VIC1 experienced sustained negative pricing across 3 intervals on 20 September 2026, with the regional reference price falling to −$1.13/MWh. The negative prices persisted across an 8-interval window from 14:30 to 15:05, indicating a period of structural oversupply in the region.
The generation mix shows exceptional wind availability (approximately 6,440 MW combined across wind generators) paired with dispatchable brown coal generation (1,999 MW), creating a supply profile that substantially exceeded contemporaneous demand. The binding constraint F_T+LREG_0050 carried consistently positive marginal values (ranging from 27 to 42 $/MWh), indicating this constraint was actively restricting further generation and preventing prices from falling further negative; the constraint's binding status reflects network or operational limitations that forced generators to offer at negative prices to maintain dispatch.
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.