EROEI: Energy Returned on Energy Invested (merged)

trespam · Posted: Thu Dec 16, 2004 8:22 pm Post subject: DOE Report on Shale lacks EROEI

I looked through this report on Shale Oil and couldn't find anything that tells me they've seriously considered EROEI. Checkout volumes 1 and 2: [Volume I] [Volume II]

Volume II does discuss "total energy cost" and energy efficiency, but I'm not sure this tells me anything about EROEI.

big_rc · Posted: Thu Dec 16, 2004 9:11 pm Post subject:

Look down in the General Comments section in Vol. 1. (page 44) They somewhat mention something that might be construed as an EREOI argument.
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trespam · Posted: Thu Dec 16, 2004 10:03 pm Post subject:

I checked out the text on page 44. One could almost sort of kind of maybe somehwhat call this an EROEI discussion. I think the writers of this report either (a) are hiding something because they want to get funding for themselves or others or (b) are stupid. I don't think they are stupid. Therefore I think they are just sneaky.

savethehumans · Light Sweet Crude Joined: Oct 20, 2004 Posts: 1541

As always, consider the source....

MonteQuest · Posted: Sat Dec 18, 2004 1:11 am Post subject:

From everything I have read on oil shale, it is an energy sink, not to mention the environmental costs. But if we need "oil" for our addiction, perhaps they will go ahead with an EROEI < 0. Crying or Very sad

Talk about eating your food faster to avoid starvation! Shocked

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MonteQuest · Last edited by MonteQuest on Fri Apr 07, 2006 9:43 pm; edited 1 time in total

How important is understanding EROEI with regard to peak-oil? What does it mean? When the EROEI ratio for oil exploration declines to the point that it merely breaks even--that is, when the energy equivalent of a barrel of oil must be invested in order to obtain a barrel of oil--the exercise will become almost pointless, regardless of any economic consideration. . Even if oil remains a useful lubricant or a feedstock for plastics, it will have ceased to be an energy resource. EROEI is also an essential consideration in the substitution of one energy resource for another. If we replace an energy resource that has, say, a 4:1 EROEI ratio with an alternative that has a 2:1 EROEI ratio, we will have to produce twice as much gross energy to obtain the same net quantity. Thus, when a society adopts lower-EROEI energy sources as we find with solar technologies, the amount of energy available to do work in that society will inevitably decline.

In any human activity, there tends to be what is often referred to as the Law of Diminishing Returns. This means that for any activity, the first part of the process produces the greatest profits or advantages. For example, when a successful oil well is sunk, the oil gushes up under considerable pressure. As the oil reservoir depletes, more energy has to be applied to extract what remains. The amount of energy required to extract the same amount of oil increases as the depletion grows. You finally reach a point where it takes more energy to pump and refine the oil than you get once it is extracted. For each barrel of oil you extract from the Middle East, it costs you approximately the energy of 1 barrel of energy to extract 31 barrels, refine it, move it around the world and pump it into the tank of a vehicle.

To produce any energy, whether it is pumping oil out of the ground, or building and operating a wind turbine, you need to use some energy in the process. If the energy returned is less than the energy you produce, it is considered a "heat sink." No power sourcing project can sensibly be undertaken without Energy Return on Energy Investment (EROEI) assessments. Purely financial analysis is wholly inadequate, especially where signals are distorted by government subsidies as with ethanol and tar sands.

Some simple definitions:
An EROEI of 1 means that for every unit of energy you put in, you take 1 unit of usable energy out.
An EROEI of greater than 1 means you take more energy out than you put in.
If you burned more calories chewing your food than the food had it in, every mouthful would be a net energy loss to your body and you could not sustain life. That is what an EROEI of less than 1 amounts to.
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pip · Posted: Wed Dec 22, 2004 9:25 am Post subject:

Can anybody give an example of a negative EROEI that is economically positive? All this discussion of EROEI and I don't know of any industry that uses this term. It's impossible to calculate. Economic costs are much easier to figure and will correspond to EROEI in every case I can think of.
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Xelat

pip · Posted: Wed Dec 22, 2004 12:42 pm Post subject:

Gold isn't energy.
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TrueKaiser · Intermediate Crude Joined: Oct 28, 2004 Posts: 539

MonteQuest · Posted: Wed Dec 22, 2004 9:33 pm Post subject:

Thanks, True Kaiser...2nd law rules again as always. And for instance, with wind you have only a 20% consistency, therefore to have a 1000 mega watt facility, you need a 5000 megawatt ability and a backup.

MQ
_________________
A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.