AER to review cost benefit analysis of expanding QNI transmission transfer capacity

The Australian Energy Regulator (AER) has received a request from TransGrid to make a determination that the preferred option identified through its Expanding NSW-QLD Transmission Transfer Capacity Regulatory Investment Test for Transmission (RIT-T) satisfies the requirements of the RIT-T cost benefit analysis.

TransGrid and Powerlink have investigated options for expanding electricity transmission transfer capacity between New South Wales and Queensland. Their RIT-T process focussed on options for an incremental upgrade to the existing Queensland-New South Wales Interconnector (QNI) transfer capacity in the near term, consistent with the ‘Group 1’ QNI upgrade project identified in AEMO’s 2018 Integrated System Plan (ISP) and the 'QNI Minor' upgrade in the draft 2020 ISP.

TransGrid and Powerlink released their final RIT-T report on 20 December 2019, which identified the following preferred option:

  • uprating the Liddell to Tamworth 330 kV lines; and
  • installing new dynamic reactive support at Tamworth and Dumaresq, and shunt capacitor banks at Tamworth, Armidale and Dumaresq.

The AER will assess the application of the RIT-T to this project and make a determination as to whether the preferred option satisfies the RIT-T, in accordance with the requirements of the National Electricity Rules.

We expect to make our determination in the first quarter of 2020.


The RIT-T is a cost‒benefit analysis that transmission businesses apply before making network investments in excess of $6 million. The purpose of the RIT-T is to identify the network or non-network investment option with the highest net economic benefits across the National Electricity Market. This promotes efficient investment decisions and helps ensure that consumers pay no more than necessary for electricity network infrastructure.

Issued date: 
23 December 2019
AER reference: 
AC 198/19
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