QLD1 experienced sustained negative pricing at $-2/MWh across two consecutive intervals (00:05 and 00:20–00:25 on 26 July 2026), with a minimum of $-2.15/MWh. The negative pricing occurred during high solar generation (combined ~5,958 MW) and moderate overall demand conditions in the pre-dawn period.
The negative pricing was likely driven by high non-dispatchable solar generation coinciding with relatively low demand during overnight hours, creating an oversupply condition. The binding constraint F_T+RREG_0050 with a marginal value of approximately $3.66/MWh indicates that a transmission or regulating raise requirement was actively constraining the dispatch, forcing generators to bid below zero to manage the surplus generation and maintain network security.
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.