels associated with wind farms are predicted using engineering methods. The international standard ISO 9613 Acoustics – Attenuation of sound during propagation outdoors has been chosen as the most appropriate method to calculate the level of broadband A-weighted wind farm noise expected to occur at surrounding receptor locations. This method is considered to be the most robust and widely used international method for the prediction of wind farm noise.

The use of this standard is supported by international research publications, measurement studies conducted by Marshall Day Acoustics and direct reference to the standard in the South Australian EPA 2009 wind farm noise guidelines, AS4959:2010 Acoustics – Measurement, prediction and assessment of noise from wind turbine generators and NZS6808:2010 Acoustics – Wind farm noise.

The standard specifies an engineering method for calculating noise at a known distance from a variety of sources under meteorological conditions favourable to sound propagation. The standard defines favourable conditions as downwind propagation where the source blows from the source to the receiver within an angle of +/-45 degrees from a line connecting the source to the receiver, at wind speeds between approximately 1m/s and 5m/s, measured at a height of 3m to 11m above the ground. Equivalently, the method accounts for average propagation under a well-developed moderate ground based thermal inversion. In this respect, it is noted that at the wind speeds relevant to noise emissions from wind turbines, atmospheric conditions do not favour the development of thermal inversions throughout the propagation path from the source to the receiver.

To calculate far-field noise levels according to the ISO 9613, the noise emissions of each turbine are firstly characterised in the form of octave band frequency levels. A series of octave band attenuation factors are then calculated for a range of effects including:

Geometric divergence

Air absorption

Reflecting obstacles

Screening

Vegetation

Ground reflections

The octave band attenuation factors are then applied to the noise emission data to determine the corresponding octave band and total calculated noise level at receiver locations.

Calculating the attenuation factors for each effect requires a relevant description of the environment into which the sound propagation such as the physical dimensions of the environment, atmospheric conditions and the characteristics of the ground between the source and the receiver.


Wind farm noise propagation has been the subject of considerable research in recent years. These studies have provided support for the reliability of engineering methods such as ISO 9613 when a certain set of input parameters are chosen in combination. Specifically, the studies to date tend to support that the assignment of a ground absorption factor of G=0.5 for the source, middle and receiver ground regions between a wind farm and a calculation point tends to provide a reliable representation of the upper noise levels expected in practice, when modelled in combination with other key assumptions; specifically all turbines operating at identical wind speeds, emitting sound levels equal to the test measured levels plus a margin for uncertainty (or guaranteed values), at a temperature of 10 degrees and relative humidity of 70% to 80%, with specific adjustments for screening and ground effects as a result of the ground terrain profile.

In support of the use of ISO 9613 and the choice of G=0.5 as an appropriate ground characterisation, the following references are noted:

A factor of G=0.5 is frequently applied in Australia for general environmental noise modelling purposes as a way of accounting for the potential mix of ground porosity which may occur in regions of dry/compacted soils or in regions where persistent damp conditions may be relevant

NZS6808:2010 refers to ISO 9613 as an appropriate prediction methodology for wind farm noise, and notes that soft ground conditions should be characterised by a ground factor of G=0.5

In 1998, a comprehensive study8 (commonly cited as the Joule Report), part funded by the European Commission found that the ISO 9613 model provided a robust representation of upper noise levels which may occur in practice, and provided a closer agreement between predicted and measured noise levels than alternative standards such as CONCAWE and ENM. Specifically, the report indicated the ISO 9613 method generally tends to marginally over-predict noise levels expected in practice

The UK Institute of Acoustics journal dated March/April 2009 published a joint agreement between practitioners in the field of wind farm noise assessment (the 2009 joint IoA agreement), including consultants routinely employed on behalf of both developers and community opposition groups, and indicated the ISO 9613 method as the appropriate standard and specifically designated G=0.5 as the appropriate ground characterisation. It is noted that this publication specifically referred to predictions made to receiver heights of 4m in the interest of representing 2-storey dwellings which are more common in the UK. Predictions in Australia are generally based on a lower prediction height of 1.5m which tends to result in higher ground attenuation factors for a given ground absorption factor, however conversely, predictions in Australia do not generally incorporate a -2dB factor (as applied in the UK) to represent the relationship between LAeq and LA90 noise levels. The result is that these differences tend to balance out to a comparable approach and thus supports the use of G=0.5 in the context of Australian prediction methodologies.

8 Bass, Bullmore and Sloth - Development of a wind farm noise propagation prediction model;

Contract JOR3-CT95-0051, Final Report, January 1996 to May 1998.


The IoA document A good practice guide to the application of ETSU-R-97 for the assessment and rating of wind turbine noise (IOA GPG) published in May 2013 provides detailed descriptive advice to assist with the use of ETSU-R-97 for noise assessment of UK wind farm developments. The good practice guide recommends a ground factor of G = 0.5 when used in conjunction with the inputs described in the UK (IoA) journal article noted above.

A range of comparative measurement and prediction studies9, 10, 11 for wind farms in which Marshall Day Acoustics’ staff have been involved in have provided further support for the use of ISO 9613 and G=0.5 as an appropriate representation of typical upper noise levels expected to occur in practice.

The key findings of these studies demonstrated the suitability of the ISO 9613 method to predict the propagation of wind turbine noise for:

the types of noise source heights associated with a modern wind farm, extending the scope of application of the method beyond the 30m maximum source heights considered in the original ISO 9613;

the types of environments in which wind farms are typically developed, and the range of atmospheric conditions and wind speeds typically observed around wind farm sites. Importantly, this supports the extended scope of application to wind speeds in excess of 5m/s.

In addition to the choice of ground absorption factor referred to above, the ISO 9613 standard has also been used with due regard to the recommended adjustments for terrain recommended in the Joule Report. The following adjustments have been made:

In instances where the ground terrain provides marginal or partial acoustic screening, the barrier effect should be limited to not more than 2dB

In instances where the ground falls away significantly between the source and receiver, such as valleys, an adjustment of 3dB should be added to the calculated sound pressure level. A terrain profile in which the ground falls away significantly is defined as one where the mean sound propagation height is at least 50% greater than would occur over flat ground

9 Bullmore, Adcock, Jiggins & Cand – Wind Farm Noise Predictions: The Risks of Conservatism; Presented at the Second

International Meeting on Wind Turbine Noise in Lyon, France September 2007 10

Bullmore, Adcock, Jiggins & Cand – Wind Farm Noise Predictions and Comparisons with Measurements; Presented at

the Third International Meeting on Wind Turbine Noise in Aalborg, Denmark June 2009 11

Delaire, Griffin, & Walsh – Comparison of predicted wind farm noise emission and measured post-construction noise

levels at the Portland Wind Energy Project in Victoria, Australia; Presented at the Fourth International Meeting on Wind Turbine Noise in Rome, April 2011


APPENDIX H NOISE CONTOUR MAP (INDICATIVE)


APPENDIX I COONOOER BRIDGE WIND FARM INFORMATION

All information relating to the Coonooer Bridge Wind Farm used for the cumulative noise assessment has been sourced from the Marshall Day Acoustics’ report 001 2012420ML titled Coonooer Bridge Wind Farm – Noise Impact Assessment and dated 14 December 2012.

I1 Turbine coordinates - Coonooer Bridge Wind Farm (MGA94 Z54)

Turbine ID Easting Northing

C1 711277 5966933

C2 711587 5966662

C3 712172 5965086

C4 711641 5964957

C5 711952 5964916

C6 711255 5964912

I2 Receiver coordinates – Coonooer Bridge (MGA94 Z54)

Property ID Easting Northing Berrimal Wind Farm reference

C1 (S) 713556 5964997 H18

C2 (S) 713406 5965249 H19

C3 (S) 713411 5966390 H20

C4 714024 5968218 H21

C5 712969 5968818 H40

C6 709250 5966354 H3

C7 708688 5963756 H41


APPENDIX J AW125/3000 NOISE ASSESSMENT

J1 WIND TURBINES

Turbine type

The ACCIONA Windpower AW125/3000 turbine has a rated power of 3MW and a rotor diameter of 125m. Details for this turbine model are provided in Table 15 below.

Table 15: WTG manufacturer specifications

Details

Make ACCIONA Windpower

Model AW125/3000

Rotor Diameter (m) 125

Hub Height (m) Up to 120

Orientation Upwind

Nominal rotor speed (rpm) 13.2

Cut-in Wind Speed (hub height, m/s) 3.5

Rated Wind Speed (hub height, m/s) 10.5

Cut-out Wind Speed (hub height, m/s) 25

Sound Power LWA at 10.3m/s (hub height, dB) 109.2*

Tonality audibility (La,k>0dB) See following tonality section

Sound power levels

Sound power data for the ACCIONA Windpower AW125/3000 turbine has been provided by ACCIONA Windpower in document DG200383 dated 23 November 2012. We understand the data is not guaranteed data. The validity of the data should be confirmed through an independent test report.

The profile of A-weighted sound power levels per wind speed is presented in Figure 15 below, referenced to hub height wind speeds in the range 8.8m/s – 14.7m/s.


Figure 15: Provided sound power level for the AW125/3000




8.8 10.3 11.8 13.2 14.7

LWA (dB) 108.4 109.2 109 108.9 108.7

The reference A-weighted octave band sound power spectrum is presented in Figure 16.

Figure 16: A-weighted octave band sound power level spectra for the AW125/3000,

108.4

109.2109.0

108.9108.7

105

106

107

108

109

110

8 9 10 11 12 13 14 15

Sou

nd

Po

we

r Le

vel,

L WA

(dB

)


86.1

95.5

102.0

104.6 104.1

99.0

88.4

82.1

65

70

75

80

85

90

95

100

105

110

63 125 250 500 1000 2000 4000 8000

Sou

nd

Po

we

r Le

vel,

L WA

(dB

)

Frequency (Hz)



Table 17: Reference A-weighted octave band sound power level spectra for the AW125/3000


63 125 250 500 1000 2000 4000 8000

LWA (dB) 86.1 95.5 102.0 104.6 104.1 99.0 88.4 82.1

Tonality

The DG200383 document states that:

A tonal audibility of ΔLa ≤ 2dB[12

] can be expected over the entire operational range.

J2 Predicted noise levels

The predicted noise levels from the AW125/3000 turbine based on the information in Appendix B are provided in Table J4.

Table J4: Predicted noise from the Berrimal Wind Farm, LAeq dB

Hub height wind speed (m/s) Compliance with

noise limits? House 8.8 10.3 11.8 13.2 14.7

H17 35.6 36.4 36.2 36.1 35.9

H18 33.7 34.5 34.3 34.2 34.0

H19 32.9 33.7 33.5 33.4 33.2

H20 32.6 33.4 33.2 33.1 32.9

H21 31.2 32.0 31.8 31.7 31.5

H22 30.8 31.6 31.4 31.3 31.1

It can be seen from Table J1 that predicted noise levels from the proposed wind farm comply with the applicable noise limits at all six (6) assessed receivers within the range of assessed wind speeds. Predicted noise levels at all six (6) assessed receivers also comply with the lowest possible NZS6808:2010 noise limit of 40dB LA90 at all wind speeds by at least 3dB.

Wind farm noise at all residential properties further from the wind farm will be lower than 31dB LAeq and therefore comply with the lowest possible NZS6808:2010 noise limit at all wind speeds.

If the turbine selection and/or layout are to be changed, compliance with the relevant noise limit will need to be reassessed

12

DG200383 refers to tonal audibility with the descriptor La. For the purposes of this assessment, the reference has

been interpreted as relating to La,k.levels


Special audible characteristics

The specification for the proposed AW125/3000 turbine detailed in ACCIONA Windpower

document DG200383 states that tonal audibility levels (La,k)13 are expected to be less than

2dB as assessed in accordance with IEC 61400-11:2002. However, detailed tonal audibility assessment results are not provided.

For the purposes of this informative assessment, a penalty for special audible characteristics (tonality) has not been applied. If this secondary candidate turbine is nominated as the formal candidate for installation on-site, a detailed IEC 61400-11 test report should be provided by the manufacturer to assess measured tonal audibility levels and this informative noise assessment must be revised.

J3 CUMULATIVE ASSESSMENT

We understand there is one other wind farm currently proposed in the general vicinity of the Berrimal Wind Farm: Coonooer Bridge Wind Farm.

Predicted wind farm noise levels

30dB LAeq noise contours have been calculated for each proposed wind farm and are shown together in Figure J4. It should be noted that the noise contour maps generated by SoundPlan are not able reflect the Joule Report adjustments directly. Therefore, the noise contour maps are provided for informational purposes only.

Figure J4: Indicative 30dB LAeq noise contours for the Coonooer Bridge Wind Farm and the Berrimal Wind Farm

13

DG200383 refers to tonal audibility with the descriptor La. For the purposes of this assessment, the reference has

been interpreted as relating to La,k.levels


It can be seen that there are three (3) residential properties located in the region of intersection for the two 30dB LAeq contours.

Table 18 below presents the predicted cumulative level of wind farm noise for these three (3) noise sensitive locations.

Table 18: Cumulative predicted noise levels, LAeq dB

Distance to nearest Berrimal wind turbine (m)

Distance to nearest Coonooer Bridge wind turbine (m)

Predicted noise level, LAeq dB

House Berrimal Wind Farm

Coonooer Bridge Wind Farm

Cumulative

H18 2364 1451 34.5 32.3 36.7

H19 2477 1241 33.7 33.8 36.8

H20 2253 1802 33.4 31.6 35.6

It can be seen from Table 18 that the predicted noise contribution of the approved Coonooer Bridge Wind Farm to the predicted level of noise from Berrimal Wind Farm at the identified dwellings is up to 3dB across the considered noise sensitive locations.

Predicted cumulative noise levels from the Berrimal and Coonooer Bridge wind farms comply with the lowest possible NZS6808:2010 noise limit of 40dB LA90, at all assessed wind speeds, at all assessed noise sensitive locations.


APPENDIX K DOCUMENTATION

K1 Predictions

(a) Map of the site showing topography, turbines and residential properties: See Appendix B

(b) Noise sensitive locations: See Section 5.0 and Appendix B

(c) Wind turbine sound power levels, LWA dB (also refer to Section 2.0)

Hub Height Wind Speed (m/s)


Overall 63 125 250 500 1000 2000 4000 8000

8.8* 106.8 83.7 93.1 99.6 102.2 101.7 96.6 86.0 79.7

10.3 108.0 84.9 94.3 100.8 103.4 102.9 97.8 87.2 80.9

11.8* 107.9 84.8 94.2 100.7 103.3 102.8 97.7 87.1 80.8

13.2* 107.1 84.0 93.4 99.9 102.5 102.0 96.9 86.3 80.0

14.7* 107.5 84.4 93.8 100.3 102.9 102.4 97.3 86.7 80.4

* based on the sound power level spectrum for 10.3m/s at hub height

(d) Wind turbine model: ACCIONA Windpower AW116/3000, details provided in Table 1 of

Section 2.1.1

(e) Turbine hub height: Up to 120m

(f) Distance of noise sensitive locations from the wind turbines: See Table 5 of Section 2.1.3

(g) Calculation procedure used: ISO9613-2:1996 prediction algorithm as implemented in SoundPLAN v7.2 (See Section 8.0 and Appendix D)

(h) Meteorological conditions assumed:

Temperature: 10°C

Relative humidity: 70%

Atmospheric pressure: 101.325 kPa

(i) Air absorption parameters:

Octave band mid frequency (Hz)

Description 63 125 250 500 1k 2k 4k 8k

Atmospheric attenuation (dB/km) 0.12 0.41 1.04 1.93 3.66 9.66 32.8 116.9

(j) Ground attenuation: G=0.5 (See Appendix D)

(k) Topography/screening: Screening effects in accordance with ISO9613-2:1996 prediction algorithm, limited to 2dB, as detailed in Appendix D

(l) Predicted far-field wind farm sound levels: See Table 11 of Section 8.0


K2 Background Sound Levels

(a) Description of sound monitoring equipment: See Section 6.1

(b) Location of sound monitoring positions: See Table 7 of Section 6.1 and Appendix D

(c) Description of the anemometry equipment: Available upon request

(d) Position of wind speed measurements: See Table 8 of Section 6.2

(e) Time and duration of the monitoring periods: See Table 7 of Section 6.1

(f) Averaging period (wind and noise data): 10min

(g) Atmospheric conditions:

Wind speed: See Appendix D

Wind Direction: Available upon request

Rainfall: Available upon request

(h) Number of data points measured: See Table 9 of Section 7.2

(i) Description of the regression analysis: See Table 9 of Section 7.2

(j) Graphical plots of the data scatter and the regression curves: See Appendix F

Predicted noise levels from the proposed wind farm at all residential properties identified in Table 6 of Section 5.1 are presented in Table 11 for each available wind speed.

Predicted noise levels are compared with the applicable NZS6808:2010 noise limits detailed in Appendix F.

Documents

BERRIMAL WIND FARM Noise Assessment Rp001 R04 2012437ML · 2017. 8. 15. · Reports produced by Marshall Day Acoustics Pty Ltd are prepared based on the Client’s objective and are