Tasmania experienced sustained negative pricing at -$5.43/MWh during the 12:00 settlement period on 27 July 2026, with negative prices recorded across 2 intervals as the region transitioned from near-zero pricing. The event occurred during a period of elevated renewable generation, with combined hydro output exceeding 2,800 MW alongside wind generation above 250 MW.
The negative pricing resulted from binding constraint conditions that created an economic requirement to reduce generation or increase consumption. A binding constraint with a marginal value of $8.35 million (T_BLINK_TV_NGZ) and multiple binding constraints associated with regulatory requirements (F_T+LREG_0050) collectively forced the market into a position where marginal generation had negative economic value. With substantial hydroelectric generation (1,147 MW in the final interval) unable to be economically curtailed due to dispatch requirements, marginal bidders were required to pay to operate, driving prices negative.
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.