Powerlink has recently published a ‘Project Assessment Conclusions Report’ (PACR) to address the secondary systems condition risks in the Gladstone South area.
Gladstone South Substation, located approximately 5km southeast of the Gladstone CBD, was established in the early 1960s as a 132kV injection point for the 66kV regional distribution network owned by Ergon Energy (part of the Energy Queensland Group). A second interconnected 132kV substation was established on an adjacent site in 2002 to meet a growing demand for electricity in the local area. The QAL West Substation, also established in 2002, is one of three injection points for the Queensland Aluminium (QAL) refinery in Gladstone. Planning studies have confirmed there is a long-term requirement to continue to supply the existing electricity services provided by Gladstone South and QAL West Substations to support a diverse range of customer needs in the area.
The secondary systems at Gladstone South and QAL West Substations broadly perform the functions of transmission element protection, data collection, remote (and local) control and monitoring. Commissioned almost 20 years ago, most of these systems are reaching the end of their technical service lives and are no longer supported by the 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 February 2020 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 May 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 Option 2; full replacement of all secondary systems at Gladstone South and QAL West Substations by April 2024. The indicative capital cost of this option is $23.8 million in 2019/20 prices. Powerlink is the proponent of this network project.
Under this option, design work will commence in late 2020 and construction in 2022, with all works completed by April 2024.
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.