Electrical Power Data In Pictures – Supply And Consumption And Renewables – Part 3

Posted on Sat 09/03/2022 by

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By Anton Lang ~

Again be aware that this data is not for any time far into the past, as this data is current to just three days ago.

Every image you see in this Post is sized at a smaller size to best fit the page. If you click on any of the images, each one will open on a new page, and at a much larger size so you see the detail better.

The last image I showed you from the earlier Post was this one.

What appears to be such an innocuous looking image contains such a wealth of so much information, it will take me four separate Posts to explain it all.

I mentioned earlier that I use three sites for all of my data gathering, and this image above is from the one I use the most, and have been using now for so many years, and that is the Aneroid Energy site at this link.

The third site I use is the AEMO recording site for power generation data, and while I mentioned that I will be attempting to do these explanations with images and then explaining the images, this one site I will refer you to and show just the two images, but this is the only time I will refer to it.

The image at left shows the informational links at the site, and here’s the link to that site, the NEMWEB Dispatch Reports. Each of those blue links are single reports on the power generation of every Unit at every power plant in the AEMO coverage area. If you look closely at the image, you’ll see the time relationship between reports, and that is a new report every five minutes. That’s why I have only shown a partial image here of the bottom part of the page, because there are 288 reports to the page, and each page covers just a single 24 hour day to a single page, so as the new report is released, the oldest one drops off the top of the page. Each report is shown at the link, one of all of those blue links at the right of the image. You can see that the bottom one is a slightly different colour, because that’s the one I used for the second image, at right of the page. If you click on the link, it will be saved as a Zip File to the Downloads section of your computer. When you then go to the Downloads section of your computer and click on that zip file, you computer unzips it, and saves it as a Spreadsheet file. You then have to open your Spreadsheet, and open the file, and that shows you what I have used here as the second image. Again, it is a very long file, so here I have only shown the bottom of that spreadsheet file as an image.

As you can see there are 416 entries. Each one of those entries is for an individual power plant across the AEMO coverage area. Where individual power plants have more then one Unit, then each Unit has an entry, so as you look here at the last four entries on the page, you’ll see the code in the second last column shown as YWPS1,2,3, and 4, and these are the four Units at the YallournW brown coal fired power plant in Victoria. So here, Unit 4 at that YallournW Plant was delivering 378+MW of power at that recording time. So there are 416 different sources of power generation. Each report shows the power delivered by that Unit or plant in the most recent five minute period, and the SCADA Reports are generated in real time, as it happens, and shown at the site almost immediately.

Both of the other two sites I use take these instantaneous reports, and using their own software, convert that data to the images you see here, the images from the earlier Posts, and the image at the top of this page, and they are also shown in real time, at the same five minute time rate.

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Okay then, you should already have that top image open in a new and larger window, so here’s the explanation for that.

This image shows the power generation from all sources across the day I am using for the year round ‘average’ for all power generation, September 7 2021, and that day was a Tuesday, so a good indicative day, as weekend power consumption is way different to normal work and school day weekdays. Each day (naturally) starts at Midnight, and goes across the page to the next Midnight in one hour divisions. Those divisions are shown in this still image I have taken, but at the site, you can hover your mouse over anywhere on the page, and it shows the power again at the recording rate of each and every five minutes.

The black line at the top of the image is the total power for the day. This black line is referred to as the Load Curve. While that is the generated power, I have told you that it is also the same as for the power being consumed as well.

Note that from Midnight, it falls to the overnight low at around 3.30AM to 4AM. Then it rises again, and this is the usual Morning peak, when everyone gets out of bed, tidies up, has breakfast etc, and gets ready for the usual work or school day, and then leaves the home for the day. That morning Peak is usually between 7AM and 8AM, and you can see that where the colours UNDER the yellow one begin to fall again. The yellow colour is rooftop solar power, and as the Sun rises, so the power from those panels increases. The power then falls away in the mid morning and early afternoon, and then begins to rise again towards the usual evening Peak which happens at around 6.15PM to 6.45PM. That’s when everyone gets home from work, and school, and fires up all the power being used in normal everyday life at home, cooking for the evening meals, heating in Winter, and cooling in Summer, all the chores at home which require power, and entertainment as well. That evening Peak is at around the same time, ALL the year round, each and every day, and is the highest point of power consumption during the day.

The shape of that black line is similar to the one you see here for 6 Months of the year, the cooler Months leading into and out of Winter, when that dip in the middle of the day is deepest, and where you will see two distinct Peaks, with that evening one always the highest. In Summer, there is no Midday dip, as power consumption consistently rises to a peak which in Mid Summer can be higher than that usual evening Peak, which is still there, just now hidden by extra power consumption during the middle of the day. That extra power consumption is mostly from what is called HVAC, (Heating Ventilation, and Air Conditioning) and that power is consumed in every single high rise building in the Country as they work hard to keep the inside of those towers cool, and supplied with circulated breathing air. That gap between the mid Winter dip and the mid Summer bulge can be anything up to 5000MW to even 8000MW, a huge added power consumption.

That’s the black line at the top.

Under that are the colours indicating all of the power sources, and each one has a different colour, and each colour corresponds to  what is shown in the ‘legend’ under the graph itself. This shows the makeup of power generation across the whole grid, the total power generation mix for that day in question.

As I get further into these Posts, I will be explaining the colours, some of them just in passing, and concentrating on just four of those sources,  those four renewable sources of power generation, and their relationship to the overall total power generation and more importantly, their relationship to that other aspect of that same black line, actual power consumption.

However, let’s get one thing out of the way right at the start, and it concerns that black line. See the steps in it, those jagged ups and downs in the mid morning and the late afternoon, after Sunrise and at Sunset. Well, they are due solely to rooftop solar power. I mentioned above that all power is recorded on a five minute basis. That’s easy for the AEMO to do. However, when it comes to Rooftop Solar Power, that is power that the AEMO CANNOT record, because it is connected to individual households roofs, and there is no way that they can record it at all. So what is done here is that they make a best case guess on how much power is being generated by rooftop solar power, and that is noted, but only noted every half hour. So, while power plant power is recorded on that five minute basis, it makes for a smoother graph across the whole 24 hour day, so 288 separate recording of each individual Unit. Rooftop solar power is noted with that half hour guess. So that gives us a graph for rooftop solar power and that is shown on the image at left below, just showing rooftop solar power on its own. One recording, and then the next recording half an hour later, hence the steps as power rises, and then falls back. So,when it is shown at the same scale as the main graph, what you get is the image at right, showing the steps, only a little smaller, and when shown on the total power (black line) you see those jagged ups and downs, the steps of rooftop solar power.

Okay, with that explanation done, let’s get into it. Firstly, what I would like to show you is just some images of the simplest part of the graph, that solitary black line at the top, and the image below will make up the next Post, and while it is so simple, that back line can show so much. However, what I have added here is a little extra as a lead in.

This Post, while posted separately on this day, will be added to the main Sticky Post at the top of our site.

Anton Lang uses the screen name of TonyfromOz, and he writes at this site, PA Pundits International on topics related to electrical power generation, from all sources, concentrating mainly on Renewable Power, and how the two most favoured methods of renewable power generation, Wind Power and all versions of Solar Power, fail comprehensively to deliver levels of power required to replace traditional power generation. His Bio is at this link.

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