“We can do that:” AEMO says power system can be run on 100 pct renewable energy
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Giles Parkinson
Jul 29, 2025
Renewables
The head of the Australian Energy Market Operator says he confident that the country’s main grid – and its smaller ones for that matter – can be run on 100 per cent renewable energy.
“At AEMO, I set an ambition in 2021 for us to understand what it takes to run a power system on 100% renewable energy,” Westerman said in an address to the Clean Energy Summit in Sydney on Tuesday.
“And today, we’re confident that with targeted investments in system security assets, we can do just that. I’m incredibly proud of this, but the future is coming at us fast and those system security investments are needed urgently.run a power system on 100% renewable energy.”
This is, of course, not the first time that Westerman has said this.
But it bears repeating whenever the comments are made because, too often it is the voices of technology denial, urged on by ideologues and vested interests, and amplified in much of mainstream media, who insist this is simply not possible, particularly in light of the blackouts in Spain in April.
AEMO has been working on an engineering roadmap for several years to put in the protocols to allow renewables to account for 100 per cent of electricity demand – initially, at least, for short periods – without threatening grid security.
There have been periods when the amount of solar and wind that could have been generated would have been more than overall grid demand, but the current highest penetration level on the country’s main grid has been 75.6 per cent, limited by voluntary withdrawal because of negative prices, or network limitations and grid security issues.
In the isolated grid in Western Australia, the maximum penetration of renewables has been 85 per cent, Westerman says. States like South Australia reach more than 100 per cent renewables almost every day, but are able to export surplus power to neighbouring states.
“That is right at the top end of major international power systems,” Westerman said.
AEMO’s most recent engineering update identified the key tasks being pursued in the next year. Ultimately, it seems, grid forming inverters are expected to deliver most of these services – although Westerman still insists not all of them – with the gap to be filled by spinning machines such as synchronous condensers and traditional gas turbines with a clutch.
Westerman notes that the grid operator is already dealing with extreme variations, particularly in consumer energy resources such as rooftop solar, which can at times meet all demand in states like South Australia and create an unexpected new challenge, dealing with periods of “minimum demand.”
He noted the experience in Spain, the country-wide blackout in late April that was quickly blamed on renewables, but which is likely to focus mostly on management and preparedness, the sort of technologies that are or are not deployed (grid forming inverters being one of them), and system controls.
“It’s a stark reminder that a secure and reliable supply of energy is the backbone of modern society,” he said. “Power systems are complex, and detailed investigations are still ongoing, but it’s very clear that there was not just one single event or root cause.
“Up to 12 simultaneous issues have been identified as contributing to the cascading trips of generation, and ultimately the complete collapse of the power system.
“Their system saw: swings in voltage; reductions in reactive power; unexpected behaviour of grid connected equipment; oscillations in system frequency, and more …. all things that we broadly put in the category of system security.”
“And while I’m sure there will be learnings from the Spanish event, AEMO’s annual assessment process already clearly identifies any system security shortfalls in the planning horizon, which then require remediation, typically by transmission networks and planners.”
Westerman says that investment in wind, solar and storage is increasing, and he NEM has historically added between 3-4 GW of new generation and a new wave of projects is expected to be delivered in the years ahead.
The AEMO connections scorecard, released last week, showed a record 4.4 GW across 29 projects were commissioned to full output in the last 12 months, and another 9 GW across 37 projects had their registration approved.
“And a staggering 15.7 GW across 60 projects had their application to connect approved,” he said. “Those projects in the earlier stages clearly need positive investment decisions, planning and community consultation, and construction.
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