TAS1 experienced sustained negative pricing of approximately -$6/MWh across two consecutive intervals (04:50–05:00) on 19 August 2026, following a sharp price collapse from $24.77/MWh. The negative pricing occurred during a period of elevated renewable generation (wind and hydro combined at ~780–1050 MW) and moderate OCGT supply.
The negative pricing reflects local excess supply in TAS1 that could not be economically exported or curtailed. The binding constraint F_S+HYSE_L1 carried a marginal value of $95/MWh, indicating a severe transmission limitation preventing outward flow of surplus generation. Combined with binding regulations constraints (F_TASCAP_RREG_0220, F_TASCAP_LREG_0210, and F_T+RREG_0050) exhibiting positive marginal values, the region faced constrained export capacity whilst managing high renewable output, forcing the system to pay down generation to maintain supply–demand 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.