A few quick questions for those knowledgable of energy and the production of electrical power.
I read somewhere, can’t remember where now, that the residue of coal after it is burned is dangerous, or radioactive. In fact, I heard it is even more dangerous than the stuff produced by nuclear power plants. Is this true?
Secondly, how long does it take for the residue of a nuclear power plant to decay down into something harmless, or harmless enough that it won’t kill with exposure.
And thirdly, and lastly; A friend said something about California looking for alternative power sources. Sources he claimed would run the household, yet not use electricity. To me this sounds, well hoaky. Nothing my mind can comprehend seems to be able to replace electricity, and nothing I have ever heard of could be used in similar ways. This friend is generally reliable in his information, yet this sounds like something a very ignorant person would say, not my friend. Is there some truth to this, or is he finally off his rocker?
#1- Anthracite will be with you shortly. In the meanwhile I’d say it is possible that the ashes may have a higher radioactivity just because they concentrate certain things which do not burn but I cannot imagine it would get to be dangerous. I believe the ashes are used for certain industrial processes so I imagine they are quite safe from that standpoint.
#2- Several thousands of years. Longer than you are going to live at any rate.
#3- huh? he has invented computers and TVs and VCRs which run by cranking them? Sounds like the original steam-powered vibrator.
Burning coal releases various radio active isotopes that are present in the coal into the air. Because you burn a whole lot of coal I don’t have problem with believing that burning coal releases more radioactivity that you would get from a nuclear plant.
Coal plants leave a lot of ash that has to be disposed of and I believe that it certainly is somewhat radio active but enough to worry about I don’t know. I have a real hard time believing that this ash is more radio active than the high level waste from a nuclear power plant. There vast amount more of ash than actual spent fuel from a nuke plant.
One of the guys at work who seems very knowledgeable about this says that about 10,000 people die prematurely each year due to pollution from coal fired power plants. Primarily the particulate emissions causing breathing problems.
How is that for a reliable source some guy with a dopey nick name saying he heard from a friend who knows about these things. What do you want to bet someone comes along to say this is a load of horse droppings and all I will be able to say is well Bill is a good guy he wouldn’t be wrong about this.
I think that it depends on what you mean by exposure. I believe that when the waste in no longer radio active that it will still be poisonous because it will be heavy metals. But the ash and CO2 from coal plants are not really going anywhere either. Well maybe the CO2 but if you believe in global warming and that it is caused by CO2 we are talking about changing the climate of the whole world as apposed to making a very small portion of it unhabitable.
As far as running the house with out electricity that would be a pretty Spartan life. As for running a house without being tied to the electric grid. You can certainly do that with photo voltaic cells that charge batteries so you have electricity at night. But it will be very expensive. People who do this mostly live far away from the electric grid so they don’t have much option but to do it.
Somewhat distorted. Just about everything is radioactive, including thee and me. This is one of those perfectly true but utterly meaningless statements that are used purely for the sake of confusing the issue.
Does a coal-burning power plant emit more radioactivity than a fission reactor? Why yes, due to thorium (mostly) in uncontrolled particulates. Is that radioactivity harmful? By no means; it’s just that a fission reactor emits even less than that. You may want to look at this site concerning radiation risk if you really want to calm your nerves (or scare yourself to death, depending on your viewpoint; did you know that you get more than 200 times the radioactivity from the [sup]40[/sup]K in your body than from a typical coal-fired power plant?)
Well, again, this depends. Without getting into the whole plutonium debate at this point, let me say that fission wastes not containing significant amounts of plutonium will decay to about the radioactivity of the original ore in about 600 years. As gazpacho correctly points out, some of even the stable isotopes to which they decay are heavy metals and metalloids (like arsenic) that you don’t want in your water supply. OTOH, as Anthracite’s data have shown, coal-fired power plants produce much larger quantities of even more toxic elemental poisons.
(Incidentally, if you’ve wondered, "WTF is fission waste made of, anyway, the answer is here.)
To me, alternative power sources are ways of producing electricity without nuclear or coal power plants. For example, solar, wind and water energy. It’s possible they are considering using something like that in California, and your friend has his terminology confused.
Maybe you could try asking him exactly what he meant?
As for the alternative power source, during our discussion(as I was trying to figure out what he meant) he mentioned that electricity itself (the flow of electrons) will become obsolete. Even batteries and such involved electricity, as do Wind, solar, geothermic power plants and such. I think he was leaning towards a revolutionary breakthrough in physics that allowed things like microwaves, refrigerators, computers, phones, and things that run by running an electrical current through them, to run, well by some other mystical way I suppose.
Now that I have slept on it, it seems pretty absurd really, and I still cannot imagine anything generating a similar effect as electricity. I will probably try to talk him out of his viewpoint on the subject, but I really am not knowledgeable about the subject (took electronics in High school, but doesn’t seem to give me as much ammo as I would hope), and he is pretty stubborn.
The links will help to convince him that nuclear power plants are safer as was my side on the argument, so thank you immensely. I tried to explain what was happening to California was largely due to deregulation or political reasons, as their power supply could be fixed by building more power plants, but lacked the data to convince him. (this is when he mentioned that they were working on non-electrical ways of running things) He also mentioned something about a limited amount of power a plant can produce, and that the amount of people in the world using electricity has exceeded mans ablility to produce any more. I wonder lightly if he thinks there is a limited pool of electrons, sort of like the finite pools of petrolium, and once we run out, its gone forever…
The problem with waste from coal fired plants is that it emits radon gas. The burned coal comes out of the boilers as cinders. Think of small misshapen black pebbles. It’s run through crushers and ground down into a very fine yellow powder. This powder is called “fly ash” and is used in the production of ready mixed concrete. Ready mixed concrete producers use it because it makes the concrete easier to finish and it costs less then cement. The concrete plant can cut back on the amount of cement powder used in the concrete by ten to thirty-five percent. When I used to be in the bulk dry transport business I recall that a load of fly ash (50,000 pounds) was going for around 800.00 and the same quantity of cement was around 1200.00. The big problem with the radom gas is that it continues to come out of the cement for years after it is poured to make the foundation of your house. Radon gas occurs naturally in a lot of soils, but disperses naturally out in the air. Having it coming out of the concrete inside your well sealed house will lead to your breathing it at levels much higher than would be found naturally oudoors.
Just to clarify Raving Nude Hermit’s point a bit (gotta love that nickname!): Radon is a byproduct of radioactive decay of other elements. Radon has a triple-whammy attached to it: It’s a gas, it’s radioactive, and it’s heavy. A litre of radon has a mass of about 10 g; a litre of air, 0.67 g. So it comes out of the concrete in your walls, sinks to the floor, and in many cases accumulates in basements. The only way to get rid of it, short of waiting for it to decay into lead (yum!), is really good air circulation in your house. If you can get it outside, there’s enough air around to dilute the radon to “harmless” levels.
Ah, I discovered my friend has a streak of desire for the big debate. I sent him a link on this message board about Coal Vs Nuclear, he discussed the points he disagreed with (most of it of course) and doubted the sources. His thing is, he can’t know it is accurate data, unless he measures it himself, thus weasling himself out of the debate. (because I know it is never going to get measured by him) He thinks that the danger of a nuclear power plant blowing up(snicker), combined with the ecological danger of waste, outweights the danger of coal. (according to his “beliefs”) It’s a free world I suppose.
I querried further about the power source that will replace electrons moving through things. (crude, I know) He said that he thinks that our current knowledge of physics allows us to achieve the same result with, say, magnetism. Phones, microwaves, computers(and computers will change so much, programmers will be out of a job in the next 10 years), answering machines, refrigerators, etc, will be replaced with ones that work off of magnetism and not electricity. (apparently he doesn’t know how most generators generate their electrons) I think I will stick to debating philosophy, religion and perhaps movies and books with him, and tend to skirt around the edges when science is brought up.
He’s in luck: We already do use magnetism. The energy transfered by an electrical wire isn’t transfered in the moving electrons themselves, but in the electromagnetic fields of the electrons. The electrons move at rates measured in millimeters per minute, but the fields move at whatever is the speed of light in the medium (about .3 c, for most metals).
How this is supposed to help the power situation in California or anywhere else, I have no clue.
Well, it’s possible that your friend isn’t alltogether off the rocker, merely 100 years after his time. In the 19th century hydraulic power was used to power certain mechanical machinery. A great example is the London hydraulic company:
And they didn’t pull the plug, so to say, till 1977!!!
Pushing around water at high pressure might seem archaic to us, but it did indeed work pretty well! I’m sure that one could build a (very clumsy) fridge, vacuum cleaner or hairdryer, and maybe even an LP player using nothing but water. Computers, microwave ovens or CD players, however, do require electricity to operate.
I just hope they’re not looking at this as a solution to our electrical power problems - from what I’ve heard, pumping water is already one of the major uses for electrical power.
When I first read the OP, what came to my mind were the small-scale fuel cells being envisioned as a means to remove homes from the electric grid. While they certainly involve “electricity,” they remove the necessity of being connected to the grid. (They produce electricity much more efficiently than conventional electric generators, and if located in a home, don’t require the long distance transmission of electric power.) I understand that some hospitals have them as a backup power source.
When I read the friend’s comment about “magnetism” replacing electricity, though, I concluded that he doesn’t know what he’s talking about. As Chronos mentioned, this statement is meaningless.
Do you have any information about fuel cells being more efficient than other ways of generating electricity? I was under the impression that new natural gas plants are around 60% to 70% efficient. This link for plug power states an efficiency of 40%. Going to 80% if you use the waste heat to heat you water or home. Recovering that much heat seems pretty optimistic to me but I live in southern California where heating is not a major energy expenditure.
I was mostly going by my past experience. I would be greatly surprised if anyone could find an efficiency for any conventional generator that was much better than 30%. This number correlates well with the site mentioned above. Note that this number is the efficiency of the entire generating system, including the prime mover, and not just the electrical end.
For any conventional generator, involving rotating, moving parts, I think you are going to get huge frictional losses as well as the inevitable heat engine losses. I was always under the impression that a fuel cell would have a huge efficiency advantage simply by avoiding moving parts.
Unfortunately, the page is not available, but Google’s cached version confirms much of what I said above. They cite efficiencies of 40-60% for a natural gas fuel cell. They state that this is “more efficient” than conventional, but no definitive numbers (for the conventional).
So what is the big disadvantage of fuel cells? At the moment, it is $ (of course). This may change.
This says a combined cycle gas plant is getting about 57% efficient. A combined cycle plant fires a first turbine by burning natural gas. The it uses the extra heat to generate steam for a second turbine. So this is not as efficient as I previously thought.
Some other stuff I have read but cannot find a cite for are more advanced composites for the gas fired turbines allowing them to run at higher temperatures will get the efficiency up some more. But that is research so they are not ready.
