South Australia raises alarm on green energy modelling miss

South Australia has grand plans to develop a major green energy industry, accusing the national operator of failing to deliver modelling to match its ambition.

South Australia’s ElectraNet has flagged concerns over flawed modelling undermining a shift to green energy. Picture: Getty Images

South Australia’s electricity operator has accused mainland states of “unduly influencing” a roadmap plotting a shift to green ­energy, warning its plan to build a $3bn transmission project and double renewable capacity may be sidelined due to conservative modelling.

ElectraNet, South Australia’s power transmission company, took aim at forecasts used in the integrated system plan developed by the Australian Energy Market Operator, saying it severely ­underestimated future electricity demand in the state.

South Australia, targeting 100 per cent renewables by 2027, forecasts a major jump in electricity demand over the next decade spanning mining, green iron, data centres to power AI along with desalination and hydrogen projects.

Industrial loads could deliver 15,000 megawatts of new connections compared with the state’s current average grid demand of 1300MW, with ElectraNet considering sign-off in March 2027 for its Northern Transmission Project at a cost of up to $3.3bn to help deliver the green shift.

ElectraNet said the next growth phase had been compromised by AEMO’s national scenario planning, which fails to take into account South Australia’s “advanced position” in the energy transition. “We are concerned that the jurisdictional transmission development arrangements and associated energy policies in NSW, Queensland and Victoria are unduly influencing AEMO’s national planning outlook,” ElectraNet said in its transmission ­annual planning report. “This exposes South Australia to risks to its energy security in the event of delays in proposed developments interstate and threatens to crowd out efficient generation and transmission developments that are needed in the state, underlining the need for a South Australian transmission framework.”

ElectraNet, which is operating the South Australian section of Transgrid’s 900km transmission line Project EnergyConnect, said AEMO’s progressive change scenario was not ambitious enough for the state.

Instead, it wants a bespoke green energy industry variant to reflect its desire to get behind initiatives such as Anthony Albanese’s Future Made in Australia policy.

ElectraNet said the NSW, Queensland and Victorian governments had introduced specific “jurisdictional arrangements” but that national approach was no longer fit for it own needs.

“If you’re a data centre or a miner and you weren’t guaranteed access to 100 per cent of the load you needed, why would you invest if you didn’t have access to the power,” ElectraNet chief executive Simon Emms told The Australian.

“We can see one scenario where South Australia achieves 100 per cent net renewable but then starts slipping back because we haven’t been able to build or connect new renewables to ­deliver the power needed.”

AEMO said it was speaking with the industry to review and update its electricity demand forecasting methodology, including ongoing discussions with ElectraNet. “We’re committed to ensuring our forecasts and planning insights support the best investment outcomes for consumers. Once finalised, this scheduled review of the demand forecast methodology will apply to upcoming planning publications,” said AEMO’s executive general manager for system design, Merryn York.

The state with the biggest renewables share is concerned a failure to deliver investment in green energy meant it would increasingly be forced to lean on supplies of gas as its main back-up energy source under an annual tender scheme known as the Firm ­Energy Reliability Mechanism.

Emergency diesel supplies were also made available for the state over summer to back up a grid that is increasingly struggling to coexist with record renewable penetration.

“We’re considerably ahead of the eastern states in that we’ve shut down all our coal, and we’re just seeing a different set of scenarios that seem to be evolving very rapidly. Now we need an agile planning framework that actually can take that into account,” Mr Emms said.

South Australia’s underlying electricity demand grew by 7.6 per cent to a new all-time quarterly high in the first three months of 2025 while system security directions were in place in the state for 61 per cent of dispatch intervals, reflecting volatility in its grid.

Originally published as South Australia raises alarm on green energy modelling miss