TAS1 experienced sustained negative pricing at −$15/MWh across two consecutive intervals (13:20–13:25) on 12 June 2026, representing a minor severity event. Prices had been declining from around $70/MWh in the preceding hour before reaching the negative floor, suggesting a supply–demand imbalance favouring generation.
The negative pricing appears driven by excess renewable generation in Tasmania, with combined hydro and wind output totalling approximately 1,536–1,565 MW during the negative pricing window. Multiple binding constraints on the main transmission path and Tasmania regional regulation (F_MAIN+RREG_0220, with marginal values ranging from $3.49–$9.23/MWh, and F_T+RREG_0050 at $4.98/MWh) were active, indicating transmission limitations prevented economical export of surplus generation, forcing the region to price at the negative floor to incentivise demand response or reduce local generation.
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.