Commodity Demand — SA1: Wednesday 12 August 2026
South Australia's spot price sits at $68.58/MWh at 06:25 AEST with demand at 1489 MW, down from the overnight evening peak of 2081 MW at 18:35 AEST (local time) that pushed prices to $107/MWh. Demand has been on a steady overnight decline from that peak through the early hours, bottoming near 913-1000 MW between 11:40 and 12:15 AEST with prices frequently touching zero or slightly negative (as low as -$6/MWh), reflecting the region's high wind output overnight. The current price-demand relationship shows clear sensitivity: every 100 MW of demand movement corresponds roughly to $8-15/MWh of price swing in the sub-2000 MW range, steepening sharply above 1900 MW where gas peaking plant sets the marginal price.
Wind generation currently sits at 784 MW against total generation of approximately 1023 MW, putting renewable penetration at 77.8% and carbon intensity at 0.124 tCO2/MWh — both easing from the stronger 90%+ renewable readings recorded between 21:00 and 07:00 AEST when wind was more dominant and gas output minimal. Solar is at zero given the pre-dawn hour, with battery storage contributing a modest 11.5 MW. Gas CCGT (131 MW) and OCGT (96 MW) are covering the shortfall as wind eases from its overnight highs and demand builds into the morning ramp.
The forecast trajectory points to a volatile day ahead. AEMO's own forecasts show prices climbing through the morning, hitting $130-170/MWh in the 06:00-10:00 AEST window as demand ramps, then surging further to a forecast peak range of $174-191/MWh between 10:00 and 11:00 AEST evening peak equivalent (20:00-21:00 UTC target times correspond to Thursday afternoon/evening AEST peak load). Prices are expected to ease to $100-130/MWh through the afternoon before a renewed evening peak push toward $130/MWh from 16:00-17:00 AEST. This pattern is consistent with the low wind/solar potential outlook for today (avg wind potential just 0.9, solar potential 2.4, cloud cover 78%), meaning gas and interconnector flows will likely need to cover a larger share of the afternoon and evening peak than yesterday, reinforcing the sharper price response to demand increases above 1900-2000 MW.
On demand-side risk, AEMO's MT PASA reserve notice flags unserved energy risk in SA between August 2027 and August 2028, with Low Reserve Conditions specifically declared for July 2028 — not an immediate concern for today's trading but relevant context for anyone assessing SA's medium-term reliability margin. No active demand-response or load-shedding notices are in effect for today's trading period; the most recent SA-specific market intervention (08 August) has been cancelled and normal market conditions apply.