Powerlink has recently published a ‘Project Assessment Conclusions Report’ (PACR) to address the secondary systems condition risks at Mt England Substation.
Mt England Substation is a 275kV switching station located approximately 40km north-west of the Brisbane Central Business District. It was established in 1983 to provide a connection point for Wivenhoe Power Station and facilitate the flow of energy from Tarong Power Station into the greater Brisbane transmission network via feeders to South Pine, Blackwall and Abermain Substations. Planning studies have confirmed there is a long-term requirement to continue to supply the existing electricity services provided by Mt England Substation.
The secondary systems at Mt England broadly perform the functions of transmission element protection, data collection, remote (and local) control and monitoring. Many of these systems are reaching the end of their technical service lives, and are increasingly no longer supported by their manufacturer, with limited spares available. Increasing failure rates, along with the increased time to rectify the faults due to the obsolescence of the equipment significantly affects the availability, reliability and technical capability of these systems to continue to meet the requirements of the National Electricity Rules (the Rules).
In December 2019 Powerlink published a ‘Project Specification Consultation Report’ (PSCR) identifying the proposed preferred option to address the risks and claiming exemption from producing a ‘Project Assessment Draft Report’ as allowed for under NER Clause 5.16.4(z1).
There were no submissions received in response to the PSCR, which closed in March 2020. As a result, no additional credible options that could deliver a material market benefit have been identified and the outcomes of the economic analysis contained in the PACR remain unchanged from those published in the PSCR.
The PACR recommends implementation of the preferred network option; Replacement of selected 275kV secondary systems within the existing building by October 2023. The indicative capital cost of this option is $10.26 million in 2019/20 prices. Powerlink is the proponent of this network project.
Under this option, design work will commence in mid-2020 and installation, with commissioning of the new secondary system to be completed by October 2023.
In the context of engagement activities with consumers and the general community, Powerlink has assessed this project as ‘minor’ on the RIT-T Stakeholder Engagement Matrix.
A copy of the Project Assessment Conclusions Report is available below.