A major binding constraint event occurred in TAS1 on 31 May 2026, with the T_BLINK_TV_NGZ transmission constraint reaching an exceptionally high shadow price of $7.308 million, indicating severe transmission congestion. Regional electricity prices remained relatively stable in the $80–97/MWh range during the constraint activation period, suggesting the constraint was effectively limiting generation dispatch rather than driving spot price spikes.
The T_BLINK_TV_NGZ constraint (Basslink to Tasmanian network interface) became binding due to high renewable generation output—approximately 1,700 MW of hydro generation and 880 MW of wind generation—attempting to flow through limited transmission capacity. The extremely high shadow price reflects the economic cost of curtailing low-marginal-cost renewable generation, as thermal generation (GAS_OCGT) was offline, leaving no flexible dispatchable resources to relieve congestion; this scenario is typical during periods of high hydro availability and wind generation coinciding with mainland demand levels that cannot absorb Tasmanian exports.
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.