Commodity Demand — SA1: Sunday 6 September 2026

South Australia demand sits at 1,344 MW as at 20:30 AEST, with spot price at $63.67/MWh — down sharply from this morning's peak but still elevated relative to the overnight trough. The day's demand-price relationship has been tightly coupled: overnight demand bottomed near 460-500 MW between 04:00-05:00 AEST, coinciding with prices collapsing to single digits and briefly negative territory (a low of $2.66/MWh at 00:00 AEST). As demand climbed through the morning ramp — from 767 MW at 06:30 AEST to a daily peak of 1,594 MW at 09:40 AEST — prices tracked in lockstep, breaching $100/MWh from 07:35 AEST and holding in the $92-105/MWh band for nearly five hours through midday.

The price sensitivity to demand is pronounced above the 1,300 MW mark. Once demand cleared 1,200 MW around 07:15 AEST, every 100 MW of additional load added roughly $10-15/MWh to spot price, with the tightest correlation visible between 08:00-11:00 AEST when demand held above 1,500 MW and prices sat consistently in the low-to-mid $100s/MWh. Wind generation of 904 MW is currently covering the bulk of demand alongside 129 MW gas OCGT and 123 MW gas CCGT, keeping the region's carbon intensity at 0.1227 tCO2/MWh and renewable penetration at 78.6% — though renewable share dropped as low as 39.7% around 08:00 AEST when demand peaked and thermal plant ramped to cover the shortfall.

AEMO's forecast trajectory points to a second demand-driven price event tomorrow morning. Forecast RRP climbs from $67/MWh at 07:00 AEST to $101-119/MWh through the 08:00-11:30 AEST window, mirroring today's pattern and consistent with the low wind potential (1.9 average) and modest solar potential (5.1 average) forecast for 7 September — thinner renewable output means thermal and interconnector flows will need to cover more of the morning ramp. Overnight into early Monday, forecast prices fall to near zero or negative between 00:00-06:00 AEST, reinforcing the five identified low-price load-shift windows (all under $4/MWh, saving up to $123/MWh versus peak) for flexible load or battery charging. Note AEMO issued and then cancelled a voltage-related intervention event in SA on 6 September (effective to 16:00 hrs), plus an active direction to Torrens Island B4 to synchronise and follow dispatch — both signal the system operator is managing tight local network conditions that could recur given similar demand and weak-wind conditions forecast today.