TAS1 experienced sustained negative pricing at $-4.06/MWh across two consecutive intervals (18:40 and 18:45) on 13 July 2026, representing a minor severity event. Prices recovered slightly to $-4.04/MWh in the following interval before the negative pricing episode concluded.
The negative pricing was driven by a binding constraint (F_T+RREG_0050) with a marginal value of approximately $3.91–$4.92/MWh, indicating significant congestion or operational limitations in the transmission network during the evening peak demand period. High levels of renewable generation (wind at 400–453 MW and hydro at 665–783 MW) combined with relatively low gas generation (124–125 MW) created oversupply conditions that, when constrained by the binding network limitation, forced prices negative to incentivise load acceptance and manage system conditions.
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.