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trendal
J♠


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EROEI - A Lesson in Energy Sources
#5909727 - 07/28/06 06:18 PM (17 years, 6 months ago) |
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The topic of energy production comes up quite a lot in this forum, and I see a lot of people asking if "device X" could produce enough energy to solve our energy needs. With that in mind, I'd like to make a concept known to everyone.
The concept is "EROEI", which stands for "Energy Returned on Energy Invested".
This is a vital concept to understanding energy production and why some methods work while others don't.
The idea itself isn't hard to grasp, I think. All known methods of producing energy also require the use of energy - you can't get something for nothing.
Oil is a ready example: it takes energy to find an oil field, then to drill the oil wells, then more to pump all the oil out of the wells, then even more to transport the oil to refineries, some more to refine the oil into usable products, and finally a little more to get those products to wherever they will be used for energy production.
The EROEI for any given energy source is the amount of energy you get for each unit of energy you spend.
For any viable energy source, the EROEI must be positive - you must get more energy than you put in initially. This is the only way something can be termed an "energy source".
If you have a negative EROEI, what you have is an "energy sink". It doesn't matter how much energy you put into it...you will never get that much energy back.
Now the harder part about understanding EROEI is knowing that there are usually a lot of "hidden costs" with energy production.
Take a nuclear power plant as an example. Many people will falsely assume that the energy output of a working reactor is all they need to worry about. On the contrary, every step in the life of a nuclear reactor must be taken in to account. It takes energy to build a nuclear plant (a lot of energy). It takes energy to find and then mine the nuclear fuel for the plant. It then takes energy to run the plant itself. Finally it takes a whole lot more energy to decommission and tear-down the plant (which you have to account for, unless you intend to leave it sitting there forever).
Now the EROEI for oil is very positive. That's what makes oil such a good, cheap energy source. Currently the EROEI is about 10 - meaning we get 10 barrels of oil for every barrel we use in the process. It used to be far higher than it is today. Back in the 1950's the EROEI for oil was around 100.
Many other so-called energy "sources" actually have a negative EROEI...but this fact is hidden to some extent by the high EROEI of oil along with its general availability. The as of late often-touted "hydrogen economy" is one of these examples. Hydrogen can be made easily. However it can't be made with a positive EROEI - it always takes more energy to make the hydrogen than you can get back out of it.
Biofuels are a border-line example. It may take more energy in the form of farming practices than you can get out of the biofuels made from the crops.
Even nuclear energy is on the borderline. It may take more energy to build, run, and decommission a nuclear power plant than the plant will ever produce in its lifetime.
EROEI is so vital to any discussions about energy, that I am surprised more people haven't heard of the concept. Hopefully this can help some of the discussions going on in this forum!
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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ZippoZ
Knomadic


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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5909978 - 07/28/06 08:26 PM (17 years, 6 months ago) |
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and to what extent is financial information played into this? I would imagine it likely that even some things with a negative EROEI can be financially profitable.
For instance, bio fuels. I believe that the yeild on sugar cane ethanol is somthing to the tune of %350 at manufacturing facilities in brazil, but in the USA im quite sure that the current EROI is well under %100 http://www.eroei.com/eval/net_energy_list_p.html
also for a business aplication you are really looking at your energy being invested on return in a financial light, how much that energy is going to cost you for how much it can return to you.
yes?
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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TODAY
Battletoad


Registered: 09/25/03
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Re: EROEI - A Lesson in Energy Sources [Re: ZippoZ]
#5913218 - 07/29/06 09:16 PM (17 years, 6 months ago) |
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EROEI seems kind of self-evident, which is probably why there isn't much discussion on it.
Nobody would buy a house for $1 million, put $100 thousand into fixing it up then selling it for $900 thousand. In the same way, nobody is going to build a power plant if they expect it to cost more to build it than it does to sell the energy over a pre-determined time period.
Energy is only relative to cost in practical applications. There is more energy expended in generating energy but those energy inputs are, if you want an economically advantageous system...duhhhrppp...who wouldn't, less expensive than what the energy output can be sold for.
We expend more energy producing energy because the nature of energy and entropy state that every reaction comes from an action and that every reaction isn't a perfect transfer of energy because some of it is lost as not useful energy. It only matters how expensive it is to harvest energy, not how much energy input it takes to get energy output.
There may be more potential energy in the oil than it physically takes to scout, pump, refine, deliver to consumers...I'm not sure. Trendal, I don't think you mentioned EROEI as a cost per unit analysis. I think you talked about it as an energy input vs energy ouput kind of analysis when it really is only necessary to consider the cost per input and the profit or loss per output.
*EDIT...I missed that Zippoz mentioned the point about the financial practicality of energy generation.
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
Edited by TODAY (07/29/06 09:17 PM)
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Madtowntripper
Sun-Beams out of Cucumbers


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Re: EROEI - A Lesson in Energy Sources [Re: TODAY]
#5913854 - 07/30/06 02:29 AM (17 years, 6 months ago) |
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I'm not at all familiar with this concept, and I'm more than a little drunk.
But it seems to me that any cost-benefit analysis of a potential energy source is incomplete without an assessment of the environmental costs. While oil, in the short term, may take less energy to get out of the ground and burn, it seems to me that in the long term, considering clean-up costs and the effect on the environment of that burned oil, that you'd be better off going w/ the slightly more expensive but cleaner burning E85.
No?
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
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TODAY
Battletoad


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Re: EROEI - A Lesson in Energy Sources [Re: Madtowntripper]
#5914454 - 07/30/06 08:56 AM (17 years, 6 months ago) |
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Yes, the environmental costs SHOULD be considered. At every point in the production of most goods, CO2 and other pollutants are released into the atmosphere. The good thing about renewable sources of energy (photovoltaics, solar heating devices and electricity generation for example) is that when the components are forged there are some pollutants release into the air but for the rest of the life of that device it is pollution free source of energy. This seems much better than burning fossil or other combustable fuels.
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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trendal
J♠


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Re: EROEI - A Lesson in Energy Sources [Re: TODAY]
#5914581 - 07/30/06 10:23 AM (17 years, 6 months ago) |
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Trendal, I don't think you mentioned EROEI as a cost per unit analysis. I think you talked about it as an energy input vs energy ouput kind of analysis when it really is only necessary to consider the cost per input and the profit or loss per output.
No, I purposely left out any talk of financial costs...as in the end financial costs make no difference. You can't beat the laws of thermodynamics, no matter how much money you have
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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TODAY
Battletoad


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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5915637 - 07/30/06 05:04 PM (17 years, 6 months ago) |
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Quote:
trendal said: You can't beat the laws of thermodynamics, no matter how much money you have
A challenge you say?? 
Ok, I re-read your post more carefully and I understand your point. Do you know any figures of EROEI of hydrogen production? Are developers of hydrogen technology close to a positive EROEI?
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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trendal
J♠


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Re: EROEI - A Lesson in Energy Sources [Re: TODAY]
#5915772 - 07/30/06 05:45 PM (17 years, 6 months ago) |
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Do you know any figures of EROEI of hydrogen production?
I have some serious doubts that hydrogen will ever be a viable energy source, unless we figure out some really easy way to do fusion (which, I'm afraid, will also be a net energy loser).
Most hydrogen today is produced using natural gas - so it's not actually an "alternative" energy source...just a different way of using the energy from fossil fuels. It requires natural gas as feedstock and more natural gas to boil water and make steam which is used to produce the hydrogen. As far as this process stands, it is a net energy loser - we would be far better off using the natural gas in its natural state.
The other way of obtaining hydrogen is to split water into oxygen and hydrogen using electricity (called 'electrolysis'). It takes about 1.3 billion kWh of electricity to produce the equivalent in hydrogen of just 1 billion kWh - so a net loss of about 300,000,000 kWh of electricity.
So that's an EROEI ratio of 1 to 1.3 which is negative.
Are developers of hydrogen technology close to a positive EROEI?
Nowhere near it, unfortunately.
Hydrogen is not a fuel source here on Earth...for the simple reason that there isn't any elemental hydrogen laying around in large quantities. It will always have to be produced by splitting the hydrogen off of another molecule...and that will always require more energy than you will get out of the hydrogen that you produce.
Hydrogen is only an energy "source" for stars...and that's only because the vast quantities of free hydrogen (meaning not bound in a molecule) that exists in outer space. If we could get there already we might be able to mine hydrogen from Jupiter with a net energy gain...but I think that is definitely at least a few decades away (if not a century...).
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
Edited by trendal (07/30/06 05:47 PM)
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Asante
Mage


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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5915916 - 07/30/06 06:31 PM (17 years, 6 months ago) |
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Quote:
we might be able to mine hydrogen from Jupiter with a net energy gain...
That'd be silly technology, because you then use up oxygen 
I'm a fusion believer, hydrogen fuel is just a glorified storage battery for the energy which is released in other ways.
-------------------- Omnicyclion.org higher knowledge starts here
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TODAY
Battletoad


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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5916336 - 07/30/06 08:28 PM (17 years, 6 months ago) |
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Thanks for those figures Trendal. I'm familiar with electrolysis and I knew you'd get less power in the resultant hydrogen than you put electric power into it, just as energy is wasted when you burn natural gas to boil water and convert it to electricity. There's always a net loss of energy in systems like this but the economics are what is important in practical applications.
If you could collect the heat needed to boil water to turn turbines to generate electricity to produce hydrogen repeatedly at an economic profit, then that's all there is to it. That's the practicality. If the source was renewable then the EROEI would be positive over the longer run.
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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trendal
J♠


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Re: EROEI - A Lesson in Energy Sources [Re: Asante]
#5916390 - 07/30/06 08:45 PM (17 years, 6 months ago) |
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I was thinking of hydrogen for fusion 
But as far as fusion goes...I am not convinced that we are anywhere near fusion as a truly viable energy source.
ITER will be a huge step forward, in the sense that the reactor itself will have a positive return on energy. On the other hand I think the project as a whole is at a large net loss of energy, considering the up-front energy costs of construction and the end of life decommissioning (which will take at least several years).
Beyond ITER, I am just not convinced that stable nuclear fusion can be achieved with a real net energy gain anywhere outside the core of a star. That is the only known place in the universe where fusion occurs "naturally".
Just look at nuclear fission. It happens everywhere, all the time, whether we want it to or not, but even it can't produce much of a net energy gain - mostly due to the enormous energy costs in construction and deconstruction, plus fuel production and processing.
It takes, at the very minimum, the gravitational energy of tens of quintillions of kilograms of hydrogen to create enough to cause fusion in a star core. We may be able to replicate the fusion itself here on earth, but I'm not sure we can do it sustainably without all that extra energy.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
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Re: EROEI - A Lesson in Energy Sources [Re: TODAY]
#5916422 - 07/30/06 08:53 PM (17 years, 6 months ago) |
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There's always a net loss of energy in systems like this but the economics are what is important in practical applications.
No this I don't agree with. Perhaps with anything else...but not energy sources. Energy sources are what allow any economy to exist at all - because energy sources are what allow anything to exist at all 
If a so-called "energy source" is really a sink, economics will have no bearing on the inevitable.
If you could collect the heat needed to boil water to turn turbines to generate electricity to produce hydrogen repeatedly at an economic profit, then that's all there is to it. That's the practicality.
That's a big if.
If the source was renewable then the EROEI would be positive over the longer run.
No, if the entire process has a negative EROEI, it will never become positive even with an extended run time. If it costs you more energy to produce your fuel and run the whole process, the process itself is not renewable - regardless of whether or not the fuel is.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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TODAY
Battletoad


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Posts: 10,218
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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5916919 - 07/30/06 10:51 PM (17 years, 6 months ago) |
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I respect your opinions on the matter Trendal, but I will attempt to show you that it doesn't matter what the EROEI of a project is in a practical application. Please don't think I'm trying to dumb down economics to you, I'm just trying to prove a point. I know you are a smart guy 
**Edit** Deleted calculations because I forgot to account for raw material cost and overhead cost not related to input energy per, lets say photovoltaic panel. I could refigure things but I'd rather get back to reading my book...sorry if it is a quitter attitude.**
I maintain the economic practicality as being the only measure of importance, not the net gain or loss of energy.
**EDIT**Bah, without the calculations my argument doesn't have a backbone**
Edited by TODAY (07/30/06 11:20 PM)
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ChuangTzu
starvingphysicist



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Re: EROEI - A Lesson in Energy Sources [Re: TODAY]
#5918044 - 07/31/06 09:23 AM (17 years, 5 months ago) |
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Quote:
I maintain the economic practicality as being the only measure of importance, not the net gain or loss of energy.
In the short term, you're right. But if your energy "source" operates at a net loss of energy (making it actually a "sink"), you eventually will not have any more energy to sell, for any price. The laws of thermodynamics trump those of economics in the long term.
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ZippoZ
Knomadic


Registered: 06/17/03
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Re: EROEI - A Lesson in Energy Sources [Re: ChuangTzu]
#5918183 - 07/31/06 10:43 AM (17 years, 5 months ago) |
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thats true, buthe governmtnt requiring certain amounts of "green" energy to be produced regardless of EROEI and large amounts of funding getting dumped into the programs, it does happen.
for a while ethanol was indeed being produced with a negative EROEI, ask agreatfulchick greatfulj's wife about it. she went to school for all of this and relayed the info to me. she is also employed by a major agricltural company and works on corn alll day.....
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: EROEI - A Lesson in Energy Sources [Re: ChuangTzu]
#5919163 - 07/31/06 05:02 PM (17 years, 5 months ago) |
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Quote:
ChuangTzu said: The laws of thermodynamics trump those of economics in the long term.
That is the simple truth, and there's no way to get around it.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: EROEI - A Lesson in Energy Sources [Re: ZippoZ]
#5919184 - 07/31/06 05:08 PM (17 years, 5 months ago) |
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Quote:
zippoz said: thats true, buthe governmtnt requiring certain amounts of "green" energy to be produced regardless of EROEI and large amounts of funding getting dumped into the programs, it does happen.
for a while ethanol was indeed being produced with a negative EROEI, ask agreatfulchick greatfulj's wife about it. she went to school for all of this and relayed the info to me. she is also employed by a major agricltural company and works on corn alll day.....
Once again: I am not contesting the fact that an energy sink (negative EROEI) can be economically profitable. Economics has, in the end, nothing at all to do with the physics behind energy sources and energy production. This is a physics concept - not economics.
The government is pouring money into "green" or "alternative" energy "sources" (though many/most of them are energy sinks, not sources) and this will make these forms of energy profitable in the short-run....but it will cost us all dearly in the end.
The result of such actions is an actual waste of energy. We waste valuable hydrocarbon energy to subsidise the use of energy sinks in the form of "alternative" sources.
Until you can show me an ethanol-producing farm that uses no hydrocarbons anywhere in its process...you won't be showing me a viable form of renewable energy. That includes hydrocarbons used in producing the farm equipment, hydrocarbons used as fertilizer, and hydrocarbons used directly as fuel to run the farm equipment. If/when all of those hydrocarbon uses are converted over to ethanol - and it must be no more ethanol than is produced on the specified farm - we will have a viable energy source.
Until then...we're just fooling ourselves.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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Asante
Mage


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Posts: 86,795
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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5919323 - 07/31/06 05:53 PM (17 years, 5 months ago) |
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Bio-diesel and ethanol are fuels, for which we can afford them being endothermic (thats basically the issue) as long as we have a primary energy that is exothermic. This is a different approach.
Cultivating and then combusting whole biomass is more energy-efficient, but only works for powerplants. In essence its a means of capturing solar energy, without panels.
I'm a nuclear man. I favor developments in fusion, but in the current situation I'm also in favor of fission (uranium) energy, using 21st century designs. At the moment anything goes as long as it decreases our pumping CO2 in the atmosphere.
-------------------- Omnicyclion.org higher knowledge starts here
Edited by Asante (07/31/06 05:55 PM)
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ZippoZ
Knomadic


Registered: 06/17/03
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Re: EROEI - A Lesson in Energy Sources [Re: Asante]
#5919513 - 07/31/06 06:54 PM (17 years, 5 months ago) |
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this all ties back to my secret project muah ha ha
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: EROEI - A Lesson in Energy Sources [Re: Asante]
#5919565 - 07/31/06 07:06 PM (17 years, 5 months ago) |
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Quote:
Wiccan_Seeker said: I'm a nuclear man. I favor developments in fusion, but in the current situation I'm also in favor of fission (uranium) energy, using 21st century designs. At the moment anything goes as long as it decreases our pumping CO2 in the atmosphere.

I'm with you on that one! Nuclear is going to be the best option for the near and mid term, I think.
I don't think fusion will become viable before another, entirely new technology is discovered - rendering fusion obsolete in the process.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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ZippoZ
Knomadic


Registered: 06/17/03
Posts: 13,227
Loc: Pongyang, North Korea
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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5919777 - 07/31/06 08:13 PM (17 years, 5 months ago) |
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think of the massive amount of nuclear waste that is produced, with no long term plan for its storage?
i think that even canada has this problem, and this is a large amount of waste, ALOT. And from what i remember easily convertable to weapons grade material.
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: EROEI - A Lesson in Energy Sources [Re: ZippoZ]
#5919882 - 07/31/06 08:44 PM (17 years, 5 months ago) |
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Nuclear waste isn't really "waste" - it still contains most of the energy it had in the first place.
Current long-term storage practices have proven more than adequate for spent nuclear fuels. Storing them long-term as they are, with the ability to access them if need be, allows for future advances in fission technology - reactors will be invented that are able to use the energy still remaining in nuclear "waste".
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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ZippoZ
Knomadic


Registered: 06/17/03
Posts: 13,227
Loc: Pongyang, North Korea
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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5919926 - 07/31/06 08:56 PM (17 years, 5 months ago) |
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yeah i suppose, for most of the countries that refine the waste, which i believe are all but the usa..... 
we have a LOT of nuclear waste laying about on site at all of the nuclear facilities. and despite the fact that one day we might be able to use it, there has to be somewhere to put it in the mean time.
this stuff is highly toxic, and is also a security issue as it can be used to create irty bombs and so on.
So for now it sits distributed through out the country on site at nuclear power plants. the proposition on hand is to bury it all in nevada, the countries wasteland, but having all of that waste in one place just dosent sound good to me
im a bit jaded for a few reasons in regard to nuclear waste. the remains of the manhattan project are burried about 10 miles from my house. i have been to the site where they are burried, and stood on top of them. back in the 50's and 60's the government had a storage solution, it was to bury the shit, with a concrete cap over it, nothing under it.
lo and behold it got into some local municipalities drinking water what a shock.
so i personally do not trust that our vission of "safe Storage" well into the future could possibly , in any way, be all seeing and expecting every curve ball that will, in time, be thrown at it.
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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TODAY
Battletoad


Registered: 09/25/03
Posts: 10,218
Loc: Metropolis City, USA
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Re: EROEI - A Lesson in Energy Sources [Re: ChuangTzu]
#5920433 - 07/31/06 11:22 PM (17 years, 5 months ago) |
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Quote:
ChuangTzu said: The laws of thermodynamics trump those of economics in the long term.
I won't live any more than another 80 years tops and my love of the smoke and the drink will only bring that number down. I don't need to worry about the sun running out in my blink of the eye existence.
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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Baby_Hitler
Errorist



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Re: EROEI - A Lesson in Energy Sources [Re: trendal]
#5925349 - 08/02/06 12:52 PM (17 years, 5 months ago) |
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Quote:
trendal said: Trendal, I don't think you mentioned EROEI as a cost per unit analysis. I think you talked about it as an energy input vs energy ouput kind of analysis when it really is only necessary to consider the cost per input and the profit or loss per output.
No, I purposely left out any talk of financial costs...as in the end financial costs make no difference. You can't beat the laws of thermodynamics, no matter how much money you have
I think you're making a mistake by ignoring economics. All energy is not equal. Some forms of energy have more value than others. There is alot of energy in a 5 gallon bucket of warm water, "equivalent" to about 20 Oz. of gasoline, or 2 lbs. of wood, but it is not in a very useable form.
It all comes down to how much energy you use and how effectively you use it... and by "use" I mean you had it in a valuable useable form, then you "used" it, and then it was rendered unuseable.
Worrying about running out of energy is silly, almost as silly as worrying about running out of matter. What you should be worried about is running out of structure/order.
Once we have put all our stored energy (stored in matter in the form of fuel) through the process of going from a high state of order (fuel) to a low state of order (waste heat) then our system (society) will follow the second law of thermodynamics and begin to decay as well.
Social entropy.
-------------------- Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ Ƹ̵̡Ӝ̵̨̄Ʒ (•_•) <) )~ ANTIFA / \ \(•_•) ( (> SUPER / \ (•_•) <) )> SOLDIERS / \
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: EROEI - A Lesson in Energy Sources [Re: Baby_Hitler]
#5926343 - 08/02/06 06:28 PM (17 years, 5 months ago) |
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I think you're making a mistake by ignoring economics.
EROEI has its place in economics, no doubt, but the angle I am speaking from is 100% thermodynamics. That's why I purposely leave out any economics - it just doesn't have a bearing on the physics concept of EROEI.
Worrying about running out of energy is silly
Worrying about anything is silly 
Social entropy.
Entropy is a core function of this universe.
Social structures are also a function of this universe, thus they obey all underlying functions/laws including entropy.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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