The WEM experienced a moderate price spike to $287.47/MWh in WA1 during the 12:10 interval on 13 September 2026, representing a sharp 103% increase from the preceding five-minute settlement at $141.95/MWh. The spike was isolated to a single trading interval before prices did not return to the dataset, suggesting a transient supply-demand imbalance.
Multiple binding constraints with marginal values between $4.87 and $5.55/MWh indicate that transmission or reserve requirements were constraining dispatch during this period. The generation mix shows substantial thermal baseload (662 MW black coal, 300 MW CCGT) supplemented by gas OCGT (473 MW) and renewable sources (wind 489 MW combined, solar 125 MW), suggesting that either a rapid change in demand, a sudden generation loss, or the activation of constraint-binding security or reserve services drove the system to require higher-cost marginal generation to maintain supply adequacy within the binding constraint limits.
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.