Hunter Transmission Project approved: seven shortlisted tenderers and construction from 2027

The Hunter Transmission Project is the 110-kilometre northern section of the Sydney Ring: a new overhead 500 kV transmission line between Bayswater in the Upper Hunter and Olney in the Lower Hunter, near Eraring, connecting New South Wales's existing 500 kV lines into a ring.

The NSW Government granted planning approval on 28 July 2026. EnergyCo now expects early works to begin in late 2026, main construction to start in early 2027 and completion in 2029; the NSW approval announcement noted construction remains subject to Commonwealth Government approval. EnergyCo is procuring design and construction across two packages, and Transgrid is the preferred network operator.

The shortlists

EnergyCo announced seven shortlisted tenderers across the two packages in January 2025. As at early October 2026, no contract award had been announced for either package.

Transmission line package:

• ACCIONA and Genus Joint Venture
• Downer Utilities Australia

• Gamuda and Seymour Whyte Joint Venture
• UGL Engineering and CPB Contractors Joint Venture

Substation package:

• ACCIONA and Genus Joint Venture
• Consolidated Power Projects Australia
• UGL Engineering

Four teams on the line and three on the substations is a competitive field, with ACCIONA and Genus, and UGL, appearing on both lists.

Splitting the work into a line package and a substation package separates two scopes that need different capabilities, and lets a specialist substation contractor such as Consolidated Power Projects compete in its own right rather than partnering into a transmission consortium.

That is the packaging argument in practice, and it is worth noting on a project that has not yet started construction rather than only in hindsight.

What is being built

The new line runs from Bayswater to Olney, where it joins the existing 500 kV line between Eraring and Kemps Creek in Western Sydney. EnergyCo says connecting the state's existing 500 kV lines will create a 500 kV ring of transmission infrastructure.

Scope includes two new switching stations, at Bayswater South and Olney, plus upgrades to the existing Bayswater and Eraring substations.

Three sections, three different problems

EnergyCo's 2024 corridor update divided the route into three sections, each with a distinct access and approvals challenge:

The approved route was refined further: about 90 per cent of it now sits on mining, energy and government-owned land, the corridor moved south of the Hunter Valley Operations mine expansion, and directly affected private properties fell from around 70 to fewer than 20. South of Broke it passes through the Pokolbin, Corrabare, Watagan and Olney State forests.

For contractors, this is the substance of the job. Building 110 kilometres of 500 kV line across an operating mining complex, Defence land and four State forests is an access, environmental and stakeholder exercise as much as a construction one.

A switching station inside a State forest is an unusual requirement, with its own clearing, access road, fire management and environmental conditions.

A corridor running mostly through mining, energy and government land avoids most private landholder issues, and relies instead on access arrangements with those institutional landholders.

Funding

Hunter Transmission is one of eight projects sharing the combined $7.8 billion Federal and New South Wales package — $4.7 billion from the Commonwealth's Rewiring the Nation plan and $3.1 billion from the New South Wales Transmission Acceleration Facility.

That is the same funding package that covers HumeLink. Hunter Transmission is classified as a priority transmission infrastructure project under the NSW Electricity Infrastructure Investment Act 2020. EnergyCo has not published a project-specific cost.

EnergyCo signed a commitment deed with Transgrid as preferred network operator on 29 January 2025, covering delivery, operation and maintenance. The appointment remains subject to a final delivery contract, award of the design and construct packages and other approvals.

What to watch

1. Award of the two packages and Transgrid's final delivery contract, ahead of early works in late 2026 and main construction in 2027.
2. Whether the same bidder wins both. ACCIONA and Genus and UGL appear on both shortlists; a single winner across line and substations would reduce interface risk but also reduce the competitive benefit of splitting the packages.
3. Commonwealth approval and access agreements across the mining complex, Defence land and four State forests.
4. Whether a project-specific cost is published.
5. The Sydney Ring as a whole — Hunter Transmission is the northern section, and the southern sections carry their own procurement.

Published 1 September 2026 · Updated 4 October 2026