South Australia (SA1) experienced very high renewable penetration at 97.0% during the night of 1–2 August 2026, driven primarily by wind generation of 1,122.62 MW and solar output of 491.52 MW combined. Negative prices reached −7.14 $/MWh across multiple settlement periods, reflecting over-supply conditions typical of high renewable generation with constrained demand or export capacity.
The sustained negative pricing and high renewable penetration were supported by strong wind generation during the night-time period, which typically sees lower demand. Multiple binding constraints with marginal values between 3.44 and 4.68 $/MWh indicate that network or system limits were active in constraining the dispatch of additional generation, forcing renewable output to be curtailed or accepted at negative prices rather than exported. The persistence of negative prices across six consecutive five-minute settlement periods suggests these binding constraints remained effective throughout the interval, preventing the region from freely exporting excess renewable energy.
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.