Major Contract

NSW Central-West Orana REZ Transmission Project

NSW Central-West Orana REZ Transmission Project

The proposed transmission project aims to support the delivery of a pilot Renewable Energy Zone (REZ) in the New South Wales Central-West Orana region.

Transmission lines will run north-west from the existing network near Merriwa, passing south of Dunedoo before connecting to the existing network east of Wellington. The project will include:

  • a new switching station at Wollar, to connect the project to Transgrid’s existing Wollar Substation and onto the NEM
  • new twin double circuit 500 kV transmission lines and associated infrastructure to connect to the NEM
  • single and double circuit 330 kV single lines to connect energy generation and storage projects within the Central-West Orana REZ to the energy hubs
  • additional energy hubs and switching stations to connect energy generation and storage

Transmission upgrades will be required to support the increase in renewable generation and storage in the REZ. 


Key Dates

Apr 2023 Preferred Bidder Selection
Apr 2023 Contract Award
2024 Expected Construction Commencement
Jul 2027 Expected Construction Completion

Funding contributions

Federal Government

The Federal Government, through ARENA, has committed $5 million towards a $16.2 million feasibility study, to be undertaken by TransGrid, which will assess the technical and commercial options for the development of new high voltage transmission lines to enable the REZ.


Shortlist: Network Operator Shortlist: - ACE Energy comprising ACCIONA, Cobra and Endeavour Energy - Network REZolution comprising Pacific Partnerships, UGL, CPB and APA Group - NewGen Networks comprising Plenary, Elecnor, Essential Energy and SecureEnergy
Successful Tenderer: ACE Energy consortium comprising ACCIONA, Endeavor Energy, and Cobra
Adviser (Tenderer): Capella Capital


Jun 2020 On behalf of the Australian Government, the Australian Renewable Energy Agency (ARENA) committed $5 million in funding to TransGrid to conduct a detailed feasibility study for the project.
Jul 2020 In its 2020 Integrated System Plan, AEMO identified the Central-West Orana REZ Transmission Project as a critical project and provided updated costings for the project. The ISP estimates that the transmission project component of the Central-West Orana REZ has a cost of between $450 million and $850 million, with a modelled cost of $650 million.
Dec 2020 The Central-West Orana REZ Transmission Project was declared Critical State Significant Infrastructure by the New South Wales Government.
Mar 2021 The NSW Government released the Central-West Orana REZ Access Scheme Issues Paper for public consultation. The Paper identifies the key features of the REZ's transmission project.
Sep 2021 TransGrid submitted a Scoping Report and requested the NSW Department of Planning, Industry and Environment Secretary's Environmental Assessment Requirements for the Wollar Substation upgrade project.
Oct 2021 The NSW Department of Planning, Industry and Environment issued Secretary’s Environmental Assessment Requirements (SEARs) for the Wollar Substation upgrade portion of the project.
Sep 2022 The scoping report for the project was released and a request for SEARs for the transmission portion of the project was made.
Oct 2022 SEARs were issued for the project.
Apr 2023 EnergyCo selected ACE Energy, comprising ACCIONA, Endeavour Energy and Cobra, as the preferred bidderr for the project. The consortium will design, finance, build, operate, and maintain the REZ network infrastructure through an Availability-based Public Private Partnership-like contract.
May 2023 EnergyCo opened a Registration of Interest (ROI) for Independent Certifier Services for the project, closing 30 May.
Sep 2023 The NSW Department of Planning and Environment placed the project's Environmental Impact Statement on public exhibition, closing 26 October.
Procurement approach
Confirmed PPP |
New South Wales | National |
Tender notices