commodity demand sa — SA1

South Australia's spot price sits at $109.71/MWh with demand at 1,221 MW — a relatively modest overnight load level that is nonetheless sustaining prices firmly above $100/MWh. That price-demand relationship is notable: over the past several hours demand has been tracking in the 1,200–1,250 MW range, yet prices have held between $110–$138/MWh for most of the overnight period, pointing to thin dispatchable supply margins and gas-dominant scheduling at elevated offer prices rather than any demand-driven pressure. Wind is contributing 218 MW and gas (OCGT + CCGT combined) 282 MW, with solar at zero overnight, which explains why the marginal cost floor stays elevated despite subdued demand.

The day's price-demand trajectory earlier told a stark story. As solar generation ramped through the morning, grid demand collapsed to a trough around 156–290 MW in the late-morning period (AEST), driving spot prices deeply negative — reaching -$15/MWh at the floor. That rooftop and utility solar suppression of net demand is the defining feature of SA's Sunday demand shape: underlying consumption remains, but net grid demand shrinks dramatically mid-day, punishing generators with negative prices before the evening reset. The abrupt price jump back to $138/MWh as demand surged from ~156 MW to ~1,374 MW within a single interval around 21:50 UTC (07:50 AEST) reflects the sharp solar ramp-down and the re-commitment of gas plant.

For today's outlook, the most recent AEMO forecast for the 07:00 AEST half-hour is $110.44/MWh, with load windows signalling "excellent" price opportunities at 07:30 and 08:00 AEST at $35–$54/MWh — confirming solar penetration will again suppress net demand and prices materially through mid-morning. Demand is expected to follow the same weekend U-shape: soft now, collapsing again through the solar window, then recovering into an evening period where gas peakers re-set the price. Grid stress scores at 73.8 and price stability at just 29.8 out of 100 confirm the market remains volatile and sensitive to any supply tightness — particularly at the evening solar-off ramp where $170–$262/MWh spikes have recurred across recent intervals. Demand-side flexibility concentrated in the 07:30–10:00 AEST window carries the clearest cost-reduction opportunity today.