WA1 experienced a moderate price spike to $252.08/MWh during the 11:20 trading interval on 11 July 2026, representing a sharp increase from $166 levels in the preceding thirty minutes. Prices escalated rapidly from $236/MWh in the two intervals immediately prior to the spike.
The spike occurred with binding constraints F_MAIN++LREG_0210 (marginal value $3.18/MWh) and F_T+RREG_0050 (marginal value $3.05/MWh) active, indicating transmission or regulation-related constraints were limiting available supply. The generation mix at the time comprised substantial coal (854 MW), gas generation (854 MW combined OCGT and CCGT), and wind (476 MW total), with battery output at 322 MW, suggesting the constraint tightness rather than fuel scarcity was the primary driver of the price escalation.
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.