Commodity Demand — SA1: Wednesday 5 August 2026
South Australia's spot price sits at $170.83/MWh at 06:30 AEST with demand at 1,585 MW, well down from the overnight peak. The current interval caps off a volatile night: demand climbed steadily from an evening low near 1,390 MW to an early-morning peak of 2,384 MW at 08:50, dragging prices from the $100-140/MWh band up to a cluster of $250-360/MWh outcomes between 03:00 and 09:00. The tightest correlation is visible in that morning ramp — as demand crossed 2,200 MW around 07:30, prices held above $250/MWh for nearly 90 minutes, with a spike to $359.45/MWh at 05:50 coinciding with demand of 1,928 MW and generation intensity climbing to 0.44-0.50 tCO2/MWh as gas (OCGT and CCGT combined around 1,163 MW) covered the shortfall while wind output was constrained.
Demand has since eased back through the 09:00-16:00 period, falling from the 2,384 MW peak to a current 1,585 MW, tracking prices down through the $100-180/MWh range for most of the afternoon and evening. This inverse relationship — price collapsing as demand falls below 1,600 MW — reflects SA's reliance on gas peaking plant at the margin; once demand drops below roughly 1,700 MW, cheaper mid-merit gas and battery output (currently 125 MW) cover the load without needing OCGT to set price.
AEMO's five-minute forecast points to a further easing overnight, with forecast RRP dropping to $101/MWh by 23:00 and into the $45-80/MWh range through the early hours of Thursday 6 August as demand troughs. However, forecasts show a sharp reversal from 07:00 onward tomorrow, climbing to $176.78/MWh by 08:00 and peaking near $283.99/MWh at 13:30 — consistent with the same demand-driven pattern seen this morning. Traders should watch the 07:00-14:00 window for repeat volatility, particularly given tomorrow's forecast cloud cover (56%) will suppress solar potential to just 3.7%, reducing midday relief and keeping gas plant in the price-setting position longer than typical winter days. No load-shedding directions or demand-side interventions are currently active in SA, though the region's recent history of AEMO directions to Torrens Island units (early August) signals ongoing voltage-support requirements that could resurface if demand approaches the 2,400 MW mark again.