A binding constraint in TAS1 with an exceptionally high shadow price of $7.308 million occurred during the early morning hours of 29 June 2026, coinciding with volatile regional reference prices that spiked to $79.24/MWh before moderating. The constraint remained active as the dominant driver of pricing despite competing binding constraints with substantially lower marginal values.
The binding constraint T_BLINK_TV_NGZ achieved its extreme marginal value during a period when Tasmania's generation was predominantly hydro-based (941–1056 MW) with material wind contribution (226–272 MW) and zero OCGT availability, suggesting the constraint was activated by tight transmission or network conditions rather than fuel scarcity. The magnitude of the shadow price relative to other binding constraints indicates the T_BLINK_TV_NGZ constraint was significantly tighter than competing constraints, which had marginal values below $67, and this tightness directly drove the region's elevated spot prices during the settlement intervals.
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.