QLD1 experienced brief negative pricing at −$1.92/MWh across two consecutive intervals (03:15–03:20 on 22 June 2026), following stable positive prices of $0.73/MWh in the preceding hours. The event occurred during a period of high solar generation (approximately 2,040 MW average) combined with substantial coal and wind output, totalling over 6,300 MW of generation.
The negative pricing was driven by a binding constraint (F_T+RREG_0050) with declining marginal values ($142–$48/MWh across the relevant intervals), indicating that system dispatch was constrained by a network or ancillary service requirement rather than by conventional supply–demand imbalance. The high coincident solar generation during off-peak morning hours, combined with inflexible baseload coal generation and the constraint tightening, created an oversupply condition that the market resolved through negative pricing to incentivise demand response 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.