Regulatory test consultations

Cloncurry 66/11kV Substation (CLON) and North Cloncurry 66/11kV Substation (NOCL) are normally supplied from Chumvale 220/66kV Substation (CHUM) via a single circuit 66kV sub-transmission feeder. Chumvale Substation is supplied by a single circuit 220kV feeder from the Mica Creek 'C' Substation (MICC) at Mt Isa.

There is also a single circuit 66kV sub-transmission feeder from Mount Isa's Duchess Road 132/11/66kV Substation (DURO) to a normally open isolation point (designated DR-CC-1), which is located outside Chumvale Substation.

The thermal rating of the DR-CC-1 66kV feeder is no longer adequate to supply Cloncurry and we would not comply with the Safety Net requirements based on credible contingencies benchmarked against 50% POE load in the present configuration.

This report represents the first stage of the consultation process in relation to the application of the Regulatory Investment Test for Distribution (RIT-D) on potential credible options to address the identified need at Cloncurry.

We have prepared this Non-Network Options Report in accordance with the requirements of clause 5.17.4(e) of the National Electricity Rules (NER) and seeks information from interested parties about possible alternate solutions to address the need for investment.

We published a Notice of no non-network options in connection with the Regulatory Investment Test for Distribution (RIT-D) for the proposed East Bundaberg Substation Refurbishment on 22 June 2020.  This report represents the final stage of the consultation process on the potential credible options to address the identified need. Three credible feasible options have been investigated in this report.

Our preferred internal solution is to build a new 66kV bus on the adjacent land, build two new 66kV feeder bays and transformer bays, decommission and remove two 66kV circuit breakers, replace transformers T1 and T2 with 15/20MVA transformers and upgrade the protection scheme. These works are required to be completed by 2023. The estimated total capital cost is $8.935M.

This FPAR is therefore published in accordance with rule 5.17.4(o) of the National Electricity Rules as the final step in the RIT-D process.

Bundaberg is a regional city located 360km north of Brisbane with a population of approximately 93,000 people. East Bundaberg 66/11kV Zone Substation (EABU) is located on the eastern edge of Bundaberg city and supplies a diverse mix of industrial, residential, and agricultural zones. There are approximately 8900 customers connected to the distribution network, including a number of major commercial and industrial customers located in Bundaberg and further north at Burnett Heads.

A condition assessment of East Bundaberg Zone Substation (EABU) has identified assets that are recommended for replacement. These assets are forecast to reach retirement based on a combination of Condition Based Risk Management (CBRM) modelling and known issues with problematic plant, which are required to be replaced or decommissioned to manage the safety and network risks associated with unplanned failure.

The internal investigations undertaken on the feasibility of the non-network solutions revealed that it is unlikely to find a complete non-network solution or a hybrid (combined network and non-network) solution to provide the magnitude of network support required in the East Bundaberg area to address the identified need.

The preferred network option is to replace the assets in poor condition. This notice of no non-network options is therefore published in accordance with rule 5.17.4(d) of the National Electricity Rules. As the next step in the RIT-D process, we will now proceed to publish a Final Project Assessment Report.

Kingaroy 66/11kV Substation (KING) is located on the eastern edge of Kingaroy Town. The 11kV distribution network supplies Kingaroy and extends over 50km to supply nearby towns. KING is an important sub-transmission node in the South Burnett area, sourcing 66kV supply from Tarong Power Station which is then distributed via outgoing 66kV feeders to zone substations in the region. The 11kV distribution network supplies approximately 8,200 customers in Kingaroy town and the surrounding region, including a number of major employers such as Swickers Bacon Factory and the Kingaroy Hospital.

Kingaroy substation was established in the 1960s, according to the applicable design and construction standards of the time. It has an outdoor 66kV switchyard, two 25MVA 66/11kV power transformers and a control building with an indoor oil filled 11kV switchboard.

A substation condition assessment of Kingaroy Substation was completed and has identified some primary and secondary plant and equipment that are recommended for retirement based on Condition Based Risk Management (CBRM) analysis.

We have determined that network investment is essential in this case for it to continue to provide electricity to the consumers in the Kingaroy supply area in a reliable, safe and cost-effective manner.

An internal assessment has been carried out and it has been determined that no non-network solutions can potentially meet the identified need or form a significant part of the solution. This Notice has hence been prepared by us in accordance with the requirements of clause 5.17.4(d) of the NER.

Following the publishing of the below Notice of No Non-network Options and Draft Project Assessment Report, this Final Project Assessment Report represents the final stage of the RIT-D process to address the identified need at Pialba.

We intend to take steps to progress the recommended solution(s) to ensure any statutory non-compliance is addressed and undertake appropriately justified network reliability improvements as necessary.

The preferred network option is to replace the assets in poor condition.

We published a Notice of No Non-network Options (Notice) for the network constraints in the Pialba area on 03 April 2020.  An internal assessment had determined that no non-network solutions can potentially meet the identified need or form a significant part of the solution.

This is a Draft Project Assessment Report (DPAR), where we provide both technical and economic information about the internal options in accordance with the requirements of clause 5.17.4(i).

This DPAR is being published due to an increase in project costs which requires us to publish a DPAR before publishing the Final Project Assessment Report (FPAR). Interested parties are invited to make comments or any submissions during the consultation period.

The FPAR will be the next step in this RIT-D process.

Pialba 66/11kV substation (PIALSS) is a Zone Substation which supplies approximately 5200 customers and 16MVA of peak load. PIALSS is located near the centre of Hervey Bay town and supplies the CBD area, the Hervey Bay Hospital, and the main shopping centre. There is also an extensive distribution network that supplies residential customers in the surrounding suburbs.

A condition assessment of PIALSS has identified assets that are recommended for replacement. These assets are forecast to reach retirement based on a combination of Condition Based Risk Management (CBRM) modelling and known issues with problematic plant, which are required to be replaced or decommissioned to manage the safety and network risks associated with unplanned failure.

The internal investigations undertaken on the feasibility of the non-network solutions revealed that it is unlikely to find a complete non-network solution or a hybrid (combined network and non-network) solution to provide the magnitude of network support required in the Hervey Bay area to address the identified need.

The preferred network option is to replace the assets in poor condition. This notice of no non-network options is therefore published in accordance with rule 5.17.4(d) of the National Electricity Rules. As the next step in the RIT-D process, we will now proceed to publish a Final Project Assessment Report.

Pleystowe 33/11kV Substation is located on the southern bank of the Pioneer River approximately 13km west of Mackay and 2.5km north-west of Walkerston. Plewstowe substation supplies the township of Walkerston and the surrounding area.

Pleystowe Substation is presently supplied via two incoming 33kV feeders from T038 Mackay Substation, and there are two outgoing 33kV feeders from Pleystowe Substation which provide supply to Farleigh 33/11kV Substation and the Pleystowe Mill.

Pleystowe Substation was established in 1964 according to applicable design and construction standards during that time. It has an outdoor 33kV and 11kV switchyard with steel structures, three 5MVA 33/11kV power transformers, and a small protection and control building.

A substation condition assessment of Pleystowe Substation was completed in 2019 and has identified some primary and secondary plant and equipment that are recommended for retirement based on Condition Based Risk Management (CBRM) analysis.

We have determined that network investment is essential in this case for it to continue to provide electricity to the consumers in the Pleystowe supply area in a reliable, safe and cost-effective manner.

An internal assessment has been carried out and it has been determined that no non-network solutions can potentially meet the identified need or form a significant part of the solution. This Notice has hence been prepared by us in accordance with the requirements of clause 5.17.4(d) of the NER.

We published a Notice of No Non-network Options (Notice) for the network constraints in the Point Vernon area on 10 June 2020. An internal assessment had determined that no non-network solutions can potentially meet the identified need or form a significant part of the solution. A Draft Project Assessment Report (DPAR) was published on 24 May 2021.

This Final Project Assessment Report represents the final stage of the RIT-D process to address the identified need at the Point Vernon 66/11kV Zone Substation (POVE). We intend to take steps to progress the recommended solution(s) to ensure any statutory non-compliance is addressed and undertake appropriately justified network reliability improvements as necessary.

The preferred network option is to build a second 66kV wood pole line to POVE.

Point Vernon 66/11kV Zone Substation (POVE) supplies 10,700 customers. POVE is energised radially from Pialba 66/11kV Zone Substation (PIAL) via a 5.1km single circuit concrete pole 66kV feeder (M023). Load at POVE peaked at 21MVA in February 2020 and is forecast to increase to approximately 23MVA by 2032. Proposed residential and commercial developments in the suburbs of Dundowran, Craignish, Toogoom and Eli Waters are continuing and may result in load growth in excess of the forecast.

The purpose of this project is to address compliance with the Safety Net provisions of the Distribution Authority.

The internal investigations undertaken on the feasibility of the non-network solutions revealed that it is unlikely to find a complete non-network solution or a hybrid (combined network and non-network) solution to provide the magnitude of network support required in the Point Vernon area to address the identified need.

The preferred network option is to extend a new 66kV feeder to POVE to address Safety Net requirements. This notice of no non-network options is therefore published in accordance with rule 5.17.4(d) of the National Electricity Rules. As the next step in the RIT-D process, we will now proceed to publish a Draft Project Assessment Report.

Rockhampton South 66/11kV Substation is located in the southern part of the central business district (CBD) of Rockhampton. Rockhampton South substation supplies a large portion of Rockhampton CBD, and the surrounding areas to the south of Rockhampton.

Rockhampton South Substation was established in 1968 according to applicable design and construction standards during that time. It has an outdoor 66kV switchyard with steel structures, two 20MVA 66/11kV power transformers, an indoor 11kV switchboard supplying seven outgoing 11kV feeders, and a protection and control room.

A substation condition assessment of Rockhampton South Substation was completed in 2019 and has identified that significant primary plant and majority of secondary plant and equipment are recommended for retirement based on Condition Based Risk Management (CBRM) analysis.

We have determined that network investment is essential in this case for it to continue to provide electricity to the consumers in the Rockhampton South supply area in a reliable, safe and cost-effective manner.

An internal assessment has been carried out and it has been determined that no non-network solutions can potentially meet the identified need or form a significant part of the solution. This Notice has hence been prepared by us in accordance with the requirements of clause 5.17.4(d) of the NER.

A condition assessment of the Turkinje (TURK) 132/66kV Substation (T055) 66kV primary plant and secondary systems has identified assets that are nearing the end of their technical services lives with identified condition, safety and obsolescence issues.

These primary plant and secondary system assets:

• are forecast to reach the end of their technical services lives based on a combination of Condition Based Risk Management (CBRM) modelling and known issues with problematic assets, which are required to be replaced or decommissioned to manage the safety and network risks associated with unplanned failure
• include 66kV circuit breakers, 66kV voltage and current transformers, electromechanical and static protection relays, porcelain post and segmented porcelain insulators used on rotary isolators

Failure of the primary plant and secondary systems is a risk to network security which may lead to a breach of legislated Safety Net requirements and exposes customers to the risks and consequences of an increasingly unreliable electricity supply. Catastrophic failure of plant or secondary systems presents a safety risk to staff as well as to the general public.

Planning studies have confirmed there is an enduring need for the 66kV to maintain the supply of electricity in the Tablelands area.

The purpose of this project is to address the risk to safety and network security posed by poor condition and problematic assets.