SA1 experienced sustained negative pricing over a 35-minute period from 17:15 to 17:45 on 12 September 2026, with prices ranging from −$5.66/MWh to −$7.00/MWh across three intervals. The negative pricing reflects oversupply conditions in the region during the evening period.
Wind generation dominated the regional supply at 1569.39 MW, substantially exceeding regional demand during the early evening shoulder period when solar generation had ceased. A binding constraint (F_T+LREG_0050) exhibited marginal values between $17.95/MWh and $19.99/MWh, indicating a physical or operational limit was restricting export capacity and forcing the region to absorb excess wind output, driving prices negative as generators competed to avoid curtailment costs.
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.