AEMO governance review lands as NEM supply picture tightens into winter
Spot prices stay capped by batteries and rooftop solar, but thin investment and coal outages keep the NEM's supply cushion fragile.
South Australia's day-ahead power spot cleared at A$107.78/MWh on Monday (2026-08-10), with the market settling without emergency intervention for the first time in weeks following a volatile June in which batteries ran critically low and interconnector flows proved the last line of defence.6 The calm is real, but its foundations are not.2
A governance review of the Australian Energy Market Operator has concluded the agency needs an overhaul as its workload expands under the energy transition, adding uncertainty to how the NEM will be managed through the next phase of coal retirements. The review's findings land as AEMO's own CEO has acknowledged the operator is already running a far more complex machine than the one designed around a clear boundary between supply and demand.4
The supply side has grown more responsive but less predictable. AEMO now reports 2.8 GW of behind-the-meter batteries that respond to prices without being centrally dispatched, the equivalent power capacity of Eraring Power Station.2 That fleet can flood the market with supply when prices spike, capping upside. But it also means the operator's visibility into available capacity is worse than it was with a handful of large synchronous generators.
The Clean Energy Council's 2026 annual report quantified the investment gap. Utility-scale renewable generation investment fell 50% to $4.4 billion last year, with onshore wind commitments dropping 57%.3 New utility-scale renewable capacity reaching financial close in 2025 totalled 2.3 GW, about half what Grattan Institute senior fellow Tony Wood says is needed to meet the government's 82% renewables target.3
The demand side is not standing still. Under AEMO's Step Change scenario, data centre consumption triples by 2030 to 6% of NEM electricity.3 The fourth quarter of last year set a record for power demand in Australia's biggest grid, even as renewables supplied more power than fossil fuels across the country.1
Households have stepped in where developers have pulled back. Private investment of almost $10 billion over 11 months deployed over 400,000 home battery systems, a pace reshaping the demand curve from the bottom up.3 Every one of those batteries charges on cheap solar and discharges into the evening peak, quietly undercutting the wholesale price signals that might otherwise attract utility-scale capital.
Summer offered a warning about the fragility underneath. Ninety unscheduled coal outages across summer 2025-26 left 25% of coal capacity offline at any given time across Queensland, New South Wales and Victoria.3 The fleet that was supposed to anchor reliability is now an intermittent resource.
The sequence in South Australia in late June illustrated how quickly the new dynamics can compound. On Saturday (2026-06-27) net transfers into the state of 300-400 MW relieved pressure on batteries just after 8pm, buying the fleet time while it still held moderate charge.6 But on Sunday (2026-06-28) batteries began with about 1,000 MWh less energy in storage than the day before and were substantially depleted before forced outflows to Victoria reversed.6 The whole episode showed how dependent the system has become on interconnector flows aligning at the right moment — a coordination problem that AEMO's current governance structure was not built to handle at this frequency.
That combination of declining new-build investment and increasingly unreliable coal is why the governance review carries market weight beyond the institutional. AEMO is being asked to run a more volatile system with less central control, and the review's finding is that its governance structures have not kept pace.4
The spot market has cleared at A$107.78/MWh in South Australia on Monday (2026-08-10) with no intervention, and consensus signals point to continued neutral-to-soft pricing. But the forward picture is where pressure accumulates: investment in generation is running at half the required rate, coal is failing at a quarter of capacity, and the operator tasked with managing the transition is being told its governance needs a fix.
The next concrete signal is AEMO's summer readiness statement, due in the coming weeks. In late November 2024, the operator delayed that statement because managers were busy keeping New South Wales from blackouts in spring.5 This year the questions will be sharper: how many of those 2.8 GW of behind-the-meter batteries will actually respond when called, given that June showed them running empty before interconnector relief arrived.6,2