Regional Outlook — SA1: Thursday 10 September 2026
South Australia's spot price sits at $89.85/MWh as of 06:30 AEST, tracking near the upper end of an overnight range that swung wildly from $101.02/MWh floor prints to a deep negative trough of -$294.71/MWh around 13:20-13:25 UTC (roughly 22:50-22:55 AEST) as wind generation surged against soft demand. Demand currently reads 1,395 MW, down from evening peaks above 1,800 MW seen around 09:00-09:30 UTC. The 24-hour pattern shows the classic SA signature: prices collapse to negative territory overnight when wind output dominates a low-demand system, then rebound sharply through the morning ramp as demand climbs past 1,700 MW.
Generation mix at the current interval is wind-dominated at 1,302 MW, comfortably the largest source, alongside gas OCGT at 87 MW, gas CCGT at 60 MW, and batteries contributing 67.5 MW net. Solar reads zero, consistent with the 06:30 AEST timing before sunrise generation ramps up. Renewable penetration sits at 90.3%, though this has been volatile across the day — troughing near 55-59% during the 05:00-06:00 AEST demand ramp when wind eased and gas filled the gap, before climbing back above 96% through the middle of the day as wind resumed strongly.
Carbon intensity is currently 0.0567 tCO2/MWh, up from an intraday low of 0.0126 tCO2/MWh recorded around 16:00 AEST yesterday, reflecting the current higher gas contribution relative to the low-carbon overnight and midday periods. Looking at predispatch, prices are forecast to soften into negative territory again through the overnight trough, with forecast RRP falling to around -$15/MWh by 13:30 AEST and staying negative until approximately 16:00-16:30 AEST, before a sharp rebound to $60.86/MWh at 17:00 AEST and climbing steadily to a forecast peak of $110.53/MWh around 19:30 AEST as the evening demand ramp coincides with reduced solar output. Prices are then forecast to ease slightly through the afternoon, settling near $77-90/MWh into the evening.
On notices, AEMO has been managing recurring negative settlement residue constraints on the VIC-SA and NSW-VIC interconnectors through the day, with several starting and ceasing cycles reflecting high renewable output pushing negative price spillover across regional boundaries — the latest VIC1-SA1 constraint ceased at 17:00 AEST. Separately, AEMO flagged a foreseeable intervention in SA for voltage support from 10:00 AEST today, following a pattern of voltage-related directions issued to AGL's Torrens Island units over the preceding week. Traders should watch for a possible directed synchronisation event if market response remains insufficient, which could affect merit order and local pricing during the low-demand overnight window. Load-shifting opportunities are strongest between 01:00-06:00 AEST tomorrow, with forecast prices as low as -$14/MWh offering savings of up to $124/MWh versus peak.