Commodity Demand — VIC1: Friday 18 September 2026
Victoria's spot price sits at $0.01/MWh at 20:30 AEST, with demand at 4,428 MW — well below the 6,400 MW evening peak recorded 24 hours earlier. The overnight trough is already underway: AEMO's forecast has prices diving to -$50/MWh by midnight and as low as -$135/MWh around 03:30 AEST tomorrow, tracking a demand collapse toward sub-3,200 MW territory in the early hours. Wind is currently supplying 3,305 MW against total generation of roughly 5,415 MW, pushing renewable penetration to 61.7% and carbon intensity down to 0.467 tCO2/MWh — conditions that typically coincide with negative or near-zero pricing in VIC given minimal thermal load-following requirement.
Price sensitivity to demand shifts is stark today. Yesterday evening's ramp from 4,428 MW to 6,530 MW (a 47% increase between 20:30 and 21:00) drove prices from near-zero to $91.57/MWh in the space of six 5-minute intervals, then prices reversed to negative territory within an hour as demand fell back below 4,000 MW overnight. This morning's demand build from the 3,000 MW overnight floor to the 5,800-5,900 MW mid-morning plateau (07:00-09:00 AEST) saw prices spike briefly to $74.88/MWh before settling into the $8-12/MWh band once solar and wind output matched load. The pattern confirms VIC's price curve is highly convex around the 5,500-6,000 MW threshold — below that, brown coal and wind cover demand comfortably; above it, marginal gas or interconnector flows get called on and prices jump.
The forecast trajectory for today (19 September) shows a similar but slightly sharper shape: negative pricing persists through the early hours (-$68 to -$135/MWh between 01:00 and 04:00 AEST), then a rapid morning ramp pushes forecast prices to $80.75/MWh by 09:00 AEST as demand rebuilds. Prices ease back to the $10-13/MWh band through midday before falling to near-zero by early afternoon — consistent with today's forecast solar potential of 20.5% and daytime highs reaching 26.3°C, which should support rooftop PV output and cap midday demand growth. The AEMO load-shift opportunities flagged for 02:00-06:00 AEST (avg prices -$68 to -$106/MWh) offer the clearest arbitrage window, saving up to $187/MWh versus peak-period costs for flexible load.
One operational factor worth noting: AEMO issued an inter-regional transfer notice at 20:50 AEST for a short-notice outage on the Hazelwood-South Morang No.2 500kV line, invoking constraint set V-HWSM affecting VIC1-NSW1 and Basslink flows. This has potential to tighten VIC's effective supply margin during tonight's evening peak if it persists, though with demand already receding past the 20:30 peak, near-term price risk from this constraint looks limited. Watch for its status heading into tomorrow's morning ramp.