WEM WA1 region experienced a moderate price spike to $270.32/MWh during the 06:55 trading interval on 18 June 2026, representing a sharp 24.8/MWh increase from the previous interval. Prices remained elevated at the spike level through the following two intervals (07:00 and 07:05), suggesting sustained tight supply conditions.
The price spike coincided with binding constraints F_MAIN+RREG_0220 and F_T+RREG_0050, with the former exhibiting marginal values up to $8.54/MWh during the spike period, indicating these constraints were actively limiting available generation dispatch. The generation mix at the time shows heavy reliance on gas-fired generation (1,510 MW combined OCGT and CCGT output), whilst battery discharge (814.59 MW) and wind generation (182.71 MW) provided supplementary supply, suggesting the market was operating under binding constraint pressure during an early morning demand period with limited flexible capacity headroom.
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.