Central West Orana REEZ

  • Snapshot

The Central-West Orana Renewable Energy Zone is Australia’s first REZ. A roughly 20,000 km² zone in Central West NSW, centred on Dubbo and Dunedoo, that will connect new wind, solar and storage generation to the grid. Its transmission network is the first competitively procured REZ transmission project in the country.

Turnbull Engineering has been involved across the life of the project, providing civil and structural design during the competitive tender phase, and now supporting design management and delivery for the network operator, ACEREZ.

  • Location
    Central West NSW (around Dubbo and Dunedoo)

  • Project
    Australia’s first Renewable Energy Zone - transmission network

  • Network Operation
    ACEREZ (ACCIONA, COBRA and Endeavour Energy)

  • Turnbull’s role
    Bid-phase design; current design management and delivery support

  • Project Value
    $5.5 billion (transmission)

  • Program
    2022-2029

  • Timeline
    Tender from 2022 • in delivery 2025-present (energisation 2028)

Project Overview

The $5.5 billion transmission project will build new high-voltage lines, energy hubs and supporting infrastructure to carry renewable power from the REZ to load centres in Newcastle, Sydney and Wollongong. It comprises around 90 kilometres of 500 kV and 150 kilometres of 330 kV overhead transmission lines, together with an energy hub at Merotherie and switching stations.

The network will unlock at least 4.5 gigawatts of new capacity from 2028, connecting 7.7 gigawatts of wind and solar and powering more than two million homes and is expected to grow towards 6 gigawatts by 2038. EnergyCo appointed ACEREZ, a partnership of ACCIONA, COBRA and Endeavour Energy, to design, build, finance, operate and maintain the network for 35 years, reaching financial close in April 2025. Construction began in June 2025.

 
 

Design and delivery scope

Turnbull’s scope across the project has spanned:

  • Road design

  • Pavement design

  • Flood modelling and drainage design

  • Civil design for transmission towers and substations

  • Structures (excluding transmission towers)

  • Public utility impact coordination

Turnbull’s Involvement

Tender phase (from 2022)

During EnergyCo’s competitive procurement, Turnbull provided civil and structural design as part of the CPB and UGL design-and-construct team within one of the shortlisted consortia bidding to deliver the transmission network.

Delivery phase (2025–present)

Following ACEREZ’s appointment, Turnbull was engaged by ACEREZ (ACCIONA) to support design management and delivery broadly across project work that is continuing as construction progresses.

Project Highlights

  • Australia’s first Renewable Energy Zone

    The Central-West Orana REZ is the first REZ formed in Australia and the first competitively sourced REZ transmission project building a template for the renewable energy zones to follow under the NSW Electricity Infrastructure Roadmap.

  • Involvement across the project life

    From design support during the competitive tender through to current delivery support for the network operator, Turnbull has built deep familiarity with the project across both phases.

  • Powering the transition

    From 2028 the network will carry power from 7.7 gigawatts of new wind and solar, helping keep the lights on and ease pressure on prices as coal-fired generation retires.

  • Building the backbone

    Around 240 kilometres of new 500 kV and 330 kV transmission line, energy hubs and switching stations across a 20,000 km² zone.

By the numbers

20,000 km²

REZ Area

$5.5B

transmission project

4.5 GW

initial capacity

2M+

homes powered

Previous

Batemans Bay Bridge
Next

Garfield Road East Upgrade