SA1 experienced sustained negative pricing over three consecutive intervals (04:15–04:20) on 10 September 2026, with the minimum price reaching −$255.42/MWh. The region's generation mix was dominated by wind (123 MW) and gas-fired plant (85 MW CCGT), with battery storage and solar also contributing. Negative pricing persisted across an 8-interval window, indicating structural oversupply conditions during this period.
The binding constraint F_T+LREG_0050 was active across all intervals with marginal values ranging from $19.92 to $35.54/MWh, indicating that this constraint was preventing efficient generator dispatch and forcing the market price negative. The sustained negative prices reflect a situation where available generation, particularly wind and gas-fired output, exceeded the region's demand and system capability to absorb or export this energy, forcing marginal generators to pay to remain online as the constraint limited further export or load-balancing options.
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.