The WEM in WA1 experienced a sharp price spike to $337.87/MWh in the 16:20 trading interval on 5 August 2026, representing a $97.82/MWh jump from the previous interval. Prices remained elevated at $338.23/MWh in the following interval before the data series concluded, with the spike occurring during an evening demand period.
The price spike was driven by a binding constraint (F_TASCAP_RREG_0220) with a marginal value of $13.82/MWh, which contributed materially to the increase in marginal cost of supply. The WA1 generation mix at the time was heavily dependent on gas-fired generation (1,007 MW OCGT and 331 MW CCGT representing approximately 67% of total output) and battery support (419.63 MW), suggesting limited availability of lower-cost alternatives and potential reserve scarcity during the critical pricing interval.
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.