South Australia (SA1) experienced sustained negative pricing at -$0.1/MWh across 8 consecutive intervals from 23:55 on 12 June 2026 through 00:30 on 13 June 2026. The pricing floor reflects oversupply conditions driven primarily by high wind generation (1417.34 MW) coinciding with overnight low demand.
The negative pricing was driven by excess renewable generation relative to system demand during off-peak hours, with wind output substantially exceeding requirements. Multiple binding constraints with positive marginal values—including F_Q++BCDM_L6 (5.62 $/MWh), F_I+RREG_0220 (4.35 $/MWh), and F_Q++BCDM_L60 (3.3 $/MWh)—indicate physical network or operational limits prevented efficient dispatch of surplus generation, forcing the market to incentivise load through negative pricing rather than curtailing renewable output.
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.