The WEM in Western Australia experienced a price spike to $253.22/MWh during the 13:15 trading interval on 18 June 2026, a 50% jump from the previous interval's $237.51/MWh. The spike was isolated to a single trading interval before prices stabilised at the elevated level in the following period.
The price spike was driven by binding constraints, with F_MAIN+RREG_0220 exhibiting the highest marginal value (9.24 $/MWh) and remaining the dominant constraint throughout the period. The combination of active constraint binding, substantial reliance on peaking capacity (OCGT generation at 935.56 MW alongside CCGT at 574.42 MW), and limited renewable output (wind at 182.71 MW, solar at 36.13 MW combined) constrained the system's ability to meet demand flexibly, pushing prices toward the dispatch ceiling.
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.