Tasmania (TAS1) experienced sustained negative pricing at −$0.05/MWh for two consecutive intervals (03:10 and 03:15 on 12 August 2026), representing minor severity. The negative pricing occurred within a broader context of price volatility, with rates falling from $40/MWh to $15/MWh before reaching negative levels.
The negative pricing was driven by high renewable generation levels, with combined hydro and wind output averaging approximately 882 MW across the event window, creating local oversupply conditions in Tasmania. The binding constraint NSA_Q_GSTONE34_250 maintained consistently high marginal values (ranging from $23,102 to $23,202/MWh) across these intervals, indicating a tight physical constraint that limited Tasmania's ability to export excess generation, forcing marginal generation to be dispatched at negative prices to maintain system balance.
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.