Victoria to NSW Interconnector (VNI) Upgrade


Boosting power flows between states

This major upgrade to the transmission network will boost interstate power flows and help deliver safe, reliable, lowest cost electricity to customers.

Read our VNI Upgrade fact sheet.

Why do we need an upgrade?

An electricity interconnector is a connection that allows power to flow in both directions between regions in the National Electricity Market, providing access to a larger number of electricity generators.

Upgrading the Victoria – New South Wales Interconnector (VNI) will allow cheaper generation to be transferred between the two states. This will help lower the cost of wholesale electricity across the National Electricity Market and put downward pressure on customer bills.

It will also:

  • support the development of renewable generation in new energy zones, which are expected to provide the bulk of energy in the future.
  • help ensure more reliable supply of electricity to customers at all times, including during periods of peak demand.

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

What does the project involve?

TransGrid plans to install ‘smart wires’ power flow controller technology within Yass substation in NSW and our new Stockdill substation in the ACT. 

‘Smart wires’ technology enables the real-time control of electricity flows along power lines. The system detects areas of congestion in the network and automatically redirects flows to less congested lines. It will help unlock spare transmission capacity, allowing more energy to be transferred between Victoria and NSW. 

AEMO will undertake complementary upgrades to the transmission network in Victoria.

Key dates

Late 2019
Preliminary investigations
Early 2020
Detailed design
August 2020
Environmental assessment complete
October 2020
Development approval from ACT Government
Early 2021
Construction commencement
Late 2021
Project commissioning 

Project approval

Together with AEMO, TransGrid is undertaking a Regulatory Investment Test for Transmission (RIT-T). The RIT-T is a formal consultation process designed to:
  • Inform stakeholders of investment need and proposed options to address it
  • Test the market for alternative and more efficient solutions
  • Explain to stakeholders the basis on which the preferred option has been selected. 
The RIT-T consultation process has three stages:


Submissions and next steps 

TransGrid and AEMO received nine public submissions on the PSCR and six on the PADR. Submissions received (and approved for publication by proponents) can be viewed on the AEMO website.

TransGrid has submitted a Contingent Project Application to the Australian Energy Regulator seeking approval to vary TransGrid’s current 2018-23 Revenue Determination by an amount that reflects the prudent and efficient costs of the NSW component of the project.