South Australia (SA1) experienced high renewable penetration of 90.85% during the 00:05–00:30 UTC period on 6 September 2026, driven predominantly by solar generation (359–373 MW) and wind (56 MW), with minimal thermal support. Despite the high renewable share, regional prices remained volatile, ranging from $9.10 to $42.02/MWh across five-minute intervals.
The volatility in spot prices despite abundant renewable supply reflects binding constraints on interconnector or network flows, with binding constraint F_TASCAP_RREG_0220 (marginal value $4.69/MWh) and F_T+RREG_0050 (marginal value $3.45/MWh) restricting the region's ability to export surplus generation or balance local demand. The price spikes to $42.02/MWh at two intervals align with peaks in gas-fired generation (42.02 MW CCGT), suggesting that when renewable output fluctuates or network constraints bind, thermal units set the marginal price despite their small contribution to the overall mix.
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.