Category Archives: Energy

Pumped hydro more expensive than batteries: the calculations

Now let’s take a look into the calculations that Ronald Brakels made to prove that hydro power (Snowy Hydro 2.0) is more expensive than battery storage (Hornsdale Power Reserve). His arguments were spread over many paragraphs and at first glance it was not very clear what he was calculating exactly and why. Therefor, I thought it might be a good idea to redo his calculations. This reconstruction will be the subject of this post and I will clearly write out all his calculations in order to better understand his arguments.

The calculation can be divided into three parts.

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Pumped hydro more expensive than batteries: the intro

At the end of last week, I came across a SolarQuotes article about Snowy Hydro 2.0 being more expensive than batteries. Snowy Hydro 2.0 is a pumped hydro project in Australia (New South Wales and Victoria) and is currently under construction. The brunt of the article is that pumped hydro is too expensive compared to (grid sized) batteries and the plea is made to halt the project in favor of batteries.

That was new to me. As far as I know, pumped hydro is the cheapest way of dispatchable backup in order to counter intermittency and definitely cheaper than batteries. Yet, the author of this article argues that it is the exact opposite.

The name of the author of the article, Ronald Brakels, rings a bell. Not even a year ago, I wrote a post on his claim that South Australia has the second cheapest electricity in Australia, despite it having the most expensive electricity. He did this by applying two neat tricks, sneakingly morphing South Australia from by far the most expensive to the “second cheapest”.

With that in the back of my mind, I expected some trick(s) to be performed in this one too.

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If the goal is to limit emissions…

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
  • Wind
    • 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:

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Nuclear undercutting wind?

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:

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Belgium benefits “extra” from surplus German solar and wind

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 shortage 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. Yet, in that same story Belgium shuts down (some of) its offshore windmills.

Do I understand it correctly that Belgium benefited from German import using German solar and wind surplus … just to shut down its own windmills? That doesn’t make much sense. Or is that imported electricity so insanely cheap that it would be more advantageous for Belgium to shut down some of its windmills?

The Minister of Energy provides this chart to support her claim:

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Belgium has the “lowest prices”

When does the good news ever stops? At the end of last month, our green Minister of Energy sent out this cheering tweet (translated from Dutch, my emphasis):

Due to a lot of German wind & sun + imports, Belgium has the lowest prices.
Due to negative prices, a shortage 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

This is the screenshot:

Tweet TinneVdS 20210729: 1 of 5

It is a thread of in total 5 tweets and the first two detail an issue occurring on July 29 when (some) offshore windmills were shut down. There are several things in this thread to look closer into, but I will solely focus in this post on the “lowest price” claim in the first sentence of the first tweet.

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And the second position goes to … Uruguay

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.

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Solar and wind growth failing to outpace demand growth (except during an economic crisis)

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.

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Virtual energy plant: cheap and (going towards) 100% renewable

Hooraaaaay, our energy problems were just solved! I just viewed a short video about a “smart” energy system (Dutch ahead) that will power a new residential area called “De Nieuwe Dokken” in Ghent (Belgium). According to the video, the components of this system are:

  • solar panels on the roof
  • a big battery
  • charging points for electric vehicles
  • heat pumps
  • a very smart computer system to control all those energy flows.

Of course, it will be cheap, dirt cheap even. At several occasions in the video, the economic benefits of the system were praised. For example, electricity prices went negative on May 30 and one even got paid to take electricity from the electricity grid.

Wow, where do I have to sign up for that!?

When there is no(t a lot of) sun combined with high consumption, don’t worry, then the system could provide the electricity stored in the car batteries (after those gorged themselves with plentiful of energy during day) to the households.

Easy peasy. See, it doesn’t have to be that complicated.

Our Minister of Energy also made an appearance, proudly stating that this is how our (national) energy system will look like in the future, just on a larger scale. How cool is that! Our tiny country is showing the world how it is possible to realize 100% renewable energy on the cheap.

You are welcome, just thank us later 😉

There are however some, ahem, small details that for some reason were not explained in the video…

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Intermittent versus base load when aiming for a balanced grid: a simple test

In previous post, I assumed that a grid with a base load might be easier/better than a grid based on intermittent power sources when the aim is a balanced grid. I based this on the hypothesis that in the former system much less energy needs to be displaced than in the latter, therefor it would be easier to balance.

That is something that I can check. I could put some grid data in a model and then change a parameter in order to see which one of the two is easier/better and to what extent.

Without further ado, this is what I did:

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