SA1 experienced sustained negative pricing at $-1.09/MWh during the 03:50 interval on 29 July 2026, preceded by a minor dip to $-0.78/MWh in the preceding interval. This minor negative pricing event occurred during a period of elevated renewable generation, particularly from solar (226–326 MW) and wind (184 MW) sources.
The negative pricing was likely driven by binding constraints that restricted the ability to export excess generation or reduce output further. The constraint F_T+RREG_0050 with marginal values of $2.65–2.66/MWh and F_TASCAP_LREG_0210 with a marginal value of $1.96/MWh were active during the negative price intervals, suggesting these constraints limited dispatch flexibility. With high renewable supply and these binding export or ramping constraints, dispatchable plant (particularly gas generators totalling ~320 MW) could not reduce sufficiently, forcing prices negative to incentivise load response.
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.