Transgrid has recently published a Project Assessment Conclusions Report (PACR) for managing risk on Line 23 (Vales Point-Munmorah).
Line 23 is a single-circuit 330 kV, steel tower transmission line with a route length of 7 km that was constructed in 1965. The line is a key link in the Central Coast transmission network and its route traverses rural areas near the Vales Point and Colongra power stations near Lake Macquarie.
Condition assessments have identified a number of condition issues on Line 23. These condition issues increase the likelihood of conductor drops and tower collapse 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 Line 23 as it traverses substantial sections of bushland, much of which surrounds residential 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 Line 23 in March 2023.
In the PSCR Transgrid presented two 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 2 (replacement of all suspension structures and remediation of line components on tension structures) – 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 2 (replacement of all suspension structures and remediation of line components on tension structures) remains the preferred option at this stage of the RIT-T process. This option is estimated to have a capital cost of $13.4 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