Jo Nova has flagged the probability of spikes in the price of power in Victoria and South Australia tomorrow. This follows an interesting day today when the demand peaked at 32GW in the evening, well above the 28 that I thought marked the beginning of the red zone.
It looks as though the black and brown coal maxed out at 19 GW and the wind was a bit thin so the hydro and the gas had to be ramped up to provide 10GW between them. Hydro was still only operating at 50% of capacity but I suspect that the water supply will not sustain that flow for very long.
The sun was still contributing 1 GW and that faded away over the next hour.
An interesting addition to the mix is (I think) Coal Seam Methane that turns up as a brown smear on top of the solar late in the day. That becomes more visible when you eliminate the big players, then you find it contributed a valuable 0.8GW to the peak load, almost on a par with the Sun and the Wind (operating at 20%).
When you eliminate enough of the others you can find Bagasse and a bit of Waste Coal Mine Gas.
Tomorrow promises to be interesting. The real worry is the loss of a coal station for maintenance or emergency outage, and then the loss of 2GW when Liddell closes. The system is too fragile to stand the loss of any more baseload.