QLD1 experienced sustained negative pricing of approximately $-2/MWh across two consecutive 5-minute intervals (00:15 and 00:20 on 30 May 2026), representing a minor market event during the overnight period. Prices subsequently recovered to $-1.35/MWh before returning to zero, indicating temporary oversupply conditions that were quickly resolved.
The negative pricing was driven by excess renewable generation, with combined solar output of approximately 5,130 MW accounting for roughly 60% of total dispatch during overnight hours when demand is typically lowest. Thermal generators (black coal and gas) remained inflexible at high output levels, creating a structural oversupply situation that forced the market into negative prices to incentivise load or curtail generation, compounded by active binding constraints (particularly the TASCAP and transmission flow constraints) that limited the ability to export excess generation interstate.
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.