NEM Overview: Sunday 13 September 2026

Spot prices sit in a tight $48-57/MWh band across the eastern states this morning, with NSW leading at $56.80/MWh, QLD at $54.50/MWh, SA at $53.21/MWh, VIC at $50.42/MWh and TAS at $48.65/MWh. WA1 is the outlier at $108.81/MWh, more than double the eastern seaboard, reflecting its isolated grid and separate market dynamics. Total scheduled demand across the NEM mainland regions is running at roughly 19,880 MW, led by NSW (7,277 MW) and QLD (6,156 MW).

Renewable penetration is uneven by region. SA and TAS are the standouts, running at 84.8% and 88.6% renewables respectively, with carbon intensity near-zero (0.088 and 0.074 tCO2/MWh) — SA's output is dominated by 740 MW of wind, and TAS by 745 MW of hydro. NSW, VIC and QLD are tracking in the 31-34% renewable range, with carbon intensity between 0.59-0.80 tCO2/MWh, as black and brown coal remain the largest single generation source in each (NSW 4,675 MW, QLD 4,296 MW, VIC 3,798 MW). NEM-wide renewable penetration is scored at 52.1%, aided by strong wind output in QLD (1,558 MW) and NSW (1,121 MW), plus battery dispatch of over 1,000 MW in VIC alone. The grid stress score of 66.1 and market conditions score of 52.6 point to a moderately tight but manageable operating state.

SA remains the region to watch. AEMO has an active MINIMUM SYSTEM LOAD notice flagging a forecast MSL1 condition on 19 September, with demand expected to dip to -111 MW around 1330 hrs — a sign of high rooftop solar offsetting grid demand in shoulder-season conditions. This follows a string of voltage-related interventions this week, including a direction to AGL's Torrens Island B4 unit to synchronise for voltage support, effective until 1400 hrs today. Traders should note the V-S-MNSP1 and VIC1-NSW1 interconnectors are both binding, with Heywood flows constrained (import limit -40 MW) and VIC1-NSW1 exporting at 560 MW, near its limit — worth monitoring for congestion pricing risk through the day.

Today's weather outlook adds context: NSW and QLD see solar potential build modestly (17-22%) with mild cloud cover, while VIC stays overcast (89% cloud) with negligible solar and wind potential, likely keeping VIC leaning on thermal and battery dispatch. SA's wind potential is soft today (2.4%) but cloud clears markedly from Thursday, setting up stronger solar contribution into the weekend — a factor likely feeding into next week's forecast MSL event.