Hunter Transmission: seven shortlisted bidders across two packages, and construction due this year

The Hunter Transmission Project is the 110-kilometre northern section of the Sydney Ring: a new above-ground 500 kV transmission line between Bayswater and Eraring that closes the northern loop of New South Wales's existing 500 kV network.

Construction is expected to commence in 2026, with completion in 2029. EnergyCo is procuring it, and design and construction is going to competitive open market tender across two packages.

The shortlists

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 bidders on the line and three on the substations is a notably competitive field. Compare it to the two-bidder shortlists on Brisbane Stadium, Macquarie Point, Melton Hospital and Melbourne Airport Rail Stage 1.

Infrastructure Australia has identified limited competition among Tier 1 contractors as a driver of cost escalation nationally. Splitting the work into a line package and a substation package is a large part of why this project attracted seven bids — the two scopes need different capabilities, and separating them lets specialist substation contractors like Consolidated Power Projects bid without 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 Hunter Transmission Project closes the loop between two existing pairs of 500 kV lines:

• East — connecting Central Coast power stations at Eraring and Vales Point through to Kemps Creek substation in Western Sydney
• West — connecting Bayswater Power Station in the Upper Hunter to Mt Piper near Lithgow and Bannaby in the Southern Tablelands

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

Three sections, three different problems

The preliminary corridor divides into three, and each carries a distinct access and approvals challenge:

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

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

Transmission projects in New South Wales have consistently found approvals and landholder access to be the binding constraint on program rather than construction capability. A corridor running through mining, Defence and forest land avoids some private landholder issues but substitutes institutional ones that are no quicker to resolve.

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 — and the same regulated-asset mechanism on which the Australian Energy Regulator, on 1 September 2026, issued a preliminary refusal of Transgrid's bid to recover more than $1 billion of overspend on Project EnergyConnect. No project-specific cost for Hunter Transmission appears in the ANZIP record.

A Preferred Network Operator was selected in January 2025, following shortlisting in December 2024.

What to watch

1. Award of the two packages, and whether construction actually starts in 2026 — the year is nearly gone.
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. Approvals and access agreements across the mining complex, Defence land and three State forests.
4. Whether a project-specific cost is published, and whether it follows HumeLink into an AER cost-recovery process.
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 7 September 2026