Commodity Demand — SA1: Thursday 20 August 2026
South Australia demand sits at 1,454 MW at 06:30 AEST, with the spot price at $101.02/MWh — steady through the last five dispatch intervals despite demand climbing from 1,348 MW to 1,454 MW. This follows an extreme overnight round trip: demand collapsed to a low of 364 MW around 13:20 AEST yesterday (13:20 UTC-adjusted, effectively 3:20am local) as prices briefly turned negative (-$1.10/MWh), before demand surged back above 1,890 MW by mid-morning yesterday, pushing prices into the $85-102/MWh band. That whipsaw illustrates SA's characteristically thin overnight demand base and how quickly the region can swing from negative pricing to triple-digit prices as load rebuilds.
Price sensitivity to demand in this region remains high but non-linear. Through yesterday's evening peak, demand climbed steadily from 1,403 MW to a high near 1,892 MW around 08:30 AEST, and prices tracked that build reasonably closely in the $85-110/MWh range — until a sudden spike to $375/MWh at 23:10 UTC (09:10am AEST) coincided with demand actually falling from 1,340 MW to 1,267 MW. This confirms price direction in SA is driven as much by generator availability and wind/solar output shifts as by raw demand levels — the $155-375/MWh spikes yesterday afternoon occurred during a renewables pullback, not a demand peak.
Today's forecast curve points to a firming price track: AEMO's forecasts show $87-101/MWh holding through the next few hours, stepping up to $130/MWh near midday trading (00:00 UTC target), then a pronounced afternoon risk window with forecast prices reaching $255/MWh around 09:30 UTC (7:30pm AEST) and $188/MWh at 11:00 UTC (9pm AEST) — consistent with the evening demand ramp typically seen in SA between 17:00-20:00 AEST as solar output fades. Current generation mix shows wind at 345 MW and battery discharge at 141 MW supplementing 603 MW of gas (OCGT and CCGT combined), with solar at zero given current 100% cloud cover and 12.1°C temperatures — limited rooftop PV support today keeps thermal and battery dispatch central to meeting the evening peak.
On the demand-side and system security front, an active MTPASA reserve notice flags Low Reserve Conditions risk for SA in July 2028, not an immediate today concern, but the 18 August system intervention (AEMO direction to Torrens Island for voltage control due to inadequate synchronous generation) signals ongoing tightness in synchronous plant availability that traders should watch if wind output drops sharply during today's evening ramp. Carbon intensity currently sits at 0.324 tCO2/MWh with renewable penetration at 44.6%, down from an overnight peak above 92% during the low-demand trough — a reminder that today's evening price risk period will likely coincide with lower renewable share as gas plant carries more of the incremental load.