Commodity Demand — SA1: Monday 24 August 2026
South Australia's spot price sits at -$1.00/MWh at 06:30 AEST, with demand at 1,516 MW — well below the overnight peak of 2,147 MW recorded around 18:30 AEST yesterday. Wind generation of 1,620 MW is comfortably covering current demand, pushing the region into negative pricing territory for the third consecutive half-hour, following a run of sub-zero intervals between roughly 05:00 and 06:30 AEST (-1 to -25.52/MWh). This confirms the now-familiar SA pattern: whenever wind output exceeds demand and interconnector export capacity to Victoria is constrained, prices collapse regardless of underlying demand strength.
The price-demand relationship today is asymmetric and driven far more by wind availability than by load. Overnight, demand climbed steadily from 1,389 MW at 06:30 AEST yesterday to a peak near 2,147 MW around 18:30 AEST, and prices tracked that climb reasonably well, spiking to $262/MWh at 08:50 AEST peak-equivalent-time on tight supply. But through the low-demand overnight trough (1,700-1,900 MW), prices were volatile between $12 and $156/MWh, and now at similarly low demand levels, we've swung negative. This tells traders that SA pricing this cycle is being set by wind output and export constraints, not by the demand curve itself.
AEMO's forecast trajectory points to a sharp reversal ahead. Forecast RRP holds negative through to around 12:30 AEST (-$6.02 to -$4.21/MWh), consistent with continued high wind output and soft demand. From there, prices are forecast to climb steadily: $36.54/MWh by 13:30 AEST, $82-96/MWh through the afternoon, and a step up to $101-130/MWh from 17:30 AEST as demand rebuilds into the evening peak — mirroring yesterday's pattern where the 18:00-22:30 AEST window produced the day's highest prints ($156-262/MWh). Traders should watch the 17:00-19:00 AEST ramp closely; that's where wind typically fades faster than demand rises, and yesterday's data shows this transition window is where volatility concentrates.
On demand-side factors, AEMO's active market notices flag no unusual load-shedding or demand-response actions in SA, but there is an ongoing voltage-support requirement — directions issued to AGL's Torrens Island and Barker Inlet units to maintain synchronous generation for voltage control, reflecting the system's need for conventional plant even during high-wind, high-renewable intervals (renewable penetration is currently 97.4%, carbon intensity just 0.0128 tCO2/MWh). This underlying synchronous generation requirement is a structural feature to monitor, as it can constrain wind dispatch and contribute to price volatility independent of demand levels. Overnight low-demand periods (02:00-06:00 AEST) remain the most attractive load-shifting windows today, with forecast prices as low as -$6/MWh, before the evening ramp reasserts upward pressure.