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:
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.
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.
This is the graph he is talking about:
In previous post, I left off concluding that the displacement of nuclear by natural gas will increase emissions. This based on the notion that displacing a low emission power source by one with a higher emissions will logically result in more emissions.
The big question is of course by how much? Not all nuclear capacity will be replaced by natural gas and solar and wind capacity will increase. To summarize, this is the change that is proposed:
- Solar/PV: from 4787.56 MW now to 11 GWp by 2030
- Offshore wind: from 2,254.4 MWp now to 4,000 GWp by 2030
- Onshore wind: from 2,578.809 MWp now to 3,500 GWp by 2030
- Natural gas: from 5,300 MW now to 5,600 MW
- Nuclear: from 6,000 MW now to 0 MW.
Although the needed capacity of dispatchable power decreases very slowly compared the rapidly increasing peak production, the total amount of electricity produced by natural gas fired power plants will get smaller, therefor less emissions will be produced. This makes the dispatchable power sources less to not economical viable, but it might limit those extra emissions within reasonable bounds.
It might even be possible to find ways to lower emissions instead of limit them. There was an interesting response to the tweet of our Minister of energy. It was in French and if his twitter account information is truthful, the response came from an economist connected to an energy company:
This is already the third post in the series on the tweets of the Belgian Minister of Energy about offshore windmills that were temporary shut down on July 29. The first post was about the “low pricing”, that were in fact day-ahead prices and nothing to cheer about. The second post dug deeper in the statement that Belgium benefited from the import from Germany’s surplus electricity from solar and wind. Yet, when Germany had high production of electricity from solar and wind that day, Belgium had a high production too and it was primarily exporting its own surplus, so there was no import from Germany to benefit from at that moment…
The subject of this post will be the inflexible power source that, according to the Minister, was the root cause of this curtailment. The first tweet didn’t name the culprit, it was in the fourth tweet that she used the n-word (nuclear):
There you have it, today a practical example that shows how our energy system must change and that nuclear energy stands in the way. They simply undercut sustainable CO2-free production. 4/5
There were several charts added to the first tweet to support her claims, however there was no chart illustrating the claim that “nuclear is in the way” (although it would have been pretty simple to do, just show a quasi straight line for nuclear while having a nose dive for wind). If she would have looked at what nuclear did on July 29, this is what she would have seen:
Central in the tweet of our Minister of Energy (see previous post) is the role of Germany in the event of July 29, when Belgian offshore windmills were shut down: (translated from Dutch, my emphasis)
Due to a lot of German wind & sun + imports, Belgium has the lowest prices.
Due to negative prices, a lack of flexibility and storage, offshore wind is currently being shut down.
100% renewable via flex & storage. Look to the future, instead of recipes from the past. 1/5
Followed by (translated from Dutch, my emphasis):
Production in Germany: 24 GW wind and 16 GW solar. Belgium benefits extra thanks to its import capacity, flow-based (flow factor competition) and the minram70%. 2/5
As I understand it, (forecast of) surplus electricity by solar and wind from Germany kept Belgian (day-ahead) prices low and Belgium benefited extra from this surplus electricity on July 29 because of its import capacity. I can understand the statement that this day-ahead price combined with a lack of flexible power sources and storage can lead to wind mills being shut down. I however find it highly unlikely that we benefited extra from import of German electricity.
The Minister of Energy provides this chart to support her claim:
The first place on the list of the 15 countries with the largest share of solar and wind is occupied by Denmark, which is not really a surprise to me. What is a surprise is the second position, occupied by Uruguay with 44% of its electricity generated by solar and wind. When it comes to solar and wind, I heard a lot about for example Denmark, Germany and (South) Australia, but not yet about Uruguay.
That got me somewhat curious, wondering what the story of Uruguay is in order to cope with such a large share of intermittent power sources. I already wrote about the strategies of for example Denmark (having two big neighbors with a lot of dispatchable hydropower to balance out the intermittency on the Danish grid) and Germany (exporting its surplus to the neighboring countries at low to negative prices). Now what is the strategy of Uruguay?
First things first. I know Uruguay is a country somewhere in South America, but that is about it. I wouldn’t be able to point it out on a map, so let’s start there. Uruguay is a relatively small country on the East coast of South America. I colored it in red on this map and also named its two (big) neighbors: Brazil to the North-East and Argentina to the South-West.
The good news keeps on coming: Belgium is worldwide in the top 15 of “Wind and Solar countries”. More specifically, we are at 9th place having a share of 20% of our electricity production from solar and wind in 2020:
It didn’t end there. China, the EU-27 and the United States are responsible for more than two-thirds of global generation, Vietnam went from 0 to 14 TWh in just 3 years, Chile and South Korea have quadrupled their wind and solar generation since 2015, and many other countries (Brazil, China, India, Mexico, Turkey and Uruguay) have tripled it. Also, many countries now get around a tenth of their electricity, which is the global average for electricity generation from solar and wind.
Of course, the transition to solar and wind is going to be cheap. According the article, the cost for solar and wind are at a tipping point with almost two-thirds of wind and solar projects built globally last year will be able to generate electricity cheaper than even the world’s cheapest new coal plants.
That all sounds pretty impressive, but as usual in alternative energy reporting, this is just half of the story. Luckily, the author also showed the readers a glimpse of the challenges ahead, putting these glorious numbers somewhat in perspective.
The Hornsdale Power Reserve is about to get an upgrade. The Hornsdale Power Reserve is a grid-sized battery build by Tesla in South Australia. It has a capacity of 100 MW and can deliver 129 MWh. I did a series on it back in March, starting with the claim that this battery could replace natural gas for peaking and gap-filling (which is not the case). The upgrade will add a capacity of 50 MW and it can deliver 64.5 MWh.
The pv-magazine article points out that the additional capacity will be put to use for frequency control and inertia. I could understand that, the main function of the original 100 MW battery is already frequency control and this service generated quite some money for its owner. There was also this claim (my emphasis):
ARENA, which contributed an AU$8 million grant toward the expansion, also believes the upgraded battery could also help to reduce renewable curtailment in South Australia. Indeed, AEMO’s Chief System Design and Engineering Officer, Alex Wonhas, said that the expansion enabled the “optimal use of this world leading battery to support higher levels of renewable integration.”
The author also didn’t shy away from using terms like “mega” and “highly successful” in the article. That all sounds very promising, but from looking into the Hornsdale Power Reserve while writing the earlier series, I think it is presented way nicer than it actually is. Even a “mega”-battery of 100 MW / 129 MWh is still tiny grid-wise and adding another 50 MW / 64.5 MWh will probably not make much of a difference.
This made me wonder: what is the current share of battery power in the South Australia grid? And what difference would this upgrade make once it gets online (the homepage of the Hornsdale website states that the expansion is still “under construction”)?
Time to look at the data.
Let’s continue with the open letter from the energy company Eneco (see previous post), in which its CEO complains that his company “felt obliged” to shut down some of their windmills despite it was windy. It is framed as the result of the “inflexibility” of nuclear power that pushes wind aside and, most importantly for this post, as a choice for better air and cleaner electricity (translated from Dutch, my emphasis):
Renewable energy could provide half of our consumption. In itself this is a good prospect: better air and cleaner electricity from wind & sun. We should all be pleased with that.
The framing in the open letter made me wonder how much wind power was curtailed exactly? Also, assuming that nuclear power would get turned down a notch during the lockdown, how much cleaner would electricity production then get?
Never could imagine that the words “wind energy” and “nicely balanced” would be used in the same sentence. This was achieved in this tweet (for the international readers, “BE” is the country code for Belgium):
BE update: Wind offshore dropped as of 10am, onshore as of 11am. And it is keeping the system nicely balanced. But of course, if only we could have dynamic demand response to this, society wouldn’t have to loose this cheap energy.
This are the graphs that accompanies the tweet:
There was indeed a sudden loss of wind capacity somewhat before noon, correlating with a negative price and leading to positive prices again. Initially, I assumed that the twitterer was being sarcastic, mocking a sudden wind lull, but scanning through his Twitter time line suggested that this might not be the case…