A major binding constraint (T_BLINK_TV_NGZ) emerged in Tasmania on 28 May 2026 with an exceptionally high shadow price of $7.308 million, indicating severe transmission congestion on the Basslink interconnector between Tasmania and Victoria. Regional retail electricity prices remained relatively stable in the $97–102/MWh range during the constraint event, reflecting the constraint's localised impact on interconnector flow rather than wholesale price spiking.
The binding constraint likely arose from elevated hydro generation in Tasmania (averaging ~1,046 MW across three periods) combined with transmission limitations on the Basslink TV (Tasmanian–Victorian) corridor, preventing efficient export to mainland markets. The T_BLINK_TV_NGZ constraint nomenclature suggests a north-to-south flow restriction in the no-load zone, which typically activates when Tasmanian generation cannot be economically exported due to interconnector saturation or thermal limits, forcing local dispatch optimisation and creating large constraint rents.
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.