AusNet has progressing the Regulatory Investment Test for Test (RIT-T) to investigate and evaluate options to replace towers on the Heywood Terminal Station to Alcoa Portland 500 kV Nos. 1 and 2 lines (HYTS- APD), which are at risk of failure if no remediation actions are performed. As explained in the Project Specification Consultation Report (PSCR), which was published in February 2024, there are no non-network options that could address the identified need, and we did not receive any submissions in response to the PSCR.
In accordance with the Rules and the AER’s RIT-T guidelines, the next phase of the RIT-T is to publish the Project Assessment Draft Report (PADR), which sets out the detailed cost-benefit analysis of the credible options for addressing the identified need. Our PADR for this project shows that the preferred option (Option 1) is to replace the existing corroding transmission towers with painted steel lattice towers that comply with current design standard AS/NZS 7000. This option entails replacement in a staged approach, starting with the most corroded structures in the circuit, involving the replacement of nine towers. This option:
- Maintains the reliability of supply to the Alcoa smelter at Portland Victoria, a major customer of AusNet.
- Reduces the safety risks to the public and the environment.
- Helps provide clarity on the timeframes to rectify corroded members and bolts on the towers.
Our analysis shows that this option is preferred to the alternative option (Option 2), which would replace the existing transmission towers with painted steel transmission poles but would not eliminate the risk of in-service failure of the other line elements, i.e., insulator, conductor, groundwire. In accordance with the RIT-T, therefore, Option 1 is expected to maximise the present value of the net economic benefit to all those who produce, consume and transport electricity in the NEM.
The capital costs of the preferred option are expected to be approximately $40 million. The planned commencement date of the works is January 2025, for completion and commissioning by February 2026.
AusNet welcomes submission in response to the PADR, which should be emailed to rittconsultations@ausnetservices.com.au by Friday 11 October 2024. In the subject field, please reference ‘RIT-T PADR Tower Replacement HYTS-APD’. AusNet’s preference is that any 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.