Australian Daily Electrical Power Generation Data – Tuesday 25th December 2018 – The Christmas Day Outlier

Posted on Fri 12/28/2018 by


By Anton Lang ~


This one day, Christmas Day, is always the day of lowest power consumption across Australia. That’s because no workplaces, shops, schools, or Industry are open except for the rare few. Everyone is at home to celebrate the day with family. That also points to something else as well. With everyone at home, then it stands to reason, borne out by the data, that this one day is also the highest power consumption day of the year in the Residential sector. People are consuming more power in their homes, because everyone is at home, cooking Christmas lunch or dinner, opening and closing the fridge, which consumes more electricity than having it closed with no one at home, causing the fridge’s compressor to operate more often, and that compressor is the largest consumer of electricity in that cooling system. It also stands to reason that Christmas, and that’s in mid Summer here in Australia, is probably the highest power consumption day for home air conditioning as well, as those units are working for most of the day as well with people turning them on earlier, and having them running for longer as well, hence the big electricity consume in an aircon Unit, the compressor is working more regularly. That of itself tells me that home airconditioning is not the major problem it is made out to be, when on the day with the highest power consumption in that Residential sector, it is still ….. far and away, the day of lowest overall power consumption. The Base Load remains the same as it usually is on a year round basis, close to that total of 18000MW, because all the things which operate electrically across the Country still operate as they always do. It’s just that on this day, those workplaces schools shops etc are not consuming any extra electricity, caused by normal work day practices and all those work places heating up inside due to that and the presence of so many people, also heating up the inside of those work places and high rise buildings which also are places of work. Look at the data below and the text following where I compare today’s overall with the same day, Tuesday, of last week, a regular work day.


This Post details the daily power consumption data for the AEMO coverage area in Australia. For the background information, refer to the Introductory Post at this link.

Each image is shown here at a smaller size to fit on the page alongside the data for that day. If you click on each image, it will open on a new page and at a larger size so you can better see the detail.

Note also the scale change for some of the images. That scale (the total power shown on the left hand axis) has been changed to show the graph at a larger size.

Tuesday 25th December 2018 (Christmas Day)

Total Power Generation All Sources

Here, the black line across the top of the graph shows the total power generation from every source. This is also similar to the total power consumption, which is slightly lower after minor grid losses are taken into account.

The dark grey colour is for the black coal fired power generation. The yellowish colour is for the brown coal fired power generation. The purple colour is for natural gas fired power generation. The blue colour is for Hydro (water) power generation. The green colour is for wind power generation. The red colour in the dip between the two peaks is for solar power plant generation. Rooftop solar power is not included on this graph, as this shows just the power generation from all power plants only.

In the data below, both of those (exact) figures for total power consumption for the daily minimum and the daily Peak are taken directly from the AEMO site, adding up the totals for each of the five States in this coverage area. Also, note the slight difference between Total Consumed Power and Total Generated Power. That indicates some of the losses in the grid system

Daily Minimum Power Consumption – MW

Daily Peak Power Consumption – MW

Daily Minimum Generated Power – 16800MW

Daily Maximum Generated Power – 22000MW

Average Total Power Generation – 19000MW

Total Power Generation In GWH – 456GWH

All Fossil Fuels Total – Coal Fired and Natural Gas Fired Power Generation

Here, the upper black line is the total from all fossil fuels, and this is the same as the blue line in the image directly above.

The black line just under that top black line is the Sub Total just for coal fired power. Note here how closely that coal fired line follows the shape of the upper Load Curve, and this indicates that coal fired power can be ramped up and down to follow actual power consumption.

Daily Minimum Coal Fired – 14450MW

Daily Peak Coal Fired – 17570MW

Average Coal Fired Generation – 15520MW

Total Generated Power – 372.48GWH

Average Percentage Of Total – 81.68%

Natural Gas Fired Power Generation

This image for Natural Gas Fired Power Generation shows the gap between the total for all Fossil Fuelled Sources of power generation and Coal Fired Power Generation in the image directly above.

Note here how closely the shape follows the total power generation Load Curve in the top image, indicating how these natural gas fired plants are used to smooth out the load curve to match actual power consumption.

Note also that while coal fired power provides the bulk of the power, these natural gas fired plants are used to add more power to the system during those time periods during the day when consumption rises for the morning peak, and the main evening Peak

Daily Minimum – 540MW

Daily Peak – 820MW

Average Natural Gas Fired Generation – 610MW

Total Generated Power – 14.64GWH

Average Percentage Of Total – 3.21%

All Renewable Power Generation Versus Total Power Generation

This Image shows just the gap between total power generation from every source and the total power from renewable sources only. It is the same image as the first image at the top here, only with the fossil fuelled total (the grey, yellow and purple colours) removed from the graph, As in that top image, it shows Hydro Power, (blue colour) wind power, (green colour) and solar power. (red colour)  This image is used here to highlight the gap between the total power generation and the total from renewable sources alone.

All Renewable Power Generation (Does not include rooftop solar generation)

This image is the same as for the one directly above for all renewable power, only with the total from all sources removed from the graph. As the scale of the left hand vertical axis has now changed, you can better see the detail of all renewable power. Again, the blue colour is for hydro, the green colour is for wind, and the red colour is for solar. The other colours you can just make out indicates smaller plants, mostly using biofuels as their fuel source, tiny plants adding up to a very small total and for a short time duration. For this data, I have added the times for the daily minimum, and the daily maximum, to show how they do not correlate with the actual times of minimum power consumption (4AM) and maximum power consumption. (around 6/6.30PM)

Daily Minimum – 1600MW

Daily Peak – 3800MW

Average Renewable Generation – 2650MW

Total Generated Power – 63.6GWH

Average Percentage Of Total – 13.95%

Generation From Other Sources

This image shows the power being generated from the seven smaller sources other than the major sources of power generation. These include Natural Gas/Diesel, Natural gas/Fuel Oil, Coal Seam Methane, Diesel, Kerosene, Waste Coal Mine Gas and Bagasse. All of these are fossil Fuels, excepting Bagasse which is sugar cane waste mostly used to provide main and auxilliary power at sugar mills.

Note the scale change here, as these are smaller producers of power, and the scale is changed so they can be more easily shown on the graph.

For the data here, I have just added the average generation across the day, the total generated power from all these sources, and the percentage of the total.

Average Generation – 220MW

Total Generated Power – 5.28GWH

Average Percentage Of Total – 1.16%

Hydro Power Generation

This image shows all Hydro power generation. It is the same as the orange line in the top image for power generation from all sources.

Again, note here that the shape of this load curve follows the shape of the main load curve for all power generation, in that it has similar peaks in the morning and for the man evening Peak. The coloured lines at the bottom of this graph indicate the power generation from each of the hydro plants in this coverage area.

Daily Minimum – 640MW

Daily Peak – 1650MW

Average Hydro Generation – 1000MW

Total Generated Power – 24GWH

Average Percentage Of Total – 5.26%

Wind Power Generation

This image shows the total power generated by every wind plant in this vast coverage area. It is the same as for the purple coloured line in the image at the top showing generation from all sources.

The total Nameplate for all these wind plants is 5452MW.

Note that the shape of this load curve does not follow the shape of the main load curve for total power generation. Wind power generates its power only when the wind is blowing, hence it does not follow actual power consumption levels.

For this data, I have added the times for the daily minimum, and the daily maximum, to show how they do not correlate with the actual times of minimum power consumption (4AM) and maximum power consumption. (around 6/6.30PM)

Daily Minimum – 370MW (11.05AM)

Daily Peak – 2180MW (9.45PM)

Average Wind Generation – 1130MW

Total Generated Power – 27.12GWH

Average Percentage Of Total – 5.95%

Solar Power Plant Generation

This image shows the total power generated from all the solar power plants in this coverage area. This is the same as for the red coloured area you can just see in that top image.

The total Nameplate for all these 29 solar plants is 2021MW.

Daily Minimum – Zero

Daily Peak – 1380MW

Average Solar Plant Generation for hours of generation – 890MW (5.30AM till 7.30PM)

Average Solar Plant Generation across the whole 24 hour day – 520MW

Total Generated Power – 12.48GWH

Average Percentage Of Total across the whole 24 hour day – 2.74%

Rooftop Solar Power Generation

As this source of power generation is classed as ‘behind the meter’, it is not included in the total power generation. Note here that the State of Queensland (QLD on the legend under the graph) is broken down into four separate areas as this is the largest State with the largest number of installations.

While the total Nameplate changes often, the latest information is that the total is now 7800MW, and that is a large total. However, that total equates to 1.8 Million homes with panels on their roof. That equates to an average sized installation of 4.3KW. Most of the power is consumed by the homes with the panels, and what is fed back to the grid, while seemingly still high is spread across that huge number of installations across the whole of this coverage area.

Daily Minimum – Zero

Daily Peak – 4570MW

Average For Hours of Generation – 2410MW (5.00AM till 8.00PM)

Average Rooftop Solar Generation across the whole 24 hour day – 1500MW

Total Generated Power – 36GWH

Average Percentage Of Total across the whole 24 hour day – 7.89%

Wind And Solar Power Generation Versus Total Power Generation

This image shows the total power generated from all the wind plants, and all the solar power plants in this coverage area, combined in the one image, and compares it to the overall total generated power, the black line at the top of the graph. Wind power is the green coloured area, and solar plant power is the red coloured area, and these are the same as shown in those other coloured images at the top of the Post.

I have also added the total generated power for both wind and solar plant power combined, and the percentage of the overall total below for the maximum power from both sources with respect to the overall total, both at the maximum for both, and then for the total for both at the daily peak Power time.

Daily Peak for Wind and Solar Plant Power – 2200MW

Average Across the whole day – 1650MW

Total Generated Power – 39.6GWH

Average Percentage of Total across the whole 24 hour day – 8.69%

Total Generated power at the daily maximum for both wind and solar plant power, the time of that maximum, and percentage of the total at that daily maximum –  2200MW – 6.30PM – 11%

Total Generated power for wind and solar plant power at Peak Power Consumption time for the day, and percentage of total at that daily Peak Power time – 2100MW – 6.00PM – 9.55%


  1. Finding Averages – On each (non solar) graph, there are 25 hourly time points, starting with midnight and finishing with midnight. I have added the total at each time point together, and divided by 25.
  2. For both solar power averages, I have used the same addition of hourly time points and then divided by the same number of those time points of actual generation. Every so often, as the days get longer (or shorter after Summer) I change the hours of generation as those hours change.
  3. For total power in GWH, multiply the average daily power by 24, and then divide by 1000.
  4. The total percentages for coal fired power, natural gas fired power, all renewables, and those other smaller sources add up to 100%.
  5. The total percentages for Hydro, Wind, and Solar adds up to the total percentage for all Renewables.
  6. Total Generated Power is expressed here as GWH (GigaWattHours) and a GWH is a MWH (MegaWattHour) multiplied by 1000

Comments For This Day

The Outlier of Christmas Day.

As you can see from the data, the overall power generation was way down on even the usual low totals for weekend days. This is not an aberration, but entirely normal for this one day of the year, Christmas Day, when overall power consumption is at the lowest level for the year. Even so, I was a little surprised as I actually did not think it would be even this high at all, as in previous years it has been as low as 18000MW, and in some earlier years even lower than that. I have included two images below to show the difference between overall power generation on this day, and comparing it to the Tuesday (the same week day) from just seven days ago. As with all images on the page, they are sized to fit the page, and if you click on each image, it will open on a new page, and at a larger size so you can better see the detail

The graphs actually look similar when you see them alongside each other like this. However, when you look at the larger individual images you can see that the scale is different by looking at the left side vertical axis. For last Tuesday it goes to 28000MW, and for the Christmas Day, that same axis only shows a maximum of 24000MW.

You can see that the dip in the early hours of the morning does not look as deep, due mainly to the scale of the graphs, as the low point of that dip is lower on Christmas Day than on the same day last week.. Note that following that dip for last Tuesday, power generation rises sharply at an earlier time, and to a much higher level for the usual morning Peak. Then there is the afternoon dip where generation fall away slightly to rise again to the main Evening Peak, the time of maximum power consumption, and generation for every day.

The lowest point for both days are, last Tuesday when it was 18500MW and for Christmas Day, when it was 16800MW a full 1700MW lower. Note that even on this day of traditionally lower power consumption, that Base Load figure at around 4AM is still high at that figure of 16800MW. The main evening Peak for last Tuesday was 26500MW and for Christmas Day it was 22000MW, a huge 4500MW lower.

The averages show an even larger difference across both days. For last Tuesday the average power generation per hour was 23300MW, and for Christmas Day only 19000MW, and that’s 4300MW lower, or, expressed as a percentage, then that’s 18.5% lower.

Of note here on this one day when that overall is so much lower, note here that the average for coal fired power was actually higher, by 60MW. Even on this day, those coal fired power plant Units shut down. I News South Wales Unit 2 at the Eraring plant wound back to zero at 3.30PM, and in Queensland Unit 5 at the old Gladstone plant also went down, at 1PM. Neither was really missed on a day of low power needs, and this was in the afternoon, during that dip between the two peaks. There are five of those coal fired Units off line.

The averages for all other modes of power generation were lower. The average for natural gas fired power was lower by 350MW and the average for hydro power was lower by 340MW. The average for those smaller Other sources was lower by 40MW and the average for solar plant power was lower by 40MW also.

The average for wind power was lower by 190MW to an hourly average of 1130MW, giving wind power a daily operational Capacity Factor of 20.7%, but here, note that low point for wind power of only 370MW, from a Nameplate of 5452MW, so at a Capacity Factor at that point in time of only 6.8%, a pitiful total from a power source supposedly the major supplier in a renewable power future.

On this one day with overall power generation so low, and with coal fired power actually higher, it was coal fired power which virtually ‘ran’ Christmas Day, delivering just under 82% of every watt of power being consumed on the day.

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.