Commodity Demand — SA1: Sunday 21 June 2026

South Australia is at $3,130/MWh at 06:00 AEST on a current demand of 1,597 MW, with prices subject to AEMO review under the Manifestly Incorrect Inputs provisions for the 06:15–07:00 AEST window. Demand has climbed sharply from an overnight trough of around 686 MW (circa 13:00 AEST) through the morning ramp, tracking in lock-step with price escalation: as demand crossed 1,800 MW around 17:30 AEST prices broke above $295/MWh, and the subsequent push toward 2,058 MW by 19:10 AEST drove intervals to $490–$20,300/MWh during a sustained high-price episode between 19:35 and 20:45 AEST. The grid stress score of 64.5 reflects this supply tightness, with gas OCGT (849 MW) and gas CCGT (605 MW) carrying the bulk of the 1,597 MW load, wind contributing just 44 MW, solar zero, and battery dispatching 109 MW — renewable penetration sitting at 9.5% and carbon intensity at 0.5279 tCO2/MWh.

The demand-to-price relationship across today's data is highly non-linear above 1,700 MW. Below that level, prices ran broadly in the $250–$415/MWh band from 17:00–19:30 AEST; once demand exceeded 1,980 MW in the 08:30–10:30 AEST window (UTC+9:30 offset), prices spiked repeatedly to $3,290–$20,300/MWh. A critical network factor is compounding this sensitivity: the Roseworthy–Templers 132 kV line has been out since 09:30 AEST, invoking constraint set S-TPRS and tightening interconnector headroom on V-SA and V-S-MNSP1 (Murraylink). That constraint reduces SA's ability to import from Victoria precisely when local generation is stretched, steepening the price response to incremental demand increases.

The forecast trajectory into this morning points to continued elevated pricing. The 07:30 AEST interval is forecast at $567/MWh, 08:00 AEST at $713/MWh, and 08:30 AEST at $717/MWh — consistent with the pattern seen this morning where demand rebuilds through the working-day ramp from a current 1,597 MW toward the 1,900–2,050 MW range that triggered extreme prices. Today is Monday, which typically anchors a stronger commercial load profile than the weekend pattern visible in the overnight data. Weather is not a relief factor: temperature sits at 5.2°C with a heating demand index of 12.8 and 85% average cloud cover forecast for today, suppressing solar generation and sustaining heating load through the morning peak.

Prices are forecast to ease back into the $138–$350/MWh range from 13:00 AEST onward as demand falls away from the midday peak, with the lowest-cost windows clustered between 00:30 and 06:00 AEST tonight at $139–$195/MWh. Traders and demand-response operators should note that the Roseworthy–Templers outage status remains the