NEM Overview: Friday 18 September 2026

Spot prices show a sharp regional split heading into Saturday trade. NSW sits at $64.31/MWh and QLD at $64.83/MWh, while VIC, SA and TAS are all pinned at the $0.01/MWh floor — a wide intra-NEM spread driven by strong wind output in the south. VIC1-NSW1 interconnector flow is binding at 720 MW (full export limit), pushing surplus southern generation north into NSW and QLD. WA1, outside the NEM proper, is trading at $107.07/MWh. Demand is soft across the board: NSW at 6,797 MW, QLD at 5,496 MW, VIC at 4,428 MW, SA at 1,287 MW and TAS at 920 MW.

Generation mix reflects the price split. SA is running at 96.9% renewable penetration with wind contributing 1,336 MW against negligible gas (42 MW CCGT, 0.1 MW OCGT) and carbon intensity of just 0.015 tCO2/MWh. TAS sits at 100% renewable (hydro 239 MW, wind 427 MW). VIC is at 61.7% renewable with wind at 3,305 MW offsetting 2,073 MW of brown coal, giving intensity of 0.467 tCO2/MWh. NSW renewable share is 32.5%, with black coal still the largest single source at 4,216 MW alongside 1,592 MW of wind. QLD is the outlier at 13.5% renewable penetration, black coal dominant at 4,778 MW against 354 MW wind and 211 MW solar, and carbon intensity of 0.757 tCO2/MWh — the highest of the five regions. NEM-wide renewable penetration sits at 59.2% on the platform's composite score.

Grid stress reads 74 and market conditions 53.8, consistent with the active operational notices out of SA. AEMO has a standing direction on AGL's Torrens Island B4 unit for voltage control support, running until 1700 hrs today, and has flagged a forecast Minimum System Load (MSL1) event in SA between 1130 and 1430 hrs, with minimum demand projected at -178 MW around 1330 hrs — a reminder that rooftop solar plus strong wind can push SA operational demand negative around midday. Traders should watch for AEMO intervention risk in SA if voltage support proves insufficient. In TAS, lightning-related contingency reclassifications on the Gordon-Chapel St and Farrell-Reece 220kV lines have both been cancelled, and the network augmentation at Glencoe substation in QLD has been commissioned, adding transmission capacity in that region. A VIC network outage (Hazelwood-South Morang No.2 500kV) from 2050 hrs last night remains in force, invoking constraint set V-HWSM across several interconnectors — watch for continued binding on VIC1-NSW1 through the morning as this constraint persists alongside strong wind generation.

Outlook for today: clear skies and moderate wind across SA and VIC should keep southern prices depressed through midday, with the MSL event in SA likely to test negative pricing risk again. NSW and QLD carry firmer prices on cooler, low-wind conditions (QLD wind potential near zero this morning) and coal-heavy dispatch. Expect the north-south price spread to persist until wind eases or southern demand picks up into the evening.