Commodity Demand — SA1: Tuesday 12 May 2026
South Australia's spot price sits at $86.39/MWh at 06:30 AEST with demand at 1,378 MW — a level that has been climbing steadily over the past 30 minutes from $70–74/MWh as demand recovered from its overnight low. This evening ramp is the key price driver right now: demand troughed near 1,070 MW in the early hours (around 13:30–14:00 AEST), where overnight prices pushed into the $130–280/MWh range despite low demand volumes, reflecting tight gas dispatch conditions. Through the mid-morning peak, demand reached 1,770 MW at around 18:50–19:00 AEST, but prices were comparatively subdued at $103–121/MWh — wind generation of 741 MW and 67% renewable penetration at this interval are softening the price response to demand relative to the overnight period.
The demand-price relationship across today's trading shows a notable inversion between the overnight and daytime periods. From approximately 10:30 to 18:30 AEST, demand ranged 1,070–1,770 MW with prices consistently held between $60–103/MWh. By contrast, overnight from 00:30 to 03:30 AEST, demand sat in the relatively modest 1,150–1,220 MW band yet prices spiked repeatedly to $170–280/MWh. This decoupling points to a supply-side constraint during low-wind overnight hours rather than a demand-volume problem: the carbon intensity data confirms this, with grid intensity reaching 0.4776 tCO2/MWh at 13:30–14:00 AEST (overnight in UTC terms, equivalent to the local pre-dawn period) before falling sharply to 0.1966 tCO2/MWh now as wind output increased.
Looking ahead to today's price trajectory, forecast RRPs for the 07:00 AEST interval (21:00 UTC) are converging around $81–87/MWh across the most recent pre-dispatch runs, broadly consistent with the current print. The 07:30 AEST interval is forecast higher at $104–113/MWh, signalling that the market expects demand to continue building through the post-sunrise morning ramp. With demand currently at 1,378 MW and the historical intraday peak today reaching 1,770 MW around 18:50–19:00 AEST, the trajectory points toward another ~400 MW of demand addition over the next few hours. At current wind conditions — 741 MW output, calm weather at 8.2 km/h — any softening in wind output during the morning ramp is the principal upside price risk, particularly given SA's demonstrated sensitivity to gas dispatch pricing when wind backs off.
The MTPASA reserve notice (issued today) confirms no Low Reserve Conditions are identified, removing any immediate reliability premium from pricing. The voltage-driven AEMO direction on Quarantine PS Unit 5 on 6 May is now cancelled and has no ongoing pricing relevance. For demand-side managers, load windows through 09:30–11:30 AEST (00:00–02:00 UTC tomorrow) show forecast prices in the $10–25/MWh range — the deepest discount opportunity of the next 24 hours — consistent with the overnight pattern observed across today's low-demand trough.