The WEM in WA1 experienced a moderate price spike to $252.50/MWh at 03:45 on 4 August 2026, representing a 57% increase from the preceding interval at $161.23/MWh. The spike was isolated to a single 5-minute trading interval before prices are not shown to have returned to baseline.
The binding constraint F_T+RREG_0050 was active across the price spike period with a peak marginal value of $19.87/MWh, contributing materially to the elevated pricing. The constraint remained binding in subsequent intervals with lower marginal values ($4.07–$4.10/MWh), suggesting that relief from the constraint's tightness in the spike interval was the primary mechanism driving the sharp price elevation, though the data does not isolate whether this was driven by supply reduction, demand increase, or transmission limitation.
Causal analysis generated by gridIQ's synthesis model from live AEMO market data: dispatch prices, generation mix, interconnector flows and market notices in the interval surrounding the event.