Commodity Demand — SA1 — Friday 8 May 2026

South Australia's spot price sits at $107/MWh with demand at 1,299 MW as of 6:30 AEST — a level roughly 500 MW below today's peak of 1,831 MW reached around 18:25 AEST, when prices were holding in the $88–$90/MWh range. The day's price-demand relationship has been notably inverted from the typical pattern: the morning ramp from around 16:30 AEST drove prices sharply into the $61–$90/MWh band as demand climbed from ~1,300 MW toward the 1,800 MW peak, but prices actually stepped higher into the $100–$123/MWh range through the afternoon and evening as demand fell back toward 1,250–1,300 MW. That decoupling points to tightening thermal supply conditions as wind generation fell away — wind is currently contributing just 62 MW and solar zero, with gas OCGT at 81 MW and gas CCGT at 208 MW carrying the bulk of local supply at a carbon intensity of 0.44 tCO2/MWh and only 17.7% renewable penetration.

The overnight price profile earlier this morning tells the other half of the story. Between roughly 13:30 and 15:30 AEST, prices collapsed to negative or near-zero levels — reaching as low as -$4/MWh — as demand troughed below 1,100 MW and generation surplus pushed the market into oversupply. That extended negative-price window, spanning nearly two hours, reflects the structural overnight surplus that characterises SA's supply stack when thermal units remain committed for system security. The morning ramp — demand surging from ~1,200 MW at 15:30 AEST to over 1,800 MW by 18:25 AEST in under three hours — drove prices from near-zero to $90/MWh within 45 minutes, a sensitivity of roughly $2–$3/MWh per 10 MW of demand increase during that ramp phase.

For the remainder of today, forecast prices for the 07:00–07:30 AEST window (21:00–21:30 UTC) are tracking in the $107–$114/MWh range, with the most recent dispatch forecast settling at $107/MWh — consistent with current actuals. Demand is expected to ease gradually through the late evening as the Saturday residential load profile winds down, which historically brings SA prices back toward the $80–$100/MWh band by midnight. Weather conditions are not supportive of demand spikes — Adelaide sits at 13.2°C with 6.2 km/h winds and 59% cloud cover, generating a heating demand index of 4.8 but no material cooling load. Wind potential is rated at just 0.4 out of scale, consistent with the minimal wind output currently observed, and tomorrow's outlook of 76% average cloud cover with average wind potential of 1.3 suggests the generation mix profile is unlikely to shift materially into the morning.

Traders should note that the elevated price floor in the $100–$123/MWh band observed throughout the afternoon — despite demand falling 400 MW from its peak — reflects gas-fired generation setting the marginal price at its short-run cost with minimal wind competition. Any further wind drop or unexpected demand lift above 1,400 MW this evening carries upside price risk toward the $120/MWh range seen intermittently at 18:15