The WEM WA1 region experienced a moderate price spike to $285.29/MWh in a single trading interval at 19:05 on 1 September 2026, representing a sharp increase from the preceding baseline of approximately $123–129/MWh. The spike was isolated to one interval before prices stabilised.
The binding constraint F_T+RREG_0050 was active throughout the period with marginal values of $4.42–$4.43/MWh, indicating a tightness in system capability. The generation mix at the time shows substantial reliance on thermal plant (coal and gas), with wind and solar providing only modest contributions, suggesting limited reserve margin during a period of elevated demand or reduced flexible generation availability.
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.