Tasmania experienced sustained negative pricing of approximately −$59/MWh for two consecutive intervals (04:45 and 04:50 on 14 September 2026), representing a moderate severity event. Prices recovered to modest positive levels in preceding intervals before the sharp decline and partial recovery.
The negative pricing was driven by binding constraints with substantial marginal values, most notably constraint F_T+NIL_ML_L6 at $102,549/MWh, indicating severe transmission congestion or export limitations that forced local generation to be dispatched at loss-making rates. The concurrent binding of multiple constraints (F_T+LREG_0050 and F_T+RREG_0050, each exceeding $31,000/MWh) suggests simultaneous pressure from network limits and regulation service requirements, compounding the economic dispatch challenge and necessitating negative pricing to manage excess supply in the constrained region.
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.