Demand Management and Planning Project · emission abatement system be installed at any site participating in a standby generation demand ... The Demand Management and Planning Project

Demand Management and PlanningProject

REPORT

Partial Load Standby Potential Final 7 April 2008

The SKM logo trade mark is a registered trade mark of Sinclair Knight Merz Pty Ltd.

Demand Management and Planning Project

REPORT Final 7 April 2008

Sinclair Knight Merz ABN 37 001 024 095 100 Christie Street PO Box 164 St Leonards NSW Australia 1590 Tel: +61 2 9928 2100 Fax: +61 2 9928 2500 Web: www.skmconsulting.com COPYRIGHT: The concepts and information contained in this document are the property of Sinclair Knight Merz Pty Ltd. Use or copying of this document in whole or in part without the written permission of Sinclair Knight Merz constitutes an infringement of copyright.

LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz Pty Ltd’s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz and its Client. Sinclair Knight Merz accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party.

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SINCLAIR KNIGHT MERZ

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Contents

1. Executive Summary 1

2. Introduction 3 2.1 Project Background 3 2.1.1 Site Selection 3 2.2 Generator Connection Options 3 2.3 Abbreviations and Acronyms 5

3. Site 1: 363 George Street – CBA Building 6 3.1 SGP Facilities 6 3.1.1 Generators 6 3.1.2 Fuel Storage and Handling 6 3.2 Electrical Considerations 7 3.2.1 Switchboards 7 3.2.2 Transfer Switches 7 3.2.3 Synchronization 7 3.2.4 EA Substation 8 3.3 Environmental Considerations 8 3.4 Demand Reduction Options 8 3.5 Cost Estimates 9

4. Site 2: 88 Phillip Street – ABN AMRO Building 11 4.1 SGP Facilities 11 4.1.1 Generators 11 4.1.2 Fuel Storage and Handling 11 4.2 Electrical Considerations 12 4.2.1 Switchboards 12 4.2.2 Transfer Switches 12 4.2.3 Synchronization 12 4.2.4 EA Substation 13 4.3 Environmental Considerations 13 4.4 Demand Reduction Options 13 4.5 Cost Estimates 14

5. Site 3: 225 George Street – Grosvenor Place 16 5.1 SGP Facilities 16 5.1.1 Generators 16 5.1.2 Fuel Storage and Handling 16 5.2 Electrical Considerations 17

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5.2.1 Switchboards 17 5.2.2 Transfer Switches 18 5.2.3 Synchronization 18 5.2.4 EA Substation 18 5.3 Environmental Considerations 18 5.4 Demand Reduction Options 18 5.5 Cost Estimates 19

6. Health and Environmental Considerations 21 6.1 Health Impacts 21 6.2 Environmental Impacts 21 6.3 Further Considerations 23

7. Summary and Recommendations 24

Appendix A 363 George Street – Single Line Diagrams 26

Appendix B 88 Phillip Street – Single Line Diagrams 27

Appendix C 225 George Street – Single Line Diagrams 28

Appendix D Protection of the Environment Operations (Clean Air) Regulation 2002 29

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SINCLAIR KNIGHT MERZ I:\HARB\Projects\HA00931\400 Standby Reports\Deliverables\Site Survey Report_Final.doc PAGE iii

Document history and status Revision Date issued Reviewed by Approved by Date approved Revision type

0 6 March 2008 I Cutler I Cutler 6 March 2008 Draft

1 7 April 2008 P Adams B Kearney 7 April 2008 Final

Distribution of copies Revision Copy no Quantity Issued to

0 1 x Electronic 1 Chris Tully

1 1 x Electronic 1 Chris Tully

Printed: 7 April 2008

Last saved: 7 April 2008 03:17 PM

File name: I:\HARB\Projects\HA00931\400 Standby Reports\Deliverables\Site Survey Report_Final.doc

Author: Peter Kruger / Peter Adams / Anthony Hadley

Project manager: Peter Adams

Name of organisation: Department of Planning

Name of project: Demand Management and Planning Project

Name of document: Report

Document version: Final

Project number: HA00931.400

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SINCLAIR KNIGHT MERZ I:\HARB\Projects\HA00931\400 Standby Reports\Deliverables\Site Survey Report_Final.doc PAGE 1

1. Executive Summary SKM has prepared this report to communicate the findings of three site surveys that were carried out on behalf of the Demand Management and Planning Project (DMPP). The purpose of the site surveys was to determine the practicality, costs and implications of using existing standby generation for reducing electricity demand.

The sites were selected from 228 sites identified by DMPP according to the size of the standby generator capacity and the generator unit reliability. They are listed as follows:

363 George Street – CBA Building

88 Phillip Street – ABN AMRO Building

225 George Street – Grosvenor Place

As the existing standby generator connections at the three sites are island mode configurations, SKM consider that upgrading the existing standby generation for SCTT to be the most appropriate option for demand management purposes. Conversion to an SCTT configuration would avoid the need for an interruption in the power supply when switching from grid supply to standby generator supply. An SCTT configuration also avoids the distribution network fault level issues that are associated with a full parallel connection.

SKM has estimated the capital costs for upgrading to SCTT at the three sites, which average $262 per kVA of standby capacity.

Estimates have also been made for the operational costs involved with running the standby generators for demand management for a total of 100 hours over a one year period.

SKM notes that there are various health and environmental implications from using diesel standby generation. As diesel-fuelled engines are high emitters of Nitrogen Oxides (NOx) and particulates, it is likely that the standby generation plant may fail to meet air emission limits set by the NSW Department of Environment and Climate Change (DECC). SKM therefore recommends that an emission abatement system be installed at any site participating in a standby generation demand management program.

In addition, SKM found that the three sites had generator exhausts that discharge horizontally at low levels in the building. As a horizontal discharge concentrates the exhaust emissions into a relatively small area, the emission levels – as a result – are quite intense. Therefore, it is also likely that DECC will require that the exhaust ducts be extended to discharge above the building roof level so that emission readings are more diluted.

The average cost estimates for the three sites are shown in Table 1-1.

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Capex Costs* SCTT conversion (typical)** $262 per kVA Roof level exhaust Not estimated* Opex Costs*** Fuel, O&M $43 per kVA Refuelling guarantee Not estimated* Total Costs $305 per kVA

Table 1-1 Average costs for using standby generation for demand management in an SCTT configuration

* Note – these costs are strongly site specific and can vary by orders of magnitude and hence it is not possible to provide a representative average figure.

** Capex costs include the cost of an emission abatement system. The cost estimates for these were obtained from the DMPP and have not been verified by SKM.

*** Opex costs are based on 100 hours run-time per annum, or approximately 1% of the time.

Finally, the feasibility of a standby generation demand management program will depend on whether the building tenants agree to such a program. SKM were informed that concerns have been raised by the tenants of Grosvener Place at the increased risk to supply security associated with switching from grid supply to diesel generator supply. It is therefore highly unlikely that this site would participate in a standby generation demand reduction program. In addition, the DMPP encountered significant difficulties finding sites that were willing to participate in this study. This indicates that the take-up rate of standby generation demand management is likely to be low, even at sites that are technically suitable. It is therefore prudent that the DMPP’s ‘identified standby capacity’ is not regarded as an indicator of ‘practical capacity’ for demand management purposes.

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2. Introduction

2.1 Project Background The Demand Management and Planning Project (DMPP) under the NSW Department of Planning was established to identify and explore opportunities to reduce peak electricity demand in Sydney, in order to defer the need for costly grid capacity expansion.

In accordance with the Conditions of Consent placed on the DMPP, standby generation has been investigated extensively to gauge its effectiveness as a means to reduce peak demand. As part of this investigation SKM has been commissioned to carry out three site surveys to determine the following:

The practicality of using standby generation for reducing electricity demand;

The costs associated with any modifications that may be required;

Any implications that may arise from the use of standby generation for network management.

2.1.1 Site Selection Three sites were selected as case studies to explore the technical and non-technical issues involved with using standby generation for demand management. These sites are listed as follows:

363 George Street – CBA Building

88 Phillip Street – ABN AMRO Building

225 George Street – Grosvenor Place

The three sites all have relatively large standby generation capacities (> 3.5MVA each) and were hence chosen for the study as these sites could potentially have a substantial impact in reducing the demand on the electricity network. The generator units at the three sites are also maintained regularly (at least twice per year) which is an important factor in determining whether a standby generator is suitable for demand management. Another important factor in determining a standby generator’s reliability and hence suitability for demand management is its age. In past reports the DMPP have considered only standby generator units less than 15 years old as suitable for demand management. According to this criterion, the units at Grosvenor Place would be deemed unsuitable as they were manufactured in 1984; however the site was still investigated regardless of this drawback as there was a shortage of sites that were willing to participate in this study.

2.2 Generator Connection Options There are three connection modes in which a standby generator can operate: Island mode (standby); Synchronise Close Transfer Trip (SCTT); and Full Parallel.

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Island mode (standby) can be employed when the generator is of sufficient capacity to supply the entire site load or at least the essential services load. Island mode requires a brief supply interruption to the site in order to transfer from the network supply to the standby generator supply. Due to the supply interruption, this mode would most likely not be suitable for supplying sensitive loads.

The SCTT mode of operation can be employed when the generator is of sufficient capacity to supply the total building load or alternatively, with switchboard modifications, to supply part of the building load. In the event that the generator cannot supply the full load, the remaining load can be supplied by the network provided that the switchboard allows for a separation (disconnection) of the standby generator and the network.

The full parallel mode provides the most flexible operation; however, it is the most costly and technically challenging. The standby generator can be used both when the capacity is larger and smaller than the peak site load. In the case where the capacity is larger, the surplus generation can be exported to the network. In the case where the generator cannot supply the total site load, the network can provide the additional requirements.

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2.3 Abbreviations and Acronyms

EA Energy Australia

DECC NSW Department of the Environment and Climate Change

SKM Sinclair Knight Merz

NOx Nitrogen Oxides

SFL Safe Fill Level (for bulk fuel tanks)

MD Maximum Demand

SGP Standby Generating Plant

SCTT Synchronise-Close-Transfer-Trip

MCCB Moulded Case Circuit Breaker

ACB Air Circuit Breaker

ATS Automatic Transfer Switch

SCR Selective Catalytic Reduction

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3. Site 1: 363 George Street – CBA Building

3.1 SGP Facilities

3.1.1 Generators The SGP plant at 363 George Street comprises four generators located in the Diesel Generator room on level 32, as follows:

3 x 1120kVA Cummins generators, plus

1 x 550kVA Perkins generator.

The 550kVA diesel generator serves the York St building, covering 100% of the base building and tenancy loads. Two of the 1120kVA diesel generators serve the George St office tower, covering 100% base building and tenancy loads. It is SKM’s understanding that the third 1120kVA generator acts as a standby generator for the tower.

The generators were manufactured in 1998. The generators are rated for standby operation, which Cummins define as a maximum of 200 hours of operation per annum at a load factor of less than 80% and a maximum of 25 hours per year at 100% of its rating. No overload capacity is provided for standby rated sets.

Each generator is equipped with electrical starting gear, a nominal 1000L fuel day tank and jacket water preheating.

Ventilation and combustion air for the SGP is drawn in through wall mounted louvers by the base frame mounted radiator fans and discharged through two built-in riser ducts (one at each end of the DG room) at roof level, two floors above. The risers also house the generator exhaust ducts.

Operation of the SGP is tested monthly for about an hour.

3.1.2 Fuel Storage and Handling A single underground nominal 10,000 L bulk diesel storage tank is located at level B3. The safe fill level (SFL) of the tank is nominated as 7,600 L. The fuel transfer pumps were not sighted however it is assumed that these are located within locked confined space areas located in the walls at level B3.

The tank filling point is located inside the building’s loading dock and parking area access roller door at York Street in a locked wall mounted metal cabinet.

Based on the bulk fuel tank SFL of 7,600 L and a minimum draw off of say 350 L, approximately 7,250 L of diesel fuel would be available to the generators for running, prior to the need to shut down. In addition, each fuel day tank would contain approximately 750L of usable fuel, thereby

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providing a further 3,000 L of diesel fuel. Typically, a standby generator would consume approximately 250g of diesel per kWh generated. One mL of diesel fuel weighs approximately 0.85g.

The maximum output of the SGP is approximately 3,910kVA, which at a power factor of 0.85 equates to approximately 3,300kW. The total amount of fuel available (approximately 10,750 L) would provide for approximately 11 hours of operation at full load if all tanks were full at the start of the run. Assuming that a peak demand reduction period is eight hours or less in duration, this fuel capacity is sufficient. It should however be noted that if the standbys are to be used for demand management for consecutive days, it may be necessary to refill the bulk fuel tank overnight. Hence it may be necessary for the site to engage in a ‘guaranteed’ fuel delivery arrangement so as to ensure the diesel supply is secure. The cost for such an arrangement has not been allowed for in the cost estimates.

3.2 Electrical Considerations

3.2.1 Switchboards The site consists of 2 main switchboard sections (415V) supplied via Energy Australia’s Substation 53676. Main Switchboard Section 1 supplies the George St office tower whilst Main Switchboard Section 2 supplies the York St building. Each main switchboard section then supplies two sub boards.

The sub boards supply both tenant loads and common loads via riser mains, each supplied via moulded case circuit breakers (MCCB). Tenant loads are tee’d off at each floor via fuses and are separately metered at each floor. It appears that essential supplies are separated from non-essential supplies only for the George Street tower via one of the main switchboards.

The George Street building has a diesel generator switchboard which connects all 4 generators to the emergency diesel supply.

Appendix A contains single line diagrams for 363 George Street.

3.2.2 Transfer Switches Each main switchboard is supplied via a transfer switch which allows for the transfer from grid supply to emergency diesel generator supply during mains failure. In this arrangement, the transfer switches separate the network from the diesel supply. This arrangement is ‘island mode’.

3.2.3 Synchronization Synchronising facilities are provided for each of the 1,120kVA diesel generators which allow them to be synchronised to the generator bus individually. However, information from the site visit

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suggests that synchronising to the EA supply is not currently possible. In addition it appears from the drawings available that the 550kVA generator does not have synchronising facilities.

3.2.4 EA Substation The EA substation is located adjacent to the main switchrooms in a separate fire rated room. The transformer capacity is not known, however the standard EA practice is a 3 x 1500kVA substation arrangement. EA have advised that prospective fault levels in the CBD are close to standard equipment fault ratings, meaning that the paralleling of generators with EA supply is unlikely to be practical due to the possibility of fault currents exceeding equipment ratings during a network fault.

3.3 Environmental Considerations Each generator is provided with attenuated air intakes, silenced engine exhausts and presumably attenuators on the ventilation air discharges. This should be confirmed with the building manager.

It is unknown whether any catalytic filters have been provided for the engine exhausts to reduce particulate matter (smoke) and/or hydrocarbons (smell) from the exhaust gases.

There are several high-rise buildings located in close proximity to 363 George Street, including the Telstra building and the Grace Hotel. The nearby buildings have fresh air intakes that could be impacted upon by the generator exhaust fumes when atmospheric conditions are unfavourable. The cost of retrofitting a more dispersion-efficient roof-level exhaust has not been included in estimates.

Section 6 explores the environmental considerations for standby use in detail.

3.4 Demand Reduction Options There are three possible connection configurations for demand management standby use. These are as follows:

Island mode

SCTT

Full parallel

As the standby generators are already in an island mode arrangement this is the cheapest option. However the building will experience an interruption in the power supply for up to two minutes when switching from grid supply to standby generator supply. It is unlikely that building tenants would agree to such an outage.

Although connection upgrades would be required to convert to an SCTT configuration, this option may be feasible as an SCTT arrangement would allow for a transfer from grid supply to standby generator supply without any supply interruption. The required connection upgrades would include

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the removal of the interlocking control on the ATS’s such that the diesel generators could be paralleled with the network for a short time. Additional synchronising facilities would also be required to synchronise the generators to the network. As there are nearby buildings with fresh air intakes that could be impacted upon by the standby generators at 363 George Street, it is reasonable to assume that an emission abatement system would also need to be installed if the standby generators were to be used for demand management.

As the prospective fault levels in the EA substation are close to standard equipment fault ratings, a full parallel configuration is not viable.

3.5 Cost Estimates Indicative costs to upgrade to SCTT are given in Table 3-1. The cost calculations for the emission abatement system were obtained from the DMPP and have not been verified by SKM. The cost estimates assume that the standby generation demand management program consists of 100 hours of standby use over a one year period. It should be noted that these cost estimates are indicative only, and a more detailed site investigation would be required to determine the economic feasibility of engaging in such a program.

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Capex 363 George St

Number of generators considered for DM 4Current Configuration Island modeProposed DM Configuration SCTTElectrical Costs ($) 600,000 Mechanical Costs ($) - Engineering Costs ($) 50,000 Testing & Commisioning Costs ($) 50,000 Project Management Costs ($) 50,000 Emission Abatement System 343,428 Roof level exhaust Not estimated*Capex Total 1,093,428 Capex per kVA 280 Opex Total Standby Capacity (kVA) 3910Fuel Costs ($/hour of operation) 1302Hours of Operation per Year 100Fuel Costs per Year ($) 130,151 Operations & maintenance Costs ($) 64,000 Refuelling guarantee Not estimated*Opex Total 194,151 Opex per kVA 50 Total $ per kVA 329

TOTAL COSTS FOR A ONE YEAR DEMAND REDUCTION PROGRAM ($) 1,287,580 Table 3-1 Estimated costs for using standby generation for demand management at 363

George Street

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4. Site 2: 88 Phillip Street – ABN AMRO Building

4.1 SGP Facilities

4.1.1 Generators The SGP plant at 88 Phillip Street comprises three generators located in the Diesel Generator room on level 3, as follows:

3 x 2250kVA MTU generators

The first two generators were manufactured in August 1999 and the third unit in September 2001. Each generator is equipped with electrical starting gear, a nominal 1000L fuel day tank and jacket water preheating (TBC).

The generators are rated for standby operation, which MTU define as maximum 500 hours of operation per annum at a load factor of less than 85% and no overload capacity is provided.

Ventilation air and combustion air for the SGP is drawn in through wall mounted louvers and the hot ventilation air is discharged through wall mounted louvers on the north side (Phillip Lane) of the building at level 3. The engine exhaust ducts also discharge through the wall to Phillip Lane at level 3.

The generator cooling water system comprises heat exchangers for the jacket water and lube oil and a base frame mounted radiator.

Generator maintenance is undertaken on contract by Viking Diesel of Mona Vale, NSW.

The operation of the SGP is tested monthly for about one hour.

4.1.2 Fuel Storage and Handling Three above ground nominal 20,000 L bulk diesel storage tank are located in a dedicated tank room at level B4. The safe fill level (SFL) of the tanks is not nominated, but assumed to be around 19,000 L. The fuel transfer pumps were not sighted.

The lockable tank filling points are located inside the building’s parking area access roller door at Phillip Lane.

Based on the Bulk Fuel Tank SFL of 19,000 L and a minimum draw off of say 350 L, approximately 55,950 L of diesel fuel would be available to the generators for running, prior to the need to shut down. In addition, each fuel day tank would contain approximately 750L of usable fuel, thereby providing a further 2,250 L of diesel fuel. Typically, a standby generator would

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consume approximately 250g of diesel per kWh generated. One mL of diesel fuel weighs approximately 0.85g.

The maximum output of the SGP is approximately 6,750, which at a power factor of 0.85 equates to approximately 5,750kW. The total amount of fuel available (approximately 58,200 L) would provide for approximately 34 hours of operation at full load, if all tanks were full at the start of the run. If the generator units are run for consecutive days, there is the potential for fuelling issues. A fuel delivery guarantee has not been allowed for in the cost estimates.


4.2.1 Switchboards The site consists of 2 main 415V switchboards (MSB-1 and MSB-2), each supplied via a separate Energy Australia Substation. Main Switchboard 1 supplies services such as fire services, lifts, mechanical plant and chillers whilst Main Switchboard 2 supplies house lights and power as well as tenant risers.

These main switchboards supply both tenant loads and common loads via separate sub boards within the main switchboards and riser mains, each supplied via moulded case circuit breakers (MCCB) or air circuit breakers (ACB). Tenant loads supplied via MSB-2 are tee’d off at each floor via fuses and are separately metered at each floor. It appears that essential supplies are not separated from non-essential supplies, although this would have to be confirmed.

The main switchboards have a normal bus and a standby bus. The standby bus is connected to a diesel generator switchboard supplying standby loads in the case of loss of EnergyAustralia supply(s). The building single line diagrams suggest that a separate standby generator supply feeds each switchboard.

Appendix B contains single line diagrams for 88 Phillip Street.

4.2.2 Transfer Switches Each main switchboard sub board is supplied via a transfer switch which allows for the transfer from EA supply (normal) to emergency diesel generator supply (standby) during mains failure. In this arrangement, the transfer switches separate the network from the diesel supply. This arrangement is known as ‘island mode’.

4.2.3 Synchronization Synchronising facilities are provided at the standby generator power switchboard for each of the diesel generators which allow them to be synchronised to the generator bus individually. However, information from the site visit suggests that synchronising to the EA supply is not currently

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possible. It should be noted that the building manager indicated that such functionality is being sought at the present time.

4.2.4 EA Substation No details of the EA substations were made available at the time of the site visit. However, the standard EA practice is a 3 x 1500kVA substation arrangement. EA have advised that prospective fault levels in the CBD are close to standard equipment fault ratings, meaning that the paralleling of generators with EA supply is unlikely to be practical due to the possibility of fault currents exceeding equipment ratings during a network fault.

4.3 Environmental Considerations Each generator is provided with attenuated air intakes, silenced engine exhausts and attenuators on the ventilation air discharges. This should be confirmed with the building manager.

It is not known whether any catalytic filters have been provided for the engine exhausts to reduce particulate matter (smoke) and/or hydrocarbons (smell) from the exhaust gases.

There are several high rise buildings located in close proximity to 88 Phillip Street, including several that have fresh air intakes at or near Phillip Lane. The fresh air intakes of these nearby buildings could be impacted upon by the generator exhaust fumes when atmospheric conditions are unfavourable. It should be noted that complaints have already been received from 131 Macquarie Street regarding the diesel fumes. The cost of retrofitting a more dispersion-efficient roof-level exhaust has not been included in estimates.


4.4 Demand Reduction Options There are three possible connection configurations for demand management standby use. These are as follows:

Island mode

SCTT

Full parallel

As the standby generators are already in an island mode arrangement this is the cheapest option. However the building will experience an interruption in the power supply for up to two minutes when switching from grid supply to standby generator supply. It is unlikely that building tenants would agree to such an outage.

Although connection upgrades would be required to convert to an SCTT configuration, this option may be feasible as an SCTT arrangement would allow for a transfer from grid supply to standby

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generator supply without any supply interruption. The required connection upgrades would include the removal of the interlocking control on the ATS’s such that the diesel generators could be paralleled with the network for a short time. Additional synchronising facilities would also be required to synchronise the generators to the network. As there have already been complaints made by 131 Macquarie Street regarding the diesel fumes from 88 Phillip St, it is reasonable to assume that an emission abatement system would also need to be installed if the standby generators were to be used for demand management.


4.5 Cost Estimates Indicative costs to upgrade to SCTT are given in Table 4-1. The cost calculations for the emission abatement system were obtained from the DMPP and have not been verified by SKM. The cost estimates assume that the standby generation demand management program consists of 100 hours of standby use over a one year period. It should be noted that these cost estimates are indicative only, and a more detailed site investigation would be required to determine the economic feasibility of engaging in such a program.

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Capex 88 Phillip St Number of generators considered for DM 3Current Configuration Island modeProposed DM Configuration SCTTElectrical Costs ($) 900,000 Mechanical Costs ($) - Engineering Costs ($) 70,000 Testing & Commisioning Costs ($) 70,000 Project Management Costs ($) 70,000 Emission Abatement System 592,875 Roof level exhaust Not estimated*Capex Total 1,702,875 Capex per kVA 252 Opex Total Standby Capacity (kVA) 6750Fuel Costs ($/hour of operation) 2229Hours of Operation per Year 100Fuel Costs per Year ($) 222,867 Operations & maintenance Costs ($) 48,000 Refuelling guarantee Not estimated*Opex Total 270,867 Opex per kVA 40 Total $ per kVA 292


Phillip Street

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5. Site 3: 225 George Street – Grosvenor Place

5.1 SGP Facilities

5.1.1 Generators The SGP plant at 225 George Street (Grosvenor Place) comprises of four sets of two generators located in Diesel Generator rooms on levels B4, B5, 10 and 33, as follows:

Level B4: 2 x 1500kW MAN 18V20/27 generators Level B5: 2 x 1500kW MAN 18V20/27 generators Level 10: 2 x 1500kW MAN 16V20/27 generators Level 33: 2 x 1500kW MAN 16V20/27 generators

The generators were manufactured in August 1984 and each is equipped with compressed air starting gear, a nominal 1000L fuel day tank (shared between the two generators in the room) and jacket water preheating.

The generators operate at 1000rpm and are rated for continuous operation, with 10% overload capacity for one hour in every twelve hours of operation.

Ventilation air and combustion air for the SGP is provided by the main building ventilation system and the hot ventilation air is cooled by means of a radiator and roof mounted building cooling towers. The engine exhaust ducts discharge to atmosphere horizontally through the wall of the generator rooms at each level.

The generator jacket water and lube oil cooling is provided via a shell and tube heat exchanger and the building’s common cooling towers mounted on the roof of the building.

Generator maintenance is undertaken on contract by TSF Engineering. The jacket water preheaters were not performing well on the day of the inspection. Mr Arthur Arvantis, Building Services Manager advised that these have not performed well for a long time and have suffered, or are suffering from burnt out elements and other similar problems.

The operation of the SGP is tested monthly for about five minutes (ie check start up only) and quarterly for one hour under no load conditions. An annual running test is carried out with the building house load, plus any cooperating tenant load.

5.1.2 Fuel Storage and Handling Two nominal 70,000 L bulk diesel storage tanks are located in a pit at level B1. The safe fill level (SFL) of the tanks is set at 115,000 L. The two tanks are interconnected by means of a balance pipe connected at the bottom of each tank. Eight fuel transfer pumps are also installed in the tank pit and arranged in such a manner that two pumps provide each of the four fuel day tanks.

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The tank filling points are located inside the building’s parking area access roller door at Carrington Street.

Based on the Bulk Fuel Tank SFL of 115,000 L and a minimum draw off of say 350 L, approximately 114,650 L of diesel fuel would be available to the generators for running, prior to the need to shut down. In addition, each fuel day tank would contain approximately 750L of usable fuel, thereby providing a further 3,000 L of diesel fuel. Typically, a continuously rated generator would consume approximately 230g of diesel per kWh generated. One mL of diesel fuel weighs approximately 0.85g.

The maximum output of the SGP is approximately 12,000kW. The total amount of fuel available (approximately 117,650 L) would provide for around 36 hours of operation at full load, if all tanks were full at the start of the run. If the generator units are run for consecutive days, there is the potential for fuelling issues. A fuel delivery guarantee has not been allowed for in the cost estimates.


5.2.1 Switchboards The site consists of 4 main switchboards (415V), each supplied via an Energy Australia substation (6029, 6030, 6031 and 6328). These main switchboards supply floors as follows:

Switchboard 1 (Zone 1) – Floors B1 to 14

Switchboard 2 (Zone 2) – Floors 8 – 32(tenants 10 -14 supplied from Zone 1 switchboard)

Switchboard 3 (Zone 3) – Floors 33 – roof

Switchboard 4 (Zone 4) – Plaza, B5 and solarium

These main switchboards supply tenant loads, house loads and emergency lights via separate riser mains. Tenant loads are tee’d off at each floor via fuses and are separately metered at each floor.

A diesel generator switchboard is provided for each zone and is connected to each switchboard. A temporary connection has been made between Zones 1 and 4.

A manual load shedding system is provided for each switchboard.

Appendix C contains single line diagrams for 225 George Street.

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5.2.2 Transfer Switches Each zone switchboard is supplied via a transfer switch which allows for the transfer of normal supply to diesel generator supply during mains failure. The current arrangement provides emergency supply upon mains failure, where the network is separated from the diesel supply via the transfer switches. This arrangement is known as ‘island mode’.

5.2.3 Synchronization There are no synchronising facilities on site.

5.2.4 EA Substation It is SKM’s understanding that the EA substations are located on the ground floor in separate fire rated rooms. The transformer capacity is not known, however SKM was advised that each can supply up to 3000A. EA have advised that prospective fault levels in the city area are close to standard equipment fault ratings, meaning that the paralleling of generators with EA supply is unlikely to be practical due to the possibility of fault currents exceeding equipment ratings during a network fault

5.3 Environmental Considerations Each generator is provided with silenced engine exhausts and a closed circuit ventilation air system.

No catalytic filters have been provided for the engine exhausts to reduce particulate matter (smoke) and/or hydrocarbons (smell) from the exhaust gases.

There have been no external complaints regarding the operation of the SGP to date despite there being several high rise buildings located in close proximity to 225 George Street, including several which have fresh air intakes facing Grosvenor Place. The fresh air intakes of these nearby buildings could be impacted upon by the generator exhaust fumes when atmospheric conditions are unfavourable. The cost of retrofitting a more dispersion-efficient roof-level exhaust has not been included in estimates.

Several complaints have been received from existing tenants within the building, mostly relating to diesel fumes in or from the fire escape corridors.


5.4 Demand Reduction Options As the standby generators are already in an island mode arrangement this is the cheapest option. However the building will experience an interruption in the power supply for up to two minutes

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when switching from grid supply to standby generator supply. It is unlikely that building tenants would agree to such an outage.

SCTT is a feasible demand reduction option. Upgrading to an SCTT configuration would require the retrofitting of synchronising facilities and automated load shedding (or splitting the existing bus). However, in conversation with the building manager, concern has been raised by the tenants (Barclays, JP Morgan and Deutsche Bank) at the increased risk to supply security in the event of transferring from grid supply to diesel generator supply. It is therefore highly unlikely that the building manager for Grosvener Place will participate in the demand reduction project.


5.5 Cost Estimates Although concerns from the tenants mean it is unlikely that Grosvenor Place would participate in a standby generation demand management program, the indicative costs to upgrade to SCTT at the site are given in Table 5-1. The cost calculations for the emission abatement system were obtained from the DMPP and have not been verified by SKM. The cost estimates assume that the standby generation demand management program consists of 100 hours of standby use over a one year period. It should be noted that these cost estimates are indicative only, and a more detailed site investigation would be required to determine the economic feasibility of engaging in such a program.

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Capex 225 George St

Number of generators considered for DM 8Current Configuration Island modeProposed DM Configuration SCTTElectrical Costs ($) 2,100,000 Mechanical Costs ($) - Engineering Costs ($) 80,000 Testing & Commisioning Costs ($) 80,000 Project Management Costs ($) 80,000 Emission Abatement System 1,238,450 Roof level exhaust Not estimated*Capex Total 3,578,450 Capex per kVA 254 Opex Total Standby Capacity (kVA) 14100Fuel Costs ($/hour of operation) 4457Hours of Operation per Year 100Fuel Costs per Year ($) 445,734 Operations & maintenance Costs ($) 128,000 Refuelling guarantee Not estimated*Opex Total 573,734 Opex per kVA 41 Total $ per kVA 294


George Street

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6. Health and Environmental Considerations

6.1 Health Impacts Diesel engine exhaust emissions comprise a mixture of gases, vapours, liquid aerosols and substances made up of particles. They contain the products of combustion including:

carbon (soot); nitrogen; water; carbon monoxide; aldehydes; nitrogen dioxide; sulphur dioxide; polycyclic aromatic hydrocarbons.

The carbon particle or soot content varies from 60% to 80% depending on the fuel used and the type of engine. Most of the contaminants are adsorbed onto the soot.

The quantity and composition of diesel fumes emitted may vary depending on:

the quality of diesel fuel used; the type of engine, eg standard, turbo or injector; the state of engine tuning; the fuel pump setting; the workload demand on the engine; the engine temperature; whether the engine has been regularly maintained.

Breathing in diesel fumes can affect an individual’s health, and exposure to the fumes can cause irritation of the eyes or respiratory tract. Skin contact with cold diesel fuel may also cause dermatitis. These effects are generally short term and should disappear when one is removed from the source of exposure.

However, prolonged exposure to diesel fumes, in particular to any blue or black smoke, could lead to coughing, chestiness and breathlessness. In the long term, there is some evidence to suggest that repeated exposure to diesel fumes over a period of about 20 years may increase the risk of lung cancer.

6.2 Environmental Impacts Nitrogen oxides (NOx) emissions from power plants are a pre-cursor to photochemical smog formation, with ozone (O3) being the indicator of smog events. The two primary NOx formation mechanisms in gas turbines are from thermal NOx and fuel NOx. In each case, nitrogen and

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oxygen present in the combustion process form NOx. Thermal NOx is formed by the dissociation of atmospheric nitrogen (N2) and oxygen (O2) in the turbine combustor and the subsequent formation of NO. When fuels containing nitrogen are combusted this additional source of nitrogen results in fuel NOx formation. Because most reciprocating engine based generator installations burn natural gas or light distillate oil fuels with little or no nitrogen content, thermal NOx is the dominant source of NOx emissions from such plant.

Thermal NOx formation is a function of the temperature of the flame, the emission level increasing exponentially with flame temperature. Because the flame temperature firing fuel oil is higher than that of natural gas, NOx emissions are higher for operations using fuel oil rather than natural gas.

Techniques to control NOx emissions from diesel engines are generally divided into those which occur at combustion (and so reduce thermal NOx production) and post combustion controls which reduce emissions in the exhaust gas stream.

Combustion controls include modifications to combustion chamber geometry, pressures and timing. Post combustion controls include selective catalytic reduction (SCR) in the exhaust system.

The NSW Department of Environment and Climate Change (DECC, formerly known as the EPA) sets air emission limits for power stations under the Protection of the Environment Operations (Clean Air) Regulation 2002. The emission limits outlined in Schedule 3 (and part of Schedule 4) of the Regulation apply. The proposed plant development would belong to Group 6, which relates to plants that operate after 1 September 2005. The relevant standards are provided in Appendix D.

Notwithstanding the limits set out in Appendix D, it would be expected that reciprocating engine based plants would need to comply with best practical control technologies as a minimum. Emission limits would be defined within any Environment Protection Licence issued by DECC for the development.

A detailed air dispersion modelling study may need to be undertaken as part of the environmental assessment and approval process. If required, the study would need to be undertaken in accordance with the following document:

Environment Protection Authority (August 2001). Approved methods and guidance for the modelling and assessment of air pollutants in New South Wales.

The study would also need to reference the following guidelines and standards:

National Environment Protection (Ambient Air Quality) Measure;

National Health and Medical Research Council (NHMRC) guidelines; and

World Health Organisation (WHO) guidelines.

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The proposed assessment methodology would need to be discussed with DECC before commencement of the air dispersion and modelling study to gain their in-principle support.

6.3 Further Considerations SKM understands that standard SGP is generally exempted from the emission level limits stipulated in the Protection of the Environment Operations (Clean Air) Regulation 2002. However, SKM believes that the exemption relates to monthly testing of the SGP and during periods of emergency operation when the public grid is not available. SKM considers that it is unlikely that DECC would provide similar exemptions to building owners and facility managers for operating the plant for demand peak lopping, as this may be construed as ultimately being for the purpose of financial gain.

In particular, SKM believes that the issue of exceeding air quality limits may be a potential barrier to installations where the generator exhaust discharge points are at a low level in the building and discharging horizontally. A horizontal discharge concentrates the exhaust emissions into a relatively small area, thereby significantly increasing the emission level strength. A vertical discharge plume will more readily disperse the emissions over a larger area, generally resulting in more diluted measurement readings.

It is likely that DECC will require, as a minimum, that the exhaust ducts be extended to discharge above the building roof level. DECC are also likely to require the retrofitting of a combustion control or SCR as discussed in section 6.2.

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7. Summary and Recommendations SKM believes that an SCTT connection is the most feasible configuration for using the existing standby generators for demand management. However, one drawback to SCTT that must be considered is that there is an increased risk to supply security when transferring from grid supply to diesel generator supply. This has led to tenants raising concerns at Grosvenor Place about using the standby generators for demand management. As a result it is unlikely that the site would participate in a standby generation demand reduction program.

SCTT also means the full capacity of standbys may not be available for demand management. The effective reduction is the building load that is disconnected from the grid – not the standby rating. If the standbys are conservatively sized for the building load then some capacity will not be utilised. With full parallel mode however, any additional standby capacity available is fed back into the grid, hence resulting in a more efficient demand management system. A full parallel connection was not viable at the three surveyed sites however, due to the technical barrier of the fault levels in the adjacent EA substations already being close to standard equipment fault ratings

Capital upgrades are necessary to convert from the existing island mode configuration to an SCTT connection. These works should include the removal of the interlocking control on the ATS’s and the installation of a new synchronising and load control panel. To conform with environmental regulations set by DECC and to minimise the adverse health affects associated with the diesel fuel emissions from standby use, the installation of an emission abatement system may also be necessary. The average capital cost has been estimated at $262 per kVA of SCTT generation capacity. This includes the cost of an emission abatement system.

The average operational cost has been estimated at $43 per kVA of generation capacity. This is based on a 100 hour standby generation program that runs over a one year period.

The average total cost has been estimated at $305 per kVA of SCTT generation capacity.

In addition, there are a number of health and environmental impacts from using diesel standby generation that must be considered. Breathing in diesel fumes can affect an individual’s health, and exposure to the fumes can cause irritation of the eyes or respiratory tract. Prolonged exposure to diesel fumes can lead to coughing, chestiness and breathlessness. There is also some evidence to suggest that exposure to diesel fumes over a period of about 20 years may increase the risk of lung cancer.

Diesel-fuelled engines are also high emitters of NOx and particulates. These emissions have environmental implications and it is possible that they may lead to the standby generation plant failing to meet air emission limits set by DECC. SKM therefore recommends that any capital

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works upgrades to enable the use of existing standby generator units for demand management include the installation of an emission abatement system such as an SCR or combustion control. The cost calculations for the SCR emission abatement system used in the site survey capital cost estimates were obtained from the DMPP and have not been verified by SKM.

In addition, SKM found that the three surveyed sites had generator exhausts that discharge horizontally at low levels in the building. As a horizontal discharge concentrates the exhaust emissions into a relatively small area, the emission levels – as a result – are quite intense. Therefore, it is also likely that DECC will require that the exhaust ducts be extended to discharge above the building roof level so that emission readings are more diluted. The cost of retrofitting a more dispersion-efficient roof-level exhaust at the three sites has not been estimated as this was a high level study and would need to be treated on a site-by-site basis. If these sites are further considered for demand management, a detailed cost assessment would need to be carried out.

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Appendix A 363 George Street – Single Line Diagrams

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Appendix B 88 Phillip Street – Single Line Diagrams

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Appendix C 225 George Street – Single Line Diagrams

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Appendix D Protection of the Environment Operations (Clean Air) Regulation 2002

Schedule 3 Standards of concentration for scheduled premises: activities and plant used for specific purposes – Electricity Generating Plant

Schedule 4 Standards of concentration for scheduled premises: General activities and plant General standards of concentration Air impurity Activity or plant Standard of concentration Nitrogen dioxide (NO2) or Nitric oxide (NO) or both, as NO2 equivalent

Stationary reciprocating internal combustion engines

Group 6 450 mg/m3

Air impurity Activity or plant Standard of concentration

Solid particles (Total) Any activity or plant using a liquid or solid standard fuel or a non-standard fuel

Group 6 50 mg/m3

Volatile organic compounds (VOCs), as n-propane equivalent

Any activity or plant using a non-standard fuel

Group 6 40 mg/m3 VOCs or 125 mg/m3 CO

Group 2, 3, 4, 5 or 6, in approved circumstances

Ringelmann 3 or 60% opacity

Smoke Any activity or plant using a liquid or solid standard fuel or a non-standard fuel

Group 2, 3, 4, 5 or 6, in other circumstances

Ringelmann 1 or 20% opacity

Documents

Demand Management and Planning Project · emission abatement system be installed at any site participating in a standby generation demand ... The Demand Management and Planning Project