Commodity Demand — SA1 — Wednesday 6 May 2026

South Australia's spot price sits at $44.02/MWh with demand at 1,411.7 MW as of 06:30 AEST — a moderate evening load level that has pushed prices up from the near-zero and negative territory that dominated throughout the day. The demand-price relationship today has been textbook: prices traded at or below $0/MWh for the bulk of the 11:00–19:00 AEST window as demand ranged between 1,330 MW and 1,510 MW, with wind generating 592.22 MW and the grid running at 83.67% renewable penetration and 0.08 tCO2/MWh carbon intensity. As daylight faded and solar output dropped to zero, evening load recovery began lifting demand from a 06:30 AEST trough near 1,315 MW toward the current level, and prices have responded in near-lockstep — rising from single digits at 05:00 AEST to the current $44 range as each incremental 50–100 MW of demand has required progressively more expensive gas dispatch to balance.

The overnight demand arc earlier this morning illustrates today's price sensitivity clearly. Demand bottomed near 1,018 MW around 03:40 AEST, when prices hit $0/MWh, then rebounded sharply toward 1,850 MW by 09:00 AEST as the morning ramp took hold — pulling prices up to the $37–$51/MWh range. That morning peak of approximately 1,867 MW at 09:10 AEST represents today's demand ceiling so far, and prices held between $37 and $52/MWh throughout, reflecting a generation stack where gas CCGT output at 115.56 MW is setting the marginal price as wind alone cannot cover full demand. Notably, AEMO directed Origin Energy's Quarantine PS Unit 5 to synchronise this morning for voltage control, with the direction cancelled at 13:00 AEST — confirming that low synchronous generation was a binding constraint during the midday low-demand window, independent of price signals.

The forecast trajectory points to a softer price outcome for the rest of today. Forecasts for the 07:00 AEST half-hour (21:00 UTC) are clustered around $18–$21/MWh, while the 07:30 AEST period carries a wider spread with some forecasts reaching $44/MWh — reflecting uncertainty over how quickly demand climbs through the morning ramp on this overcast 14.8°C maximum day. Overnight periods from 09:00 AEST onward are consistently forecast below $10/MWh, with many intervals showing negative prices as wind output is expected to remain strong (average wind potential of 4.7 today versus near-zero solar on 86% cloud cover). The demand-side picture is straightforward for today: no solar contribution, mild autumn heating load around 6.1 kW equivalent, and a demand profile likely to stay well below the morning's 1,867 MW peak — keeping afternoon prices suppressed and limiting the evening ramp's ability to push materially above the $40–$50/MWh range without a significant wind drop.