Major Contract

Hunter Transmission Project

Hunter Transmission Project

The Hunter Transmission project is the 115 kilometre northern section of the Sydney Ring. It involves building a new above-ground 500 kilovolt (kV) transmission line between Bayswater and Eraring in the Hunter region to connect the State’s existing 500 kV transmission lines.

The HTP will close the northern loop between existing transmission lines: 

  • two 500 kV transmission lines in the east, which connect the power stations on the Central Coast (Eraring and Vales Point) via Eraring to the Kemps Creek substation in Western Sydney, and 
  • two 500 kV transmission lines in the west, which connect Bayswater Power Station in the Upper Hunter to Mt Piper Power Station near Lithgow, and Bannaby substation in the Southern Tablelands.

The Hunter Transmission Project's preliminary corridor is divided into three sections: 

  • HTP Central – Pokolbin to Corrabare. Most of the central section of the preliminary corridor runs through the Pokolbin and Corrabare State forests.
  • HTP North – Bayswater to Broke. Most of the northern section of the preliminary corridor runs through power station, mining and Department of Defence land.
  • HTP South – Olney to Eraring. The southern section of the preliminary corridor runs mostly through the Olney State Forest before joining and then running alongside the existing 500 kV transmission line through Martinsville and Corranbong to Eraring.

Funding contributions

In December 2022, the Federal Government confirmed that the Hunter Transmission Project would be one of eight projects to receive funding until the combined $7.8 billion Federal and NSW funding package. The package is funded by $4.7 billion from the Commonwealth’s Rewiring the Nation plan and $3.1 billion from the NSW Transmission Acceleration Facility.


Jun 2022 AEMO's 2022 Integrated Systems Plan lists the project as 'actionable' and estimates the costs of the project at $0.9 billion ±50%.
Jul 2022 The NSW Minister for Planning declared the project as Critical State Significant Infrastructure via the Environmental Planning and Assessment Amendment (Hunter Transmission Project) Order 2022.
Dec 2022 The Federal and NSW governments announced a $7.8 billion deal to support eight critical transmission and REZ projects, including Sydney Ring - Hunter Transmission Project.
Jun 2023 Transgrid released its System Security Roadmap confirming that the expected delivery date for the project is 2028. Transgrid also confirmed the project was declared Critical State Significant Infrastructure (CSSI) and will progress as a Priority Transmission Infrastructure Project (PTIP) under the Electricity Infrastructure Investment Act 2020 (NSW). The Southern Sydney Ring network option may subsequently proceed, through the NSW, ISP or RIT‑T framework.
Aug 2023 TransGrid released its Transmission Annual Planning Report 2023 confirming length of the project is 110 kilometres.
Nov 2023 The project's overview document is released, identifying that the expected length of the project is 115km.
Dec 2023 AEMO's draft 2024 ISP lists the project as 'actionable'. An updated construction completion timeline identifies the Hunter Transmission Project is expected to be completed by December 2027.