Tasmania experienced brief negative pricing in TAS1 during the 12:00–12:05 UTC intervals on 2 July 2026, with prices reaching −$4.91/MWh. The event occurred amid substantial renewable generation (hydro and wind contributing over 1,000 MW combined) and followed a period of positive but low prices ($5–$11/MWh).
The negative pricing was driven by high renewable supply in combination with binding network constraints. Multiple binding constraints with non-trivial marginal values (F_T+LREG_0050 at $7.25/MWh and F_TASCAP_RREG_0220 ranging $3.43–$6.79/MWh) indicate that local transmission or regulatory limits prevented efficient dispatch of surplus renewable generation. When renewable output cannot be economically exported or curtailed due to constraint binding, prices fall below zero to incentivise demand response and generator withdrawal.
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.