South Australia (SA1) experienced high renewable energy penetration of 88.55% during the early morning period of 11 September 2026, with combined solar and wind generation totalling approximately 1,096 MW. The region recorded negative spot prices ranging from −$0.91 to −$5.74/MWh across the settlement intervals, indicating an oversupply of renewable generation relative to local demand.
The negative pricing reflects the characteristic outcome of high instantaneous renewable generation coinciding with low morning demand in a region with limited energy storage capacity (battery storage was offline during this period). Multiple binding constraints with marginal values between $3.16 and $16.33/MWh were active, suggesting that network limitations or system security requirements were constraining the dispatch of additional generation, preventing further price reduction and forcing acceptance of negative-priced renewable energy to maintain balance.
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.