Carbon Forecast: Tuesday 19 May 2026

NEM-wide carbon intensity sits at sharply contrasting levels across regions at 06:30 AEST. Tasmania is at 0.00 tCO2/MWh with 100% renewable penetration, driven entirely by hydro (915 MW) and wind (312 MW) with no fossil generation online. South Australia is the next lowest at 0.14 tCO2/MWh with 76% renewables — wind at 490 MW and battery at 172 MW are carrying the bulk of local supply, with gas OCGT (148 MW) and CCGT (59 MW) providing the remainder. Both regions are currently at or near their day's intensity floor given the absence of solar at this hour.

NSW and Queensland are running in a tighter band, with NSW at 0.64 tCO2/MWh (27% renewables) and QLD at 0.59 tCO2/MWh (32% renewables). Black coal dominates both — 5,347 MW in NSW and 4,373 MW in QLD — with wind contributing meaningfully (776 MW and 1,369 MW respectively) but not enough to materially shift intensity at current demand levels. Batteries are dispatched in both regions (316 MW NSW, 651 MW QLD), reflecting evening discharge from earlier solar charging. Victoria is the highest-intensity region at 0.80 tCO2/MWh with 35% renewables; brown coal at 4,414 MW underpins the grid there, supplemented by 1,696 MW of wind and 636 MW of battery — gas is off in Victoria at this interval.

The intensity trajectory through today follows a predictable autumn pattern. NSW and QLD saw their lowest intensity windows overnight between roughly 01:00–05:00 AEST, where NSW touched 0.49 tCO2/MWh and QLD dipped toward 0.59 tCO2/MWh as coal dispatch eased and wind held up. SA's overnight trough ran from approximately 23:30 AEST through to 12:00 AEST today, with intensity as low as 0.07 tCO2/MWh during peak wind periods — that low-intensity window has now largely passed. Victoria's best window was around 03:30–04:30 AEST at 0.63–0.67 tCO2/MWh, also behind us. From here, solar generation will begin lifting renewables penetration in NSW and QLD from roughly 07:00–08:00 AEST, providing a secondary intensity dip through the mid-morning into early afternoon; NSW reached 0.49 tCO2/MWh at the 04:00 AEST interval and mid-morning solar could push it toward similar levels again between 10:00–13:00 AEST.

For carbon-sensitive loads, the actionable windows today are: SA and TAS remain low-intensity throughout the day and continue to represent the best scheduling opportunity on the NEM. In NSW and QLD, the mid-morning solar ramp (approximately 09:00–13:00 AEST) is the next viable low-intensity window, though neither region will approach SA levels. Victoria's intensity is likely to remain above 0.75 tCO2/MWh through the business day given the baseload brown coal profile and limited solar contribution at this time of year — no material green window is expected there until wind strengthens overnight.