A binding constraint (V_T_NIL_BL1) with a marginal value of $278.70/MWh affected VIC1 pricing on 12 June 2026, causing significant price volatility with spot prices ranging from -$614.77 to $88.35/MWh over a 25-minute period. The constraint dominated the dispatch outcome, creating a substantial gap between the constraint's shadow price and the regional reference price.
The high marginal value of the V_T_NIL_BL1 binding constraint indicates a physical or operational limitation was restricting the dispatch solution and creating significant economic scarcity at that location. High wind generation (approximately 8,075 MW combined) and substantial brown coal generation (3,851 MW) were present in the market, with the binding constraint preventing full utilisation of available supply and forcing the market to rely on alternative dispatch paths that created localised price separation from the broader region.
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.