QLD1 experienced a moderate price spike to $303/MWh across two consecutive intervals (13:55–14:00) on 23 September 2026, representing a sharp increase from the preceding $130–157/MWh range. Prices had already elevated to $299/MWh in the two intervals immediately before the spike, suggesting escalating scarcity conditions.
The binding constraint F_T+RREG_0050 was active across both spike intervals with marginal values of $39.96 and $36.93/MWh, accounting for the majority of the price elevation and indicating a tightness in a regional regulation service requirement. The concurrent generation mix—dominated by black coal (4,221 MW) with substantial contributions from wind (1,295 MW), gas OCGT (565–576 MW), battery (420 MW), and hydro (191 MW)—suggests supply was adequate in volume but constrained by network or service requirements rather than absolute generation shortage.
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.