Monthly Archives: December 2021

A “skewed” distribution: synchronizing intermittency

According to some of our politicians (among them our federal Minister of Energy) we are missing out on cheap electricity from solar and wind. They look forward to abundant electricity from abroad, specifically from Germany, and to be able to import this cheap electricity.

We surely will get dependent on imported electricity soon. Belgium is going to decommission 6 GW of nuclear capacity (currently producing roughly half of our demand) by 2025 and replace it with 2.3 GW of gas fired power plants plus increasing solar and wind capacity. It is expected that Belgium will get structurally dependent on import for about 25 to 30% of its demand (and likely a whole lot more by 2050).

As I wrote several times before, I have my doubts whether that import will be cheap and my suspicion has to do with the time when this cheap electricity is produced. I think that the three dates explored in previous post can shed some light on why the prices of imported electricity from Germany will not be cheap. Let’s just look what prices did during those three days.

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A “skewed” distribution: interconnecting intermittency

While creating the graph that I used in previous post, I noticed something that I expected for a long time. Remember, my graph was a recreation of this graph showing the sorted daily contribution of solar and wind in the Netherlands:

Sorted contribution of solar and wind of the Netherlands

It shows that the lowest daily production of solar and wind between January 1 and November 16 was measured on November 16. When I was creating my graph depicting the Belgian sorted daily contribution, I found that the lowest production of solar and wind in Belgium over the same period was also November 16. That should not have come as a surprise, Belgium and the Netherlands are neighboring countries.

That November 16 date was not the only date that appeared in that original graph. Besides November 16 (lowest production) there are also July 29 (highest production) and August 2 (in between). That made me wonder whether those two other days match as well and to what extent this is also true in other neighboring countries. I have some data from solar and wind in Germany, so I will also include Germany into this comparison. Let’s dive right in.

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A “skewed” distribution: the volatility of solar and wind

This tweet sums up the biggest problem with intermittent power sources:

Yesterday, a fairly dramatic low in terms of solar & wind output. Fortunately, there were also great days this year.
Although sun and wind often complement each other, the total forms a rather ‘skewed’ distribution. We will have to learn to deal with that soon.

Tweet WM_visser 2021-11-17

This is the graph he is talking about:

Sorted contribution of solar wind (The Netherlands)

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