Upgrading the Queensland-NSW Interconnector (QNI) will boost interstate transmission capacity and increase power flow on existing lines. This will make it easier and more efficient to share lower-cost generation between the two states, and help to reduce electricity bills for customers.

QNI will also help to support the development of renewable generation in new energy zones.

The project has been identified as a priority by both the Australian Energy Market Operator in the 2020 Integrated System Plan and by the State Government in the NSW Transmission Infrastructure Strategy.

The Integrated System Plan stated the upgrade is critical to address cost, security and reliability issues.

The Commonwealth and New South Wales Governments supported the early delivery of QNI through a $102 million joint-underwriting of the project.

What does the project involve?

The project involves upgrading transmission lines between Liddell power station, Muswellbrook and Tamworth substations. Activities include:

  • Replacement of pole structures
  • Removal of existing pole structures
  • Installation of new mid-span structures
  • Strengthening pole structures
  • Replacement or rearrangement of transmission line insulators.

We are also upgrading substations at Tamworth, Dumaresq, Armidale and Muswellbrook. Activities include replacing conductors and other equipment to ensure the quality and reliability of electricity supply.

Latest update

The $236 million Queensland-NSW Interconnector (QNI) upgrade was completed in June 2022 on time and on budget.

The work included upgrading 300 kilometres of existing transmission lines and replacing 58 towers between Liddell power station and Tamworth substation.

The successful completion of the project allows more energy to flow between the two states and reduces constraints on the NSW transmission network.


queensland nsw interconnector map


  • Preliminary investigations and project scoping - Completed

    Early 2019

  • Detailed design and site investigations - Completed

    Late 2019

  • Approval by the Australian Energy Regulator - Completed

    April 2020

  • Construction starts - Completed

    May 2020

  • Project completed - Completed

    June 2022

  • Inter-regional testing - In progress

    Early 2024

Regulatory approval

The project approval timeline is outlined below: 

Q4 2018
  • RIT-T Project Specification Consultation Report (PSCR) published. The PSCR detailed the need to increase the existing Queensland to New South Wales interconnector capacity and described the credible options to meet the need, including technical characteristics. 

Q2 2019
  • Preliminary investigations and project scoping.

Q3 2019
  • RIT-T Project Assessment Draft Report (PADR) published - The PADR outlined how we addressed the issues raised in submissions to the PSCR and explained the basis on which the preferred option at the draft stage was selected.

Q4 2019
  • RIT-T Project Assessment Conclusions Report (PACR) published - The PACR addresses PADR consultation responses and determines the final preferred option.
  • Announcement of  joint-underwriting of up to $102 million to support the construction upgrade of the NSW–Queensland Interconnector (QNI) by TransGrid.
  • Detailed design and site investigations.

Q1 2020
  • Australian Energy Regulator (AER) RIT-T determination (March 2020).
  • Regulator approval of Contingent Project Application (CPA) (April 2020).

Environmental approval


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02 March 2022

Major transmission project on track to deliver more renewable energy to NSW

The Queensland-NSW Interconnector (QNI) project, a major grid transmission upgrade that will ensure more reliable supply of electricity to customers at all times, including during periods of peak demand, is on track for completion by May 2022.


16 February 2022

Tamworth substation complete, QNI to deliver $170 million of benefits to NSW and the ACT

Civil works are now complete at Tamworth substation, the largest of five substations to be upgraded as part of the Transgrid Queensland-NSW Interconnector upgrade, a major infrastructure project that will lower energy prices to consumers by enabling better energy sharing between the two states.


09 December 2021

QNI approaches completion as ninth capacitor bank installed

The last capacitor bank of the Queensland-NSW Interconnector (QNI) upgrade has now been installed, with the project, started in June 2020, almost 90 per cent complete.