A coordinated transmission strategy could save Australia more than $30 billion over the next 25 years while fast-tracking industrial decarbonisation in the Pilbara, according to new modelling commissioned by the Clean Energy Finance Corporation.
The Marsden Jacob Associates report, Common User Transmission and Decarbonising Pilbara Energy Demand (PDF), found that a Common User Transmission Infrastructure (CUTI) approach would significantly reduce the capital burden, land use, emissions, and system complexity compared to the current fragmented energy network.
Currently, around 98 per cent of the Pilbara’s energy is fossil-fuelled, with industry in the region accounting for 40 per cent of Western Australia’s and 23 per cent of Australia’s industrial emissions.
The report compares a coordinated CUTI buildout with a ‘go-it-alone’ (autarkic) model, where each miner constructs and operates their own private infrastructure without sharing transmission assets.
In the CUTI scenario, the Pilbara’s North West Interconnected System would be expanded to support shared connections between generation hubs and major industrial loads.
The modelled CUTI scenario requires 2,362 kilometres of new and upgraded transmission lines – 407 kilometres less than the autarkic scenario – and delivers the same energy reliability and emissions outcomes with 29 per cent less new line construction and 21 per cent less land use.
CUTI also reduces the renewable generation and storage capacity required by 16 per cent, avoiding up to $26 billion in capital costs over the study period. Transmission capital savings are estimated at $4 billion. Total avoided costs from generation, storage, and transmission reach $30 billion.
The coordinated model would enable deployment of 4.0 GW of solar, 5.0 GW of wind, and 6.3 GW of batteries by 2035 under the base case. In high-demand scenarios, enabled by CUTI, those figures rise substantially to support electrification of not only mining but also LNG production and emerging industries like green hydrogen, ammonia, and iron.
Without CUTI, isolated grids would require roughly 19 per cent more generation and storage capacity to meet the same demand, due to inefficiencies in resource sharing across networks.
Diesel use in mining could be cut by 2.8 to 3.6 billion litres annually through electrification, representing $4.2–$5.8 billion in annual fuel savings. Further savings of $2.2 billion per year are expected from reduced gas use in electricity generation.
The emissions reduction benefits are substantial. The CUTI base case avoids an average of 24 million tonnes of carbon dioxide equivalent (CO₂-e) annually, valued at $7.6 billion a year. In the high-demand scenario, avoided emissions reach 35 million tonnes of CO₂-e annually, worth an estimated $10.4 billion.
“This is a clear opportunity to build it once and build it right,” said Rob Wilson, CEFC Executive Director – WA and Resources.
“The economic case is overwhelming. And the coordination required is both achievable and essential.”
The WA Government has taken early steps, awarding preferred developer rights for four priority transmission corridors in late 2024. The CEFC has flagged up to $3 billion in concessional finance through the federal Rewiring the Nation program.
The report warns the cost of delay is high.
“It takes years and many millions of dollars in early investment to identify corridors, conduct engineering, and secure approvals,” said Wilson.
The modelling underscores the need for urgent and unified action among governments, major miners, transmission developers and Traditional Owners to avoid replicating the costly, fragmented infrastructure patterns seen in the Pilbara rail sector.