WEM WA1 region experienced a moderate price spike to $252.5/MWh during the 17:10 settlement interval on 11 July 2026, representing a 44% increase from the preceding interval's $176.18/MWh. The spike was concentrated in a single 5-minute trading interval amid an evening peak demand period.
Multiple binding constraints with marginal values between $3.06/MWh and $3.44/MWh contributed materially to the elevated clearing price, indicating transmission or system security limits constrained the available generation dispatch. The generation mix shows reliance on thermal (coal, gas CCGT and OCGT totalling ~1,708 MW) and battery output (322 MW) alongside wind (476 MW), suggesting the constraint binding occurred under conditions where rapid load-following or transmission capacity limitations restricted economical generation supply.
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.