SA1 experienced sustained negative pricing at −$1.1/MWh across two consecutive intervals (23:15 and 23:20 on 16 September 2026), representing a minor pricing event. Prices fell sharply from $0.25/MWh in the preceding interval, following a period of moderately elevated pricing in the $40–$55 range.
The negative pricing occurred during a period of substantial renewable generation, with wind contributing 884.92 MW and solar 742.81 MW combined across the region, totalling over 1,600 MW of must-run output. Multiple binding constraints with measurable marginal values indicate transmission or network constraints were active during this period, suggesting that renewable generation output could not be efficiently dispatched and excess supply in the constrained region required negative pricing to reduce 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.