Transgrid has published a Project Specification Consultation Report (PSCR) for Maintaining safe and reliable operation of Tamworth substation. Publication of this PSCR represents the first step in the Regulatory Test for Transmission (RIT-T) process.
Tamworth 330 kV substation is located in Transgrid's Northern NSW network. It connects to Transgrid's 330 kV Armidale, Liddell and Muswellbrook substations as well as Transgrid's 132 kV Narrabri, Tamworth and Gunnedah substation, which all support Essential Energy's 66 kV network.
There are three transformers at Tamworth's 330 kV substation. The No.1 and No.2 transformers were commissioned along with the substation in 1967 and the No.3 transformer was commissioned in 1998.The No.3 transformer at Tamworth substation is in satisfactory condition and not part of this need.
Replacement of the Tamworth transformers will significantly reduce the likelihood of prolonged and involuntary load shedding in the northern region and help Transgrid manage its safety obligations.
The key economic benefits associated with addressing this need are summarised as:
- Reduction of risk as valued as direct impact to Transgrid and consumers including:
- Changes in involuntary load shedding
- Safety and environmental hazards associated with a catastrophic failure. - Avoided operating expenditure related to an escalation of corrective maintenance.
We have classified this RIT-T as a ‘market benefits’ driven RIT-T as the economic assessment is not being progressed specifically to meet a mandated reliability standard but by the net benefits that are expected to be generated for end-customers.
In the PSCR Transgrid presents two credible network options that would meet the identified need from a technical, commercial, and project delivery perspective. This PSCR finds that implementation of Option 1 is the preferred option at this draft stage of the RIT-T process. Option 1 involves the replacement of the No.1 and No. 2 transformer at Tamworth substation.
The capital cost of this option is approximately $17.76 million (in $2023/24). Transgrid welcomes written submissions on materials contained in this PSCR. Submissions are due on 14 November 2024.
In accordance with the requirements of the Rules, a summary of the Project Specification Consultation Report is made available on the AEMO website. A copy of the PSCR can be obtained from Transgrid’s website or by emailing regulatory.consultation@transgrid.com.au.