TAS1 experienced high renewable penetration of 89.8% on 23 September 2026 at 07:05–07:30 UTC, driven predominantly by hydro generation (approximately 2,919 MW across three sample periods) with minimal wind output. Prices rose steadily from $97.54/MWh to $122.14/MWh over the 25-minute window, indicating tightening system conditions despite the high renewable contribution.
The price rise was supported by multiple binding constraints with non-zero marginal values, notably constraint F_T+RREG_0050 (marginal values ranging from $3.99–$4.99/MWh) and constraint F_TASCAP_RREG_0220 ($3.99/MWh). These binding constraint marginal values indicate that dispatch flexibility was becoming increasingly limited, likely due to operational or network limitations that constrained the system's ability to absorb or redistribute the high hydro output, thereby lifting regional prices despite the abundance of renewable generation.
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.