Commodity Demand — SA1: Thursday 10 September 2026
South Australia's spot price sits at $89.85/MWh at 06:30 AEST with demand at 1395 MW, down from the overnight evening peak of ~1793 MW recorded around 09:15-09:50 (AEST equivalent, 19:15-19:50 UTC on 10 September) when prices held in the $80-100/MWh band. The overnight trough tells the real story: as demand collapsed to below 200 MW between 03:00-04:00 AEST, prices fell deeply negative, printing as low as -$294.71/MWh, with a sustained run of sub-zero pricing from roughly 23:00 through 06:25 AEST. This is a textbook high-wind, low-demand dynamic — wind generation is currently supplying 1302 MW against total demand of 1395 MW, effectively saturating the region and pushing surplus output into negative-price territory whenever demand drops below wind output levels.
The demand-price relationship today is unusually tight and non-linear. Small demand movements around the 1300-1800 MW band are driving price swings of $20-40/MWh, evident in the 08:00-09:30 AEST window where demand climbed from 1503 MW to 1793 MW and prices lifted from $94.50/MWh to a session peak above $100/MWh. Once demand eased back below 1500 MW through the afternoon, prices settled into the $60-85/MWh range. AEMO's forecast curve points to a firmer trajectory into the evening: forecast prices climb from $72.62/MWh at 21:00 AEST to a local peak of $98/MWh at 22:00 AEST, before demand-driven softening pushes prices negative again overnight (-$1 to -$15/MWh forecast from 23:30 through 06:00 AEST tomorrow), consistent with the same wind-oversupply pattern.
Looking at today's demand trajectory, forecast prices then rebound sharply from 07:00 AEST, lifting to $60.86/MWh and climbing steadily to a forecast peak around $110.53/MWh at 09:30 AEST, coinciding with the typical morning demand ramp. Prices are expected to stay elevated in the $95-110/MWh range through the middle of the day into early afternoon (10:00-14:00 AEST), reflecting sustained demand alongside more moderate solar potential (33.2% average) forecast for the day. Wind potential is forecast at just 0.6% for today, a marked drop from the current 90%+ renewable penetration, meaning the price floor seen overnight is unlikely to persist once wind eases and demand rebuilds through the morning.
No demand-side market interventions are currently active for SA. The relevant notices this period relate to voltage-driven generator directions (AGL's Torrens Island units under direction for system strength, now concluded) and settlement residue constraints on the VIC-SA and NSW-VIC interconnectors — these affect interconnector flow economics rather than SA demand directly, but are worth monitoring given SA's reliance on Victorian imports when local wind output drops later today.