Regional Outlook — SA1: Wednesday 19 August 2026
South Australia's spot price sits at $80/MWh as at 06:30 AEST, holding on the same level it has bounced between since 20:00 last night. This follows an extremely volatile 24 hours: overnight prices collapsed deep into negative territory, bottoming at -$496.77/MWh around 03:30 AEST on excess wind supply against light demand, before snapping back sharply through the 07:00-08:00 morning ramp to peaks above $100/MWh as demand climbed past 1,800 MW. Total demand currently reads 1,380 MW, tracking through the evening step-down from this afternoon's ~1,850 MW peak.
Generation mix at the last interval shows wind leading at 505 MW, followed by gas-fired plant at 457 MW combined (277 MW OCGT, 180 MW CCGT), batteries dispatching 241 MW, and solar at zero given the after-dark interval. Renewable penetration sits at 62% and carbon intensity reads 0.223 tCO2/MWh — both figures moving with the wind and solar cycle, having been as clean as 0.028 tCO2/MWh and above 93% renewable overnight when wind supply was abundant, then climbing to a peak intensity of 0.316 tCO2/MWh around 16:30 AEST as gas plant ramped to cover the wind lull and evening demand build. Weather settings for today show minimal solar potential (12.8% average) under 64% cloud cover, with modest wind potential of 4.3%, consistent with the current gas-heavy contribution to firm the evening peak.
Predispatch forecasts point to prices holding near current levels through the evening peak — $87-95/MWh into the 22:00-23:00 AEST window — before easing sharply overnight as wind resumes, with forecasts showing sub-$15/MWh from 00:30 AEST and troughs near zero between 02:00-05:00 AEST tomorrow. The load-shifting windows confirm this, flagging 01:00-06:00 AEST as low-price, low-carbon periods offering $119-133/MWh savings versus peak. Prices are then forecast to rise again through tomorrow's morning ramp, reaching $101-130/MWh between 08:00-16:00 AEST as gas generation fills the gap during today's overcast, low-wind conditions.
On notices, AEMO issued directions to AGL SA Generation's Torrens Island B2 unit on 18 August to synchronise and provide voltage control support, reflecting insufficient synchronous generation to maintain secure voltage conditions in SA — that intervention event remains logged as active. Negative settlement residues on the VIC-SA interconnector triggered constraint NRM_VIC1_SA1 during yesterday's price collapse, which AEMO has since ceased managing as of 18:00 AEST. Separately, AEMO's August MTPASA flags a Low Reserve Condition for SA in July 2028, a longer-term reliability signal rather than an immediate operational concern.