Tasmania experienced two intervals of negative pricing at -$0.11/MWh on 17 August 2026 at 23:50–23:55, following an earlier negative price at 23:25. Prices returned to positive levels ($10–14/MWh) in the intervening periods, indicating transient oversupply conditions rather than sustained constraint-driven scarcity.
The negative pricing episodes align with elevated renewable generation, particularly hydro output reaching 819.92 MW in the final interval, combined with modest gas OCGT generation of approximately 125 MW. Multiple binding constraints with marginal values between 4.95 and 12.72 $/MWh suggest that network limitations restricted the ability to export excess generation, forcing local supply to clear at negative prices to balance demand within the region.
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.