A textbook overnight oversupply pattern swept the NEM, with all five eastern regions posting negative prices between roughly midnight and 6:30am as wind and solar output ran high against soft demand — NSW1 hit −$11/MWh, SA1 touched −$10.14/MWh across three intervals, and VIC1, QLD1 and TAS1 all dipped below zero at various points. Prices recovered firmly through the day, with QLD1 peaking near $85/MWh and NSW1 topping $89/MWh. Three of six NEM interconnectors were binding by 6:30pm AEST, with Heywood-Murraylink into SA sitting at its export limit (565 MW). Today, watch the morning solar ramp for a repeat of overnight negative pricing and continued interconnector congestion into SA.
South Australia was the standout region, swinging from 94.8% renewable penetration and prices as low as −$10.14/MWh overnight to a firm $60.09/MWh by 20:30 AEST as demand climbed to 1,132 MW. SA also recorded the NEM's lowest carbon intensity this morning at 0.047 tCO2/MWh, running almost entirely on wind and battery with negligible gas support.
WA1 remained the tightest region in the country, averaging $104/MWh over the past 24 hours with a peak of $138/MWh — well above every NEM region. No specific event data was flagged for WA1 overnight; conditions appear driven by underlying demand and supply balance rather than a discrete constraint.
No LOR conditions are forecast across the NEM in the next 48 hours. Gas hub prices firmed slightly day-on-day, with STTM Sydney at $10.79/GJ, Brisbane at $11.27/GJ and Adelaide at $10.95/GJ on 5 September. LGCs rose to $8 for the week ending 4 September, up from $7.25 the prior week, though still below the $8.50 seen in mid-August.