[sjn]

I'm pleased to see a few more coming to accept this aspect of depletion. There is an awful lot of resistance, I think mainly due to the gravity of the problem. Many just don't want to accept it.

There is a strong tendency to claim that ERoEI is irrelevant because oil is just a source of liquid fuel and doesn't have to be a primary energy source, that nuclear or solar (or more likely other fossil fuels) could provide the additional energy. While technically true, it ignores the system effects and the inevitable treadmill from having to constantly put more energy in, just to remain in place; energy that is then unavailable for any other activity. In fact this is where we are now. Increasing amounts of all resources are being redirected to make up for the primary energy deficit, this includes raw materials, food and water, and additional load on environmental sinks (polar ice cap loss) I did mention system effects!

[shortonoil]

sjn said:

$this->bbcode_second_pass_quote('', 'I')'m pleased to see a few more coming to accept this aspect of depletion. There is an awful lot of resistance, I think mainly due to the gravity of the problem. Many just don't want to accept it.

There is a strong tendency to claim that ERoEI is irrelevant because oil is just a source of liquid fuel and doesn't have to be a primary energy source, that nuclear or solar (or more likely other fossil fuels) could provide the additional energy. While technically true, it ignores the system effects and the inevitable treadmill from having to constantly put more energy in, just to remain in place; energy that is then unavailable for any other activity. In fact this is where we are now. Increasing amounts of all resources are being redirected to make up for the primary energy deficit, this includes raw materials, food and water, and additional load on environmental sinks (polar ice cap loss) I did mention system effects!

[yesplease]

I'm curious about a couple other things regarding the results. In the graph used, where would that line tangent to the EROEI/available energy function intersecting the Y-axis at the same place as the EROEI function and intersecting the x-axis at peak production rates be? Also, Do you have the details for statement four? Lastly, do you have the data set you used w/ Fig(5) from Cleveland's paper?

[Mastodon]

Shortonoil,

Good work. According to your graph the eroi of US 48 oil should be about 1 about now, however Cleveland 2005 arrives at an eroi of 18 (without quality correction) or about 11 with.

Could you post the full calcs/figures you used so disparities such as this could be resolved. (I will attempt to get input from those that started the whole eroi thing!)

Best

C

[shortonoil]

Mastodon said:

$this->bbcode_second_pass_quote('', 'S')hortonoil,

Good work. According to your graph the eroi of US 48 oil should be about 1 about now, however Cleveland 2005 arrives at an eroi of 18 (without quality correction) or about 11 with.

Could you post the full calcs/figures you used so disparities such as this could be resolved. (I will attempt to get input from those that started the whole eroi thing!)

Best

[shortonoil]

This is the ERoEI graph (except obviously the logistic curve) from which the other curves shown at the beginning of this thread are constructed. The other graphs are a function of the ERoEI graph, and the ERoEI graph is a function of the logistic curve.

As explained above, it was derived from Cleveland’s data set from his 2001 paper “Net Energy from the extraction of oil and gas in the United States”. His work is undoubtedly the best energy study ever completed on a major oil field.

The ERoEI decline of the US fields was not linear, as is shown. This is of little consolation as each year the percentage of available energy lost from the remaining energy grows larger. It is also necessary to remember that it is the ERoEI of the finished product that is of concern. For example, when the ERoEI of the finished product is 10:1, a drop of .47 removes almost 5% of the fuels total energy contribution. The ERoEI of the finished product lies 10 to 16 points below the ERoEI of the oil at the well head.

It should also be noted that the US fields did not employ enhanced extraction methods on a wide bases until after the fields had peaked. Many of the world’s fields have had enhanced extraction methods applied from the very beginning of the field’s development. This will make the Total AE curve much steeper toward the end of the field’s life span.

[yesplease]

Edit- NVM, Mastodon pointed out my mistake. At ~22:1 EROEI assuming no energy extraction costs only refinery inputs in CA circa 1997, how could we have seen ~100:1 EROEI in the 30s?

[Mastodon]

$this->bbcode_second_pass_quote('yesplease', 'C')urrent refining efficiency in terms of energy is ~80% for all products and ~90% if excluding non-fuel products, which is an EROEI of ~5-10:1 assuming little to no energy used in extraction. I doubt the energy efficiency of refining oil has dropped since the 1930s, so how could the EROEI of oil be 100:1 at that time?

[yesplease]

Ah, I gotcha. But still, even assuming no energy extraction costs and 100% refinery efficiency, the EROEI in CA circa 1997 is still ~28:1 (~1.1 trillion kWh at 100% efficiency compared to ~40 billion kWh of inputs), so how can we have seen 100:1 in the past? Refineries probably weren't as efficient and while it was much less costly in terms of energy to get the oil, it still required more than nothing.

You can upload images by creating an account at a site like flikr or photobucket or similar and uploading one there, then insert it by using it's link/location on their website within the [img] tags, or just click the little picture (hills and the sun) icon up top and enter the url of your picture there.

[Mastodon]

$this->bbcode_second_pass_quote('yesplease', 'A')h, I gotcha. But still, even assuming no energy extraction costs and 100% refinery efficiency, the EROEI in CA circa 1997 is still ~28:1 (~1.1 trillion kWh at 100% efficiency compared to ~40 billion kWh of inputs), so how can we have seen 100:1 in the past? Refineries probably weren't as efficient and while it was much less costly in terms of energy to get the oil, it still required more than nothing.

You can upload images by creating an account at a site like flikr or photobucket or similar and uploading one there, then insert it by using it's link/location on their website within the [img] tags, or just click the little picture (hills and the sun) icon up top and enter the url of your picture there.

[yesplease]

Mistakes regarding efficiency aside, how can we only have a theoretical/practical peak EROEI of ~28/22:1 assuming no energy costs for extraction today and have had ~100:1 in the past? Is there some fundamental difference in the products and ratio of them between now and 1930 that would reduce refinery energy inputs by two thirds? And if so, is it even a valid to relate the two? Supposedly oil was used in China to produce salt hundreds of years ago, so w/ only human inputs the EOEI was likely astronomically high, but considering the difference in use I don't think relating it to current use would be reasonable.

Regarding complexity, that depends on how it's defined. For instance, using a lever to move a rock is more complex than simply trying to push it by any technological measure, but at the same time it also requires less energy overall. I imagine a lot of industrial apps are similar. Sure, it requires a ton of hardware to make a ball bearing, but over it's amortized life, we may use less energy using complex tools to produce them than we would using simpler tools. Clearly this depends on application, for example an internal combustion engine w/ hundreds of moving parts uses more energy than an electric motor with at most a few moving parts, so in this case more complexity does entail more energy use, but as a whole I wouldn't generalize.

[Mastodon]

$this->bbcode_second_pass_quote('yesplease', 'M')istakes regarding efficiency aside, how can we only have a theoretical/practical peak EROEI of ~28/22:1 assuming no energy costs for extraction today and have had ~100:1 in the past?

[yesplease]

$this->bbcode_second_pass_quote('Mastodon', '')$this->bbcode_second_pass_quote('yesplease', 'M')istakes regarding efficiency aside, how can we only have a theoretical/practical peak EROEI of ~28/22:1 assuming no energy costs for extraction today and have had ~100:1 in the past?

[Mastodon]

Yesplease,

Refining adjusts total eroi by a factor, a percentage. It does not define any maximum eroi, it is only one step in a complex process.

Get to your local university library, get a copy of "Energy and resource Quality" by Hall, Cleveland and Kauffman, read it. You have not yet grasped eroi.

2H2+O2=> 2H2O is a simple reaction
The manufacture of Ammonium nitrate however is a far more complex process with many more steps and many more inputs. This is complexity.

Willful ignorance will not help you on the eroi downslope.

[yesplease]

$this->bbcode_second_pass_quote('Mastodon', 'Y')esplease,

Refining adjusts total eroi by a factor, a percentage. It does not define any maximum eroi, it is only one step in a complex process.

[Mastodon]

$this->bbcode_second_pass_quote('yesplease', '')$this->bbcode_second_pass_quote('', 'O')nly looking at refinery efficiency does result in a maximum because all the other processes such as extraction and transportation can only lower the EROEI of oil, not increase it. The only way oil's EROEI could've been higher than ~28/22:1 would be if it wasn't used in the same way as it is now, which is likely the case.

[yesplease]

The refinery inputs, in terms of electricity and natural gas used, and amount of oil refined were from this California government web page. The high end of the ratio assumes the oil is refined w/ 100% efficiency, and the low end assumes the energy from oil's refined products (including non-fuel) that's available after refining, ~83% according to the EPA IIRC.

[Mastodon]

$this->bbcode_second_pass_quote('yesplease', 'T')he refinery inputs, in terms of electricity and natural gas used, and amount of oil refined were from this California government web page. The high end of the ratio assumes the oil is refined w/ 100% efficiency, and the low end assumes the energy from oil's refined products (including non-fuel) that's available after refining, ~83% according to the EPA IIRC.

[shortonoil]

Mastodon said:
$this->bbcode_second_pass_quote('', '
')Charlie Hall suggests a minimum eroi of 5 is necessary to support any reasonably technologically complex civilisation, seems sensible to me when you look at the raft of stuff we need to support just the simple act of making a bearing...

[yesplease]

$this->bbcode_second_pass_quote('Mastodon', '')$this->bbcode_second_pass_quote('yesplease', 'T')he refinery inputs, in terms of electricity and natural gas used, and amount of oil refined were from this California government web page. The high end of the ratio assumes the oil is refined w/ 100% efficiency, and the low end assumes the energy from oil's refined products (including non-fuel) that's available after refining, ~83% according to the EPA IIRC.