VIC1 experienced sustained negative pricing at approximately −$2.50/MWh across eight consecutive intervals during the evening of 12 June 2026, with the minimum price reaching −$2.67/MWh. The negative pricing persisted despite a substantial generation portfolio comprising over 6,300 MW of wind capacity and 3,120 MW of brown coal generation.
The negative pricing reflects an oversupply condition in VIC1 where available generation exceeded demand requirements. Multiple binding constraints with positive marginal values (ranging from $3.35 to $5.73/MWh) indicate that network or system security limits were constraining dispatch, preventing generators from reducing output to clear the market at non-negative prices. The high wind generation output during this period, combined with inflexible coal plant generation, created a situation where the market clearing mechanism pushed pricing negative to incentivise demand response or reduce generator output below economic levels.
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.