TAS1 experienced sustained negative pricing during the 00:20–00:25 interval on 7 September 2026, with prices reaching −$0.58/MWh and −$0.57/MWh respectively. This minor pricing event occurred during a period of high renewable generation, with combined hydro output exceeding 1,867 MW and wind generation above 530 MW.
The negative pricing reflects an excess generation condition where the marginal cost of dispatch fell below zero, requiring market participants to pay to dispatch power. The binding constraint F_T+LREG_0050 operated with a marginal value of approximately $21.38–$21.95/MWh across the affected intervals, indicating it was restricting dispatch capability; this constraint limitation, combined with high inertial renewable output that could not be reduced without incurring constraints, likely forced the market to accept 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.