SA1 experienced two intervals of negative pricing at -$0.09/MWh on 8 June 2026 during the 17:15 and 17:25 settlement periods, with prices recovering to near-zero levels immediately before and after. The negative prices occurred within a brief window of sustained low pricing (between $0.83 and $4.58/MWh) across a five-interval band.
Wind generation dominated the region at approximately 1,801.55 MW during the event, whilst solar and battery output remained minimal, creating a supply-heavy generation profile typical of conditions favouring negative pricing. A binding constraint with marginal values between $3.81–$3.82/MWh was active across the event interval, indicating a physical network limitation was forcing dispatch economics negative, though the magnitude of the constraint shadow price suggests it was a secondary factor rather than the primary driver of the sub-zero settlement.
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.