QLD1 experienced sustained negative pricing on 22 September 2026 during early morning hours, with the region settlement reaching a minimum of -$7.11/MWh across 2 intervals. The negative pricing occurred during a period of high solar generation (approximately 2,500–2,600 MW) combined with substantial black coal output (2,763 MW), creating an oversupply condition in the region.
The negative pricing reflects a fundamental supply–demand imbalance driven by high renewable generation coinciding with moderate underlying demand during overnight-to-morning transition periods. The binding constraints with marginal values (F_TASCAP_RREG_0220 at $3.43/MWh and F_T+RREG_0050 at $2.91/MWh) indicate that regional network limitations were active during this period, preventing efficient surplus generation redistribution and forcing the market to price generation uncompetitively to incentivise load or curtailment.
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.