commodity demand sa — SA1

South Australia's spot price sits at $55.1/MWh with demand at 1,258 MW as of 06:30 AEST — a significant step down from today's intraday peak of 1,639 MW reached around 18:35–18:40 AEST, when prices were holding in the $85–$103/MWh range. The day's demand profile followed a classic April pattern: a deep overnight trough bottoming near 436 MW around 13:30 AEST, accompanied by sustained negative pricing reaching as low as -$20/MWh during the 15:15 AEST interval, before a sharp morning ramp from around 16:00 AEST that drove demand up more than 1,200 MW over roughly three hours and pulled prices firmly into the $80–$138/MWh band through the business day peak.

The price sensitivity to demand is pronounced and asymmetric today. Intervals below approximately 700 MW correlated consistently with negative or near-zero prices, while demand above 1,400 MW saw recurring excursions to $103–$138/MWh. The current 1,258 MW level sits in a middle zone where the supply stack is relatively flat — prices in the $55–$70/MWh range have prevailed across most of the 1,200–1,350 MW demand band since around 03:00 AEST. Wind is generating 664 MW and gas CCGT 119 MW, with solar contributing nothing at this hour; the generation mix is consistent with the 84.74% renewable share and 0.0748 tCO2/MWh carbon intensity reported for the current interval.

The forward price outlook is the key signal for today. AEMO forecasts for the 07:00 AEST half-hour are converging around $77–$82/MWh, and forecasts for the 07:30 AEST interval similarly cluster in the $85–$103/MWh range — indicating the dispatch engine anticipates a demand lift back toward the 1,300–1,400 MW zone as the Saturday morning progresses. Being a weekend, the peak is likely to be moderate and delayed relative to a workday, which may cap prices below the $120–$138/MWh spikes seen during this morning's business-day ramp. However, the Tarrone–Heywood/APD 500 kV line unplanned outage (constraint set V-HYTR, invoking limits on the V-SA interconnector) remains an active network notice and introduces upside price risk if SA's net import capacity via Heywood is constrained when demand climbs.

The AEMO direction issued to Origin Energy's Quarantine PS Unit 5 for voltage control — requiring synchronisation and dispatch from 12:00 AEST — is a notable demand-side-adjacent factor. The direction, driven by insufficient synchronous inertia in SA rather than an energy shortfall, confirms the grid is operating at relatively low synchronous unit counts during high renewable penetration periods. This does not directly shift the spot price but constrains the generation dispatch stack and adds to system strength costs that flow through to uplift. Flexible load operators and battery dispatch strategies should note that the overnight negative price period (approximately 11:30–15:15 AEST) is the structural low point of the daily cycle, and today's load windows confirm forecast prices near or below zero persisting from approximately 08:30 AEST through to 11:00 AEST tonight,