The WEM experienced a moderate price spike in WA1 at 06:10 on 21 June 2026, with the region schedule price (RSP) jumping to $268.54/MWh from $199.63/MWh in the prior interval. This represents a 34% increase within a single 5-minute trading interval during the early morning peak demand period.
The price spike was driven by binding constraints with the highest marginal value constraint (F_MAIN+RREG_0220) contributing $19.68/MWh to the regional price. A secondary constraint (F_T+NIL_MG_RECL_R6) added a further $11.20/MWh. The generation stack at the time comprised substantial coal (1115 MW) and gas CCGT (460 MW) contributions alongside renewable generation (wind at 1004 MW combined), suggesting the spike reflects physical network or system security limitations rather than fuel scarcity, with these binding constraints restricting the economic dispatch of available capacity.
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.