SA1 experienced sustained negative pricing across five consecutive intervals on 4 June 2026 between 07:15 and 07:45, with the minimum price reaching −$3/MWh. The region's generation mix was dominated by wind (1,662.82 MW) and solar (75.88 MW combined), with modest gas-fired capacity (100.92 MW combined), creating an oversupply condition during low demand periods.
The negative pricing was driven by excess renewable generation that could not be economically curtailed or exported, forcing generators to pay for dispatch. Multiple binding constraints with substantial marginal values—most notably constraint F_T+NIL_MG_RECL_R6 at $17.98/MWh—restricted the region's ability to relieve this surplus, preventing equilibration through interconnector flows. The brief price spike to $15.62/MWh at 07:35 and the subsequent return to −$3/MWh suggest constraint relief was temporary, after which oversupply conditions reasserted themselves.
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.