South Australia (SA1) experienced sustained negative pricing at −$2/MWh across two settlement intervals on 1 June 2026, with prices remaining negative throughout a seven-interval window. This minor severity event reflected typical renewable energy oversupply conditions characteristic of the South Australian market.
The negative pricing was driven by exceptionally high wind generation (1,930 MW) significantly exceeding regional demand, whilst minimal solar contribution (0 MW) and negligible battery discharge (0.23 MW combined) limited supply-side flexibility. The binding constraint F_T+RREG_0050 with marginal values of approximately $6.29−6.30/MWh indicates a network or frequency constraint was active, forcing continued dispatch of low-marginal-cost wind generation and preventing economic withdrawal, thereby pushing prices negative as generators paid to maintain output.
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.