SA1 experienced a sharp price spike from $331.58/MWh to $375/MWh across two consecutive intervals on 19 August 2026 at 23:05–23:10 UTC, representing a 168% increase from prices of ~$140/MWh just 25 minutes earlier. The spike was moderate in duration but acute in magnitude, with prices returning to baseline levels immediately after.
The binding constraint F_TASCAP_RREG_0220 was active across both spike intervals with marginal values of $7.78 and $7.75/MWh, contributing materially to the elevated cost but insufficient alone to explain the full $375 spike. The sharp price movement suggests demand-side pressure or rapid generation withdrawal coinciding with constraint tightening, though the generation mix snapshot does not isolate temporal changes during the spike intervals. The constraint's consistent activation indicates a structural supply limitation that, combined with other unspecified dispatch or demand factors, drove the severe pricing outcome.
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.