The WEM in Western Australia experienced a moderate price spike to $263.34/MWh during the 03:55 trading interval on 5 June 2026, representing a sharp increase from the preceding $247.67/MWh settlement. This single-interval event occurred during the night-time period when solar generation was minimal and demand drivers supported elevated pricing.
The binding constraint F_MAIN+RREG_0220 was active throughout this period with a marginal value of $7.62/MWh at the time of the spike, indicating it was limiting available supply. The generation mix at this time was heavily weighted towards thermal (black coal at 848.95 MW and gas at 1,166.02 MW combined) and wind (637.90 MW), with battery providing 419.32 MW of dispatchable capacity; the tightness reflected in the binding constraint's marginal contribution suggests supply-demand balance tightened during this interval, likely requiring higher-cost dispatch to meet demand.
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.