Commodity Demand — SA1: Friday 5 June 2026

South Australia sits at $101.95/MWh with demand at 1,394 MW as of 06:25 AEST — a relatively modest load level for a mid-morning Saturday in winter, but prices are holding firmly above $100/MWh. The disconnect between this moderate demand and triple-digit pricing reflects both the generation mix and market structure: gas OCGT is carrying 364 MW and gas CCGT a further 202 MW, with wind contributing 244 MW. With renewable penetration at just 30% and carbon intensity at 0.4135 tCO2/MWh — the highest point so far across the overnight history — thermal plant is setting the marginal price. The overnight trough tells the demand-price story clearly: demand bottomed near 1,100 MW around 11:25–11:55 AEST, with prices in the high $60s, before climbing back to current levels as the morning ramped up.

Today's demand profile has been tracking the typical Saturday winter shape: a sharp overnight decline to around 1,100 MW, a secondary trough in the low $50s at 10:02 AEST (49.02 $/MWh), a pre-dawn build through ~12:00 AEST (02:00 UTC), and a current morning lift toward ~1,400 MW. The price sensitivity to demand is non-linear and pronounced — the transition from 1,100 MW to 1,950+ MW during the earlier morning peak (07:00–09:30 AEST, corresponding to the 17:00–19:30 UTC price history) pushed prices consistently to $100–$142/MWh, peaking at $142.66/MWh at 18:00 AEST when demand crossed 2,045 MW. That $142 print at a demand level barely above 2,000 MW indicates the SA supply stack turns expensive quickly above ~1,900 MW.

The forward forecast signal for tonight is relatively benign. The most recent 06:00 AEST (20:01 UTC) forecast has the 21:00 AEST (07:00 UTC) interval at $95.57/MWh, while the 21:30 AEST period is centred around $85–$101/MWh across the forecast run cluster. Demand is currently building gradually — up from 1,369 MW at 06:00 AEST — and this slow Saturday ramp, with a forecast high of 15.2°C and cloud cover at 98%, means minimal solar contribution through the day and heating demand of 7.6 index units. That cloud load keeps demand supported but not exceptional; the more interesting price risk is the late-afternoon to evening demand lift, when SA historically prints above $100/MWh as gas plant dominates dispatch and wind potential is forecast near 1.0 average for today.

Demand-side managers and flexible loads should note the 06:30 AEST window (tonight, 20:30 UTC) carries forecast prices of $84–$88/MWh — a relative softening before any late-evening thermal tightening. The pattern so far shows SA prices are highly sensitive above 1,850 MW of demand and relatively stable in the $68–$85/MWh range between 1,300–1,600 MW. With today's max temperature forecast at 15.2°C and no wind acceleration until Monday, demand is unlikely to push above 1,800 MW during daylight,