NSW1 experienced sustained negative pricing at −$0.57/MWh across two consecutive intervals (00:20 and 00:25 on 7 September 2026). This occurred during an overnight period characterised by high solar generation (2,474 MW) and substantial wind output (551 MW), alongside significant coal baseload (2,575 MW), resulting in excess supply relative to demand.
The negative pricing was driven by a binding constraint (F_T+LREG_0050) with marginal values ranging from $21.38–$21.95/MWh, indicating that this constraint was actively limiting generation dispatch and preventing the market from clearing excess supply through normal dispatch mechanisms. The combination of high renewable generation (primarily solar, likely from late afternoon/early evening conditions) and inflexible baseload coal generation created an oversupply condition that the binding constraint exacerbated, forcing the market price into negative territory to incentivise load and discharging resources.
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.