Transgrid has published the Project Assessment Conclusions Report (PACR) for Maintaining safe and reliable operation of Murray substation. Publication of this PACR represents the final step in the Regulatory Test for Transmission (RIT-T) process.
Murray 330 kV Substation is an ex-Snowy Mountains Hydro-electric Authority site which was commissioned in 1964. Murray Substation connects approximately 1500 MW of renewable hydro-electric energy generation, supports four 330kV transmission lines in the southern New South Wales network, and provides electricity flow paths between the Snowy Mountains and Victoria. The 132kV network connects Guthega Hydro (60MW), Jindabyne Pumping Station, Munyang and Cooma Substation.
The condition of certain 330 kV and 132 kV high voltage and secondary system assets at Murray substation has deteriorated over time, leading to an increasing risk of failure which could result in reliability, safety, environment and financial consequences. The secondary systems assets are also impacted by obsolescence of the equipment, increasing the time to rectify defects and increasing the risk that primary assets at the substation may not be able to reliably operate.
Condition assessments performed through our routine maintenance program has shown degradation in the condition of these high voltage and secondary systems assets which will increase their risk of failure. Without intervention, other than ongoing business-as-usual maintenance, the assets are expected to deteriorate further and more rapidly. This will increase the risk of supply interruptions to our customers as well as safety, environmental and financial consequences.
The secondary system assets are also subject to obsolescence of the equipment. This means that the technology is no longer being manufactured or supported and reactive replacement of failed secondary systems component is not sustainable and impacts our ability to meet the requirements of the National Electricity Rules (NER).
In the PSCR Transgrid presented one 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 PACR – Option 1 – is the preferred option to meet the identified need at this stage of the RIT-T. Option 1 involves targeted replacement of high voltage and secondary system assets at Murray substation that have deteriorating condition and have reached (or will soon reach) the end of their technical lives and for which only limited manufacturer support and spares are available.
No submissions were received in response to the PSCR during the consultation period which closed in March 2024 and no additional credible options have been identified.
The estimated capital cost of this option is approximately $21.79 million ($2023-24) +/- 25 per cent. Transgrid is the proponent of the proposed network project.
In accordance with the requirements of the Rules, a summary of the Project Assessment Conclusions Report 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.