Victorian Temporary Standby Emergency Power Supply Project
Last updated: Thursday 19 April 2018
Modelling by the Australian Energy Market Operator (AEMO) forecast that during the 2017-18 summer there was the risk of an electricity shortage of around 220 MW in Victoria. Under extreme scenarios (a heatwave across Victoria and South Australia) this could have increased to 760 MW. If additional reserves of electricity or reductions in demand were not achieved, parts of the grid were at risk of needing to be shut down to avoid a blackout.
Temporary standby emergency power supply was needed to help meet Victoria's power needs under extreme conditions over summer 2017-18. Aggreko was contracted to provide 110 MW of power supply to meet part of this need. As such, 105 diesel-fired generators were temporarily installed on land surrounding the former Morwell Power Station and briquette factory, in the Latrobe Valley, Victoria.
This project was part of the broader 'summer readiness' program managed by AEMO that includes maximising the availability of existing generation and transmission and managing demand. Details of AEMO's full summer readiness activities can be found on their website at: www.aemo.com.au/Media-Centre/AEMO-releases-summer-readiness-report-for-2017-18.
2. Modelling of Noise and Air Quality
In consultation with the Environment Protection Authority (EPA) Victoria, noise and air quality specialists assessed the potential impacts of the temporary power station at nearby receptors (e.g., homes and industrial sites). Modelling included data on local meteorological conditions, topography, background noise and air quality, the layout of existing structures on site, and the layout and typical emissions of the diesel generators.
The closest receptors are industrial properties to the west, south and east, and the nearest residential receptors are to the north, northwest and southeast. Under the likely operating conditions (i.e., heatwaves), the predominant northerly winds will blow air and noise emissions away from receptors.
Air Quality Modelling
For diesel generators, the key air emission of interest is nitrogen dioxide (NO2). Modelling showed that under likely operating conditions, EPA criteria would not be exceeded at any homes or public facilities. Emissions would also be well below Workplace Exposure Standards at nearby industrial sites.
Modelling showed that particulates (including PM2.5) will be below EPA criteria at all sensitive/residential receptors, and well below Workplace Exposure Standards at nearby industrial sites. Modelling results for sulfur dioxide (SO2) and volatile organic compounds (VOCs) were well below EPA criteria even at the Energy Brix property boundaries.
The noise specialists advised that evening (6:00 to 10:00 pm) was the most important assessment period for noise - noting that the most likely operating time is in the hottest part of an afternoon (e.g., 2:00 pm to 6:00 pm), and therefore outside of this period. It is a condition of the EPA's approval that the project cannot operate after 10:00 pm.
Noise modelling showed that in calm conditions or when winds blow away from receptors, noise criteria will not be exceeded. When winds blow in the direction of Morwell, there may be minor exceedances of noise criteria. Such winds occur less than 4% of the time in summer, and are even less frequent during heatwaves. Modelling showed that noise levels at industrial/commercial sites would be well below criteria in the Victorian OH&S Regulations.
3. Monitoring of Air Quality and Noise
The Victorian EPA reviewed the findings of the noise and air quality specialists, and approved the project in December 2017. The approval included a requirement that Aggreko must implement a monitoring program that includes:
- Continuously monitoring for nitrogen dioxide (NO2) when the generators are in operations.
- Monitoring noise levels at sensitive receptors.
- Making air quality monitoring data from the monitoring program available to the EPA and the public as soon as practicable.
Given that the air quality modelling results showed that only NO2 was a parameter of interest, the EPA did not require monitoring of other aspects of air quality. However, as some community groups expressed interest in emissions of particulates, Aggreko elected to monitor PM2.5 emissions also.
The project monitoring program provided information additional to that already provided by the EPA AirWatch air monitoring program, which monitors air quality in Moe, Churchill, Traralgon and Morwell (which includes two sites: Morwell East and Morwell South) (www.epa.vic.gov.au/our-work/monitoring-the-environment/epa-airwatch).
Air Quality Monitoring Sites
As shown in Figure 1, Aggreko set up three (3) NO2 monitors around the perimeter of the Morwell Power Station (Energy Brix) property:
- Site 1: Property Boundary - Northwest.
- Site 2: Property Boundary - East.
- Site 3: Property Boundary - South.
Figure 1 – Air Quality Monitoring Sites
Monitoring of air quality on property boundaries is a standard approach recommended by air quality specialists. The monitoring data collected at boundaries can then be used in conjunction with EPA AirWatch monitoring data (from Morwell East and Morwell South) to estimate potential air quality impacts at nearby receptors. The Victorian EPA approved this monitoring approach for the project.
In addition to the NO2 monitors, monitors for PM2.5 (not required by the EPA) were set up at Site 1 and Site 3 as above. These two sites are the closest to neighbouring industrial receptors.
Reporting of Air Quality Data
To ensure consistency with the EPA AirWatch monitoring program, the monitoring results were provided using the same Air Quality Categories as outlined in Table 1 below.
Table 1 - Victorian EPA Air Quality Categories
|Category||NO2 (1 hour average) ppb||PM2.5 (1 hour average) μg/m3|
|Very Good||0 to 39||0.0 to 13.1|
|Good||40 to 78||13.2 to 26.3|
|Fair||79 to 119||26.4 to 39.9|
|Poor||120 to 179||40.0 to 59.9|
|Very Poor||180 or greater||60.0 or greater|
Noise Monitoring Sites
Aggreko set up three (3) noise monitors at locations around Morwell:
- Site 4: Morwell Town Centre.
- Site 5: Buckleys Hill Reservoir, Morwell.
- Site 6: Church Road, Hazelwood North.
Results of noise monitoring will be considered in accordance with the following Victorian EPA policy and guideline:
- State Environment Protection Policy (Control of Noise from Commerce, Industry and Trade) No. N-1 (SEPP N-1)1. Applicable to areas of Morwell town (Sites 4 and 5).
- Noise from Industry in Regional Victoria (NIRV) Guidelines2 . Applicable to more rural areas outside of Morwell town (Site 6).
The policy and guidelines provide methods for assessing noise emissions from commercial and industrial premises, and for determining corresponding noise level targets to be achieved at residences.
Assessing the Noise Environment
The ambient (surrounding) noise environment includes noise from both man-made and natural sources. Man-made noise sources will primarily be from traffic on nearby and distant roads. Natural noise sources include wind, rain, insects and birds. Both man-made and natural noise sources vary from moment to moment, day to day, and from weekday to weekend. The combination of man-made and natural sources can result in significant variations in the ambient noise environment. The ambient noise environment is assessed by monitoring for several days or more, during which there will typically be significant variation in the ambient noise levels.
The ambient noise environment is defined by both:
- The background noise level (measured by the noise level exceeded for 90% of the measurement period, and called the L90).
- The 'equivalent continuous noise level' (effectively the average noise level, equivalent to the actual varying noise level in a given period, and called the Leq).
Under the EPA policies and guidelines, assessment of commercial and industrial noise at residential premises is based on the Leq over any 30-minute period. The generators will be a relatively constant noise source and as such, the Leq and L90 values are equal. When assessing a constant noise source in a very variable ambient environment, the L90 can often be more useful than the Leq because the Leq is significantly influenced by short term noise events, whereas the L90 is less so.
Noise Level Targets
The intent of noise level targets is that when assessed at residential premises, noise emissions associated with commercial and industrial premises should be within the range of typical ambient environment noise levels, and consistent with expectations based on the mix of planning scheme zonings around residences.
Noise level targets vary depending on the time of the day, evening or night. The relevant EPA-defined assessment periods are summarised in Table 2.
Table 2 - Noise Assessment Time Period
|EPA Assessment Period||Relevant Days||Relevant Time Periods|
|'Day'||Monday to Friday||7:00 am to 6:00 pm|
|Saturday*||7:00 am to 1:00 pm|
|'Evening'||Saturday*||1:00 pm to 6:00 pm|
|Sunday, Public Holidays*||7:00 am to 6:00 pm|
|All Days||6:00 pm to 10:00 pm|
|'Night' *||All Days||10:00 pm to 7:00 am|
* Note that the generators are not licensed to operate beyond 10:00 pm ('Night') on any days, and operation on weekends and public holidays is unlikely due to the expected lower electricity demand.
Noise level targets are determined primarily on the basis of the applicable land zoning surrounding residences, with secondary consideration of the ambient background noise levels.
The established EPA practice is for noise level targets to be based on the lowest background L90 levels as identified during noise monitoring for each of the EPA-defined time periods.
Based on work carried out by noise specialists Watson Moss Growcott Acoustics Pty Ltd (WMG) - including a review of planning scheme zonings, and ambient background noise measurements carried out at the site - the adopted noise limits and NIRV recommended noise levels are outlined in Table 3.
Table 3 - Noise Level Targets
|Noise Level Target||Assessment Location|
|Site 4 (SEPP N-1)||Site 5 (SEPP N-1)||Site 6 (NIRV)|
|Day*||50 dB(A) Leq||50 dB(A) Leq||45 dB(A) Leq|
|Evening*||44 dB(A) Leq||44 dB(A) Leq||37 dB(A) Leq|
* See Table 2 regarding time periods
Due to normal noise variations in the ambient environment, there will be times during which the L90 and Leq associated with the ambient environment are higher than the noise targets, even in the absence of commercial and industrial noise emissions.
WMG were engaged to review and analyse noise monitoring data to identify noise contributions from generator operation, as distinct from the general background noise environment.
4. Monitoring Results
Operation and Monitoring Times
During the 2017-18 summer, the generators were not required to operate for the generation of emergency electricity for Victoria.
A 15-minute test run of the generators was undertaken on 23 January 2018, between 8:00 pm and 8:15 pm (20:00 to 20:15), to ensure that all equipment was fully operational and capable of generating electricity if this was required during the remainder of the summer.
Monitoring results are provided below for the 23 January test run period. Table 4 below shows the days and times when monitoring has been undertaken, along with the timeframe/s of generator operation, if or when applicable.
Table 4 – Environmental Monitoring Details
|No.||Day/Date||Time of Generator Operation||Time of Air Quality Monitoring||Time of Noise Monitoring||Notes|
|1||Tue 23/01/2018||20:00 to 20:15||15:50 to 23:59||17:25 to 23:59||15-minute test run only|
Nitrogen Dioxide Results
Nitrogen dioxide (NO2) results for the time period/s outlined in Table 4 are provided in Table 5 and illustrated in Figure 2. Note that the relevant EPA criteria (SEPP for Ambient Air Quality3) for NO2 is a maximum concentration of 120 ppb, over a one hour averaging period. As per the EPA AirWatch program, monitoring results of 120 ppb and above are considered 'poor' to 'very poor', while results below this level range from 'very good' to 'fair'.
During the generator test run conducted for 15 minutes on 23 January 2018, all three NO2 monitors recorded results well below the relevant criteria, rated as 'very good' air quality according to the EPA AirWatch program. See Figure 2.
Table 5 – Nitrogen Dioxide Monitoring Results (Hourly Average NO2 and Air Quality Rating)
|23/01/18 20:00 to 21:00||1.8||Very good||1.8||Very good||0.9||Very good|
*Very good = 0 to 39 ppb, Good = 40 to 78 ppb, Fair = 79 to 119 ppb, Poor = 120 to 179 ppb, Very poor = 180 ppb or greater
Figure 2 – Most Recent NO2 Monitoring Results (ppb)
Fine particulate (PM2.5) results for the time period/s outlined in Table 4 will be provided in Table 6 and illustrated in Figure 3. Note that as per the EPA AirWatch program, monitoring results of 40 μg/m3 and above (over a one hour averaging period) are considered 'poor' to 'very poor', while results below this level range from 'very good' to 'fair'.
During the generator test run conducted for 15 minutes on 23 January 2018, both PM2.5 monitors recorded results well below the relevant criteria, rated as 'very good' air quality according to the EPA AirWatch program.
Table 6 – PM2.5 Monitoring Results (Hourly Average PM2.5 and Air Quality Rating)
|23/01/18 20:00 to 21:00||0.2||Very good||0.0||Very good|
*Very good = 0.0 to 13.1 μg/m3, Good = 13.2 to 26.3 μg/m3, Fair = 26.4 to 39.9 μg/m3, Poor = 40.0 to 59.9 μg/m3, Very poor = 60.0 μg/m3 or greater
Figure 3 – Most Recent PM2.5 Monitoring Results (μg/m3)
Noise monitoring results for the time period/s outlined in Table 4 are provided in Table 7. Results for the test run period on 23 January 2018 are discussed below and illustrated in Figures 4 to 6.
Site 4: Morwell Town
- At this measurement site southeast of the town centre, during the evening time period (6:00 to 10:00 pm) of 23 January, ambient noise levels were in the range of 47 to 55 dB(A) L90 and 50 to 60 dB(A) Leq. Typical noise levels measured during the 15-minute generator test run (8:00 to 8:15 pm) were 54 dB(A) L90 and 60 dB(A) Leq. See Figure 4.
- In addition to collection of noise level data, the noise monitoring equipment simultaneously records audio files. Analysis of the audio file collected at Site 4 during the test run period showed that the acoustic environment was dominated by noise sources other than the generators. The extraneous noise at this site included localised live music noise (a marching band or similar) within close proximity of the measurement location. Noise associated with the generators was inaudible for the duration of the test run.
Site 5: Buckleys Hill Reservoir
- At this measurement site east of the town centre, during the evening (6:00 to 10:00 pm) of 23 January, ambient noise levels were in the range of 42 to 52 dB(A) L90 and 44 to 55 dB(A) Leq. Typical noise levels measured during the 15-minute generator test run (8:00 to 8:15 pm) were 43 dB(A) L90 and 47 dB(A) Leq. See Figure 5
- Analysis of the audio file collected at Site 5 during the test run period showed that the acoustic environment was dominated by noise sources other than the generators. Noise associated with the generators was inaudible for the duration of the test run.
Site 6: Church Road, Hazelwood North
- At this measurement site southwest of Morwell, during the evening (6:00 to 10:00 pm) of 23 January, ambient noise levels were in the range of 34 to 43 dB(A) L90 and 40 to 48 dB(A) Leq. Typical noise levels measured during the 15-minute generator test run (8:00 to 8:15 pm) were 42 dB(A) L90 and 47 dB(A) Leq. See Figure 6.
- Analysis of the audio file collected at Site 6 during the test run period showed that the acoustic environment was dominated by noise sources other than the generators. The extraneous noise at this site included birds, light breezes causing movement of trees, and occasional vehicle movements along nearby roads. Noise associated with the generators was inaudible for the duration of the test run.
Table 7 - Noise Levels Over Monitoring Period
|Date/Time||Site||Background Noise Level (L90)||Average Noise Level (Leq)|
|Ambient noise during relevant time period||Typical noise level during generator operation||Ambient noise during relevant time period||Typical noise level during generator operation|
|23/01/18 20:00-20:15||4||47 to 55 dB(A)||54 dB(A)||50 to 60 dB(A)||60 dB(A)|
|23/01/18 20:00-20:15||5||42 to 52 dB(A)||43 dB(A)||44 to 55 dB(A)||47 dB(A)|
|23/01/18 20:00-20:15||6||34 to 43 dB(A)||42 dB(A)||40 to 48 dB(A)||47 dB(A)|
Figure 4 – Most Recent Noise Monitoring Results – Site 4 (Morwell)
Figure 5 – Most Recent Noise Monitoring Results – Site 5 (Buckleys Hill Reservoir)
Figure 6 – Most Recent Noise Monitoring Results – Site 6 (Church Road)
4. Further Information
If you have any questions please email firstname.lastname@example.org and a project representative will contact you as soon as possible.
1 EPA. 2001. State Environment Protection Policy (Control of Noise from Commerce, Industry and Trade) No. N-1. No. S31, 16/5/1989, Gazette 15/6/1989, as varied 1992 and 2001. EPA Victoria, Carlton.
2 EPA. 2011. Noise from Industry in Regional Victoria. Recommended Maximum Noise Levels for Commerce, Industry and Trade Premises in Regional Victoria. EPA Victoria, Carlton.
3 EPA. 1999. State Environment Protection Policy (Ambient Air Quality) No. S19, Gazette 9/2/1999. EPA Victoria, Carlton.