Victoria experienced sustained negative pricing across three intervals during the early morning of 15 September 2026, with the minimum price reaching −$8.00/MWh. The event occurred during a period of high renewable generation, particularly wind (approximately 4,453 MW combined) and solar (626.84 MW), combined with brown coal baseload generation totalling 2,190.63 MW.
The negative pricing reflects an excess supply condition where the combination of inflexible coal generation and high renewable output exceeded demand during low-demand morning hours. A binding constraint (F_T+LREG_0050) with elevated marginal values (ranging from $18.13 to $104.03/MWh) restricted market participants' ability to balance supply and demand through normal dispatch mechanisms, forcing the market price into negative territory to incentivise demand response and renewable curtailment.
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.