The East Gippsland 66kV sub-transmission loop, the longest in AusNet’s system, supplies over 71,400 customers and is geographically isolated, limiting capacity transfers and making it prone to voltage issues. Originating from the Morwell Terminal Station (MWTS), it comprises six zone substations: Traralgon (TGN), Sale (SLE), Maffra (MFA), Bairnsdale (BDL), Newmerella (NLA), and Cann River (CNR).
Demand is rising due to customer growth, home gas electrification, and EV adoption, with coincidental loading expected to exceed the loop’s 144 MVA “N” capacity by 2026/27 under Probability of Exceedance (POE)50 condition and surpass the 162 MVA voltage collapse limit by 2025/2026 under POE10. Under worst-case N-1 conditions (MWTS-SLE outage), the loop’s 86.3 MVA thermal limit would be exceeded under POE50. With no remedial action, significant load shedding may be required during the peak demand period to prevent voltage collapse and thermal overload.
The Options Screening Report (OSR), which represents the first step in the RIT-D process in accordance with clause 5.17 of the National Electricity Rules (NER) and section 4.2 of the RIT-D Application Guidelines was published in February 2025. No non-network proposals were received during the RIT-D OSR consultation phase.
This report, the Draft Project Assessment Report (DPAR), is the second stage of the RIT-D process and provides information about the draft conclusions of the RIT-D.
The preferred solution is to reconductor the undersized conductor sections along MWTS-TGN 1 & 2 and TGN-MFA 66 kV line with 19/4.75 AAC conductors and redesigning to achieve a minimum summer cyclic rating of 881A. The estimated capital cost of the preferred option is $40.3 million (in real $2024).
AusNet welcomes written submissions on the credible options evaluation and draft conclusion presented in this DPAR. Submissions should be emailed to [email protected] on or before 09 January 2026. In the subject field, please reference ‘RIT-D DPAR LD TGN MFA’. AusNet’s preference is that these submissions would be published on its website and AEMO’s website. If you do not want your submission to be made public, please clearly stipulate this at the time of lodgement.
Assessments of the options and responses to this DPAR will be presented in the Final Project Assessment Report (FPAR), which AusNet expect to publish by mid-February 2026.