Author Archives: trustyetverify

When solar and wind capacity increase

When pointing to the huge fluctuations of solar and wind production in previous post, I wrote that these fluctuations will only grow when South Australia advances on its path towards 100% renewable energy. Looking at the fuel mix and demand data that I had gathered until then, I noticed a fine example of exactly that. Just look at the fuel mix and demand data:

AEMO South Australia (charts0011a) overview

Let’s focus on the minimum on September 5 at 20:00. That is around the time that I looked for the first time at the overview panel (see previous post). The data showed that the total production of solar and wind was 4.341 MWh, which is 0.29% of what was produced at that moment. Contrast this to the peak of 1,258.486 MW the next day around 22:00, just after the evening peak when energy demand was slowly starting to decrease. It is this dynamics that will lead to the fluctuations that I wrote about.

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Hornsdale Power Reserve: the share of battery power in South Australia

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.

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Increasing fossil fuel subsidies by 6 million euros and proud of it…

A remarkable tweet that I stumbled upon (translated from Dutch):

You often hear on the right that Belgium has the highest tax level. What is not told is where the money is going.

Belgium, king of the fossil fuel subsidy …

Tweet Tobias Daneels 2020-08-20: fuel subsidy

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Skepticalscience takes a … pro truth pledge?

It was not only a long time since I blogged lately, it was also a very long time since I visited the skepticalscience website. This weekend, I landed on the skepticalscience website and, looking at the right sidebar on their website, I noticed this:

SkS pro truth pledge

A pro truth pledge?!?!?

Did skepticalscience really took a … pro truth pledge?!?!

You mean … as in … pledging to write … well … the truth?

That seemed odd to me. Throughout the years, I came to know skepticalscience as not very truth-minded. The articles are one-sided and they are not wary of presenting opposing view in a misleading way, heck, they even were caught several times downright fabricating things.

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Climate misinformation having little or no effect on liberals?

It has been a while since last post. I am learning new skills and this has a negative effect on the post frequency. I am still in the learning process, but I couldn’t resist when I saw this list of quotes in a tweet from John Cook (my emphasis):

Twieet John Cook 20200724

These quotes are a collection extracted from an Independent article on “The spread of climate denial on Facebook”, which contained some quotes from John Cook. These are all interesting quotes, but I will limit myself in this post to the first quote (yellow marking):

Through his research, Dr Cook has found that climate misinformation that is spread on social media disproportionately affects conservatives and has little impact on liberals.

I can understand that conservatives and liberals have different worldviews, therefor react differently to the same information, but there is much more nuance to it than that.

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Wind keeping the system “nicely balanced”: does more wind power means better air and cleaner electricity?

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?

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Wind keeping the system “nicely balanced”: wind, meet nuclear

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:

Tweet dieterjong 20200421

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…

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Gone by 2020: worse or better than thought?

This is part 8 in the series on the prediction that glaciers in Glacier National Park will be gone by 2020. You might want to see to part 1, part2, part 3, part 4, part 5, part 6 and part 7 if you haven’t already.

Back to a previous series on the prediction when the glaciers in Glacier National Park would be gone. In hat series, I focused primarily on two specific predictions (with the end date of 2020 and 2030) and how these were presented to the public. I knew there were other predictions around, but at that time I was not particularly interested in them, so didn’t search for these specifically.

In the meanwhile, I came across the NationalReview article “Beware the Boogeyman Alarm” by Kyle Smith and that contains this interesting paragraph (my emphasis):

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Hornsdale Power Reserve: huffing and puffing old men coming to the aid of their colleague

Now it was established in previous two posts that the Hornsdale Power Reserve did surprisingly little to avert a frequency drop caused by a 560 MW capacity loss (contrary to what was suggested in the RenewEconomy article), the focus of this post will be on how the message was brought. Knowing how little the battery actually did, then how on earth could Giles Parkinson paint it as if something extraordinary had happened? This post will explain how this is done.

Let’s start with the title:

Tesla big battery outsmarts lumbering coal units after Loy Yang trips

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Hornsdale Power Reserve: the mouse that stopped the elephant from falling

After writing previous post, the RenewEconomy article kept going through my mind. The author of the article suggested that the response of the Hornsdale Power Reserve to a tripping coal fired power unit was extraordinary, when in reality it was insignificant in the grand scheme of things. I wondered why on earth the author was so lyrical about what was in fact a poor performance…

Then it suddenly struck me. It might well be a misinterpretation of how the event was represented.

Let me explain.

There were two graphs presented in the article. The first one is the frequency versus the response of the Hornsdale Power Unit and it stood central in previous post. There is however a second graph in the article and it is this graph that could easily lend itself to misinterpretation. It shows the sharp decline of the tripped coal unit combined with the response of the Hornsdale battery:

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