NSW1 experienced sustained negative pricing at −$3/MWh across two consecutive intervals (21:00–21:05 on 19 September 2026), representing a minor pricing event. Prices had been declining through the preceding intervals, dropping from $22.88 to near-zero levels before turning negative.
The negative pricing was driven by an excess supply situation with high renewable generation (solar at 1704.7 MW and wind at 770.14 MW) combined with baseload coal generation of 3220.42 MW, creating downward pressure on the regional price. Binding constraints with elevated marginal values—particularly F_T+LREG_0050 at $40.99 and $15.99—indicate that network or ancillary service limitations prevented efficient dispatch of surplus generation, forcing prices into negative territory as generators were required to stay online despite excess supply.
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.