QLD1 experienced sustained negative pricing at -$2.5/MWh for two consecutive 5-minute intervals (00:00–00:05 on 23 May 2026), representing minor severity. Prices had collapsed from $5.71/MWh just 25 minutes earlier, dropping through near-zero levels before turning negative.
The negative pricing was driven by oversupply conditions during a late evening/early morning period with combined solar generation exceeding 5,700 MW (predominantly rooftop PV) alongside substantial coal baseload (~3,148 MW) and wind (~516 MW), creating structural excess that dispatch could not easily shed. The binding network constraints (F_Q++8E series with marginal values ~$5.73/MWh) indicate localised transmission bottlenecks preventing efficient power flow out of the region, forcing operators to pay generators to reduce output rather than curtail inflexible baseload coal plant, thus pushing prices negative.
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.