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Powerlink has published a Project Assessment Conclusions Report (PACR) to address the reliability of supply to Nebo local area. Publication of the PACR is the final step in the Regulatory Investment Test for Transmission (RIT-T).
Nebo Substation was established in the late 1970s to be a major injection point and major 275kV switchyard in the state-wide transmission network, connecting North and South Queensland whilst providing bulk supplies to several key areas, including Mackay and Pioneer Valley. Two 132/11kV transformers and associated primary plant connect the Powerlink substation to the Ergon Energy (part of the Energy Queensland Group) network at Nebo supplying the local area.
The 132/11kV power transformers (Transformer 3 and Transformer 4) and associated 11kV primary plant are nearing the end of their technical lives, with an increasing risk of failure. The failure of a transformer or associated primary plant can result in an extensive replacement timeframe increasing the risk of loss of supply to the local area, and in extreme cases, could present a risk to the safety of personnel.
Planning studies have confirmed there is a long-term requirement to continue to supply the existing electricity services provided by Nebo Substation. Powerlink must therefore take action to avoid the increasing likelihood of unserved energy arising from failure of the ageing transformers and primary plant at Nebo, and ensure customers are provided with a reliable and safe supply of electricity.
In September 2023, Powerlink published a Project Specification Consultation Report (PSCR) that identified replacement of Transformers 3 and 4 and the associated 11kV primary plant by 2025 as the preferred option to address reliability of supply to Nebo. The indicative capital cost of the RIT-T project for the preferred option is $11.5 million in 2022/23 dollars.
The PSCR also indicated Powerlink’s intention to claim exemption from producing a Project Assessment Draft Report, as allowed under the National Electricity Rules. Powerlink did not receive any submissions in response to the PSCR, which closed on 22 December 2023. As a result, no additional credible options that could deliver a material market benefit have been identified and the outcomes of the economic analysis in the PACR are unchanged from those in the PSCR.
The PACR recommends replacement of both transformers and associated primary plant by 2025, at an estimated capital cost of $11.5 million in 2022/23 prices. Powerlink is the proponent of this network project.
In the context of engagement activities with customers and the general community, Powerlink has assessed this project as ‘minor’ on the RIT-T stakeholder engagement matrix.
Copies of the PSCR and PACR are available below.