There are strong winds across SE Australia these days although WA was in a wind drought yesterday, probably the front end of a high pressure system that will bring the bird-killing mills to a standstill over here in a few days.
Last night the fleet was delivering 62% of plated capacity and providing 20% of the power in the grid. During the day the wind contribution was slightly less (56%) of capacity but with the sun at its peak at noon RE accounted for 37% of demand.
Those are the numbers that encourage the wind lobby to claim that we are well on the way to 50% or 100% RE, just keep building, get over 100% of demand during the day and store the excess to use overnight. There are two fatal flaws in that argument. First there is no prospect of grid scale storage in our lifetime. And the second is the choke point factor that means you have to judge the capacity of the wind system by its lowest level of production, not the highest or even the average. Sorry.
Looking at the live NemWatch widget. In WA the wind contribution is up this morning from less than 1% yesterday but you still wouldn’t want to depend on it for your morning coffee! This is the screen shot at 7.30am.
South Australians get very excited on days like this when they are exporting power to Victoria but check out the times when they have zero wind, indeed the times when there is practically zero wind across the whole of SE Australia. Then they depend on local gas and coal power from over the border. Over 12 months they still import as much power as they export.
Given the choke point factor it only takes one “no wind” day to bring the system down in the absence of 100% backup from conventional power. Find an engineer to explain what is involved in a black start after the grid has gone down!
And recall the island effect (one of the four icebergs that will sink RE). We are on our own unless you are counting on Tasmania to be the battery of the nation. Even California during the state of emergency will not go completely black because they can reach as far as Canada to get nuclear power and hydro, not to mention the coal and gas power available in other states.
For a picture of a low point check out Victoria on 11 June. The solid line is the total for the state and the coloured lines are individual wind farms. The solid line barely cleared 5% all day.
Dan has made Victoria the wind leader with far more installed capacity than SA (2.8GW vs 2.1). So what happens when they have bad wind days? Queensland is the coal power provider of last resort!