I frequently hear claims that Germany and other European countries have a peak in electricity demand in the middle of the day, and that solar power can cover this peak. Where this belief comes from I do not know. Certainly, it is true for large parts of America, where electricity demand peaks in the middle of the day in summer when Americans are using their air conditions to excess. Not so in most of Europe where the demand is not in summer, or winter, but on cold winter nights.
To check this I pulled some data together for European countries from the website of PF Bach. Hourly load data for Germany, Britain, Ireland, France, Belgium and Denmark are available. They all show a clear peak at night.
I will show this with two straightforward graphs. The first shows maximum hourly load at each hour of the day throughout the year. To make things clearer I have scaled the graph so that 1 is the maximum for each country. In other words the hour in the graph with a peak of 1 is when the actual peak occurs.
You can see that all of the peaks occur between 6 and 9 pm in all 6 countries.
What about monthly maximums? Below I’ve plotted the maximum hourly output in each month of the year. As is clear the peak demand occurs in January or December in every country. And the summer peak is much, much lower than the summer peak everywhere.
So, these countries all have demand peaks on Winter nights. This is not likely to change either. Electrification of heating will inevitably make the seasonal peak in heating even more pronounced. An obvious consequence is that solar power cannot replace any fossil fuel capacity in these countries, because of its in ability to produce energy after 5 pm in Winter. That peak will need to be met by something other than solar. This, again, is in contrast to America where solar panels can replace some fossil fuel capacity. Perhaps I will write about this in some more depth in the future.