NSW1 experienced sustained negative pricing of approximately $-9/MWh for two consecutive intervals (03:10–03:15) on 20 May 2026. This minor severity event occurred during a period of very low electricity demand in the early morning, with prices dropping sharply from positive levels before recovering.
The negative pricing was driven by high instantaneous renewable generation (3,165 MW from solar and wind combined) coinciding with low system demand during the 03:00–03:15 pre-dawn period. With minimal gas generation online (zero OCGT and CCGT capacity) and coal units unable to ramp down quickly, the supply-demand imbalance forced prices negative to incentivise consumption and discourage further generation; network constraints (F_T+RREG_0050 and F_I+RREG_0220) with binding marginal values of $5–7/MWh suggest localised congestion also contributed to the pricing pressure in NSW1.
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.