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HCC REZ network infrastructure upgrades
Hunter Central Coast Renewable Energy Zone
Network infrastructure upgrade
Ausgrid has partnered with the Energy Corporation of NSW (EnergyCo) to deliver network infrastructure upgrades required to support the Hunter-Central Coast Renewable Energy Zone (HCC REZ).

The HCC REZ is critical to ensuring the renewables potential of the Hunter-Central Coast area can be harnessed to deliver a reliable and sustainable energy supply for the region and represents the biggest enhancement to the Ausgrid network in more than 25 years. The Hunter-Central Coast REZ will have the capacity to transfer 1 gigawatt of renewable energy by 2028.

Being able to utilise our existing easements (electricity corridor) will help to minimise any potential impact to landowners who host this infrastructure.

Proposed works

Ausgrid’s proposed works include:

  • Upgrading 85km of existing sub-transmission power lines
  • Building two new energy hubs (substations)
  • Upgrading two existing energy hubs (substations)
  • Installing 18km new underground fibre optic communications cable

The proposed network infrastructure upgrades run from Kurri Kurri to Muswellbrook.

Hunter Central Coast Renewable Energy Zone Route Map October 2024

The HCC REZ planning and design process

Ausgrid will work closely with local community and regional stakeholders on the design and location of the HCC REZ infrastructure.

In order to minimise impact on landowners, the community and environment, where possible Ausgrid has determined the sub-transmission route by utilising the existing infrastructure corridor and Ausgrid substations.

  1. Early 2025 – mid 2025

    Refine design and ongoing site investigations.

  2. Mid 2025

    Review of Environmental Factors (REF) on public display.

  3. Mid - late 2025

    Detailed design and early works.

  4. Early 2026

    Start of sub-transmission line and substation construction works.

  5. Mid 2028

    Commission and move into operation and maintenance phase.

Final Review of Environmental Factors

Ausgrid has reviewed and considered against the requirements of the Environmental Planning and Assessment Act 1979 (EP&A Act) and has determined the Hunter-Central Coast Renewable Energy Zone Network Infrastructure project approved to proceed to construction.

Review of Environmental Factors 

Under the Environmental Planning and Assessment Act 1979, Ausgrid is the determining authority for this project. As part of the REF process, an environmental assessment (known as a Review of Environmental Factors, or REF) has been prepared to assess the potential environmental impacts associated with the project.

REF Determination Report

Hunter-Central Coast REZ Network Infrastructure upgrades Review of Environmental Factors (REF) – main document

Appendix A – Drawings

Appendix B – Consultation

Appendix C – EMF

Appendix D – Noise Impact Assessment

Appendix E – Geotechnical Investigations

Appendix F – Contamination Reports

Appendix G – Ecological Assessment Report

Appendix H – Bushfire Assessment Report

Appendix I – Aboriginal Heritage 

Appendix J – Landscape Character and Visual Impact Assessment 

Appendix K – Traffic Assessment

Appendix L – Submissions Report

Frequently Asked Questions

  • What is a renewable energy zone?
    Renewable energy zones (REZs) are the modern-day equivalent of traditional power stations. They are regions where new wind and solar power generation (sometimes called ‘farms’) are grouped, so electricity can be efficiently stored and distributed throughout NSW.
  • What is the HCC REZ?

    The HCC REZ is the Renewable Energy Zone, declared by the Minister for Energy in 2022, that stretches through parts of the Central Coast, Newcastle and Hunter regions.

    This region will become host to numerous solar, wind and hydro generation projects, as well as large-scale batteries, delivering an additional 1GW network transfer capacity to the grid.

  • Why has the Hunter-Central Coast area been chosen for a REZ?

    The Hunter and Central Coast regions have excellent renewable energy resources and can utilise existing power stations, rehabilitated mining land, electricity network infrastructure, port and transport facilities, and a skilled workforce, making it an excellent choice for a REZ.

  • What upgrade works will Ausgrid undertake?

    Ausgrid’s proposed works include:

    • Upgrading 85km of existing sub-transmission power lines
    • Building two new energy hubs (substations)
    • Upgrading two existing energy hubs (substations)
    • Installing 18km new underground fibre optic communications cable

    The proposed network infrastructure upgrades run from Kurri Kurri to Muswellbrook.

  • Why are these upgrades needed?

    To enable the increase in network capacity, upgrades need to be made to the existing infrastructure.

  • What role will Ausgrid play in the HCC REZ?

    In December 2024, Ausgrid signed an agreement with EnergyCo to be the preferred network operator to provide an additional 1GW of renewable energy transfer capacity by 2028. Ausgrid is responsible for the planning, design, construction, financing, operating and maintaining the network infrastructure of the HCC REZ project.

  • What will the new poles and wires infrastructure look like?

    Ausgrid will replace approximately 85km of existing sub-transmission lines between Kurri Kurri and Muswellbrook.
    Timber poles would be replaced with taller, stronger, metal monopoles, like this:

    Ausgrid HCC REZ Infrastructure

    • 66kV single pole structures
    • 132kV two pole structures
  • Where will the new substations be located?

    The proposed new substations are located in Muswellbrook (Sandy Creek substation) and Singleton (Antiene substation).

  • What substations will be upgraded?
    The existing Muswellbrook and Mitchell Line substations will be upgraded as part of the network infrastructure works.
  • Are the HCC REZ upgrade and the Hunter Transmission Project (HTP) the same thing?

    No. The HCC REZ upgrades refer to the sub-transmission infrastructure, while the Hunter Transmission Project (HTP) is a new transmission line (lattice towers) project, to connect the Central West Orana and New England REZs with the existing 500kV transmission network at Eraring.

HCC REZ Project Factsheet

Download a printable PDF version of this information.

Community Engagement

Ausgrid will work closely with the community and regional stakeholders during the design and delivery phases of the HCC REZ.

Planning, designing and building new electricity network infrastructure in the Hunter and Central Coast regions requires a detailed understanding of the area’s future large energy users and renewable energy projects.

Ausgrid is dedicated to working with local landowners, communities and businesses, to ensure we deliver social value to the communities that will host the infrastructure required.

  • Will landowners be affected?

    Yes, some landowners will be affected.

    Wherever possible, Ausgrid has used the existing infrastructure corridor to minimise potential impact on landowners.

    We have been in contact with owners of affected land will continue to work with these important stakeholders throughout the lifetime of the Project.

  • How will impacts to landowners be managed?

    EnergyCo and Ausgrid are committed to working with potentially affected landowners to minimise impacts on farming, mining and other business activities through the life of the project.

    During the planning phase, we want to understand farming operations and other possible property impacts or concerns to inform the design and location of the sub-transmission route.

    This could include avoiding dwellings, limiting construction access, and other amenity issues.


  • What traditional lands is the HCC REZ on?
    The HCC REZ will be hosted on the traditional lands of the Wanaruah, Awabakal, Worimi and Darkinjung people, cared for by their Land Councils, as well as the Bahtabah, Biraban, Mindaribba and Karuah Local Aboriginal Land Councils.
  • What consideration is given to the traditional owners?
    During ground investigations as part of preparing the Review of Environmental Factors (REF), Ausgrid (and our sub-contractors) will coordinate with the appropriate Local Aboriginal Land Committee (LALC), to have a cultural liaison representative present.
Customers and crews talking

Community drop-ins and project notifications

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Keep me informed

About Renewable Energy Zones

Find out about Renewable Energy Zones on the NSW Government EnergyCo Website.

Working with the community

Ausgrid is committed to working collaboratively with affected landowners and communities, to ensure our stakeholders benefit from hosting this infrastructure in their communities.