Coal Fired Power Dying – Not So Fast – Part Three – Coal Fired Power In China

Posted on Sat 06/05/2021 by

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By Anton Lang ~

I mentioned in the earlier Post how there was not much that I liked about the way China does things. However, it seems that they are doing something correctly when it comes to bringing electrical power to their Country. Now, some people might say that China is very secretive about what goes on inside their Country, and I have found that also carries over into this task of finding information about getting that electrical power up and running at the scale required. I’m not sure if you can refer to it as secretive, because that information is there, but when it comes to something like this, what I have found is that information about this is a lot more difficult to find when it comes to China. With virtually every other Country in the already Developed World, I can find nearly everything I want to find relatively easily. However, with China, I find something obscure, and I have to chase that up in a manner which is more difficult. I can chase down one link, and that might lead to another, and from that, to a further link. Sometimes, it then gets away from what I was looking for in the first place, so I have to look again somewhere else. Sometimes I do find what I want, but the search has been way more complicated than finding information that is not China related. And then, when I do find some information, there are other links to follow down when I do find the thing I want. Such was the case here.

In that earlier Post (at this link) I detailed some of the reasons why China is ramping up its electrical power generation, and is on a similar trajectory that the U.S. was on starting at the end of World War Two, and is only just starting out on that trajectory.

This considerable ramping up is not happening just with coal fired power, but with every source of power generation, and in this Post I will detail what is happening with that coal fired power generation sector in China. The same happened in the U.S. with coal fired power plants being constructed more than any other type of power plant, and that continued until 2007, when coal fired power in the US began to decline, but at some stages during those years in the U.S. coal fired power was delivering up to 55% of all the generated power.

Thirteen years ago, when I started doing all this, I found a small fact that China was constructing new coal fired plants, and they were doing that at such a rate that a new coal fired power plant was opening up every seven to ten days, and that they would be doing this for many years into the future. Reading something like that was incredible, because we were told that coal fired power was becoming a thing of the past, and that soon, there wouldn’t be very many of them. Somewhat in disbelief, I tried to verify what I had seen, and found out it was true, not mentioned in just that original place I found it, but in so many articles that I stopped looking. Now, here we are, more than 13 years after I first saw it, and China is still proceeding at that same pace, a new coal fired power plant opening up every seven to ten days, with no real sign of slowing down.

They have now reached the stage (at the end of 2020) where China is generating 53% of all the coal fired power on the Planet, so more than EVERY other County in the World ….. combined. (here’s the source for that fact) Across the World, coal fired power is generating 8736TeraWattHours (TWH) of power, and that constitutes 34% of the World’s total power generation from every source. (here’s the source for that fact) From that same source, it shows that China generated 4631TWH from coal fired power. So that leaves 4105TWH for the WHOLE of the rest of the World.

China – 4631TWH

Rest of the World – 4105TWH

Okay, now look at this fact. China burned less coal to generate its 53% share of coal fired power than the rest of the World did for its 47% share of coal fired power, in fact, 4.3% less coal. That’s because the average coal burned per KiloWattHour (KWH) in China is 290grams/KWH across all its coal fired power plants compared to 340 grams/KWH for ALL the coal fired plants in the rest of the World. So, to generate considerably more power, China burned less coal than in the rest of the World, and because of that China emitted a lot less CO2 than did the rest of the World from its coal fired power plants.

Why is that?

It’s because the coal fired power plants being opened in China are nearly all of the newer technology coal fired power plants. There are five levels of technology in coal fired power plants, and they are.

SubCritical, Critical, SuperCritical, (SC) UltraSuperCritical, (USC) and now, Advanced UltraSuperCritical. (A-USC)

With each step up in technology, the efficiency of the plant increases. This efficiency is the Thermal Efficiency, and that relates to the burning of the coal, and the ‘making’ of the steam which drives the turbine which in turn then drives the generator. (in reality a turbo Alternator, but it has nearly always been called a generator)

The U.S. and nearly all of the already Developed World (the Western World) started at the end of WW2, and at that time, only the lowest level of tech was available, SubCrtitcal. Then in the late 60s and early 70’s and later, technology improved and they mostly used Critical plants, and this technology is what provide nearly all coal fired power in the U.S. and is still in use there, even though so many of those plants have now reached the end of their lives after 50 years of power delivery.

However, in China, when they started to ramp up power generation, they have used a lot of Critical plants, but they have been early implementers of the most recent technology, moving to use SuperCritical in 1994, UltraSuperCritical in 2007, and now the latest of those tech improvements Advanced UltraSuperCritical in 2019/20.

Because of that, as each level of technology improves, then efficiency increases, and as that efficiency increase then that results in less coal being burned, and consequently, less Carbon Dioxide being emitted. In fact, with each one percent increase in that thermal efficiency, it results in a two percent reduction in CO2 emissions.

So just by constructing new tech coal fired plants, then there is a reduction of emitted CO2 when compared to an equivalent old tech plant. The current Worldwide average for that thermal efficiency is just 34%, and the latest technology A-USC plant thermal efficiency is 49%, so that’s a reduction in CO2 emissions of 30%. (this is the link for that. It’s a 61 page pdf document, and the information about this is shown on page 7)

However, China has not stopped there, just constructing those new tech coal fired plants. They are now retrofitting older plants to bring them up the the newest tech low emissions, and that again needs to be explained with some care.

In the same manner that the U.S. started constructing those sub critical plants after the end of WW2, those plants were small, in the range of 1MW up to 100MW, and mostly in the range of 2WM to 20MW, and these smaller plants serviced small areas localised power generation. As the newer and larger Critical technology became available, these newer plants grew in size, with larger generators to the point that most of the large scale plants in the U.S. had four Units each driving a generator of 400MW up to 660MW, so most of them in the range of 2000MW+ in total Nameplate. Because of that, and those large plants now able to supply much larger areas, those smaller local plants began closing, nearly all of them in fact.

Exactly the same thing happened in China, lots of tiny plants servicing small areas. Then larger plants began to be constructed, most of them in the Critical tech level, and some even in the older sub critical level of technology, and in exactly the same manner, those smaller plants closed, again, almost in their totality. Because of China’s huge area and much larger population, those mid range older plants are still a vital part of China’s electricity mix. There are around 800 or so of these mid range plants in that 300MW to 600MW range. As well as these older plants, China has constructed more than 150 of those USC plants of 1000MW Nameplate and higher, along with a similar number of SC plants.

So, China set about trying to increase the efficiency of those older technology Units. They had to find a way to do this, while also trying to make the process as economically viable as was possible. What they did was to work on one of the older tech plants, in this case the Xuzhou 3 plants which had a Unit of 320 MW Nameplate. What they wanted to do was to retrofit some USC technology to this older plant, and use different turbines, and turbine technologies. What they achieved was the end result of raising the efficiency of this old plant to 42.8%, and that’s in the range of USC Unit efficiency, and here, again keep in mind that the current Worldwide average efficiency for coal fired power is just 34%. This retrofit was to a Unit three levels of tech lower than USC. They can do this retrofit for around $50 Million. It extends the whole of life for the Unit, lowers the coal consumption rate to 287 grams per KWH, (and the Worldwide average for that is 340 to 345 grams per KWH) lengthens the time between turbine overhauls out from six years to now twelve years, and reduces plant emissions by 10%.

Now that this has been achieved, the task is to retrofit those mid range older tech plants to comply with this new technology, no easy task, as there are so many of them. All this information and more is shown at this link, a long article well worth reading.

China is even upgrading its latest tech power plants to make them even more efficient as well. As I mentioned earlier, China was one of the first Countries to open up an UltraSuperCritical (USC) technology power plant. One of those was the Waigaoqiao No. 3 plant, opened in 2008, and the turbine hall of this two Unit plant is shown in the image below, and again, if you click on the image it will open at a new tab, and at a larger size.

The Power Block of the Waigaoqiao No. 3’s massive steam turbine generators, which are among the largest and most efficient in China. Courtesy: Shenergy Company Ltd.

This plant has two Units, each 1000MW in size, so the plant has a Nameplate of 2000MW.

Work on this plant has resulted in raising the efficiency of even this plant, already one of the most efficient coal fired plants on Earth. That efficiency was raised from 42.7% to what it is now, 44.5%, and while that may not sound much, keep in mind that World average of 34%, and the average for USC plants is 41%. As well as upgrading the efficiency, the work also resulted in lowering the emissions from the plant, not just of CO2, (in the range of half a million tonnes less of CO2 each year) but all other emissions as well, not just to the levels that the Chinese regulators have asked for but to considerably lower levels than that, making this one of the lowest emissions plants of this size or technology level on Earth. As well as these improvements, there was also work on the boilers with respect to the startup time from coal, and this has always been one of the minor drawbacks for coal fired plants, that they are slow to get up to full power, and some earlier technology large scale plants around 660MW can take anything up to 12 hours to reach their full output. The work done at this plant to the early stage of the process now sees this plant reaching that full output in less than two hours, even from cold startup. All of this information for this plant  is shown at this link, and again, it’s well worth reading.

So, not only is China seeking to construct the latest technology coal fired plants, they are also actively finding ways to make all their older plants and even the recent plants more efficient.

And THAT is something that China is doing right.

In the next Post on this subject, I will detail the latest technological step up in coal fired power plants, Advanced UltraSuperCritical (A-USC) and that is SteamH, which increases efficiency almost to 50%.

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.