VIC1 experienced two consecutive intervals of negative pricing at -$0.05/MWh on 28 June 2026 at 16:55 and 17:00, representing a minor severity event. Prices declined sharply from $11.48/MWh earlier in the period, with the region showing high wind generation (approximately 2,735 MW average) and substantial brown coal baseload (3,704 MW).
The negative pricing appears driven by an oversupply of generation relative to demand, with high wind output combined with inflexible brown coal generation unable to reduce output quickly. Multiple binding constraints with modest marginal values (constraint F_T+LREG_0050 at $43.40 and $4.97, and constraint F_MAIN+RREG_0220 at $7.63 and $4.97) suggest that network or operational limitations required the market to accept negative prices to manage the excess supply, rather than having substantial structural barriers preventing price recovery.
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.