Commodity Demand — SA1: Thursday 4 June 2026
South Australia's spot price sits at $83.96/MWh at 06:30 AEST with demand at 1,516 MW — a relatively modest load level for a winter Friday morning. The price-demand relationship across today's session has been sharp: when demand peaked at 2,315 MW around 08:35 AEST, prices pushed into the $56–$69/MWh range, reflecting the tight midday supply stack. Overnight, demand troughed near 1,466 MW (around 03:15 AEST) and prices sat persistently negative, ranging from -$2 to -$5/MWh, underscoring how surplus generation at low-demand periods pushes the marginal clearing price below zero. The current $83.96/MWh price at only 1,516 MW of demand signals the evening pricing structure is already asserting itself as solar generation drops to 0 MW and the generation mix shifts to wind (596 MW), gas OCGT (270 MW), gas CCGT (177 MW), and battery discharge (76 MW).
The demand trajectory today follows a textbook winter weekday pattern: a morning ramp from ~1,466 MW at pre-dawn to a broad midday plateau near 2,200–2,315 MW between 08:00 and 10:30 AEST, then a steady afternoon decline back through 1,500 MW by 16:30 AEST. Critically, prices during the 08:30–10:30 AEST demand peak ranged $56–$69/MWh — meaningfully elevated but not extreme — suggesting the supply stack accommodated peak demand without scarcity. The price-per-MW sensitivity tightens considerably in the post-sunset period: demand is now only around 1,516 MW yet prices are firming above $83/MWh, driven by the loss of daytime solar and the requirement for dispatchable plant to set price.
The evening outlook is the key risk window. Pre-dispatch forecasts for the 07:00 AEST (21:00 UTC) interval are converging around $79–$86/MWh, with some outlier runs earlier in the day reaching $141–$145/MWh before being revised sharply lower as conditions became clearer. The 08:00 AEST (22:00 UTC) window shows forecast prices nudging $88–$101/MWh across multiple runs, consistent with demand rebuilding through the evening heating peak in cold (11.8°C, heating demand index 6.2) winter conditions. With wind potential rated at only 2.3 and wind currently generating 596 MW, any softening in wind output during the 19:00–21:00 AEST window would tighten the gas-set marginal stack and push prices toward the upper end of the forecast band.
An active AEMO market notice (144179) flags a reclassification of the Para–Templers West and Magill–Torrens Island A 275kV lines in SA as credible contingency events from 1 June, still in effect. This network constraint limits the headroom available on intra-SA transmission and reduces the volume of generation that can be dispatched before binding the constraint — a factor that adds upward pricing pressure during high-demand evening intervals even at demand levels well below the day's 2,315 MW peak.