Mislead (Again) On Cap And Trade

Posted on Thu 02/04/2010 by


Electrical Engineers everywhere must be tearing their hair out in frustration.

The Carbon Cap and Trade legislation is specifically designed as a revenue raising device alone, and is not designed for the purposes of lowering Carbon Dioxide (CO2) emissions.

That’s a pretty bold thing to say, I can see, and requires some explanation, which is where the frustration of those electrical engineers comes into play.

When people discuss Cap And Trade, they do it from only one aspect, that of the political point of view. Everything that is said about it is based around that point of view.

The biggest of those Carbon Dioxide (CO2) emitters are those large coal fired power plants, and when people discuss it, the point continually stressed is that they just introduce this piece of legislation, and what it will do is to cause those plants to cut back their emissions. The legislation will place a cap on the emissions from those coal fired plants. Anything above that cap, then those plants will have to pay a large fee for each ton over that cap. The cap is then decreased each year. The theory is that the plant will just emit less over time because that cap will be forced lower each year, thus effectively lowering emissions over time.

When stated like that, it sounds all too easy.

What people fail utterly to comprehend is just how that coal fired plant does produce its electrical power, something I have tried to explain in as many different ways as is possible in an attempt to make it a little more easily understood, because, if the truth is told, there’s probably even electricians out there who are hazy on the subject.

Climate Change/Global Warming is so far down the list of what people are concerned about that it barely rates a mention at all. However, the next time someone does bring up the subject in your presence, ask them if they can explain exactly the simplified process of how they turn coal into electricity, and I’m willing to bet there would be very few people who could actually do that, and here I’m talking about the absolutely most simplified version there is.

The coal is crushed almost to powder and is then fed into a critical high temperature furnace. This furnace boils water to highly pressurised steam in the boiler. This steam then drives a multi stage turbine, and the turbine then drives the generator.

That’s the simple version.

A large coal fired power plant can produce 2000MW of power. To do this it can have two three or four generators. Let’s look at one plant that has two generators, each producing 1000MW.

Those generators are huge. Electromagnetic formers are on the rotor and these then induce a current flow in the Stators, which is the power produced from the unit. That rotor can weigh in the vicinity of 250 to 400 tons, depending on how modern the technology is. All this weight then rotates at 3,600 RPM. It needs to rotate constantly at that same speed all the time it is rotating because the frequency of the voltage needs to be kept constant, and this is how the plant produces its maximum power at all times. To keep the generator revolving at this speed all the time, it is driven by the multi stage turbine through a form of gearbox called a Constant Speed Drive, (CSD) which I suppose is fairly self explanatory. The turbine has to be driven at a speed that will enable that CSD to be able to keep the generator rotating at all times at that 3,600 RPM. Any slower and the whole unit would just drop off line, and effectively stop.

So, the turbine has to kept rotating above a certain speed. To do that, then it is intricately calculated how much steam is needed, and from that, back to how much coal is needed to be burned in the furnace.

So then let’s look at how much coal is burned to be able to do that. Those large plants burn in the vicinity of 6.5 million tons of coal to do this. Keep in mind here that very few new technology plants have been constructed in the U.S. due solely to lack of political will. Hence, those currently existing U.S. coal fired plants are all aging, and in fact the average age of the whole U.S. inventory for all coal fired power plants is 48 years. One of the few Countries actively constructing new coal fired power plants is China, at the rate of one new plant every seven days coming on line supplying power to the grid, and these are all the newer technology plants. They have generators vastly lighter in weight while producing more electrical power, and because they are lighter in weight, they are smaller all round, hence smaller turbines hence less steam is required, hence less coal is burned, and less CO2 is being emitted, and producing larger amounts of power.

So that 6.5 million tons of coal being burned each year in an average U.S. coal fired plant translates on average to around 18,000 tons of coal being burned each day. I can see some eyebrows being raised at the mention of that. This means that each and every day, that amount of coal must be burned to produce the electricity. The coal is brought to the plant in differing ways, Some plants are constructed near coal mines. Some have the coal brought in up the river by barge, and all these plants need to be near a dedicated water source so they can have that water for the steam they need to produce. However, most coal is brought to the plant by rail.

Two train loads a day. This amounts to 10,000 tons per train load. 3 locomotives haul 100 coal hoppers each hopper holding 100 tons of coal. The train is almost one mile long. That coal is offloaded on site and then fed up the conveyor belt to the crusher and then into the furnace. Continually, 24 hours a day, 236 days a year, for anything up to 50, 60, or 75 years, barring down time for maintenance, carefully calculated so as to cause the least amount of problems for the grid the plant supplies.

The plant is owned by the Authority, and that authority then has to purchase the coal it needs to keep the plant going. As I mentioned earlier, the turbine needs to be kept at a speed to keep the generator rolling at that 3,600 RPM.

The authority then carefully calculates the minimum amount of coal needed to keep that level of steam up to the turbines. The cost of steaming coal is considerable, especially when you realise they are burning 18,000 tons each day, so any excess is not really needed if you can see the point there. So, they use the minimum amount of that steaming coal as they possibly can, carefully calculated, because excess amounts of coal, while not needed, will be quite a large added cost to the running of the plant. especially when extrapolated across a whole 12 month period.

Enter Cap And Trade.

The theory is that the plant then has an upper limit placed on their emissions.

I’ve carefully explained how one tone of coal produces 2.86 tons of CO2 in this post, again something people find difficult, if not impossible to comprehend.

So, burning 6.5 million tons of coal each year means that your average large coal fired plant emits 18.6 Million tons of CO2 each year.

Let’s just say that the Government is benevolent and makes that Cap for that plant the current maximum emission, that being the 18.6 Million tons. This way the plant can operate in the same normal way it has always gone about its operation.

Then at the end of year one, that Cap is lowered.

If the plant then wishes to keep in operation, all it can do is to pay the excess. They cannot cut their emissions because that means burning less coal, hence less steam, the turbines then cannot keep the generator rotating at it’s designed specifications to produce the power at the correct frequency, and the plant then just shuts down, and there will be no power at all. To keep going, all they can do is pay the excess, the end result being that this is then passed directly down to the consumer, those consumers coming from three sectors, Residential, (38%) Commercial, (37%) and Industrial. (24%) Each of those sectors will feel the impact of the raising of their electricity costs, you directly as the residential consumer, and then you as a consumer of goods from the Commercial and Industrial sectors, so you as the consumer get caught three ways.

Each year that Cap gets progressively lower, and the amount of money flowing to the Government increases by a huge amount each year considering that the electrical power generating sector alone emits nearly 3.5 Billion tons of CO2 each and every year.

You may think this applies only to coal fired power plants. These plants supply their power to the grids and that power, always available there on the grid is drawn down by consumers. During times of excess demand, Peaking Power, then those plants specifically designed to be able to run up and down in a short space of time come on line to supply power to top up the level available at the grid. These plants are in the main Natural Gas fired power plants. The gas drives a turbine, similar in nature to a jet engine, which then drives the generator. These plants supply considerably less than the huge lumbering coal fired plants, so they can be brought on line as they are needed. The natural gas is also an emitter of CO2, so again, that Cap will also apply to them as well.

Incidentally, I’m willing to bet legislators did not have this target in mind when they crafted their legislation. Those plants deemed to be the saviour of the industry, Concentrating Solar plants (Solar Thermal) use natural gas fired turbines to drive the generator for the times when the molten compound heated by the sun via mirrors goes off its molten state and cannot boil water to steam to drive a conventional turbine and (much smaller) generator. That component where the natural gas fired turbine drives the generator will se these so called renewable plants emitting up to 1,200 tons of CO2 each day. (440,000 tons each year) This means that these plants will also be subject to Cap And Trade.

Will this lead to the construction of newer technology coal fired plants that are smaller, produce more power, burn less coal more efficiently, thus emitting considerably less CO2. Not really, because the same Cap will then apply to them also. The Cap will be set at what they do emit, and then be lowered progressively each year, so you’re in the same position as you already are with those much older plants.

It will however, unintentionally lower CO2 emissions. Bean counters at the Power supplying Authority will be doing their sums. The plant, already old, needing more intensive maintenance, burning more coal as it ages will become uneconomical to remain in operation. The plant will then just be closed down. Hence no more CO2 emissions at all. It also means the removal of that huge amount of electrical power from the grid.

You can feverishly construct all the wind towers and solar plants you like to replace that one coal fired plant. You’ll need 700 of them just to replace that one coal fired plant, and even then. you’ll only get one fifth of the power because that’s the best efficiency rate they operate at. Renewable power currently supplies only 1.6% of all consumed power in the U.S. There are currently 35,000 wind powers in the U.S. The total amount of power they supply amounts to 64 Billion KWH, the same amount of power being produced from only four of those large coal fired plants over a whole year. Why I mention this is that for every four of these large coal fired plants that do close down because of this Legislation, you will need to double the number of those wind towers. The time needed to construct that many towers and the cost for all of them would be prohibitive.

That is how I can confidently say that the Carbon Cap And Trade Legislation is only being brought into play for one reason, that being as a a revenue raising device.

It will not lower CO2 emissions. It can not lower CO2 emissions.