South Australia (SA1) experienced very high renewable penetration of 97.8% on 16 June 2026 around 11:15 AM, driven primarily by wind generation of 1,757.51 MW. This high renewable penetration resulted in extremely low spot prices, with the 11:15 AM settlement period reaching just $0.03/MWh before recovering slightly in subsequent intervals.
The collapse in spot prices to near-zero levels was driven by the combination of very high wind generation and low system demand, creating excess supply. Multiple binding constraints with marginal values between $3.45 and $10.07/MWh indicate that grid security and network constraints rather than generation scarcity were limiting factors, preventing further price suppression and forcing dispatch of high-cost or inflexible generation such as the 40 MW of gas CCGT online despite the minimal price signal.
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.