QLD1 experienced sustained negative pricing on 12 September 2026, with prices declining from $59.03/MWh to a trough of –$5.53/MWh across two intervals in the evening peak period. The region's generation mix was heavily dominated by black coal (4340.8 MW) and wind (1381.05 MW), with solar (173.79 MW combined) and gas (201.22 MW combined) providing supplementary capacity.
Negative pricing in QLD1 was driven by a binding constraint (F_T+LREG_0050) with a marginal value of approximately $14–16/MWh during the event, indicating that grid stability or network flow requirements were limiting dispatch options and forcing the market to accept negative prices to manage excess supply. The high thermal baseload generation (black coal at 4340.8 MW) combined with substantial wind output (1381.05 MW) created a supply position that could not be economically curtailed or exported within the binding constraint envelope, necessitating negative pricing to incentivise demand or voluntary generation reductions.
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.