The NEM delivered a textbook autumn week — mild temperatures, softening demand, and abundant midday renewable generation combined to keep average prices subdued across most regions. Queensland and Victoria in particular saw daily averages well below $50/MWh on multiple days, with Victoria recording a remarkable daily average of negative $9/MWh on 25 April (Anzac Day), as reduced industrial demand collided with steady solar and wind output. South Australia followed a similar pattern mid-week, touching a daily average of just $12/MWh on the 25th before recovering sharply to $56/MWh on the 26th.
Tasmania stood apart from the mainland trend, maintaining consistently firmer average prices — ranging from $69/MWh to $107/MWh across the week — underpinned by its hydro-dominated dispatch profile and a series of binding transmission constraints that drew significant market attention. Western Australia's wholesale market (ESOO-adjacent, outside the NEM dispatch engine) tracked steadily between $91–$104/MWh across the week, showing considerably less volatility than its eastern counterparts.
The week's defining themes were the persistence of negative and near-zero pricing during solar-peak hours on the mainland, sustained 100% renewable penetration periods in Tasmania, and two major transmission constraint events — one in Queensland and one in Tasmania — that carried extraordinarily high shadow prices without necessarily translating into visible regional spot price spikes. These constraint events are a reminder that the settlement price a region sees and the underlying network stress occurring simultaneously can tell very different stories.
Queensland averaged between $39/MWh and $53/MWh across the week, with overnight and solar-period pricing frequently touching negative territory — reaching as low as negative $15/MWh on 21 April. Daily highs remained capped below $105/MWh throughout, reflecting well-supplied conditions. The QNI interconnector was saturated at its import limit of negative 527 MW at points during the week, confirming Queensland was drawing maximum allowable flows from NSW during demand ramp periods.
Victoria was the standout for low pricing, recording a weekly average that trended sharply downward through mid-week. The daily average on 25 April hit negative $9/MWh — the lowest in the NEM for the week — with intraday lows touching negative $64/MWh. Even on stronger days, daily averages did not exceed $81/MWh (20 April). Evening ramp periods did produce prices back into the $90–$100/MWh range, but these were short-lived.
South Australia displayed the widest intraday price range of any region, swinging from negative $61/MWh to $361/MWh across the week. The daily average of $12/MWh on 25 April reflected deep negative pricing during midday hours, while a spike to $361/MWh on 22 April and $290/MWh on 26 April highlighted the region's sensitivity to supply-demand imbalances and the binding South East to Tailem Bend corridor constraint (F_S+SETB_L1, shadow price $990/MWh) recorded during the week.
NSW tracked a moderate path, with daily averages between $47–$67/MWh and intraday highs generally capped below $135/MWh. Tasmania held the firmest average prices of the eastern regions — consistently $69–$107/MWh — though intraday spreads remained relatively contained compared to SA and VIC.
Tasmania achieved 100% renewable penetration on every observed morning period across the entire week — recorded on 21, 22, 23, 24, 25, 26, and 27
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