Commodity Demand — SA1: Monday 14 September 2026

South Australia's spot price sits at $69.18/MWh as at 20:30 AEST, with demand at 1,380 MW — tracking through the evening secondary peak after demand crested at 1,777 MW around 08:50-08:55 this morning. That morning peak coincided with the day's highest sustained pricing, with 5-minute intervals hitting $101.04/MWh at 08:15 and again at 08:30 as demand climbed past 1,700 MW. Price sensitivity to demand is pronounced today: as demand fell from the 1,777 MW peak down to the 1,350-1,450 MW range through midday, prices eased into the $30-55/MWh band, before dropping sharply as demand tapered toward 1,290-1,330 MW in the late afternoon, with several intervals between 17:00 and 19:30 AEST printing single digits ($5.23-$11/MWh) as wind generation (currently 988 MW) covered the bulk of load.

Demand is now rebuilding into the evening peak, up from a low near 1,290 MW at 18:10 to 1,380 MW currently, and price has responded accordingly, climbing from single digits to the high $60s over the past 90 minutes. AEMO's forecast has the region's price staying firm in the near term (~$67.53/MWh forecast for 21:00 AEST) before falling into negative territory overnight from 22:00 AEST onward, with forecast prices as low as -$50.60/MWh around 04:00 AEST tomorrow — consistent with minimum demand conditions and strong overnight wind output.

Generation mix at the current interval shows wind supplying 988 MW (71% of the 1,384 MW total generation), with gas OCGT (168 MW), battery (166 MW) and gas CCGT (103 MW) filling the balance — renewable penetration sits at 80.97% and carbon intensity at 0.1121 tCO2/MWh. Traders should note two active AEMO market notices relevant to today's supply-demand balance: a direction issued to Torrens Island (TORRB4) to synchronise and follow dispatch from 07:30 AEST tomorrow for voltage control, and a foreseeable intervention flagged for SA from 09:30 AEST tomorrow, also voltage-related. These reflect thin synchronous generator coverage during high-wind, lower-demand periods rather than an energy shortfall, but they add operational uncertainty around tomorrow's morning ramp and could introduce basis risk in the 08:00-10:00 AEST window given today's forecast price already implies a steep swing from negative overnight pricing to $101.02/MWh by 09:00 AEST tomorrow.