NSW1 experienced sustained negative pricing at -$5.01/MWh during the 03:20 settlement interval on 3 June 2026, with negative prices persisting across multiple intervals in the early morning period. The negative pricing reflects a temporary oversupply condition in the region during off-peak hours when renewable generation remained elevated.
The negative pricing was driven by excessive renewable generation (solar 2,087 MW and wind 1,878 MW) during the early morning period when demand was minimal, creating a structural oversupply that generators were unable to curtail. The binding constraint F_S+TBTU_L1 with a marginal value of $66.60 indicates significant transmission congestion preventing energy export from NSW1, trapping surplus generation and forcing the market to pay participants to reduce output, particularly affecting high-marginal-cost gas plant.
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.