TAS1 experienced sustained negative pricing at −$3.10/MWh for two consecutive intervals on 20 September 2026 around 23:20, following a period of very low positive prices. The region's generation mix was dominated by renewable sources (hydro and wind totalling approximately 900 MW), with no gas generation online during the event.
The negative pricing reflects an oversupply condition where renewable generation exceeded local demand, creating downward price pressure. Multiple binding constraints with positive marginal values (particularly F_TASCAP_RREG_0220 with marginal values of $3.44–$4.00) indicate that transmission or reserve constraints were restricting the ability to export excess generation or balance supply internally, forcing the marginal plant into negative price territory to manage the surplus.
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.