QLD1 experienced sustained negative pricing at −$4.09/MWh across two intervals during the evening of 1 September 2026, with prices oscillating between negative and near-zero levels. The region had substantial solar generation (approximately 5,359 MW combined) and coal generation (3,077 MW), creating oversupply conditions typical of the shoulder period.
The negative pricing was driven by high renewable generation (solar and wind totalling approximately 5,672 MW) exceeding demand during low-demand evening hours, forcing marginal coal and gas units to accept negative prices rather than reduce output. A binding constraint with marginal value of $8.35 million (T_BLINK_TV_NGZ) suggests a significant network limitation was active, preventing the export or redistribution of surplus generation, which exacerbated localised oversupply in QLD1 and pushed prices into negative territory.
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.