NEM Overview: Sunday 21 June 2026

South Australia is the standout at 06:25 AEST, with spot prices at $2,061.37/MWh against a demand of just 1,600.6 MW — a sharp dislocation driven by constrained interconnector capacity following the short-notice outage of the Roseworthy–Templers 132 kV line yesterday morning. The S-TPRS constraint set remains invoked, binding both V-SA (at its export limit of 146.64 MW) and Murraylink (V-S-MNSP1 flowing -156.81 MW, also binding). With SA's generation mix at this hour comprising 741.8 MW of gas OCGT and 632.85 MW of gas CCGT — and wind contributing only 53.46 MW — peaking plant is setting the marginal price and there is limited room for relief via the interconnectors. AEMO flagged a potential LOR2 in SA for the 2030–2100 window last night but assessed it as transient and did not formally declare; watch that window again this evening if wind stays suppressed. SA's current renewable penetration sits at 5.3%, carbon intensity 0.5457 tCO2/MWh.

Elsewhere, prices are firm but orderly. NSW sits at $116.42/MWh on 8,657 MW of demand, with black coal supplying 6,703 MW, hydro a substantial 1,409 MW, and wind contributing 130 MW. The NSW–QLD interconnector is flowing 542 MW southbound (binding), suggesting Queensland's $106.81/MWh price is pulling supply north. VIC is at $146.23/MWh on 6,384 MW, with brown coal at 4,322 MW and gas OCGT at 764 MW carrying the evening load — wind is negligible at 11.2 MW in VIC tonight. The VIC–NSW interconnector flows 457 MW northbound. Tasmania is the lowest at $79.28/MWh, with hydro supplying 1,303 MW and Basslink exporting 60 MW to Victoria.

NEM-wide renewable penetration is 28.6% and grid stress is elevated at 62.8 out of 100, consistent with a mid-winter Monday evening profile — solar is effectively zero across all regions, wind is underperforming in SA and VIC, and dispatchable plant is carrying the load. Carbon intensity scores reflect this: VIC is highest at 1.1169 tCO2/MWh, QLD at 0.7637 tCO2/MWh, NSW at 0.7065 tCO2/MWh. Tasmania remains at zero with 100% renewable penetration via hydro and wind.

For today's outlook, weather conditions across the eastern states are cold and clear-trending for NSW and QLD, with heating demand elevated (NSW 8.9°C, SA 5.2°C, TAS 3.4°C). NSW and QLD should see some solar contribution during daylight hours given low cloud cover forecasts (13–17% average cloud), which will soften midday prices. SA faces an 85% average cloud cover forecast for today, so wind and gas will remain the primary dispatch stack through the day. The active Directlink control issue (N-Q-MNSP1 constraint set I-CTRL_ISSUE_TE still invoked) continues to limit flexibility on the NSW