Commodity Demand — SA1: Sunday 13 September 2026
South Australia demand sits at 1,315 MW at 16:30 AEST, with spot price at $53.21/MWh — down from an evening peak of $91.25/MWh recorded at 16:40 local settlement time. The day's price-demand relationship has been pronounced: overnight demand troughed near 630-660 MW between 05:00-06:00 AEST, coinciding with sustained negative pricing (-$7 to -$19/MWh) as wind generation (now 740 MW) oversupplied the region. As demand climbed through the morning ramp, hitting 1,560 MW by 09:00 AEST, prices flipped hard positive, spiking to $143/MWh territory in AEMO's own forward estimates for tomorrow's equivalent window, and today's actual 09:00-13:00 AEST period saw sustained $55-80/MWh band pricing as demand peaked near 1,540 MW.
The price sensitivity to demand this morning was stark: a swing from 1,058 MW at 07:00 AEST to 1,560 MW by 09:00 AEST (a 47% increase) drove prices from -$7/MWh to over $50/MWh — an illustration of how thin SA's dispatchable margin gets once wind output can't cover the ramp. Current generation mix shows wind at 740 MW, gas OCGT and CCGT contributing a combined 142 MW, and battery output at 55 MW, with renewables at 84.8% and carbon intensity at 0.0881 tCO2/MWh, both improving materially from the 16:00-19:00 AEST window when renewable share fell to 66-72% and intensity rose to 0.16-0.19 tCO2/MWh as wind eased and gas-fired plant picked up the evening load.
Looking at the forecast trajectory, AEMO's dispatch forecasts show prices easing to the $55-60/MWh band through 21:00-22:30 AEST tonight before collapsing toward $10-20/MWh overnight as demand falls away — consistent with the load-shifting windows flagged for 00:30-05:00 AEST tomorrow, all priced near $10-16/MWh with zero renewable curtailment risk. A minimum system load (MSL1) warning is active for 19 September, with demand forecast to dip below -111 MW (negative operational demand) between 12:00-14:30 AEST that day, reinforcing the pattern of extreme midday oversupply risk on high-solar, low-load days. Separately, two active AEMO directions on Torrens Island and Quarantine PS units for voltage support (both extended to 08:00-14:00 AEST today) reflect ongoing thin synchronous generation margins in SA, a factor traders should watch given its history of triggering price volatility during rapid demand ramps.