QLD1 experienced sustained negative pricing across three consecutive intervals on 13 September 2026 at 02:15–02:25, with prices ranging from −$9.13/MWh to −$8.87/MWh. The negative pricing persisted across a broader window (02:15–02:50) with prices oscillating between −$9.13/MWh and −$7.50/MWh. This reflects a supply-demand imbalance typical of low-demand periods with high renewable generation.
The event occurred during early morning hours (02:15) when system demand is typically low, whilst QLD1 was generating approximately 3,492 MW from solar and 132 MW from wind—substantial renewable output that could not be economically curtailed. The binding constraint F_T+LREG_0050 carried a marginal value of $74.99, indicating significant scarcity in a system service or transmission capacity, which likely prevented efficient dispatch of excess generation and forced generators to bid negatively to remain operational. The combination of inflexible must-run generation (primarily black coal at 2,908 MW) and high renewable output with constrained export or storage capacity created conditions where negative pricing became the equilibrium outcome.
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.