South Australia (SA1) experienced high renewable penetration of 85.4%, with wind generation dominating at 757.24 MW alongside significant solar and battery contributions. Regional reference prices collapsed from $80.44/MWh to $0/MWh over a five-interval period, reflecting the substantial renewable generation flooding the market.
The sharp price decline was driven by the high proportion of renewable generation displacing gas-fired plant, reducing system marginal cost. Binding constraint F_T+RREG_0050 (with marginal values of $3.70–$3.69/MWh) and F_TASCAP_RREG_0220 (marginal value $3.38/MWh) became active during this period, indicating that physical network or regulatory limits constrained further renewable output and prevented prices from falling further initially, but the underlying oversupply relative to demand ultimately drove prices toward zero.
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.