A binding constraint (NSA_Q_GSTONE34_250) in SA1 reached a high shadow price of $1,370.94/MWh during the early morning period of 11 August 2026, significantly exceeding the regional reference price which ranged from $7.86 to $40.95/MWh across the preceding settlement intervals. The constraint remained binding across multiple dispatch cycles with varying marginal values, indicating persistent operational limitations in the region.
The high shadow price on the binding constraint reflects a substantial scarcity signal, suggesting the constraint was actively limiting generation dispatch during this period. With high renewable generation output (1,527 MW wind, 600 MW+ solar) and relatively low thermal generation (142 MW gas), the constraint likely became binding as the system attempted to manage the high renewable penetration, with the large differential between the constraint's marginal value and spot prices indicating the constraint was preventing lower-cost dispatch outcomes that would otherwise have been available.
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.