Agenda

Company

Pacific Hydro Pty Ltd ACN 057 279 508

Meeting

Cape Bridgewater Consultative Committee

Date

Monday, 2 June 2014

Time

6-7:30

Location

Cape Bridgewater Surf Life Saving Club

Attendees

Rachel Watson, Head of Commercial, Pacific Hydro, Andrew Richards, Executive Manager ,External Affairs Cath Smith, Futureye (Facilitator), Dianne Thomson, Community Relations Coordinator, Pacific Hydro Steven Cooper, The Acoustic Group PTY LTD Cape Bridgewater Residents

Agenda Item

Presenter

Duration

1.

Welcome and introductions

Cath

5 mins

2.

Previous minutes tabled

Cath

5 mins

3.

Update / Presentation / Discussion with Steven Cooper re noise testing.

Steven Cooper

70 mins

General discussion, other business

Cath

10mins

4.

Page 1

44.5100.L5:MSC 28th May, 2014

Energy Pacific (VIC) Pty Ltd Level 11, 474 Flinders Street MELBOURNE VIC 3000

Attention: Mr L. Crockett

UPDATE OF SURVEY A proposed plan for testing on the windfarm and at residential dwellings was nominated for the study and to date a major proportion of the investigation and measurements allocated for the initial stages have been carried out, although issues in terms of weather and physical time limitations have had some components delayed.

Pre House Testing As a identified in the last public meeting at Cape Bridgewater a number of loggers had been installed on or out from the windfarm with permission sought to access to another property being given on the night of the public meeting.

For the southern portion of the windfarm (accessed off Blowholes Road) 3 loggers were set out in an easterly direction identified as Logger A, Logger B and Logger C.

Another 2 loggers were located north of the windfarm identified as Loggers D and E. Monitoring and installation of equipment at 1 residential premises commenced on Friday 2nd May with monitoring at 1 house for 3 days, then relocated to another house for 2 nights, then another house for 2 nights, then the equipment reinstalled back in 1 house to continue monitoring.

Update of Survey – Cape Bridgewater Wind Farm Energy Pacific (VIC) Pty Ltd

Page 2 of 5

Some work was carried out on the windfarm in relation to noise and vibration around a tower to identify the natural frequency associated with the tower structure itself. The other work envisaged on the windfarm being the substation and multiple noise and vibration measurements out from turbines did not occur in the first week due to timing constraints, the time and distance between the windfarm and the bulk of equipment at Portland, and the adverse weather that occurred.

The investigation of hotspots on the residential properties and the additional material on the windfarm is yet to occur, although some of it is envisaged to have been undertaken by the public meeting on 2nd June.

Discussions with residents during the house monitoring phase indicated that the diary procedure as used in South Australian EPA Waterloo Study had a number of difficulties and confusion with residents trialling the diary.

The diary concept was modified to separate the severity ranking (1 to 5) to consider noise, vibration, and sensation.

The concept as to the “operation” of the windfarm prior to monitoring was causing confusion from the SA EPA concept and as such was abandoned for this study.

An analysis of the diary information with the noise data that was retrieved on the first visit found some correlation in terms of severity with the operation of the windfarm but did not give rise to a correlation of the severity with respect to different noise levels even when considering various different acoustic parameters extracted from the data.

With the provision of the wind and power output information for the windfarm it became apparent in terms of our analysis that the residents had been reporting changes in their perception of the windfarm. This was not what we anticipated in the diary format, and apparently is not what has been envisaged in other such surveys. On meeting with the residents on the following fortnight (22nd and 23rd May) they were all in agreement that that was the situation in terms of the notations in the diary because in effect having experienced “noise” from the windfarm for some time the actual impacts were put aside and that it was the difference in the impacts that became noticeable.

The Acoustic Group Letter 44.5100.L5: MSC th 28 May, 2014

Update of Survey – Cape Bridgewater Wind Farm Energy Pacific (VIC) Pty Ltd

Page 3 of 5

As expressed by 1 resident when confronted with the data to indicate what had happened: “the impact was like an ongoing toothache in which one sought to block out even though it was still there but would be certainly reminded if biting on any material or cold drink or etc. would create a new pain from the tooth.”

It is considered that this breakthrough in understanding/comprehending this aspect of the diary/observations is a very significant fact that has not been understood or identified previously. Therefore this alters the concept of seeking to validate the observations versus the noise levels.

A graphical presentation of noise level versus time throughout the day has the individual sensations overlaid on a graph where a blue arrow represents noise, a green arrow represents vibration and a red arrow represent sensation. The number in each of the arrows identifying the sensitivity has been presented to the residents as a format for correlating the diary with the noise levels.

We have also from use of the 1/3 octave band logger information sought to calculate the various different acoustic parameters for correlation with the observations that in turn highlighted the nature of the diary notes being not what we expected. A revised set of instructions in relation to the observations has been provided and issued to the residents and is attached together with a sample of the diary observations that at the present time relate to changes rather than the operation of the windfarm.

In the last 2½ weeks the residents have experienced periods of windfarm operation versus shutdown with the diary comments identifying noticeable differences between those 2 operating scenarios.

Also attached are a series of graphs that relate to the 3 noise loggers to the east of the southern portion of the windfarm and 2 loggers to the north of the windfarm where the material provides the change in the A-weighted level for each of the 10 minute samples throughout the day showing the background level (L95 for the original application), the Leq level (which is an energy average) and the L10 level (which is an average maximum level).

The Acoustic Group Letter 44.5100.L5: MSC th 28 May, 2014

Update of Survey – Cape Bridgewater Wind Farm Energy Pacific (VIC) Pty Ltd

Page 4 of 5

Under the 3 (or 2) noise graphs is a graph that identify the average wind speed for the 5 turbines (northern section) or the 18 turbines (southern section) being an arithmetic average of the wind measurements recorded at each turbine. Similarly a graph showing the wind direction being an arithmetic average of the relevant turbines is shown then followed by a graph that is the apparent power output from those group of turbines where the power at the present time is expressed as volt amps (to agree with the data supplied) and is the summation of all those turbines.

Overlaid on the noise graphs are the observations from the residents relative to each group of turbines.

Examination of those graphs reveals the following matters which were expected from the outset: 

For an increase in the power output there is an increase in the noise where changes in the power output are reflected in the ambient background (L95) graph.



For the same power output there are minor changes associated with the background level by reason of changes of the wind.



At times when the turbines are off and the winds are relatively low the ambient background level at some locations is noticeably higher than what would be expected for a rural environment. The site attendance indicates that with respect to the properties off Blowholes Road that elevated background level is a result of noise from waves on the cliffs whereas at the residence to the north of the windfarm the sound of the waves/surf on the cliffs is apparent under a westerly wind condition whereas on a southerly or south-easterly condition the noise from the waves from the direction of Cape Bridgewater is apparent.



Taking into account under the relevant wind conditions the background level that is attributed to the waves there is still a noticeable increase associated with the windfarm that follows the increase in power output.

This means that in examining the ambient background level data caution will be needed to ascertain whether there is an influence from the wave/ocean which is addressed by other analysis methods.

The Acoustic Group Letter 44.5100.L5: MSC th 28 May, 2014

Update of Survey – Cape Bridgewater Wind Farm Energy Pacific (VIC) Pty Ltd

Page 5 of 5

The pre-house test logger results and the testing at houses suggests that there may be a heightened level of disturbance associated with low-power operation of the turbines of which the audible characteristics at residential properties is different at such low power/start-up conditions, compared to the and general continuous operation. These are matters that are sought to be addressed by the further detailed analysis.

Yours faithfully,

THE ACOUSTIC GROUP PTY LTD STEVEN E COOPER

The Acoustic Group Letter 44.5100.L5: MSC th 28 May, 2014