NEM Overview: Tuesday 15 September 2026

NEM spot prices sit in a tight $94-104/MWh band across all regions this morning, with NSW1 leading at $103.91/MWh against total demand of 7,767 MW, QLD1 at $99.68/MWh, VIC1 at $99.47/MWh, WA1 at $101.06/MWh, SA1 at $94.74/MWh and TAS1 at $94.07/MWh. The spread of under $10/MWh between highest and lowest regions points to a well-interconnected morning with no material congestion — VIC1-NSW1 flow sits at 201.65 MW and TAS1-VIC1 (Basslink) at 179.45 MW, both well within limits and non-binding.

Generation mix shows sharp regional contrasts. SA1 is running almost entirely on wind (1,429 MW) with negligible thermal generation, delivering 94.5% renewable penetration and carbon intensity of just 0.027 tCO2/MWh. TAS1 sits at 100% renewable, split between hydro (1,050 MW) and wind (304 MW), with zero carbon intensity recorded. NSW1 (30.7% renewable) and QLD1 (17.7% renewable) rely more heavily on black coal — 5,178 MW and 5,189 MW respectively — pushing their carbon intensity to 0.609 and 0.721 tCO2/MWh. VIC1 sits at 39.98% renewable with brown coal contributing 3,638 MW alongside 2,003 MW of wind. NEM-wide renewable penetration reads at 53.6%, with the grid stress score elevated at 86.1, reflecting the ongoing operational complexity in SA.

SA1 remains the region to watch today. AEMO has an active direction on AGL's Torrens Island Unit 4 for voltage control, expected to stay in place until 1630 hrs, and a Minimum System Load (MSL1) notice flags forecast demand dropping to -178 MW between 1130-1430 hrs on 19 September as rooftop solar and wind output outstrip underlying demand. Traders should also note the cancelled TAS1 lightning-related contingency reclassifications on the Gordon-Chapel St and Farrell-Reece 220kV lines, both reverted to non-credible status overnight, removing the associated constraint sets on Basslink flows.

Weather supports continued strong wind output in SA1 and NSW1 today, with SA1 wind potential currently low (0.3) after overnight generation but NSW1 seeing wind potential near 20.5 and improving through the day. Solar potential is muted across the southern states under cloud cover (VIC1 69%, SA1 76%), while NSW1 and QLD1 see clearer skies supporting midday solar ramp. With SA1's low-demand risk building toward the weekend and voltage support directions still active in that region, expect continued AEMO intervention notices and possible negative pricing risk around the 19 September minimum load window.