QLD1 experienced sustained negative pricing during the early morning period of 31 May 2026, with minimum prices reaching -$1.18/MWh across 2 intervals. This minor event occurred during the 02:25–02:55 period, with prices fluctuating between $0 and -$1.50/MWh across seven consecutive settlement intervals.
The negative pricing was driven by excess renewable generation (approximately 3,729 MW of combined solar and wind output) coinciding with minimum demand during the early morning trading window, creating an oversupply condition that forced price depression. The binding constraint F_T+RREG_0050 (with marginal value of $5.44) indicates network congestion in Queensland's regulated region, likely preventing efficient dispatch of excess renewable output and forcing generators to pay for export or curtailment, thereby pushing prices negative despite the constraint's marginal value suggesting some inelasticity in network capacity management.
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.