Committed projects

The existing Five Dock 33/11kV ZS equipment and associated 33kV feeders (distribution assets) are approaching the end of their service life.

The options considered include:

1. New Croydon 132/11kV ZS to decommission existing Five Dock 33/11kV ZS.
2. Retain 33kV in the Eastern Inner West load area - This option involves a like for like replacement of feeder 900 from Mason Park STSS to Rozelle STS. A new 33/11kV Croydon ZS would be constructed with new 33kV feeders from Homebush STS to replace Five Dock ZS.

No non-network alternatives were considered viable alternatives to this project. The preferred and committed option is to convert the eastern Inner West load area to 132kV, including the installation of new 132/11kV Croydon ZS. The estimated cost of this project is $30.6M.

The four aged 33kV underground gas pressure feeders supplying Crows Nest are in need of replacement.

The options considered for the refurbishment of Crows Nest ZS include:

1. Refurbish Crows Nest and retain 33/11kV supply with new 33kV feeders and new 33kV switchgear.
2. Convert Crows Nest to 132/11kV supply voltage with new 132kV feeders and new 132kV switchgear.

The preferred and committed option is to establish a new 132/11kV Crows Nest ZS and retire the existing 33/11kV ZS. No non-network options were considered viable to this asset condition driven project. The estimated cost of this project is $23.1M.

The 33kV indoor switchgear and 11kV indoor switchgear at Carrington ZS are nearing the end of their service lives. This project addresses asset issues at Carrington ZS by constructing a new zone substation on a new site at Tighes Hill.

The options considered include:

1. A new Tighes Hill 33/11kV ZS.
2. Build a new 33/11kV ZS proposed on a site provided by the Buildev Intertrade Consortium.

This option requires extensive 33kV feeder works to extend feeders 763 and 769 to the Buildev site.

This project is driven by asset condition rather than demand growth. On this basis, no investigation of potential demand management options has been undertaken. The preferred and committed option to construct a new Tighes 33/11kV ZS is the least cost option that addresses the identified network need. The estimated cost of this project is $23.9M.

At Port Hacking STS, the 33kV circuit breakers are of the bulk oil type and were identified to be replaced by 2013, due to their deteriorating condition.

Also, the 33kV busbar height no longer compliant with current standards, and due to extensive corrosion issues, the replacement of the existing 132kV outdoor steel busbar at Port Hacking has been advanced and combined with other identified issues in one project to refurbish the substation.

No non-network alternatives were considered viable alternatives to this project. The preferred and committed option is the replacement of the 33kV busbar at Port Hacking STS and a small section of the 33kV feeder 730, as well as the replacement of the 132kV busbar and circuit breakers at Port Hacking STS. The estimated cost of this project is $41.0M.

There were civil/structural integrity related issues identified at the decommissioned City Main ZS site. The original proposal of demolishing the ex-City Main ZS buildings was denied by the Newcastle City Council.

Therefore the scopes of the project has been revised to reinforce the retaining wall between the ex-City Main ZS site and Newcastle CBD ZS, and some structural stabilisation works at the south western corner of the ex-City Main ZS site.

No non-network alternatives were considered viable alternatives to this project. The estimated cost of this project is $6.2M

Aged 33kV assets and 11kV switchgear at East Maitland ZS have limited remaining service life. 

Options considered include:

1. Metford 132/11kV ZS. The new ZS will increase the capacity of the area
2. Metford 33/11kV ZS
3. Demand management. 

Non-network option investigation concluded that it was not viable for demand management to postpone the preferred network option. Building the preferred Option 2 -a new Metford ZS at 33/11kV is the most cost effective option in meeting the network needs and is the committed project. The estimated cost of this project is $26.8M.

The 11kV compound switchgear and the 33kV bulk oil type circuit breakers at Careel Bay ZS is approaching the end of its service life and has been prioritised for replacement. 

No other alternative option was considered as this is an asset condition based replacement. The estimated cost of this project is $8.8M.

The 33kV industrial busbar at Waratah STS is significantly aged and needs to be retired from service. The 33kV domestic busbar was refurbished in the 1980s but the oil circuit breakers now require replacement. Four out of seven of the 132/33kV transformers are at the end of their service lives.

Options considered include:

1. Waratah STS supply rearrangement and refurbishment.
2. Waratah STS replacement.

The preferred and committed option is to refurbish Waratah STS and rearrange existing 33kV supplies. No non-network options were considered viable to this asset condition driven replacement project. The estimated cost of this project is $17.2M. 

Oil-filled 33kV feeder 770 is approaching the end of service life and requires replacement due to asset condition issues.

The replacement of this feeder is a common requirement across all proposed strategies in the Newcastle Inner City Area Plan. No non-network alternatives were considered viable alternatives to this project.

The estimated cost of this project is $12.0M.

The 11kV switchgear in Bass Hill zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $11.7M

During 2004, 66kV switchgear at Hunters Hill ZS failed explosively with the roof of the building sustaining damage in the resulting blast. The 11kV switchgear is aged and approaching the end of service life.

This project has two stages:

Stage 1 involves rebuilding the 66kV switchroom and is close to completion;

Stage 2 involves replacement of the 11kV switchgear.

This replacement project is common across all strategies considered in the Carlingford Area Plan. Since this project is driven by asset condition requirements, there are no viable non-network alternatives for this project. The estimated cost of this project is $31.3M.

The 11kV switchgear in Singleton zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $2.8M.

The 11kV switchgear in Mona Vale zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $4.7M.

As part of the State Government’s WestConnex motorway project, Roads and Maritime Services (RMS) is widening Euston Road between Campbell Road and Maddox Street, Alexandria. WestConnex is also managing recoverable works to replace a 1.6km section of feeders 9SA and 92P. 

The 132kV feeders 9SA and 92P are Self-Contained Fluid-Filled (SCFF) cables connecting Beaconsfield Bulk Supply Point (BSP) with Campbell St and Belmore Park zone substations respectively.
Once completed, the road upgrades will increase the traffic flow, as well as the cost and difficulty in obtaining approvals to replace this section of the feeders, including the requirement to install a joint bay on this heavily congested road. Therefore to achieve construction efficiencies, it is considered beneficial to extend the early replacement of the feeders in this area by a further 0.5km, from Loveridge to Wellington Street.

As a result, the proposed early works will cover a 1.0km section of the feeders.

The scope of this project will include:

• Install, joint and commission 1.0km of underground 1600mm2 XLPE 132kV dual circuits in a single trench to replace existing feeders 9SA and 92P
• Decommission the existing SCFF feeders.

The estimated cost of this project is $7.2M.

The 11kV switchgear in Branxton zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $7.7M.

The majority of the 132kV and 33kV primary and secondary equipment at Strathfield STS are in poor condition and are approaching the end of their serviceable lives.

The options considered include:

1. Decommissioning of Strathfield STS
2. Refurbishment of Strathfield STS

No non-network alternatives were considered viable alternatives to this project. 

The preferred and committed option is to decommission Strathfield STS. The estimated cost of this project is $10.5M.

There are multiple asset condition issues at Dalley St ZS. This project is the first step of an overall strategy to address issues with ageing infrastructure in the Sydney CBD area.

Initial civil works required (conduit installation and pit enlargements) have been completed to enable the work to be undertaken with no dependencies on the completion of the CBD & South East Light Rail Project. The remaining electrical works will involve the transfer of five 11kV feeders from Dalley St ZS to City North ZS with associated cable pulling and jointing works.

The estimated cost of this project is $9.9M.

Oil-filled 33kV feeders 760 and 766 are approaching the end of their service life and require replacement due to asset condition issues. The replacement of these cables is a common requirement across all proposed strategies in the North East Lake Macquarie Area Plan.

No non-network alternatives were considered viable alternatives to this project.

This project is estimated to cost $7.9M.

The 11kV switchgear in Myuna and Cooranbong zone substation is approaching the end of their service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since they are driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $4.8M.

The 11kV switchgear in Vales Point zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $3.8M.

Most of the equipment at Blackwattle Bay has reached the end of its useful life and is obsolete. This work forms part of the overall program to convert the remaining 5kV system to 11kV operation.

The options considered include:

1. Commission 4th transformer at Camperdown ZS and transfer Blackwattle Bay load to Camperdown ZS.
2. Transfer Blackwattle Bay load to Camperdown ZS and Darling Harbour ZS.
3. Transfer Camperdown load to Leichhardt ZS and transfer Blackwattle Bay load to Camperdown ZS and Darling Harbour ZS.

No non-network alternatives were considered viable alternatives to this project.

The preferred and committed option is option 1, to commission a 4th transformer at Camperdown ZS and transfer Blackwattle Bay load to Camperdown ZS. The estimated cost of this project is $16.5M.

The 11kV switchgear and the 33kV outdoor bulk oil type circuit breakers at the existing Cessnock ZS is approaching their end of service lives, and are recommended to be replaced by 2019 and 2011 respectively. New Cessnock 33/11kV ZS was common to all strategies considered for the Greater Cessnock Area Plan.

No other alternative option was considered as this is an asset condition based replacement.

The estimated cost of this project is $19.4M.

The 11kV switchgear in Singleton zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of the project is $7.9M.

Mascot ZS is exposed to risks related to condition issues associated with its aged oilfilled 11kV switchgear and 33kV feeders from Bunnerong North Subtransmission Substation (STS). A quantitative risk analysis recommended implementing the replacement of the 11kV switchgear as soon as 2019. The proposed solution to resolve the issues at Mascot ZS is to install a new 132/11kV zone substation. However; it is recognised that such solution is dependent on the purchase of a suitable site, which is not yet complete. When typical construction periods are also considered, a solution is therefore required to mitigate the unserved energy risk in the short term. 

There are no viable non-network alternatives for this project. Two credible network options were considered to address the identified issues:

• 11kV load transfer of 25MVA from Mascot to Green Square ZS by installing cables along O’Riordan Street, which is the most direct route; or
• 11kV load transfer of 25MVA from Mascot to Green Square ZS by installing cables in alternative routes.

The option to follow an alternative route is preferred because it provides the greatest benefits. This route will transfer the load to Green Square ZS via Doody St, Botany Road, Hughes Ave and Church Ave. This route passes the most likely site for the new 132/11kV Mascot East ZS and facilitates transfer of load to this site.

The transfer or approximately 25MVA of 11kV load from Mascot ZS to Green Square ZS is the most cost effective way to mitigate the load at risk in the event of an 11kV switchgear failure. This project is expected to be completed by December 2018. This project is estimated to cost $6.9M.

Clovelly zone substation (ZS) has been identified as having aged 11kV switchgear which should be prioritised for retirement. In order to decommission the switchgear, load transfer works will need to occur to remove the associated load (38MVA) from Clovelly ZS to Waverly ZS and Kingsford ZS which have capacity to service this load. 

The scope of this project (Stage 1 Works) will include: 

•  Transfer Group 1 load, 38MVA in total, to surrounding substations
• Decommission, remove and scrap Group 1 11kV switchgear at Clovelly ZS; and
• Decommission transformers 1 and 3 at Clovelly ZS. These will be maintained on site as system spares. 

Group 2 of the 11kV switchgear at Clovelly ZS is the air insulated type and is not scheduled for retirement until 2027 and is not included as part of this project. The estimated cost of this project is $11.3M.

The 11kV switchgear in Punchbowl zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

This project is estimated to cost $23.2M.

The 33kV circuit breakers at Bankstown STS are of the bulk oil type and are at the end of their service lives. Replacement requirements are addressed in conjunction with work to address the non-compliant busbar height. The Bankstown STS 33kV switchgear replacement project is common across all strategies considered in the Bankstown Area Plan.

Since this project is driven by asset condition and Duty of Care requirements, there are no viable non-network alternatives for this project.

The estimated cost of this project is $23.5M.

The 132kV feeder 92G from Lane Cove STS to Top Ryde ZS comprises a section of two parallel oil-filled underground cables, 92GA and 92GB, approximately 7.2km long which were commissioned in the 1970’s. The 132kV feeder 92J from Lane Cove STS to Meadowbank ZS comprises a section of two parallel oil-filled underground cables, 92JA and 92JB, approximately 12.9km long which were commissioned in the 1960s.

The oil filled cables 92JA, 92JB, 92GA and 92GB have been identified as approaching the end of their service life.

Replacement options are still under consideration, however the most likely option is to replace the oil-filled cable sections with XLPE cable.

The estimated cost of this project is $20.8M.

The 11kV switchgear in Botany zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of this project is $11.9M.

The 11kV compound switchgear at Leichhardt ZS is approaching the end of its service life and has been prioritised for replacement.

No other alternative option was considered as this is an asset condition based replacement.

The estimated cost of this project is $26.9M.

33kV Gas feeders 665, 666, 668 and 669 are approaching the end of their serviceable life and require replacement due to asset condition issues.

The options considered include:

1. Refurbish Punchbowl 33/11kV ZS
2. Punchbowl 132/11kV ZS.
3. New Padstow 33/11kV ZS.

No non-network alternatives were considered viable to this project. 

The preferred and committed option is option 1, to refurbish Punchbowl ZS and replace the 33kV feeders.

The estimated cost of this project is $15.3M.

The project is required to ensure ongoing network reliability by transferring 39MVA of load from Dalley St ZS to City North ZS. This will reduce the load at risk from an in-service failure at Dalley St ZS and forms part of a broader CBD area strategy to decommission the substation. Dalley St ZS was constructed in 1969 and the majority of the on-site equipment is approaching the end of its serviceable life. The 132kV and 11kV circuit breakers and 132V fluid-filled cables that supply the substation require replacement to mitigate the risk.

All of the oil circuit breakers at Dalley St ZS have been replaced with vacuum type circuit breakers however half of the switchboard is compound insulated busbar. Of the remaining compound switchboards in Ausgrid's network this project is the highest ranked for replacement.

Ausgrid's broader strategy for the CBD involves addressing condition issues at Dalley St and City East ZS/s by retiring both sites and transferring all 11kV load to neighbouring ZS's.

The load transfers from Dalley St are to be completed in the following stages:

Stage 1 - Approximately 26MVA (31% of total load) to City North ZS. This stage is Gate 3 approved and currently in construction

Stage 2 - Approximately 39MVA (47% of total load and 68% of the remaining load) to City North ZS, the project cost of this stage is estimated to be $12.0million.

Stage 3 - The remaining load of approximately 18MVA (22% of the total load) to be transferred to Belmore Park ZS followed by the decommissioning of Dalley St zone substation. This stage is planned to be completed by 2023, subject to a future approval.

The 33kV switchgear replacement at Ku-ring-gai STS is driven by non-compliance of the 33kV bus bar with current clearance requirements, as well as the poor condition of the bulk-oil circuit breakers which have reached the end of their service lives and are scheduled for replacement.

No alternative options were considered as the asset replacement is driven by the condition of the bulk oil circuit breakers, and the 33kV busbar clearance duty of care issue.

Non-network options were not considered viable as this project is driven by asset replacement and duty of care needs.

The estimated cost of this project is $33.3M.

Feeders 773 and 775 from Merewether STS to Kotara ZS are fluid-filled cables have asset condition issues and have been recommended for replacement.

The options considered include:

1. Like-for-like replacement of feeders 773 and 775
2. Replacement of feeders 773 and 775 re-using old Charlestown 33kV feeders
3. Retirement of Kotara ZS with 11kV load transfers

No non-network alternatives were considered viable alternatives to this project. 

The preferred and committed option is to replace the feeders 773 and 775 re-using old Charlestown 33kV feeders.

The estimated cost of this project is $7.5M.

The primary driver for the installation of this new 132kV feeder is asset condition requiring asset replacement. In the past there was a capacity need as presented in the Consultation Paper published on December 2013. Recent reductions in load in the Inner Metropolitan load area has altered the primary driver of this project to be the condition of 132kV circuits 92L/3 and 92M/1 from Lane Cove STSS to Dalley St ZS.

The solution recommended in the Final Project Report is to proceed with the installation of a new 132 feeder from Beaconsfield BSP to Belmore Park ZS (Feeder 90Y), utilising a spare duct and Ausgrid and TransGrid tunnels, the partial remediation of circuits 9SA and 92P.

The construction of the new feeder 90Y and the retirement of 132kV circuits 92L/3 and 92M/1 from Lane Cove STSS to Dalley St ZS are now committed.

The project is estimated to cost $18.0M.

In August 2012, a cable termination failure damaged the switchgear and switchroom building. Rectification works were completed to mitigate the risk of a failure of the structure, however this was not a permanent solution and the construction of a new substation avoids the need for upgrade works in the existing building. 

Condition issues have been identified with the 11kV compound insulated switchgear and the 33kV gas pressure cables supplying Dulwich Hill ZS.

The options considered to address these issues include:

1. New Strathfield South 132/11kV ZS & Summer Hill 33/11kV refurbishment
2. Replace Enfield & Dulwich Hill ZS with new Ashbury 132/11kV ZS
3. Dulwich Hill & Enfield 33/11kV ZS refurbishment

No non-network alternatives were considered viable alternatives to this project. The preferred option is to option 1, to install a new 33/11kV Summer Hill ZS.

A prolonged development time was experienced as the scope of the project was refined to reduce project costs. Contracts have been awarded for major equipment, construction of the new substation along with supply and installation of new 33kV cables.

As some demolition work and further design has to be completed by the contractor, the Review of Environmental Factors (REF) is still being finalised but will be self-determined (following NSW planning laws) and accepted by January 2018.

This project is expected to be completed by December 2019.

The 11kV switchgear has bituminous compound insulated busbars and oil-filled circuit breakers. The presence of both oil and insulating compound creates a heightening fire risk in the event of failure.

The equipment is now considered beyond its service life and is recommended for replacement by 2019.

The options considered include:

1. New 132/11kV Greenacre Park ZS.
2. Decommission existing 132/11kV Greenacre Park ZS and transfer all load to Bankstown ZS.
3. Refurbishment of existing Greenacre Park ZS and replacement of 132kV feeders.

No non-network alternatives were considered viable alternatives to this project. 

The preferred and committed option is option 1, to install a new 132/11kV Greenacre Park ZS.

This project is estimated to cost $29.7M

The 11kV switchgear in Surry Hills zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The estimated cost of the project is $16.6M.

The 11kV switchgear in Matraville  zone substation is approaching the end of its service lives. The 11kV switchgear is the sole and primary issue at the zone substation, replacing the 11kV switchgear is the most cost effective solution.

Since it is driven by asset condition issues, there are no viable non-network alternatives for this project.

The project is estimated to cost $15.4M.

Lidcombe Switchgear replacement, expected completion date June 2021.

The switchboards at Lidcombe ZS contain compound insulated busbar and one of the two groups (Group Two) contains oil filled circuit breakers. Ausgrid is also progressively replacing all compound insulated switchboards with a planned completion date of 2027. A high priority has been placed on those which contain oil filled circuit breakers due to the potential for a failure, which could lead to a significant outage. The replacement of Group Two will be completed as part of this project.

Ausgrid is also progressively replacing all compound insulated switchboards with a planned completion date of 2027. A high priority has been placed on those which contain oil filled circuit breakers due to the potential for a failure, which could lead to a significant outage. The switchboards at Lidcombe ZS contain compound insulated busbar. One of the two groups (Group Two) contains oil filled circuit breakers and these will be replaced, as well as the Group Two 11kV switchboard at Lidcombe ZS and associated 11kV load transfers.

Of the 50 compound insulated switchboards on the network at the beginning of the replacement program, 34 have either been replaced or decommissioned or projects have approved to do so. Lidcombe ZS is the 1st ranked remaining site.

The project cost is estimated to be $9.1million.