Update, Tuesday morning. SA was importing up to 10 last night and at 6.15 this morning.
Last Monday the wind flexed off on Monday after doing overtime on the weekend. This weekend the wind was busy on Saturday and Sunday and decided to observe the long weekend holiday on Monday. Especially in NSW where it hit the deck at breakfast time and went into negative territory at noon.
The sun went down just before the evening peak of demand and the wind was almost down to zero, contributing 156MW towards the demand of 24GW across SE Australia. That is hardly worth mentioning – 0.6% of demand at 2.2% of installed capacity.
South Australia, the wind leader of the nation with about half the installed capacity of the NEM, was importing almost 250MW of coal power and the wind contributed 34MW, rather more than the number in the mid afternoon.
The weekend was a time of false hope for the RE warriors. The wind in NSW reached 70% of capacity for a while and during the sunny period from late morning to late afternoon RE in total peaked at 40% of demand.
Those numbers send a dangerously misleading message to people who are not up to speed on the choke point problem. It looks as though we are approaching half of our power from RE. But the numbers that count are not the installed capacity of solar and wind systems, not the average (near 20% for solar and almost 30% for wind) and not the good days.
The critical figures are the lowest levels of output. For solar that is obviously zero after sunset apart from some battery storage at the household level. For wind the lowest level can be practically zero as well, as today demonstrated.
The highest levels and even the average or the median level of RE is beside the point. If there is any need for RE – if the amount of conventional power ever falls short of the demand – the critical number is the lowest point of supply- the choke point.
After Hazelwood closed we have been travelling with virtually no reserve of conventional power. If Liddell goes in 2023 as planned we will lose 1.8GW and then we will depend on a contribution from RE at the evening peaks.
The installed capacity of wind may double to 14GW by that time and if the mills are turning at 13% capacity that will match Liddell. But in January they performed under 10% on 23 evenings in the month. On those figures hydro and gas will have to step up or the lights will dim somewhere and some time every month.