Yesplease, I started this thread to present some of my analysis, hopefully to piers. That is why it was presented mathematically. Criticism is looked for and even welcomed. However, you obviously have no proficiency in mathematics, thermodynamics or even basic physics and you continue to spout absurdities.

When you have gotten old enough to have actually learned something of value (outside of knowing how to perform a Google search) your contributions will be welcome. In the meantime please desist your annoying trolling.

The only thing that you are now accomplishing is to repeatedly demonstrate your overwhelming ignorance!

Mastodon and shortonoil, if you spent half the time posting about precisely what I don't understand and the like, instead of trolling/flaming, you could've saved yourselves a lot of time in that respect.

However, as you both have illustrated, you don't want to discuss this rationally and instead insist on flaming/trolling. Which, as I've said before, is fine, just take it to the hall of flames where it belongs.

This is such an important topic, I would hate to see it go down to [s]hades[/s] er, the hof's.

What I would like to see is some guess of a timeline affixed to this.

My guess is that price per bbl is a fairly good indicator of where we are and where we have been on the total-available-energy bell curve, peak coming during the low prices at the very end of the 90s. The exponential growth in oil price since then matches well the down slope in available energy, IMVHO.

If we are well past the peak in light sweet crude, at least, where does that put us on the down slope in available energy and when do we hit the wall where it takes more energy to get the stuff out than is embodied in the extracted oil? And what happens to the price at that point?

If the tar sands fiasco is any indication, we will start canabalizing other energy (and other) resources to keep extracting the precious black stuff at whatever price.

dohboi said:



I can give you a calculation of timelines. These are based on the model, which was derived from US oil fields, which was then mapped onto the world’s oil fields. This is a reasonable assumption because Hubbert’s curve has held up fairly well for most of the world’s petroleum reserves. As stated previously, the ERoEI curve can be extracted directly from the logistic curve.

It does not, however, include above ground factors, like J. Brown’s Export/Import Land model, which will probably greatly skew the results. Other effects such as a breakdown of global trade, as we have seen in food lately, will probably also have profound effects.

Taking the above into consideration, and defining the end of the oil age as the point when the world has extracted 95% of the energy available from the world’s oil fields (this is done because the tail of the Total Available Energy curve is asymptotic) we can derive a date.

That date is 17.4 years from the present.

So long as a significant portion of the planetary population leaves it's personal transport in the drive, and just sits permanently in front of it's TV watching 'American Idol' (or local equivalent), ordering in Pizza and Coors (or local equivalent) as required, - we might just make it.

Mankind might have to endure the sessile lifestyle of a barnacle for a number of decades during the transition away from fossil energy resources. Global enforcement of (or at least offering a stong incentive of hefty tax breaks towards following) China's 'One Child' policy would also be extremely beneficial.

Shortonoil, you seem to have one of the only two graphs I can find on the Internet that try to plot EROEI over time. The other one is the famous EROEI for Louisiana oil fieds that was posted in The Oil Drum, and a bit of research seems to show that it isn't EROEI what it was trying to plot, but net energy. (EROEI x production, if you like)

Unfortunately, I'm not convinced that you have the right result, either. I don't deny that it's the best fit that your maths software could find, but the decay curve is asymptotic to a level around 22:1, or in plain English, it's saying that EROEI will remain close to 22:1 for ever and ever. This is against what we all believe about EROEI: that it will keep declining until it's below 1:1. I can't really believe you found the best fit.

Doly said:


Excellent observation Doly. This very issue prevented me from posting these results for almost two years! There is, however, an explanation:

The ERoEI curve is asymptotic to the X axis. It is presently declining by 0.47 points per year. US fields peaked at 21.9:1 in 1971 (some say ‘70). This is the ERoEI at the well head. The important factor to be determined, however, is the ERoEI for these products at the consumer. The amount of energy available to the society to do work, is the critical variable to be considered.

Cleveland puts the decline in ERoEI from the well head to the consumer at 10 - 14 to 1. My investigations show that this loss could be as high as 16 points for some products and some fields. This puts the ERoEI to the end consumer, (the actual critical value point) at 11.9:1 for the US fields at peak (using an average loss in ERoEI from well head to end user of 10).

Assuming that the ERoEI declines at a steady 0.47 points per year (which it probably doesn’t, but the estimate is adequate short term), we have: where ERoEI is at the end user,




As you can see the energy loss is increasing geometrically; growing from 3.9 % per year in ‘72 to 8.8% in ‘86.

I believe that this is the best fit for two reasons: First: Cleveland’s data set (the one the curve is derived from) is the best that has ever been assembled. He used a bottoms up analysis directly from producer data. The second reason: the ERoEI curve can be mathematically derived directly from the logistic curve. They are both compelling evidence and together produce what has to be considered a slam dunk.

Both the conventional interpretation of ERoEI and the Available Energy Model arrive at the same destination at about the same time, they just use slightly different routes to get there.

An excerpt:

The Available Energy model has advantages that the traditional ERoEI analysis doesn’t posses. Combined with the additional work of Cleveland and other researchers, it has economic predictive capabilities. These predictive capabilities, compared to others that are now being used, can be fairly finely tuned.

you mentioned that 95% happens in 17.4 years, what % are we at now?

Is there a correlation between this and $ to extract a barrel? meaning the replacement of sweet light crude spraying out of the ground. If so I would think it would be getting worse faster now because of the tar sands and deepwater, etc

MadScientist said:



The machine that I use for my curve plotting is now laying in pieces on a table in the back office. It is what I use to do my integration’s for problems of this type. I’ll get it back together this weekend.

Going back to sharp sticks and strings (my compass and a protractor) from the drawings I get a guest-estimation of 84%. That is, we have used to present, 84% of the energy that was available from the world’s oil fields.



There is a direct correlation between the energy cost to extract a barrel and the dollar costs. Other cost like geopolitical influences can not be factored from the model. But, the amount of available energy “per unit” (gallon, barrel) is falling rapidly. That is show by the green graph. Available Energy per unit

Since the amount of AE we get from each unit (barrel) is going down, the cost of each barrel must be going up, and it is. There is a linear relationship between the amount of energy the US has used and its GDP. That relationship has held for over 100 years and has a correlation coefficient of 0.98.

The world will lose 95% of the AE contribution from oil over the next 17 years. Since oil is 38% of our total energy budget, our economy will contract by 33% on an energy bases over that period unless other energy sources can be employed. Coal and NG production increases have provided some cushioning in the last few years, but the decline rate in oil’s AE is approaching such a rate that in the future their impact will be considerably less.

The largest part of that contraction will take place in the front years (first 5) and then stabilize in the latter years.

What relationship is that?

yesplease said:



You can find it on page 891, Fig 1, Science, New Series, Vol 225, No. 4665 (Aug. 31, 1984), 890-897. Energy and the US Economy: A Biophysical Perspective by Cutler J. Cleveland; Robert Costanza; Charles A. S. Hall; Robert Kaufmann.

To use it you will have to correct the typo error in the equation GNP= -99.27 + .02. The data, however, is excellent.

Why are you basing your statement on data that's only up to 1982? From ~1980 on, energy consumption per capita in the US has remained relatively flat, but GDP and GNP have continued to grow. Since the paper was published the relationship between energy use and GDP/GNP in the US has changed significantly. Possibly due to itself and other similar observations.

US Energy consumption per capita peaked in 1978/1979 and has plateaued ever since, while real GNP and real GDP per capita have continued to increase.

yesplease said:



Because the US has shipped its energy intensive heavy industry out of the county. The economic indicators were changed during the Clinton Administration and are now all but worthless. If re-adjusted to prior data, there appears to be have been little change in the energy/$ ratio since 1900.

Since this is harder to verify, it is not used.