VIC1 experienced sustained negative pricing of approximately -$4/MWh across 2 intervals on 30 August 2026 at 01:40–01:45, with prices declining from $8.94/MWh to -$3.50/MWh over a 30-minute period. The region's generation mix during this period was dominated by large solar and brown coal output (1,264 MW and 2,907 MW respectively), alongside substantial wind generation (519 MW combined).
The negative prices were driven by excess supply relative to demand during the early morning period when dispatchable generation (brown coal and gas) could not reduce output sufficiently to balance the high renewable energy generation. A binding constraint with significant marginal values (peaking at $21.32/MWh and declining to $16.72/MWh across the intervals) indicates transmission or system security limitations that prevented efficient dispatch of the surplus generation, forcing the price setter to bid down to negative territory to manage the generation excess.
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.