TAS1 experienced sustained negative pricing at –$35.16/MWh during the 05:05 settlement interval on 29 August 2026, with negative prices persisting across multiple intervals in the early morning period. The negative pricing occurred against a backdrop of substantial wind generation (231–299 MW) and combined hydro output (358–367 MW), totalling approximately 590–666 MW of low-marginal-cost renewable supply.
The binding constraint F_T+LREG_0050 exhibited marginal values ranging from $43.70 to $63.85/MWh across the event window, indicating a system constraint was consistently active and limiting dispatch flexibility. The combination of high renewable output during a low-demand early morning period, combined with the active constraint, forced the dispatch algorithm to accept negative prices to balance supply and demand within the binding constraint limit.
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.