TAS1 experienced negative pricing in two intervals on 23 September 2026 around 00:15–00:25, with a minimum price of −$6.83/MWh. Prices were highly volatile over this period, ranging from near-zero to $35.85/MWh, before and after the negative price events. The region was generating substantial hydro output (457–603 MW) alongside moderate gas-fired generation and minimal wind.
The negative pricing episodes appear driven by binding constraints with modest marginal values (constraint F_TASCAP_RREG_0220 at $3.44–3.45/MWh and constraint F_T+RREG_0050 at $2.99/MWh), which likely created local supply-demand imbalances requiring prices to fall below zero to clear the market. The elevated hydro generation, combined with these constraint-driven limitations on export or internal dispatch flexibility, prevented the region from absorbing available supply efficiently during these intervals.
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.