WEM prices in WA1 spiked to $252.41/MWh at 14:40 on 9 July 2026, up sharply from $142.33/MWh just 15 minutes earlier. The spike persisted across a single trading interval before moderating, representing a moderate severity event in an otherwise elevated pricing environment.
The price escalation was driven by binding constraints with material marginal values, most prominently constraint F_TASCAP_RREG_0220 which exhibited marginal values between $4.94–$5.48/MWh across multiple intervals leading into and during the spike. A secondary binding constraint, F_T+RREG_0050, with a marginal value of $3.89/MWh, also contributed to the elevated dispatch costs, indicating that regional reserve or transfer capability limits were limiting supply flexibility during the period of tightening demand.
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.