A binding constraint on the VIC1-Tasmania interconnector (V_T_NIL_BL1) activated on 25 May 2026 at 23:35 with a shadow price of $245.27/MWh, indicating significant transmission congestion between Victoria and Tasmania. Regional electricity prices spiked to $130.68/MWh during this period, reflecting the constraint's impact on market dispatch.
The constraint was likely triggered by a combination of high wind generation (combined 3,102 MW across both recording entries) and substantial brown coal output (4,244 MW), creating excess generation in the southern regions that could not be efficiently exported northward due to interconnector limitations. The extremely high shadow price on the T_BLINK_TV_NGZ constraint ($7.31 million) suggests severe restrictions on power flow through the Basslink interconnector, forcing Victoria to manage localised oversupply and creating the binding transmission constraint that elevated VIC1 spot prices.
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.