Project Specification Consultation Report – Summary
Regulatory Investment Test – Transmission – July 2026
AusNet has published a Project Specification Consultation Report (PSCR) to evaluate options to maintain safe and reliable 250V direct current (DC) supply systems at nine terminal stations to meet AusNet’s regulatory obligations and community expectations. Publication of this PSCR represents the first step in the Regulatory Test for Transmission (RIT-T) process.
250V DC supply systems provide critical power supply for protection, control and SCADA/telemetry at terminal stations, which are required for the safe and reliable operation of the electricity network. Failure of duplicated 250V DC systems will result in the loss of these functions at a terminal station, which may lead to loss of supply to customers and personnel injury.
The deteriorated condition and advanced age of the existing duplicated 250V DC systems at the following nine terminal stations poses increasing risk of DC system failure:
- Ballarat Terminal Station (BATS)
- East Rowville Terminal Station (ERTS)
- Malvern Terminal Station (MTS)
- Tyabb Terminal Station (TBTS)
- Altona Terminal Station (ATS)
- Geelong Terminal Station (GTS)
- Keilor Terminal Station (KTS)
- Ringwood Terminal Station (RWTS)
- Wemen Terminal Station (WETS)
AusNet has identified a total of six options but only one option, Option 1, is considered credible. AusNet does not consider non-network solution as a credible option as these deteriorated 250V DC supply systems cannot be retired and non-network solution cannot perform the function of the DC supply systems.
Option 1 is the preferred option because it maximises the net economic benefit. It entails replacing the deteriorated 250V DC supply systems and essential fireproofing upgrades to the battery rooms at these nine terminal stations by 2031. The estimated capital cost of this option is $14.8 million. The project will commence in 2027 and is anticipated to be completed by 2031.
AusNet welcomes written feedback on this PSCR by 9th October 2026, which can be provided to [email protected]. In the subject field, please reference “Maintaining safe and reliable DC systems”.