This post follows from my post of a couple of days ago. The object is to see how much more solar and wind capacity would have been required to meet the peak demand on January 18 and 19 2018 without the dreaded “carbon emitting generators”, i.e. coal and gas.
The demand curve has been modified by removing the Hydro contribution, on the assumption that hydro is still allowed as a “carbon free” source. The next step is to find the scaling factor needed to boost wind and solar at the capacity factors that pertained on the days, focussing on the 5 minute intervals that the records provide.
After finding the maximum scaling factor needed to meet the peak demands I then found the necessary “installed capacity” for wind and solar. After that I calculated the theoretical output from the scaled up versions using the capacity factors of the day and found the overcapacity that would apply at lower demands.
The scaling factor is 45. This is the maximum found and it sets the size of the facilities needed to meet the peak demand.
This increases the wind from 6,157 MW installed capacity to 275,789 MW and solar from 2,693 MW to 120,627 MW.
The chart below plots the scaled up output against the demand curve minus hydro. Remember that there are 288 5 minute periods in one day.
The first thing to note is the massive overcapacity of the system at demands lower than the peak. The thick black line is the demand less hydro curve and the green area shows the theoretical output of the scaled up renewables. Before anyone says that the answer is to “store the excess” it needs to be understood that there is no such thing as excess electricity. Demand drives the system output so anything above the black line is illustrative only and serves to highlight the overcapacity the system needs to be “carbon free”.
This “excess” above the actual need gets even worse on days of lower demand because the installed capacity of the wind and solar installations are fixed. The only solution is to turn some of them off.
This study is illustrative not definite. The RE boosters, climate change loonies and carpetbaggers will argue that the system can be managed by judicious use of “storage” but they never define the quantum. If the purpose of an electricity system is to produce reliable and inexpensive energy for society to function properly and for businesses to thrive then RE is probably the most insane way of going about it. As always it is the details that get in the way.
The other day Judith said I was “fighting the last war” but I prefer to think of it in terms of battles won and lost in a continuing war against idiocy.