Commodity Demand — SA1: Thursday 21 May 2026

South Australia's spot price sits at $103.44/MWh with demand at 1,442.58 MW as of 06:35 AEST, placing the market in a moderate early-morning ramp phase. The current price level is consistent with the established floor pricing pattern: throughout today's price history, the $103.44/MWh mark repeatedly appears as an effective soft floor, reflecting baseload gas dispatch costs in the absence of binding supply pressure. Wind is generating 755.52 MW and gas (OCGT + CCGT combined) 563.19 MW, with renewables at 57.32% of the mix — a meaningful factor keeping prices contained relative to the morning peak period seen earlier in the session, when demand surged toward 1,780 MW and prices ranged from $120–$198/MWh between 06:00–09:00 AEST.

The demand trajectory through today's history reveals a clear price-demand relationship. The overnight trough bottomed near 700 MW around 12:00–13:00 AEST (UTC+10:30), where prices compressed to the low-to-mid $70s/MWh. As demand climbed through the morning residential and commercial ramp — breaching 1,500 MW by 17:30 AEST and peaking near 1,785 MW around 18:30–19:00 AEST — prices spiked to $193–$198/MWh at 07:20 and 06:00 AEST respectively, demonstrating SA's characteristic price sensitivity at high-demand inflection points. The evening shoulder from 04:00–08:00 AEST (14:30–18:30 local) shows demand easing back to the 1,280–1,380 MW range, with prices compressing to the $75–$106/MWh band — a textbook inverse relationship as the dispatch stack loosens.

For the remainder of today, the active inter-regional transfer constraint on the South Morang F2 500/330 kV transformer (V-SMTX_F_R, in place until 1700 hrs 22 May) limits VIC-SA interconnector flexibility and tightens SA's effective supply margin during any demand uplift. The AEMO forecast for the 07:00 AEST (21:00 UTC) interval has settled around $103–$113/MWh across recent forecast runs, with the 07:30 AEST interval forecast ranging $103–$130/MWh — signalling moderate price risk as demand builds into the next morning peak. With overnight demand typically troughing below 800 MW in the 13:00–15:30 AEST window, load windows forecast prices as low as $9–$15/MWh through the 11:30–13:30 AEST period (01:00–03:00 UTC), presenting the most significant demand-shifting opportunity of the day for flexible industrial and commercial loads.

Today's 11.8°C ambient temperature and 6.2 heating degree demand index are driving the sustained overnight and morning heating load that underpins demand staying above 1,400 MW through the evening peak. With cloud cover at 80% and solar potential at zero, there is no daytime solar suppression of the demand curve today — meaning the midday demand trough will be shallower than a clear-sky autumn day, likely keeping prices above $80/MWh through most of the active period and reducing the depth of the overnight