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Dude
SFN Die Hard
USA
6891 Posts |
 Posted - 08/19/2005 : 23:52:19 [Permalink]
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quote:
With this in mind our plants are highly efficient.
No, they aren't.
Which, as has been said already, doesn't mean they aren't as efficient as we can currently get them.
There is a BIG difference between "efficient" and "as efficient as we can currently make them".
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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dv82matt
SFN Regular
760 Posts |
Posted - 08/20/2005 : 00:10:20 [Permalink]
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quote:
Originally posted by Dave W.
Yeah, that'll do it. When do we start?
If only all of life's little problems were so easily solved.  quote:
Edited to add: one wonders (well, I wonder) how much of the inefficiency of pumped storage is due to simple evaporation. Some of the water you expend energy pumping up just floats away on the wind.
I don't know, although in rainy areas I suspect there might be a net gain, but it's significant enough that MIT is on the case.
http://alamaro.home.comcast.net/Evaporationretardation.htm
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R.Wreck
SFN Regular
USA
1191 Posts |
Posted - 08/20/2005 : 09:57:27 [Permalink]
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quote:
Originally posted by Dude:
quote:
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With this in mind our plants are highly efficient.
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No, they aren't.
Which, as has been said already, doesn't mean they aren't as efficient as we can currently get them.
There is a BIG difference between "efficient" and "as efficient as we can currently make them".
Near the bottom of this page, you'll see the theoretical maximum efficiency of a coal plant is about 73.5%. However, for a real process, you can't get that, as explained here:
quote:
Causes of Inefficiency
In the preceeding sections, cycle and component efficiencies have been discussed, but the actual causes or reasons for the inefficiencies have not been explained. In this section we will compare some of the types and causes for the inefficiencies of real components and cycles to that of their "ideal" counterparts.
Components
In real systems, a percentage of the overall cycle inefficiency is due to the losses by the individual components. Turbines, pumps, and compressors all behave non-ideally due to heat losses, friction and windage losses. All of these losses contribute to the non-isentropic behavior of real equipment. As explained previously (Figures 24, 25) these losses can be seen as an increase in the system's entropy or amount of energy that is unavailable for use by the cycle.
Cycles
In real systems, a second source of inefficiencies is from the compromises made due to cost and other factors in the design and operation of the cycle. Examples of these types of losses are: In a large power generating station the condensers are designed to subcool the liquid by 8-10°F. This subcooling allows the condensate pumps to pump the water forward without cavitation. But, each degree of subcooling is energy that must be put back by reheating the water, and this heat (energy) does no useful work and therefore increases the inefficiency of the cycle. Another example of a loss due to a system's design is heat loss to the environment, i.e. thin or poor insulation. Again this is energy lost to the system and therefore unavailable to do work. Friction is another real world loss, both resistance to fluid flow and mechanical friction in machines. All of these contribute to the system's inefficiency.
All this adds up to an overall efficiency of 35% to 45%, depending on the design and condition of the plant. Efficiency is money for a generator. Coal plant operators closely monitor their heat rate (BTU / KWh), to see how efficiently they are using their fuel. At some point, however, you run up against economics or physics, and that point determines actual plant efficiency. |
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibliities of knowledge.
T. H. Huxley
The Cattle Prod of Enlightened Compassion
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R.Wreck
SFN Regular
USA
1191 Posts |
Posted - 08/20/2005 : 10:06:48 [Permalink]
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quote:
Originally posted by Dude:
I'd say that if the incentive, political and financial, were there the technology we currently have would easily be ready to use. GE sells the things commercially.... how much more "ready" would it have to be, for wind anyway? Tidal also is just a different application of hydro power. Solar could stand to be a little more efficient, yes, but the current state of the technology is certainly viable for some use. Geothermal... still just a concept.
Wind power is subsidised by preferential tax treatment. Without that, it would not be economically attractive. Tidal is pretty much in the research stage, although I believe I have read about some pilot installations. The trick with harnessing tidal or wave power, is that although there is a lot of energy available, it is not very far above the equilibrium of the environmnent. The higher the difference between an energy source and the environment (be it temperature for a steam cycle or elevation for a hydro plant), the more efficient it is. Capturing this "low grade" energy efficiently presents some technical challenges that need more work. Geothermal is a reality. There are some geothermal plants. Its just that there aren't a lot of places with a hot enough source close to the surface (that aren't volcanoes). But where there is, there are geothermal plants working. |
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibliities of knowledge.
T. H. Huxley
The Cattle Prod of Enlightened Compassion
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 08/20/2005 : 12:31:29 [Permalink]
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quote:
Wind power is subsidised by preferential tax treatment.
But fossil fuels recieve much more preferential treatment from subsidies and tax breaks. As long as it remains this way, wind (and other cleaner, renewable sources) will remain second class citizens.
Companies are going to go with the options that generate the most profit. Currently, wind ain't it.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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dv82matt
SFN Regular
760 Posts |
Posted - 08/21/2005 : 17:55:30 [Permalink]
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quote:
Originally posted by Dude
There is a BIG difference between "efficient" and "as efficient as we can currently make them".
This is a bit like saying, "There is a BIG difference between 'fast' and 'as fast as we can currently make them.'" when talking about high performance cars.
Strictly speaking you are correct, but in common useage it is normal to say a plant is efficient if it is as efficient as we can currently make it. |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 08/22/2005 : 00:25:32 [Permalink]
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quote:
Strictly speaking you are correct, but in common useage it is normal to say a plant is efficient if it is as efficient as we can currently make it.
Then any comparison between different sources of power and their relative efficiencies is meaningless.
The term is highly subjective. And nobody that I am aware of refers to the process of converting raw fossil fuels into power, in terms of potential power vs actual power extracted, as an efficient process.
This is very far afield from the original topic anyway.
Does anyone agree or disagree with my OP? That the main barrier between cleaner, renewable, non-fossil fuel power sources is a political one as opposed to technological?
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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dv82matt
SFN Regular
760 Posts |
Posted - 08/22/2005 : 01:39:27 [Permalink]
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quote:
Originally posted by Dude
Then any comparison between different sources of power and their relative efficiencies is meaningless.
You're right, in most situations it is pretty meaningless to compare the relative efficiencies of different sources of power.quote:
Does anyone agree or disagree with my OP? That the main barrier between cleaner, renewable, non-fossil fuel power sources is a political one as opposed to technological?
As far as I can see the main barriers are economic and technological. I'm not convinced that there is any significant political opposition to renewable power. |
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R.Wreck
SFN Regular
USA
1191 Posts |
Posted - 08/24/2005 : 17:29:51 [Permalink]
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quote:
Does anyone agree or disagree with my OP? That the main barrier between cleaner, renewable, non-fossil fuel power sources is a political one as opposed to technological?
The problems with energy are technological, economical, social, and political. Just like a lot of other things. |
The foundation of morality is to . . . give up pretending to believe that for which there is no evidence, and repeating unintelligible propositions about things beyond the possibliities of knowledge.
T. H. Huxley
The Cattle Prod of Enlightened Compassion
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 08/25/2005 : 01:17:10 [Permalink]
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quote:
The problems with energy are technological, economical, social,
I wasn't saying that none of these are problems, just that the most significant problem is political.
And from what I can see, the technological and economic "problems" are much less significant, and will continue with that trend.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 08/27/2005 : 13:45:07 [Permalink]
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Was just reading some things on wind power today... There are some interesting ideas out there.
This one is particularly interesting because it overcomes the random nature of wind supply.
http://skywindpower.com/ww/home.htm
Another idea I read about, but have no link to (sorry, couldn't find any internet info), is ground based.
I'll take a shot at describing it.
Take a wide cone. Set it on the ground pointy end up. Cut it off about 2/3 of the way up. Take a tall cylinder and place it on top now. (kinda like a big funnel is what you should have at this point)
Install wind turbines horizontally at intervals up the cylinder. The cylinder has a large elevator built on the east or west side that can carry replacement wind turbines up, and the cylinder is set up so the turbines can be hot-swapped out as needed.
Build this structure large/tall enough and it will have significant vertical airflow with no assistance.
Now build a large bank of mirrors to the N and S. Mirrors that can focus the light they reflect onto the cone. Vertical airflow increases through the cylinder.
Under the cone you construct a garbage incinerator, run the incinerator at night to provide heat when you don't have the sun.
Build a farm of these things in FL or one of the deserts of the southwest... ship in garbage to keep the incinerators busy at night.
Not as elegant as the flying electric generators, but sounds just as feasible with current technology.
Both very interesting ideas.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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GeeMack
SFN Regular
USA
1093 Posts |
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BigPapaSmurf
SFN Die Hard
3192 Posts |
Posted - 08/29/2005 : 10:27:12 [Permalink]
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Ah man! I should have called Inventech!*
This is a joke, dont call Inventech or any of those other scam artists. |
"...things I have neither seen nor experienced nor heard tell of from anybody else; things, what is more, that do not in fact exist and could not ever exist at all. So my readers must not believe a word I say." -Lucian on his book True History
"...They accept such things on faith alone, without any evidence. So if a fraudulent and cunning person who knows how to take advantage of a situation comes among them, he can make himself rich in a short time." -Lucian critical of early Christians c.166 AD From his book, De Morte Peregrini |
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Siberia
SFN Addict
Brazil
2322 Posts |
Posted - 08/29/2005 : 11:13:57 [Permalink]
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| Forget wind, forget petrol, nuclear and thermal... Here's your solution. |
"Why are you afraid of something you're not even sure exists?"
- The Kovenant, Via Negativa
"People who don't like their beliefs being laughed at shouldn't have such funny beliefs."
-- unknown
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