Regional Outlook — SA1: Wednesday 12 August 2026
South Australia's spot price sits at $68.58/MWh as of 06:25 AEST, sitting mid-range against an overnight trading band that spanned from -$6.00/MWh in the early hours (01:00-03:30 AEST) to a peak of $107.78/MWh around 08:25 AEST yesterday evening. Demand currently reads 1489 MW, down from an evening peak above 2050 MW. The 24-hour pattern shows the now-familiar SA signature: deeply negative or near-zero prices overnight through to sunrise as wind output dominates and demand troughs below 1000 MW, followed by a sharp ramp into the $80-107/MWh range as demand climbs and solar hasn't yet filled the gap.
Generation mix at the last snapshot (20:30 AEST) is wind-led at 784 MW, with gas contributing a combined 227 MW (130.8 MW CCGT, 96.3 MW OCGT), and batteries adding 11.5 MW. Solar output is at zero, consistent with the overnight window. Renewable penetration sits at 77.8%, pulling carbon intensity to 0.1239 tCO2/MWh — this is elevated relative to the 0.01-0.05 tCO2/MWh readings SA posted through the middle of the day, when renewable penetration touched as high as 98%. The overnight-to-morning transition is the key driver: as wind eases and gas ramps to cover demand growth, carbon intensity climbs roughly tenfold from its daily low.
Predispatch forecasts point to a volatile day ahead. Prices are expected to ease slightly through the 21:00-23:30 AEST window (around $90-130/MWh) before spiking to $170/MWh near midnight, easing again into the early morning trough (as low as $20/MWh around 03:00 AEST), then climbing sharply from 07:00 AEST onward — forecasts show $127-190/MWh through the 07:30-11:30 AEST period, with a peak near $190.88/MWh around 10:30 AEST. This aligns with weak solar potential today (average 2.4%, cloud cover 78%) and modest wind potential (0.9%), both well below yesterday's contribution levels, suggesting renewable output will be constrained through the morning peak. Traders should note the identified load-shifting windows: the 03:00-04:30 AEST period offers the best economics at $30.78/MWh average with $160/MWh savings versus peak.
On notices, AEMO's MTPASA reserve notice from 11 August flags Low Reserve Conditions forecast for South Australia in July 2028, with unserved energy risk extending across the August 2027-2028 period — a longer-term reliability signal rather than an immediate operational concern. A prior AEMO intervention event in the SA region (08 August, related to voltage) was cancelled as of 10 August, and the AGC Heart Beat service interruption reported on 12 August has been resolved. No active constraints or directions are currently in force for SA1.