Powerlink has recently published a ‘Project Assessment Conclusions’ (PACR) to manage voltages in South East Queensland (SEQ).
Declining minimum flows and an increasing capacitive contribution from more energy efficient appliances and roof top solar systems in the SEQ area are increasing the likelihood of over-voltage events. Continued reliance on the existing network switching strategy, to ensure ongoing compliance with the National Electricity Rules (the Rules), will result in increasingly onerous reconfigurations of the network that in turn result in higher market costs, reduced system resilience and compromised system security.
Powerlink commenced the Regulatory Investment Test for Transmission (RIT-T) with the publication of the Project Specification Consultation Report (PSCR).
A number of developments since publication of the PSCR impacted both the extent and timing of the voltage management issues, as well as the scale of the potential solutions to address the identified need.
This included the Australian Energy Market Operator’s declaration of a Network Support and Control Ancillary Services gap in southern Queensland on 17 December 2021, after the commencement of this RIT-T. Powerlink issued an Expression of Interest (EOI) in May 2022 to request additional system security services to address this gap in the short-term and identifying the longer term solution would be assessed as part of this RIT-T.
As a result the Project Assessment Draft Report (PADR), published in October 2022 included revised and additional options and new scenarios that consider the reactive capability of future market-led developments in SEQ.
The preferred option in the PACR that satisfies the RIT-T is the installation and commissioning of a 120MVAr bus reactor at Belmont Substation for 2023/24 and network support services from CleanCo Queensland to operate during times of reactive power shortfalls.
The estimated capital cost of the proposed RIT-T project is $13.3 million in 2022/23 prices. Powerlink is the proponent of the proposed network project and CleanCo is the proponent of network support services.
In the context of engagement activities with consumers and the general community, Powerlink has assessed this project as ‘normal’ on the RIT-T stakeholder engagement matrix.
A copy of the Project Assessment Conclusions Report is available below.