VIC1 experienced sustained negative pricing at approximately -$1.1/MWh across seven consecutive five-minute intervals on 28 July 2026 from 16:45 to 17:15. The region was operating with high wind generation (approximately 7,488 MW combined) and significant brown coal output (3,227 MW), creating a supply-demand imbalance.
The negative pricing reflects oversupply conditions in VIC1 during this period, with renewable generation (primarily wind) substantially exceeding demand and inflexible coal generation unable to ramp down quickly. The binding constraint F_TASCAP_RREG_0220 with marginal values of $3.43–$4.69/MWh indicates that network or ancillary service limitations were restricting the region's ability to export excess generation, forcing the market to signal negative prices to incentivise demand and discourage further generation.
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.