The WEM experienced a moderate price spike in WA1 on 28 May 2026, with the spot price jumping from $178.50/MWh to $254.94/MWh over a five-minute window (10:35 to 10:50). The price escalation occurred across a single trading interval, representing a 43% increase from the preceding steady-state pricing.
The binding constraint F_T+RREG_0050 (likely a transmission flow or regulation constraint) with marginal values around $5.93–$5.97/MWh suggests network congestion or localised capacity limitations were constraining available generation. The generation mix shows adequate overall capacity (totalling approximately 2,990 MW), but the rapid price spike indicates the constraint prevented cheaper baseload or renewable generation from serving demand, forcing the market to procure additional megawatts from higher-cost plant, potentially OCGT or battery discharge, thereby driving the spot price to the constraint-binding level.
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.