South Australia 1 (SA1) experienced sustained negative pricing over three intervals on 1 September 2026, with prices reaching a minimum of –$47.28/MWh at 02:45. The region's generation mix was dominated by wind (779.3 MW) alongside modest solar and gas output, creating an oversupply condition during the early morning period.
The negative pricing was driven by a binding constraint (F_T+LREG_0050) with marginal values ranging from 10.91 to 43.94 $/MWh, indicating that constraint-driven congestion or export limitations forced the region to accept dispatch at negative prices to manage excess renewable generation. The substantial wind generation output combined with the active binding constraint created conditions where generators were effectively paying to export or reduce output, resulting in the observed price floor.
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.