Wallumbilla Gas Climbs to A$10.83/GJ as NEM Wholesale Prices Settle Near Multi-Year Lows
NEM wholesale electricity fell 47% year-on-year in Q2 2026 and east coast gas hit its lowest quarterly average since 2021, while a record capacity pipeline nears commissioning.
Wallumbilla spot gas rose 4.13% to A$10.83 per gigajoule on Monday (2026-09-21), a sharp intraday move that stands out against the structurally weak prices that defined much of 2026's first half in Australia's east coast energy markets.
East coast wholesale gas averaged A$9.08 per gigajoule in Q2 2026, the lowest quarterly average since Q2 2021, driven by softening domestic demand, according to a JD Supra market review covering the period. NEM-wide electricity spot prices averaged A$74 per megawatt-hour over the same quarter, down A$66/MWh, a 47% fall from Q2 2025.4
That degree of repricing across a full quarter reflects structural shifts in the generation mix rather than temporary demand softness alone. Grid-scale battery storage increasingly shaped intraday price outcomes, absorbing and releasing energy in ways that eroded the price spikes that once padded quarterly averages. Queensland wind output rose 80% to a new all-time high average of 842 MW in Q2, adding large volumes of near-zero marginal cost generation at peak periods.4
Yet South Australia was the exception. It was the only NEM region to record material price volatility through Q2 2026, reflecting SA's greater exposure to wind variability and its still-incomplete storage buffer. WattClarity noted in June (2026-06-21) that prices had been "largely subdued" across the NEM for months, describing the period as a "volatility drought" and citing large-scale battery expansion as a key factor. Brief episodes did emerge in Tasmania and South Australia in late June (2026-06-21 and 2026-06-22), breaking what had otherwise been a prolonged stretch of suppressed intraday price action.2,4
The 2026 Electricity Statement of Opportunities, published by AEMO in August (2026-08-24), added a longer-range dimension. Around 40 GW of new generation and storage is now committed or anticipated across the NEM, with a further 33 GW backed by government programs. The NEM's total installed base stands at 77 GW. Some 9 GW of new capacity was connected in the 12 months to August 2026, a new yearly record, and 24 GW moved into committed or anticipated status since the 2025 ESOO, a substantial shift in the forward pipeline in a single year.5
AEMO's medium-term planning runs, published Tuesday (2026-08-04) ahead of the ESOO release, flagged potential supply shortfalls in Victoria and South Australia over coming months. The MT PASA modelling identified specific stress periods rather than a broad reliability deficit, and WattClarity cautioned that the headline shortfall counts warrant careful interpretation, noting that "the devil is in the details" of the underlying modelling. Still, wholesale NEM prices showed little immediate reaction to the MT PASA warnings through Q2, suggesting the market placed greater weight on the incoming build pipeline than on near-term shortfall risk.3
August (2026) also produced a surge of regulatory activity. Data centres came under substantial scrutiny from both the Australian Energy Market Commission and the New South Wales government, with the AEMC publishing advice and NSW releasing new connection guidelines. A JD Supra analysis from September (2026-09-09) described the moves as signalling a high level of government intervention in how large new loads interact with the grid.6
AEMO's Draft 2026 Integrated System Plan, presented at Australian Energy Week in June (2026-06-11), estimated the total cost of the energy system could fall by A$7.2 billion if consumer energy resources respond adequately to market signals — placing demand flexibility, not additional generation build, at the centre of the ISP's cost case.1
But Monday's (2026-09-21) Wallumbilla move arrives before any Q3 data can confirm whether east coast gas prices have genuinely firmed from the Q2 lows. How quickly the 40 GW committed pipeline translates into commissioned plant, and whether Victoria and South Australia navigate the shortfall periods identified in the MT PASA runs, remain the forward signals that separate a durable price recovery from a seasonal single-session bounce.3,5