The WEM experienced a moderate price spike to $253.22/MWh in WA1 during the 23:15 settlement period on 16 June 2026, with prices elevated across a cluster of intervals from 22:55 to 23:30. The spike occurred during evening peak demand with a diverse generation portfolio that included substantial thermal (coal and gas) and renewable (wind and battery) output.
The price spike was driven primarily by a binding constraint with a marginal value of $20/MWh (F_S++SETB_L60), which restricted system capability and forced higher-cost generation into the market. Secondary binding constraints with lower marginal values ($7.79–$5.27/MWh) on network paths and ramping capability contributed incrementally to uplift, indicating multiple points of congestion or system stress during the evening peak period.
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.