TAS1 experienced sustained negative pricing over two intervals on 17 September 2026 around 03:50–04:05, with the lowest price reaching −$5.19/MWh. The region's generation mix was dominated by wind and hydro sources (approximately 1,197 MW combined), with no gas generation online to manage excess supply.
The negative pricing reflects over-supply conditions typical of high renewable penetration periods during low-demand overnight hours. The binding constraint F_T+LREG_0050 carried significant marginal values (ranging from 30.83 to 47.35 $/MWh) across the interval window, indicating that this constraint was actively limiting dispatch flexibility and preventing generators from reducing output, forcing the market to accept negative prices to clear excess generation.
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.