I do not understand EROEI and how it is relevant

FatherOfTwo · Posted: Mon May 16, 2005 5:17 pm Post subject:

CalgaryEng is correct, there is no universally accepted way to calculate EROEI, and that has been demonstrated in this thread over and over. Not only that, but EROEI is only of value when energy sources are scarce. (And scarcity to me necessarily includes our current inability to capture all of the solar radiation that hits the planet) If we were able to obtain fusion and had energy to burn (sorry, couldn’t resist), then we wouldn’t give a rats ass that it took a gazillion MJ of fusion energy to get at whatever oil remains, because oil has other properties than just being an energy source. Also, EROEI for a given energy source can not only decrease but also *increase* and I’ll offer up the real world example of THAI technology for the oil sands as an example.

On the other hand, EROEI has been advanced by many as a convenient way to explain Peak Oil to newbies, and there is some merit in it. There is merit because Peak Oil is all about the end of cheap oil, not the end of oil. Peak Oil just happens to be the biggest risk factor to our main concern - peaking energy. So the connection is made – in order to keep up with our production of oil, we’re spending more energy to obtain it. Since we don’t have solar oil wells handy, that energy is necessarily coming from other oil, natural gas, whatever, putting further pressure on our energy pie.

To me that is what it boils down to. Has the total energy pie shrunk or grown? If it’s shrinking you better conserve like a son-of-a-gun and you better ramp up on other sources of energy. Whether we will be able to do that is up in the air. The odds are long.

I think CalgaryEng is right. EROEI leaves a lot to be desired. Better to speak in terms of the total energy pie and how we not only are overly dependant on the oil piece of the pie, but how we're reaching the point where we are going to have to start devoting more of the other pieces of the pie to get that oil...
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mididoctors · Posted: Tue May 17, 2005 2:14 am Post subject:

FatherOfTwo · Posted: Tue May 17, 2005 1:03 pm Post subject:

FatherOfTwo · Posted: Wed May 18, 2005 9:39 am Post subject:

I clicked on one of the ads today Physics Today (doing my bit to generate revenue Smile

)

On this site I found the following:

That history illustrates the profound economic importance of the concept of net energy. The economic value of an alternative energy technology depends on the net rate of energy QNE it will deliver after the rate of energy production QPR is debited by the energy consumed for its operation QOP and the energy invested in its creation E during its lifetime T:

QNE = QPR − (QOP + E/T).

So hey, doesn't that sound an awful lot like EROEI?
_________________
Do not underestimate the difficulties of surviving the transition of peak oil, nor the dangers of global warming. We must embrace nuclear energy and renewables.

twofiftyfive · Tar Sands Joined: Apr 04, 2005 Posts: 30

0mar · Posted: Wed May 18, 2005 12:14 pm Post subject:

Well with a bountiful supply like fusion, you can do whatever the Fark you want basically.

You can take CO2 and make long chained hydrocarbons, you can take silicon and break the nucleus apart to get carbon, you can synthesize anti-matter, its really is mind-boggling what you can do with plentiful energy.
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Licho · Posted: Wed May 25, 2005 10:12 am Post subject:

Yes, and this all is true, even if EROEI of fusion would be say 3..
But the abundance of fuels (oceans) would make it look like infinite and infinitely powerfull source of energy..
Another example that EROEI is not that usefull - abundance/scarcity, complexity of exploiting source is not incuded in EROEI.

NEOPO · Posted: Sun May 29, 2005 2:49 am Post subject:

funny stuff.

Yeah right - since when does something have to be accepted by the scientific community to be correct?

And when did non-acceptance by the scientific community make something wrong?

And why cant we use EROEI to communicate a very valid and relevant concept??

Like demand destruction - I think some people make it their business to go about communication destruction.

Licho · Posted: Sun May 29, 2005 5:00 am Post subject:

Because you don't have defined "borders", EROEI value is pretty much useless given you alone .. try to read more posts .. I know its long but..

Bandidoz · Heavy Crude Joined: Mar 02, 2005 Posts: 150 Location: UK

I haven't read all of the posts in this thread, but would ask one simple question.

It's obvious that an EROEI of less than 1 is a net energy loss, or at best a level where the uncertainties become very significant.

Now is it a subtraction that's done or a division? In other words, energy loss being fractional (e.g. 0.5) or negative (e.g. -1) EROEI? (of course in the subtractional/negative scenario, the break-even point is zero as opposed to 1).

I believe it to be the "fractional" case anyway.
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Licho · Posted: Tue May 31, 2005 5:13 pm Post subject:

It's fractional..

DriveElectric · Intermediate Crude Joined: Mar 12, 2005 Posts: 639

This thread should be required reading before anyone even considers quoting EROEI for anything. It is largely a meaningless number when assigned to any energy source. The biggest mistake we seem to make is using EROEI out of context. Clearly it is almost impossible to make a fair comparison between two energy sources with different hypothetical EROEIs.

When someone pulls a number out of their butt and says, "Oil had an EROEI of 50, but now it is 25, and coal is 8 and Ethanol is 1.6, SO WE ARE ALL GONNA DIE!!!"

Post a link back to this thread and ask for clarification on what the heck they are talking about.

NEOPO · Posted: Wed Jun 01, 2005 2:35 am Post subject:

OK then there is no way for simple people like us to understand it so why are we talking about it?
Is that what you want me to believe?

I have met very intelligent people who could not change a tire!!!!
They must have been baffled by mankinds amazing advancement in tire changing technology!!! Surprised

A panel of brilliant scientist were assembled to define the terminology for the various tire changing elements.
After much debate the name for raising the vehicle became "jacking" and the tool for performing this function became known as a"jack".
One of these scientist must have had a dog named Jack Laughing

I love posting thoughts when I have not read the whole thread!! not.
Wow so much for EROEI then huh?!?!? hahahah
As if this thread is the defining moment for EROEI - hilarious!!!

I think what you are trying to say is that this concept is used to show the difference between in and out.
We can apply this concept to anything we want to - as long as we know whats going in and whats coming out.
I dont care how you wish to define it - its a tool and it helps people understand what would probably take you an hour and two blackboards to illustrate!!!!
If you wish to call it pilecream then fine but can we get on talking about it now please?

Someone has to call it something.

Science gets knocked on its ass all the time.
One discovery can change everything.

licho - ASS.U.ME all you want to about other peoples forum habits.
I dont see any proof that EROIE is not a good tool that helps with the understanding of energy depletion.
It applies equally well to alternatives.
Until you show me something better I will stick with this concept thank you very much.

I dont have any blackboards and its not something I want to draw complex equations on while trying to explain the concept to anyone less then a quantum physicist!!!

INFORMATION DESTRUCTION - These guys are agents!!!! Smile

NevadaGhosts · Intermediate Crude Joined: Aug 20, 2004 Posts: 752

CalgaryEng wrote: