Powerlink has recently published a 'Project Assessment Conclusions Report' (PACR) to address the secondary systems condition risks at Mudgeeraba Substation.
Located approximately 10km north of the Queensland-NSW border, Mudgeeraba Substation was established in 1970 as a 110kV switchyard. It was expanded in the late 1990s with the addition of a 275kV switchyard and now serves as the major injection point for the distribution networks supplying the southern Gold Coast in Queensland and north-eastern New South Wales (NSW), supporting a diverse range of customer needs in these areas.
The 275kV secondary systems at Mudgeeraba Substation broadly perform the functions of transmission element protection, data collection, remote (and local) control, and monitoring. Commissioned approximately 20 years ago, these secondary 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 and reliability of these systems and their ability to continue to meet the requirements of the National Electricity Rules (the Rules).
In June 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' (PADR) as allowed for under NER Clause 5.16.4(z1).
There were no submissions received in response to the PSCR, which closed in September 2019. 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 Option 2; full replacement of all secondary systems at Mudgeeraba in a new building by December 2021. The indicative capital cost of this option is $8.3 million in 2018/19 prices. Powerlink is the proponent of this network project.
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.