The WEM experienced a moderate price spike to $263.34/MWh in WA1 during the 04:00 trading interval on 3 June 2026, representing a sharp 56% increase from the previous interval's $168.93/MWh. Prices remained elevated across the wider period (04:00–04:15), subsequently declining as system conditions eased.
The spike was likely driven by transmission constraints binding during a period of tight system conditions in early morning hours, as evidenced by multiple active constraint equations with marginal values contributing to the price floor. The generation mix shows heavy reliance on thermal generation (black coal at 847.3 MW and gas plants at 1,292.6 MW combined), with wind output relatively modest at 542.05 MW total, reducing flexibility to manage the binding network constraints and forcing higher-cost marginal generation to set prices.
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.