TAS1 experienced sustained negative pricing at approximately -$1/MWh across three consecutive intervals on 20 September 2026, with prices ranging from -$1.14 to -$1.17/MWh. The region's generation was dominated by renewable sources, with combined wind and hydro output totalling over 1,500 MW during the period.
The binding constraint F_T+LREG_0050 with marginal values between $27 and $42/MWh was active during all negative price intervals, indicating physical transmission or operational limitations were constraining dispatch. High renewable generation (wind and hydro) combined with constrained export capability likely forced generators to accept negative prices to clear excess supply within TAS1, as the binding constraint prevented efficient energy redistribution across the interconnected system.
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.