Australia’s largest transmission project is nearing completion, positioning EnergyConnect as a central pillar of the nationwide energy transition.
Australia is undergoing an energy infrastructure revolution as the country looks to interconnect renewable energy assets and drive down wholesale and retail power costs.
According to Transgrid, this will require 2500km of new transmission lines to accompany the transmission network service provider’s (TNSP) existing 13,000km system.
The 1600km ‘Southern Superhighway’ makes up the lion’s share of this project pipeline, comprising three major projects across New South Wales, Victoria and South Australia.
As HumeLink recently constructed the first of its 800 transmission towers and Victoria to New South Wales Interconnector West (VNI West) is still in its planning phase, EnergyConnect is more than 90 per cent complete.
This 900km-long electricity interconnector – known as Australia’s largest transmission project – recently raised its final steel tower.
“EnergyConnect will help to bring Australia closer to the level of interconnection seen in leading energy markets overseas,” Transgrid executive general manager – major projects Gordon Taylor told Energy.
“It will link NSW with abundant renewable energy from South Australia and Victoria while strengthening the grid for all consumers.”
EnergyConnect’s transmission lines, which extend from the South Australian border to Red Cliffs in Victoria and up to Wagga Wagga in New South Wales, comprise 1508 towers and monopoles requiring 46,068 tonnes of steel including guyed, Danubio and self-supporting structures.
This installation required 10,385km of high-voltage conductor cabling, enough to span from Sydney to Perth three times.
A new substation has been built at Buronga in NSW, with a major expansion of the Wagga Wagga substation occurring. The world-class Dinawan substation, situated at Bundure where EnergyConnect and VNI West will interconnect, is the final piece to the project puzzle, with completion set for early to mid-2026.
Dinawan comprises two 120MVAr (reactive power output) synchronous condensers – weighing 300 tonnes each – installed in a 60m-long, 1200m² machine hall.
These machines will support voltage stability on the transmission network, providing system resilience services such as inertia, while four shunt reactors and two capacitor banks have been installed to increase power system efficiency and reduce energy losses in the transmission network.
EnergyConnect’s national significance
The Australian Energy Market Operator’s (AEMO) Draft Integrated System Plan (ISP), released in early December, called for 6000km of additional transmission lines to meet 2050 targets.
This will form the basis of the final 2026 ISP, set for release on June 25, which advises on the lowest cost path for generation, storage and transmission infrastructure in the National Electricity Market (NEM) to supply secure and reliable electricity by 2050.
Mentioned on numerous occasions in the Draft ISP, AEMO sees EnergyConnect as a central asset moving forward.
“AEMO confirmed that new transmission projects like EnergyConnect are an essential part of the optimal development path (ODP) to deliver the least-cost, most reliable energy system for consumers as coal retires,” Taylor said.
“These projects are a key part of the national energy transition, and are expected to repay their costs, support a healthier environment and a stronger economy.”
Taylor said EnergyConnect would also give industry and consumers “peace of mind” as coal generation winds down in NSW and help stabilise the grid at a time when reliability and affordability are national priorities.
So once EnergyConnect is up and running in late 2026, how will it be integrated into the NEM?
“Once the physical assets are complete and ready for energisation, AEMO will then determine the steps to integrate the project into the network ensuring the earliest benefit to consumers,” Taylor said.
Once integrated, Transgrid sees EnergyConnect connecting South Australia, NSW and Victoria to address inadequate interstate interconnections, while boosting transfer capacity by 800MW to meet growing demand.
EnergyConnect can also support the connection of up to 1800MW of renewable generation in NSW before the closure of coal-fired generators.
The first stage of EnergyConnect was successfully integrated in early 2025 through the staged release of 150MW of transfer capacity between the states, with further networking to ensue.
“Following construction, commissioning and internetwork testing of all network elements from Robertstown, South Australia through to Wagga Wagga, NSW, the full 800MW capacity is expected to be available to the National Electricity Market by late 2027,” Taylor said.
Industry takeaways
As the transmission bellwether of Australia’s energy transition, Taylor said many lessons can be learned from the EnergyConnect build.
Not only has Transgrid called on international experts for the project, but the local energy industry has also had the opportunity to boost its capacity and capabilities.
“The project has also helped train Australia’s own workforce in transmission line construction,” Taylor said.
“The Legacy 100 program has trained riggers and doggers to erect the towers and string the high-voltage conductor cabling. These personnel will be available to help deliver other new transmission line projects in Australia once EnergyConnect is completed.”
Charles Sturt University also benefited from $2 million in funding to support 100 engineering scholarships and help produce the nation’s next generation of engineers.
Launched in 2023, the Powering Tomorrow Together program enabled Transgrid to bundle procurement of highly sought-after long-lead electrical equipment for EnergyConnect, HumeLink and VNI West.
“The program has allowed Transgrid to purchase materials like substation equipment earlier and at a lower cost, enabling limited resources to be used across multiple projects,” Taylor said.
“Bundling these three major projects into the Powering Tomorrow Together program will yield savings of half a billion dollars in procurement, labour and inflation costs, and has shaved up to two years off delivery.”
EnergyConnect has seen Transgrid invest more than $264 million in supply contracts with 325 businesses across the Riverina, Murray and Sunraysia regions, demonstrating the project’s commitment to local communities.
The transmission project has also delivered valuable safety lessons.
“EnergyConnect’s strong performance in ensuring the health, safety and wellbeing of its workforce has set the benchmark for other major transmission projects in Australia,” Taylor said.
“Despite increased activity through major projects such as EnergyConnect to support the renewable energy transition, Transgrid’s total recordable injury frequency rate improved from 7.4 in the 2020–21 financial year (FY21) to a sustained rate below 3.5 since 2022.”
In April 2025, Transgrid came together with 14 other energy construction companies to sign an official charter to strengthen safety in major transmission projects being delivered in complex and remote environments.
Looking ahead
While EnergyConnect will be the first of three cornerstone transmission projects to come online across NSW, Victoria and South Australia, it’s been built with VNI West’s impending installation in mind.
“The transmission line from the Dinawan to Wagga Wagga substations has been future-proofed by designing it for 500kV operation, although it will be initially energised at 330kV until the 500kV network reaches Wagga Wagga,” Taylor said.
“This strategic approach enables a scalable increase in transmission capacity – from 800MVA (megavolt-ampere) at 330kV to 3200MVA at 500kV – supporting long-term energy needs.”
The uprated 500kV link will integrate EnergyConnect, VNI West and HumeLink to form a continuous southern backbone into the Sydney Ring – a proposed transmission network boosting supply capacity for Sydney, Wollongong and Newcastle.
This will provide the support infrastructure to unlock the NSW Government’s South West Renewable Energy Zone (REZ), set to underpin an added 3.56GW of clean energy generation capacity.
The South West REZ extends from the Dinawan substation in the east to the Buronga substation in the west, with four renewable energy and storage projects to have been granted access rights to the REZ.
This includes the Dinawan Energy Hub (battery, solar and wind), the Pottinger Energy Park (solar and wind), the Yanco Delta wind farm, and the Bullawah wind farm.
With EnergyConnect’s completion, focus will pivot towards the delivery of HumeLink and the advancement of VNI West, where community engagement continues.
If everything goes to plan, by the 2030s, NEM businesses and consumers will be the beneficiaries of a new-look energy ecosystem, placing a ceiling on wholesale and retail power costs.
This feature appeared in the March edition of Energy.
