Category Archives: Energy

Do wind and solar “complement” each other during winter?

The second fact check of the “factchecker energy” of SER is titled: Is there a future for solar energy in the Netherlands?. Although the author of this fact check admits that solar energy only has a very tiny share (0.1% of the energy consumption) and it needs to be balanced by other flexible energy sources, he is very optimistic about the future. His “fact” check seem to rely on future developments related to solar energy.

As a whole, it seems a quite bland and overly optimistic fact check, but there was one statement that caught my attention (translated from Dutch, my emphasis):

There is a factor of ten difference between summer and winter output of solar panels. What the share of solar power in the electricity mix will be, will depend to a large extent on the developments in electricity storage (for short and longer periods) and of the expansion of the electricity connections with other countries. Wind power and solar energy complement each other in that respect: the supply of wind power is higher in the winter when the supply of solar energy is lower.

That is an interesting statement. Apparently wind energy produces more power in winter and this compensates for the loss of output of solar cells during the same time. I decided to have a look at the data to find out to what extent “wind complements solar”, but also the significance of this phenomenon in a continuous working grid.

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Half News: (installed) capacity of wind energy has overtaken coal

From the half-news department comes the article titled Capacity of wind energy has overtaken coal in De Morgen (the Flemish Guardian).

Wind energy overtakes coal - De Morgen , February 9, 2017

This is how it is explained (translated from Dutch):

Last year, the installed capacity of wind power in Europe surpassed that of coal. This according to figures from the industry association WindEurope.

In terms of capacity, only gas-fired power plants preceded wind energy.

The source was an article with the same title from Belga (a news agency) and it was copied verbatim by a huge flock of news sites in Flanders.

The article in De Morgen jumped out as a sore thumb: it appeared in the section “Science”. Probably copied by a “science” journalist who had no clue that comparing installed capacity of wind with coal is meaningless and a direct comparison of the two is misleading.

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Flemish (onshore) windmills have almost the same capacity as a nuclear reactor

The journalists of our beloved Flemish media seem to go ballistic lately. Yesterday there was the item in the VTM news about the current “drought” that was “direct result of climate change”. Today the VRT news felt it had to compete with that and went full stupid in an article with the sensational title:

Flemish windmills have almost the same capacity as a nuclear reactor

vrt news 20161228 windmil

Apparently the onshore windmills in Flandres have a total capacity of 920 MW, which is only slightly below the capacity of (some of) our nuclear turbines (at somewhat above 1,000 MW).

Hurraaaah!!!

I am afraid that I have to spoil that party…

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In search of “only” 1414 MW (if non-dispatchable power sources are dispatchable)

Last Thursday, a Flemish newspaper brought the story that “the lights will go out in 2020”. We heard that many times before in the past. This time the statement was made by Andries Gryffroy, who was called the “energy expert” of N-VA (Flemish political party on the center right). He rightfully questioned the “energy plan” of current Flemish Minister of Energy, which is solely based on extra solar and wind energy. Even with those extra windmills and solar panels, we will not be able to produce enough energy to meet our demand in a few years and could face power shortages by 2020. More, several old conventional plants will need to be decommissioned in the next years and the new solar panels and wind mills need backup. He gave the example that in winter only 3% of nameplate power of solar energy is produced, while we use most energy in winter.

Okay, I dig that. Solar and wind provide less energy in the winter when we need most energy. Just adding more intermittent energy sources without backup and additionally decommissioning older conventional power plants, makes a good recipe for energy shortages. Especially in winter at peak demand. Especially with our aging power plants. Our politicians are talking about energy security for years now, but in the end go for extra windmills and solar panels. Probably to meet the EU goals.

Although I agree with what was being said, there were some things that seemed rather odd. For example, it was calculated that in winter we will have a shortage of 1,414 MWh and explained that this is the equivalent of 1.5 Belgian nuclear power plants. Which doesn’t make much sense. 1,414 MWh is the electricity that 1.5 nuclear power plants will produce in one hour. My guess was he was confused between “megawatt” (power) and “megawatt hours” (energy). Or was it the journalist that brought in the confusion?

Also the calculated number was puzzling. At first glance, it seems rather unrealistic. Apparently, we would be able to decommission older gas power plants PLUS arrange backup for a doubling of our capacity of intermittent energy sources, yet only need 1.5 conventional power plant to compensate for all that!?

Luckily, the paper version of the news paper mentioned how the calculation was actually done:

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Why no stabilization of CO2 levels in the atmosphere when emissions have fallen?

Imagine my surprise when I coincidently came across a blog post in which this surprising question was answered: Why has a drop in global CO2 emissions not caused CO2 levels in the atmosphere to stabilize? Some of their readers apparently asked why there has been no stabilization in the measured levels of carbon dioxide in the atmosphere when reported emissions of CO2 have fallen. In the post explained that it was very simple: the sinks for CO2 currently offset only about 50 percent of the emissions and additionally these sinks will slowly lose their efficiency as they start to saturate.

That is remarkable answer to a remarkable question. I wasn’t aware that global emissions dropped. The article was only written yesterday, so I was curious what new information they found. I didn’t find any new information after all, but the post linked to a IEA article which was referred to as “recent stabilization in global emissions”.

So is it a drop or a stabilization? Confusing was also the emissions graphs that were present in two places in the post. Yet at a closer look it didn’t exactly serve their case. It mentioned that there was a 2.2% increase of emissions between 1990 and 2014 and a 0.6% increase between 2013 and 2014 (which was the last year in their figure).

global emissions 1990 2014 Global Carbon Project

So what is it? A drop, a stabilization or a (modest) increase? Time to have a look at the data. Going to the source they linked to, I realized rather quickly that there is a much, much, much simpler answer than the mumbo jumbo answer about the sinks.

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Solar panels and wind turbines sufficient to run the entire German economy…

A couple days ago, I came across this curious message from a wind energy news site from the Netherlands (translated from Dutch):

German economy runs on green energy

Germany can generate sufficient electricity from solar cells and wind turbines to run the entire German economy. Last Sunday, 45.5 gigawatts was delivered (according to Agora Energiewende). There was even a surplus during 15 minutes. Despite that, our Eastern neighbors are expanding clean energy

A quarter of an hour the price dropped under €50 per megawatt-hour because of the oversupply. The Danes delivered 140% of the demand for cleaner energy last year with their windmills and solar parks. Already now they are looking for good storage in order to store surplus production of green energy.

That didn’t make much sense to me. If it is really true that wind and solar were sufficient to run the entire German economy, then how is it possible that there was only 15 minutes of oversupply? Wind and solar are intermittent, it would be one in a gazillion chance that the output of wind and solar coincides exactly with only 15 minutes of overproduction…

It was also rather sloppy reporting. The last sentence of the first paragraph was for example cut off and, although the article was about Germany, in the second paragraph Denmark was mentioned out of the blue. Was this the intention or did they wrote “Denmark” in stead of “Germany”? Or was the connection explained in the cut off sentence in the first paragraph? My guess was that this was a badly executed copy/paste from an article somewhere else.

My guess seemed to be correct. The original article was published in a Dutch news paper. There was the same cheering, but at least it had somewhat more information about what was going on.

The information was still confusing though. The story seemed to be that on Sunday May 15, wind and solar produced “45.5 GW” while the demand was “45.8 GW”. I read the same figures in other cheering media reports and that didn’t make any sense. 45.5 GW is a capacity, not a production and 45.5 is lower than 45.8 anyway. So how could they claim that production was sufficient to match consumption with even a small surplus? Time to go to their source to look what really happened that day.

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Stop and Go: not seeing the beam in their own eye

A last short post on the Stop and Go-campaign to stop with nuclear energy and go for renewable energy. Besides the arguments of small share (within the primary energy consumption) and high price, two more (non-)arguments were given. The first one is:

Moreover, nuclear power is not a CO2-neutral energy source.

They explain that during energy production no CO2 emissions are produced, but it is however produced in the other stages of nuclear energy, like mining, enrichment, transport and so on. They said it is about 1/3 of the emissions compared to natural gas. That could all be true, but they didn’t compare it to renewables. I guess they assume wind and solar are CO2 neutral energy sources.

Well, do I have a surprise! wind and solar are not “CO2-neutral” either.

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