SA1 experienced sustained negative pricing at −$1/MWh across two intervals (00:15 and 00:30) on 11 August 2026, with a low of −$1.10/MWh. The event occurred during a period of high renewable generation, with wind contributing 1589.49 MW and solar 352–319 MW to the regional supply.
The negative prices align with a period of very high variable renewable energy output relative to regional demand, which typically necessitates urgent dispatch adjustments. A binding constraint (NSA_Q_GSTONE34_250) with consistently high marginal values ranging from 1372–1617 $/MWh was active throughout, indicating this constraint was limiting dispatch flexibility and preventing generators from economically managing their output, forcing marginal supply to negative pricing levels to clear the market.
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.