Regional Outlook — SA1: Tuesday 1 September 2026
South Australia's spot price sits at $101.02/MWh as of 06:25 AEST, holding at a level it has repeatedly returned to through the evening peak. The last 24 hours have been a study in volatility: prices spent the overnight period deeply negative, touching -$119.67/MWh around 23:40 due to low demand and high wind output, before swinging sharply positive through the afternoon and evening peak, spiking as high as $220.67/MWh at 15:55 and $208.87/MWh multiple times between 16:00-17:00 as demand climbed toward 1,890 MW mid-morning. Demand has since eased back to 1,371 MW, consistent with the current $101.02/MWh print.
The generation mix at 20:30 AEST shows wind leading at 365.56 MW, followed by gas OCGT at 242.77 MW, batteries discharging at 162.84 MW, gas CCGT at 42.69 MW, and solar at zero given the evening timing. Renewable penetration sits at 64.93%, down from the near-98% levels recorded overnight when wind dominated and demand troughed below 900 MW. Carbon intensity is currently 0.2196 tCO2/MWh, up from a low of 0.0101 tCO2/MWh at 21:00 yesterday — intensity tracked below 0.02 tCO2/MWh through the overnight wind-heavy window, then climbed steadily from 08:00 as gas plant ramped to cover the demand build, peaking near 0.263 tCO2/MWh at 16:30.
Predispatch forecasts point to continued volatility overnight. Prices are expected to firm to $119-138/MWh through the 21:00-23:30 window before easing to around $98-101/MWh near midnight, then collapsing toward zero and negative territory from 01:30 AEST onward — forecasts show $10.85/MWh at 01:30, dropping to near $0/MWh between 04:00 and 06:00, before recovering through the morning ramp to $101/MWh by 08:00 and holding near that band into the afternoon. A further dip below zero is forecast for the 16:00-18:00 window tomorrow (-$4 to -$7/MWh), consistent with the low-carbon overnight and off-peak load-shifting windows identified for tomorrow's session.
On notices, AEMO has flagged a foreseeable intervention in SA from 10:30 AEST today due to voltage conditions, with a directions notice likely if market response is insufficient by 16:00 yesterday — this follows a pattern of repeated voltage-related interventions in SA through late August, including directions to AGL SA Generation units at Torrens Island and Barker Inlet for voltage control support. Traders should also note a VIC-region interconnector constraint (CA_SYDS_59A889E5) affecting V-SA and V-S-MNSP1 flows, active since 1 September, which may influence interconnector-driven price movements. Planned MarketNet maintenance is scheduled for 3-4 and 11 September; no direct dispatch impact expected but participants should confirm VPN failover configurations ahead of those windows.