Victoria experienced sustained negative pricing in VIC1 during the late afternoon of 18 June 2026, with prices reaching −$3.15/MWh across a 35-minute window. The region was supplied predominantly by wind generation (approximately 6,000 MW combined) and brown coal (2,912 MW), resulting in oversupply relative to local demand.
The negative pricing reflects excess renewable generation that could not be economically exported or curtailed. Multiple binding constraints with material marginal values indicate transmission or network limitations prevented efficient redistribution of the surplus wind output, forcing the market to pay generators to reduce output. The constraint with the highest marginal value (F_T+LREG_0050 at $26.74/MWh) suggests a significant bottleneck; combined with supporting constraints (F_MAIN+RREG_0220 at $4.68/MWh), these network limitations created locational scarcity that drove prices negative as the market sought to balance supply.
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.