commodity demand sa — SA1

South Australia's spot price sits at -$8.50/MWh with demand at 1,262.56 MW as of 06:30 AEST — a Saturday morning level that is running well below the day's peak of 1,687.73 MW recorded around 17:55 AEST during the morning ramp. The demand-price relationship across today's cycle has been unusually inverted: prices were most negative not during overnight lows (where demand troughed near 620 MW around 13:20–14:30 AEST) but during post-midnight and afternoon windows when wind generation at 850 MW is suppressing marginal cost well below demand-driven clearing levels. The morning shoulder demand ramp from roughly 620 MW at 13:15 AEST to over 1,680 MW by 17:55 AEST drove prices into positive territory — peaking at $81.15/MWh at 18:00 AEST — the only sustained positive price window in the last 24 hours.

The demand trajectory now points to a continued Saturday trough. Current 1,262.56 MW sits in the lower-mid range of today's cycle, and with solar output at zero and wind holding at 850 MW against this subdued load, the supply-demand balance remains long. Forecasts for the 07:00–07:30 AEST half-hour intervals consistently project prices around -$3.01/MWh to -$3.38/MWh, confirming the market does not anticipate demand-driven price relief in the immediate term. The broader demand trough — Saturday residential and commercial load suppressed by the ANZAC Day public holiday — means the morning ramp that typically drives prices positive on a weekday is likely to be later, shallower, and shorter today.

The overnight price history illustrates just how sharply demand level shapes price in this region. When demand fell below 700 MW between roughly 13:00–14:30 AEST, prices held at -$3.00/MWh to -$3.14/MWh as the market mechanically set floor prices against surplus wind. By contrast, the 06:15–10:00 AEST window — where demand climbed from 1,093 MW to over 1,680 MW — saw prices clear between $38.75/MWh and $81.15/MWh, a spread of over $85/MWh driven almost entirely by demand volume pulling gas capacity onto the margin. That sensitivity band is the key trading variable for today: if Saturday demand peaks fall 100–150 MW short of the ~1,680 MW seen in this morning's peak, the positive price window will be narrower and prices will clear at the lower end of the $60–$80/MWh range observed at equivalent demand levels.

Load window data signals the most negative prices of the day arrive between 13:00–15:30 AEST (08:30–11:00 UTC), where forecast clearing reaches -$56/MWh to -$85/MWh and isolated intervals show modelled prices below -$100/MWh — consistent with overnight low-demand periods where surplus wind overwhelms residual load. Flexible demand operators and battery charging strategies should note this window. The ANZAC Day public holiday profile compresses the morning demand ramp and is likely to keep prices negative or near-zero until at least 16:00–17:00 AEST, when residential evening load and reduced solar (carbon intensity has already ticked up to