QLD1 experienced brief negative pricing on 10 August 2026 at 23:50–23:55 AEST, with prices falling to −$2.50/MWh and −$1.31/MWh respectively across two consecutive intervals. The event occurred during evening peak with high solar generation (3020 MW) and substantial coal output (6907 MW combined), alongside consistently binding transmission constraints.
Negative pricing in QLD1 reflects a structural oversupply condition driven by high daytime renewable output coinciding with minimum demand during the evening transition period. The binding constraint NSA_Q_GSTONE34_250—persisting across all five intervals with marginal values between $68.69–$71.32/MWh—indicates that export or transmission capacity limitations prevented efficient dispatch of QLD's generation surplus, forcing the market to accept negative prices to clear excess supply.
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.