VIC1 experienced sustained negative pricing with a minimum of -$4.72/MWh across two intervals on 10 July 2026 at 23:20–23:30. The region was oversupplied relative to demand, with wind generation alone exceeding 3,480 MW alongside significant brown coal output totalling approximately 3,615 MW. Negative prices persisted despite gas generation being unavailable to provide flexible downward adjustment.
The negative pricing in VIC1 was driven by high renewable generation (wind and solar totalling ~3,887 MW) combined with inflexible baseload brown coal generation (~3,615 MW), creating structural oversupply during a low-demand period. Multiple binding constraints with marginal values between approximately $5–$7/MWh, dominated by constraint F_TASCAP_RREG_0220, indicate network or interconnector congestion that prevented efficient export or load balancing, forcing the market into negative pricing to incentivise demand response and curtailment of dispatchable 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.