Transgrid has recently published a Project Assessment Conclusions Report (PACR) for managing risk on Southern Sydney transmission lines.
These transmission lines link our Liverpool, Kemps Creek and Ingleburn 330 kV substations in south-west Sydney with the Sydney South 330 kV substation. The four 330 kV transmission lines covered by this RIT-T are:
- Line 12 – spanning a route of 17.5km between Liverpool and Sydney South substations;
- Line 13 – spanning a route of 24.2km between Kemps Creek and Sydney South substations; and
- Line 76 and 78 – each spanning a route of 21.3km between Ingleburn and Sydney South substations.
Each of these lines shares a section with at least one other line and, in total, there are five distinct sections of lines covered by this RIT-T. Specifically, these sections are referred to as lines 12, 13, 13/78, 12/76, and 76/78.
The Liverpool, Ingleburn and Sydney South substations linked by these transmission lines are customer connection points supplying the Ausgrid and Endeavour Energy networks across Southern Sydney from Macquarie Fields to Cronulla and the Sydney CBD.
Condition assessments have identified a number of condition issues across these lines. These condition issues increase the likelihood of conductor drops and presents consequent safety and bushfire risk to our personnel and the public, as well as resulting in reactive maintenance costs to repair the failed elements. The bushfire risks are exacerbated for these lines as they traverse substantial sections of bushland, much of which surrounds residential and urban areas.
As asset conditions deteriorate over time, the likelihood of failure and subsequent risks will increase should these issues not be addressed.
Transgrid manages and mitigates bushfire and safety risks to ensure they are below tolerance levels or ‘As Low As Reasonably Practicable’ (‘ALARP’), in accordance with Transgrid’s obligations under the New South Wales Electricity Supply (Safety and Network Management) Regulation 2014 and Transgrid’s Electricity Network Safety Management System (ENSMS). The proposed investment will enable Transgrid to continue to manage and operate this part of the network to a safety and risk mitigation level of ALARP.
The proposed investment will enable TransGrid to continue to manage and operate this part of the network to a safety and risk mitigation level of ALARP. Consequently, it is considered a reliability corrective action under the RIT-T.
Transgrid published a Project Specification Consultation Report (PSCR) for managing risk on Southern Sydney transmission lines in March 2023.
In the PSCR Transgrid presented three credible network options that would meet the identified need from a technical, commercial, and project delivery perspective. The optimal commercially and technically feasible option presented in this PSCR – Option 3 (line refurbishment addressing all components with condition issues plus installation of OPGW fibre on Line 12) – is the preferred option to meet the identified need.
No submissions were received in response to the PSCR during the consultation period which closed in June 2023 and no additional credible options have been identified.
Option 3 (line refurbishment addressing all components with condition issues plus installation of OPGW fibre on Line 12) remains the preferred option at this stage of the RIT-T process. This option is estimated to have a capital cost of $24 million +/- 25% and is expected to be completed by 2025/26. Transgrid is the proponent of the proposed network project.
In accordance with the requirements of the National Electricity Rules, a summary of the PACR is made available on the AEMO website. A copy of the PACR can be obtained from Transgrid’s website or by emailing regulatory.consultation@transgrid.com.au