TAS1 experienced sustained negative pricing on 3 September 2026 in the early morning period, with the region recording prices of −$7.94/MWh and −$6.27/MWh across two consecutive intervals. The negative pricing occurred during a period of elevated renewable generation, with wind contributing approximately 460 MW and hydro approximately 375–192 MW to the region's supply mix.
The negative pricing was driven by over-supply conditions in TAS1 during low-demand early morning hours, with substantial wind and hydro generation unable to be economically dispatched or exported. A binding constraint with a marginal value of $1,002.29 (constraint_id F_T+RREG_0050) indicates a severely tight operating condition, suggesting that export capacity or system security limits prevented downward adjustment of local generation, forcing the dispatch algorithm to accept negative prices to balance the market.
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.