The WEM experienced a moderate price spike in WA1 on 15 September 2026, with the real-time price surging to $278.94/MWh at 07:10 UTC, a sharp increase from $210.94/MWh just five minutes earlier. The spike occurred as a single-interval event, with prices rising progressively from $127.28/MWh over the preceding 25 minutes.
The price spike was driven by binding constraints with material marginal values, primarily constraint F_TASCAP_RREG_0220 which showed successive marginal values of $7.79/MWh, $4.97/MWh, and $3.44/MWh, indicating constraint-driven scarcity in the system. The generation mix at the time comprised substantial wind (772 MW) and coal (430 MW) supply alongside gas and battery generation, but the binding constraints suggest transmission or reserve requirements limited available supply to meet demand at that interval, forcing prices to the spike 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.