The push for unreliable energy has been renewed among the Wet and Green in the Liberal party in the wake of Turnbull’s revenge. It will not fly because it will come to grief on the rocks of engineering reality. Not without cost to the innocent and guilty alike.
The title should read practically 100% to allow for a few points of hydro and off grid generation by diesel and solar in remote locations.
The reason is fairly simple and it is explained in detail by the likes of Tony from Oz in comparing the cost of wind and coal power. He explains that the unreliables deliver such a small percentage of their plated capacity that they are not really cheap at all. That percentage is calculated as an average over the year, or month or whatever.
But the situation is a lot worse than that described using the average.
Considering the need of the human body for oxygen. We normally get along with some 20% of oxygen in the air we breathe. We can get by with smaller percentages, especially if we are not active. Maybe we can survive for some time with quite a small percentage.
But if the supply gets down to nil for a very small number of minutes we are first brain dead and then we are dead full stop.
Consider the contribution of Wind and Other to the grid at present. On a good day it is around 10%, suggesting the plated capacity is about three times that. To get 50% on a good day calls for five times the current plated capacity. Of course the old reliable coal burners would still be required to make up the difference.
But not all the days are good, sometimes the figure gets down to 2% or less and multiplying by five only gets up to 10% or so.
In the absence of 90% backup from fossil fuelled power the grid is now in the position of the human body with next to no oxygen.
The critical number is the lowest point, not the average, and certainly not the plated capacity.
So to keep the lights on we need at least 90% of baseload power to be available 7/24 from the old coal burners into the distant future until there is a serious revolution in storage capacity. Or nuclear power.
Until that time our Wind and Solar is merely an expensive ornament attached to the grid, a virtue-signalling fashion statement.