South Australia (SA1) experienced sustained negative pricing on 2 June 2026 at 17:50–18:05 AEST, with prices ranging from –$1.05/MWh to –$3.00/MWh across a 2-interval minimum. This minor severity event reflects a brief period of oversupply relative to demand in the region.
The negative pricing was driven primarily by high wind generation (1,761 MW) combined with minimal demand absorption, forcing marginal generation to be curtailed rather than dispatch at positive prices. The binding constraint F_T+RREG_0050 (likely a network or regional register constraint) with a marginal value of $6.08 suggests transmission limitations prevented efficient export of excess renewable energy, trapping supply within SA1 and forcing prices negative to encourage demand response and battery charging rather than gas 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.