Commodity Demand — SA1: Tuesday 4 August 2026

South Australia's spot price sits at $130.44/MWh at 06:30 AEST as demand climbs to 1,674 MW, up from an overnight low near 1,270 MW around 04:35 AEST. The morning ramp is well underway: demand rose from roughly 1,320 MW at 04:00 AEST to a peak of 2,282 MW at 06:55 AEST, driving prices with it — the $80-100/MWh band overnight gave way to a spike to $170.10/MWh at 06:15 AEST and $172.95/MWh at 07:00 AEST as demand pushed through 1,600-1,660 MW. This morning demand peak has since eased back toward 1,500-1,650 MW through the evening period, with prices oscillating between $130-170/MWh.

Price sensitivity to demand is pronounced today. Wind generation is contributing 291 MW and solar is at 0 MW (100% cloud cover, zero solar potential per current weather), leaving gas (OCGT at 444 MW, CCGT at 298 MW) to cover the bulk of the ramp. With renewable penetration at just 28.4% and carbon intensity at 0.4195 tCO2/MWh, each MW of demand growth is being met predominantly by gas-fired plant, which shows up directly in price — every 100-200 MW swing in demand this morning corresponded to $20-40/MWh price movements.

The forecast trajectory points to a much sharper evening peak ahead. AEMO's forecasts show prices climbing steeply from 18:30 AEST ($119/MWh) through a forecast spike to $375/MWh at 19:00 AEST and $489/MWh at 19:30 AEST, before an extraordinary forecast peak of $496.72/MWh at 20:00 AEST — coinciding with the typical SA evening demand peak as solar drops to zero and heating load builds (heating demand index at 11, temperature at 7°C). This mirrors the pattern already seen in the current dataset's overnight peak on 4 August, where demand cleared 2,282 MW and price held near $130-145/MWh; today's forecast peak is materially higher, suggesting tighter reserve margins are expected this evening.

For demand-side response, gridIQ's load-shifting windows are flagging the early hours of 5 August (01:00-06:30 AEST) as the low-cost opportunity, with average prices of $107-128/MWh — a saving of $369-389/MWh versus the forecast evening peak. No load-shedding or demand-side directions are currently active in SA; the most recent SA-specific intervention (AGL Torrens Island units) was cancelled on 2 August. Traders should watch the 18:00-20:30 AEST window closely given the forecast price escalation, and note that current 20:30 demand of 1,674 MW is still well below the intraday peak, implying further upward pressure into the evening.