SA1 experienced sustained negative pricing at approximately −$0.09/MWh across six consecutive five-minute intervals (10:25–10:55 on 9 June 2026), with total minimum price of −$0.09/MWh. The negative pricing occurred during a period of high wind generation (1,936.6 MW) and battery charging (193.18 MW combined), with minimal demand absorption from solar or gas generation.
The negative pricing was driven by binding constraints with significant marginal values, most notably F_T+LREG_0050 (marginal value $37.69/MWh) and F_TASCAP_RREG_0220 (marginal value $7.79/MWh), indicating tight operating margins on the transmission network. High wind generation coupled with low demand and active battery charging created an oversupply condition in SA1 that could not be fully dispatched or exported due to these network constraints, forcing the spot price into negative territory to incentivise reduced generation or increased consumption.
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.