Sunday night into Monday delivered a split-screen NEM: Victoria and South Australia ran negative or near-zero pricing for extended stretches from around 23:00 AEST, while Tasmania held firm above $68/MWh and NSW averaged $63/MWh across the session. A binding VIC–NSW interconnector export limit of 1,054.61 MW constrained southbound relief and kept the divergence structural rather than fleeting. For Monday, watch the evening demand ramp — Queensland hit 7,876 MW at its morning peak — and whether SA and VIC wind output sustains oversupply conditions into the afternoon shoulder.
Tasmania is the standout region. During the evening of 15 June, TAS1 achieved 100% renewable penetration with approximately 1,986 MW of hydro and 79 MW of wind, holding spot in a narrow $68–$70/MWh band — a notably stable outcome. The session also recorded a major binding constraint (T_BLINK_TV_NGZ) the previous evening with a shadow price of $7,308,000/MWh, briefly lifting TAS1 prices to $85.22/MWh around 21:30 on 14 June. The combination of a record generation milestone and a high-value network constraint in the same 24-hour window makes Tasmania the region to watch for transmission and dispatch dynamics.
The WEM was far from quiet. WA1 recorded three separate major price spike events across the 24-hour session: prices reached $372/MWh across five sustained intervals in the early hours (01:10–01:40 AEST), spiked to $364/MWh at 08:25, and then hit a session high of $396/MWh at 14:55 before moderating. The daily average settled at $207/MWh against a session max of $404/MWh — well above NEM regional averages. The overnight spike occurred across a mixed generation stack including coal, gas, wind, battery, and solar, pointing to supply-demand tightness rather than a