Winter Monday demand shaped the overnight session across the NEM, with SA1 the standout mover — a transient spike to $840/MWh (24h max) underpinned a daily average of $169/MWh, the highest of any NEM region. The Heywood interconnector (V-SA) ran at its export limit of approximately 200.74 MW from Victoria into South Australia through the early morning, directly driving the SA-VIC price spread. Tasmania saw repeated activation of binding constraint T_BLINK_TV_NGZ (shadow price $7.31M/MWh) across morning and evening windows, though regional prices remained low overall. Watch SA demand as it continues to recover from its overnight trough — the price-demand relationship there has been direct and pronounced today.
Tasmania delivered the session's most notable combination: 100% renewable generation during the evening of 29 June, with hydro output of approximately 890–988 MW and wind of 128–155 MW covering all regional demand at prices as low as $25.17/MWh. Running concurrently, the T_BLINK_TV_NGZ constraint recorded a shadow price of $7,308,000/MWh — roughly 140 times the concurrent regional reference price — across multiple dispatch intervals, pointing to significant internal network limitations even as the generation mix ran cleanly. The constraint activated during both the morning ($87.15/MWh spike at 08:00 AEST) and evening sessions, with prices moderating quickly on each occasion as the constraint cleared.
The Wholesale Electricity Market recorded a 24-hour average of $114/MWh with a session high of $233/MWh — above NSW1 and VIC1 averages for the same period, and second only to SA1 across all