10 Fundamental Principles of Net Energy Analysis

This is a repost from Cutler Cleveland on the underlying principles of net energy. We previously highlighted Dr. Clevelands work on the Energy Return from Wind. This post is Professor Clevelands latest installment on net energy analysis at the Encyclopedia of Earth, which I have reformatted to theoildrum. The Encyclopedia of Earth, where Prof. Cleveland is an editor/director, is a great academic/content based web clearinghouse for information on earth and our environment. I encourage everyone to follow some of the hyperlinks in the below story and peruse that site.

Outside of taxes and profits, we are a society used to thinking in gross terms. But the net is what we get to use. Net energy analysis, (and its subset EROI) get alot of airtime in peak oil discussions, but not yet in public. If the world is running on a certain total energy surplus, what are the implications for a decline in this surplus? Will the market, via dollars, treat gross production the same and forget to factor in increased costs? There seems to be much disagreement as to how best to use EROI and net energy principles, if at all, in planning for the looming energy crisis.

Introduction

Energy return on investment (EROI) is the ratio of the energy extracted or delivered by a process to the energy used directly and indirectly in that process. A common related term is energy surplus, which is the gross amount of energy extracted or delivered, minus the energy used directly and indirectly in that process. EROI is a dimensionless number, while energy surplus refers to an actual physical quantity of energy. Suppose an energy delivery system delivers 10 joules of energy, but in the process consumes 2 joules. The EROI for that process is 5 (10 divided by 2), while the energy surplus delivered is 8 joules (10 minus 2).

EROI is a tool of net energy analysis, a methodology that seeks to compare the amount of energy delivered to society by a technology to the total energy required to find, extract, process, deliver, and otherwise upgrade that energy to a socially useful form. Net energy analysis was developed in response to the emergence of energy as an important economic, technological and geopolitical force following the energy price increases of 1973-74 and 1980-81. Interest in net energy analysis was rekindled in recent years following another round of energy price increases, growing concern about energy's role in climate change, and the debate surrounding the remaining lifetime of conventional fossil fuels, especially crude oil.

The principles

1. Net energy and energy surplus are important driving forces in ecology and economic systems

The efficiency and effectiveness of energy capture is a central organizing principle in ecology. Living organisms must capture energy and allocate it among a number of life-sustaining tasks (growth, reproduction, energy storage, defense, competition). A larger surplus produced by a system of energy capture compared to competing strategies gives an organism a competitive advantage. Ecologists have used the principle of net energy to explain a wide range of phenomena, including habitat switching, long distance migration by birds, vertical migration by marine organisms, optimal foraging strategy, the pattern of the distribution and abundance of species, reproductive behavior in bats, and the effects of human disturbance on organisms.

Biologists such as Alred Lotka and Howard Odum elevated the concept to the driving force behind natural selection itself, where, in the struggle for existence, the advantage goes to those organisms whose energy-capturing devices are more effective in directing available energies into channels favorable to the preservation of the species.

Scholars from a number of disciplines have applied the same concept of net energy to social systems, with widely varying assumptions about the extent to which net energy influences the trajectory of the evolution of culture. The analogy to natural systems is straightforward: societies with access to energy sources with a higher EROI and a large net energy surplus have an economic and military advantage over societies that use lower quality energy sources. A low EROI means that more of a society’s productive resources must be devoted to energy delivery, and thus cannot be used to produce non-energy goods and services, support a powerful military, expand the arts, or be consumed as leisure time.

Net energy has been used to explain major energy transitions, including the industrial revolution and the emergence of the affluent society, the rise and fall of great civilizations, the pattern of resource depletion, and the impact of technological change on energy technologies. Net energy has been used as a methodological tool to assess and compare energy systems, as a tool to assess the climate impact of energy technologies, and it plays a central role in the longstanding debate on the viability of alternative energy technologies such as ethanol.

2. The size and rate of delivery of surplus energy is just as important as EROI

The net amount of energy delivered from the energy sector to the non-energy sectors is the energy available to generate non-energy goods and services. The size of that surplus sets broad but distinct limits on human economic aspirations. Falling water, for example, can deliver a large EROI in a specific location, but the total energy surplus available to a society from falling water is limited by the relatively sparse spatial distribution of the resource. The amount of energy surplus potentially available from diffuse energy sources such as solar and wind power is just as important as their EROI.

Contrary to popular belief, agriculture did not supplant hunting and gathering as the major food production technology because it had a higher EROI. Indeed, hunting and gathering often produced a very high EROI in specific locations and around specific resources. For example, the harvesting of energy-dense biomass in coastal whaling had an EROI in the neighborhood of 2000:1. Some hunting and gathering societies developed sophisticated social and civil institutions, and often consumed their energy surplus in the form of leisure time. But hunting and gathering ultimately is limited by the distribution of edible net primary production in the biosphere, which limits population densities to about one person per square < a href="http://www.eoearth.org/article/Meter">kilometer.

The advantage of agriculture derives from the large net energy surplus delivered per unit land area and per person compared to hunting and gathering. Agriculture thus erased the energetic limits to carrying capacity inherent in hunting and gathering, and released human labor and other productive resources from the farm. The latter was a necessary condition for the industrialization of society.

3. The unprecedented expansion of the human population, the global economy, and per capita living standards of the last 200 years was powered by high EROI, high energy surplus fossil fuels.

The penultimate position of fossil fuels in the energy hierarchy stems from the fact that they have a high EROI and a very large energy surplus. The largest oil and gas fields, which were found early in the exploration process due to their sheer physical size, delivered energy surpluses that dwarfed any previous source (and any source developed since then). That surplus, in combination with other attributes, is what makes conventional fossil fuels unique. The long run challenge society faces is to replace the current system with a combination of alternatives with similar attributes and a much lower carbon intensity.

4. The principal economic impact of a shift to a lower EROI energy system is the increased opportunity cost of energy delivery.

A shift to a lower EROI energy system means that more of society's productive resources are devoted--directly and indirectly-- to delivering the same amount of energy. That energy thus cannot be used for other purposes, notably consumption goods. Energy used to make a drilling rig or wind turbine cannot be used to manufacture iPods or provide medical care.

5. Energy quality matters

Net energy is only one attribute of an energy system that determines it usefulness to society. The usefulness of an energy system is determined by a complex combination of physical, technical, economic, and social attributes. These include gravimetric and volumetric energy density, power density, emissions, cost and efficiency of conversion, financial risk, amenability to storage, risk to human health, and ease of transport. These attributes combine to determine energy quality: differences in the ability of a unit of a fuel to perform useful services for people. No single metric of an energy system captures all such attributes, including EROI. It stands to reason, therefore, that a comprehensive and balanced comparison of energy technologies should employ a range of metrics, with their strengths and weaknesses duly noted.




Energy content per unit mass and per unit volume for various sources (click to Enlarge)

Since all forms of energy can be completely converted to heat, heat units (Btus, joules, calories, kilowatt-hours) provide an easy way to aggregate different forms of energy. For example, the world uses about 450x1015 Btu, or 450 "quads" of energy each year. That quantity is the aggregation of dozens of different energy types added together by multiplying their mass or volume used times their heat content per unit mass or volume. But this approach implicitly assumes that "all Btus are equal," i.e., that people value a heat unit of electricity the same as a heat unit of coal. Of course, this is not the case. Electricity performs important tasks that coal cannot, or it performs them more effectively. People are willing to pay 15 times more for a heat unit of electricity (in the U.S.) because of these differences. Accounting for differences in energy quality can dramatically alter the results of net energy analyses.

6. Market imperfections that distort prices and cost also affect EROI

Dollar-based assessments of energy systems are distorted by market imperfections such as externalities, subsidies, and government policies. The result is that the full social cost of energy is unaccounted for. However, EROI is plagued by many of the same problems. For example, there is no established methodology to incorporate the ecological and human health impacts of energy production and use in the calculation of EROI, so it too overstates benefits to society. In fact, economic analysis has better developed tools to estimate and aggregate external costs than energy analysis.

The calculation of indirect costs in energy analysis (e.g., the energy used to manufacture a wind turbine) often is based on economic data. Subsidies and other government policies affect decisions made in the market, and thus affect the economic data often used as inputs to energy analysis, including the pattern of capital investment. A good example of this was government regulation of the natural gas industry in the U.S. in the 1970s. Deep, new, and presumably lower EROI natural gas was assigned a higher price than shallow, old, and presumably higher EROI gas in an attempt to stimulate overall exploration. Any change in the overall EROI for gas extraction caused by this policy had little to do with “resource depletion” per se.

7. The methodologies to perform net energy analysis are well established

Conventional wisdom in the blogsphere and other Internet communities is that there are no guidelines for performing net energy analysis. In fact, there is a rich, well-established body of literature on the subject, most of which was developed in the first wave of energy research in the 1970s and 1980s. This body of work includes not only methodological detail, but also discussions about how to deal with intractable problems such as joint costs and outputs, the energy cost of human labor, choosing appropriate system boundaries, among many others. The record also has a rich history of debate about the virtues of net energy analysis, particularly in regards to what it adds, if anything, to a discussion that already includes a thorough economic assessment. The current discussion surrounding net energy analysis would be significantly enhanced if participants were better informed by previous work.

8. The relation between “peak oil” and the EROI for world oil production is unknown

This statement is true for two reasons. The first and most obvious reason is that we do not know when world oil production will peak, and won’t know definitively until sometime afterwards. Second, and more importantly, there is no comprehensive and reliable assessment of the historic EROI for world oil production. There is a distinct lack of reliable public data on the direct and indirect costs associated with oil production in many regions of the world.

The lower 48 U.S. is the only region for which we can compare the trends in EROI and oil production. There we see a remarkable convergence: crude oil production peaks in 1970 and then declines, and the EROI for that production peaks at about the same time. The timing of both peaks is consistent with a change in the underlying cost structure of the resource, when the cost-increasing effects of depletion began to outweigh the cost-decreasing effects of technological change. If such as connection holds at the global level, then the timing and impact of “peak oil” takes on added significance.

9. Technological change affects EROI just as it affects price and cost

There is a widely held assumption that the EROI for a nonrenewable energy resource such as crude oil or a renewable resource such as wind inexorably decline once the physical quality of the resource base begins to decline (e.g., smaller and deeper fields, or less windy sites). This is not necessarily the case. Technological change that lowers the dollar cost of extraction can also lower the energy cost of extraction. For example, developing the ability to drill multiple and directional wells from a single platform lowered the dollar cost per well, and it may well have lowered the indirect energy embodied in the materials required to extract oil. The well-documented technical improvements that have lowered the dollar cost of emerging technologies such as wind and solar undoubtedly exert at least some downward pressure on energy costs as well.




The decline in cost for ethanol fuel produced from sugarcane in Brazil (click to Enlarge)

Technological change exogenous to the energy industry also affects the EROI. For example, the development of more efficient combustion engines would, ceteris paribus, improve the EROI for oil extraction that relies on such engines to lift oil to the surface. Similarly, a decrease in the quantity of energy required to produce a kilogram of steel will, ceteris paribus, improve the EROI by reducing the energy embodied in oil field equipment.

10. Alternatives to the dominant energy and power systems show a wide range in EROI

Most alternatives to conventional liquid fuels have very low or unknown EROIs. The EROI for ethanol derived from corn grown in the U.S. is about 1.5:1, well below that for conventional motor gasoline. Ethanol from sugarcane grown in Brazil apparently has a higher EROI, perhaps as high as 8:1, due to higher yields of sugarcane compared to corn, the use of bagasse as an energy input, and significant cost reductions in ethanol production technology. Shale oil and coal liquefaction have low EROIs and high carbon intensities, although little work has been done in this area in more than 20 years. The Alberta oil sands remain an enigma from a net energy perspective. Anecdotal evidence suggests an EROI of 3:1, but these reports lack veracity. Certainly oil sands will have a lower EROI than conventional crude oil due to the more diffuse nature of the resource base and associated increase in direct and indirect processing energy costs.

On the power generation side, coal, and hydropower have the highest EROI among conventional power systems, although the latter has very limited potential for further expansion in most regions of the world. Nuclear power appears to have a lower EROI, but there are very few credible studies that are thorough and unbiased. We do not know what the EROI will be from the new generation of nuclear reactors that would be built if demand for them returns. Wind has a very favorable EROI in the right conditions, while solar thermal and photovoltaic systems have lower EROIs compared to coal and hydropower. As outlined above, a key issue is the size of the surplus that can realistically be delivered by those renewable power technologies.

A final point for consideration:

Carbon may trump EROI. The growing concern that climate change may impose swift and large costs on society may drive the next major energy transition. It is plausible that carbon intensity, as opposed to net energy, may be the principal attribute of future energy systems that determines the timing and pace of their adoption. Society may choose to forgo the benefits of a larger energy surplus to reduce its exposure to climate-related risks.

Further reading

Original posting of the article at the Encyclopedia of Earth here

Biopact. 2006. Brazilian ethanol is sustainable and has a very positive energy balance - IEA report

Bullard, Clark W., Peter S. Penner and David A. Pilati. 1978. Net energy analysis: Handbook for combining process and input-output analysis. Resources and Energy, 1978, vol. 1, issue 3, pages 267-313.

Cleveland, Cutler J. 2005. Net energy from oil and gas extraction in the United States, 1954-1997. Energy, 30: 769-782.

Cleveland, Cutler J., and Robert Herendeen. Solar Parabolic Troughs: Succeeding Generations Are Better Net Energy Producers. Energy Systems and Policy 13: 63-77 (1989)

Cleveland, Cutler J., Robert Costanza, Charles A.S. Hall, and Robert Kaufmann. Energy and the U.S. Economy: A Biophysical Perspective. Science 225: 890-897 (1984).

Farrell,, Alexander E. Richard J. Plevin, Brian T. Turner, Andrew D. Jones, Michael O’Hare, Daniel M. Kammen. Ethanol Can Contribute to Energy and Environmental Goals. 27 JANUARY 2006 VOL 311 SCIENCE

Gever, John, Robert Kaufmann, David Skole, Charles Vorosmarty. 1986. Beyond Oil: The Threat to Food and Fuel in the Coming Decades

Hall, C.A.S., J.A. Stanford and R. Hauer. 1992. The distribution and abundance of organisms as a consequence of energy balances along multiple environmental gradients. Oikos 65: 377-390.

Hall, Charles A.S., Cutler J. Cleveland, and Robert K. Kaufmann. Energy and Resource Quality: The Ecology of the Economic Process. (Wiley Interscience: New York, 1986). (Reprinted by the University of Colorado Press, Niwot, CO 1992).

Lenzen, M. and J. Munksgaard. 2002. Energy and CO2 life-cycle analyses of wind turbines-review and applications. Renewable Energy, 26: 3, pp. 339-362.

Odum, H. T., 1971. Environment, Power and Society. Wiley-Interscience, New York. ISBN 047165275X

Smil, V. 1991. General Energetics: Energy in the Biosphere and Civilization. John Wiley, New York. ISBN 0471629057

Spreng, Daniel T. 1988. Net Energy Analysis and the Energy Requirements of Energy Systems (Praeger). ISBN 0-275-92796-2

Tainter, Joseph A. (1990). The Collapse of Complex Societies (1st paperback ed.). Cambridge: Cambridge University Press. ISBN 0-521-38673-X.

http://sourceforge.net/projects/emsim

EMERGY SIMULATOR
EmSim simulating a the world natural resources evolution... Diagram (JGraph) driven simulator. Bondgraphs > nonlinear differantial system > plot: implemented for economics and ecology. Network analysis: emergy propagation implemented.

Any suggestions on how to actually use this? The project seems to be defunct, the links to supporting websites are broken, and there's no manual included with the downloaded source files. Any help besides the cryptic description?

Cheers,
Jerry

The long run challenge society faces is to replace the current system with a combination of alternatives with similar attributes and a much lower carbon intensity.

That's a serious and fundamental misstatement of the long run challenge. Right up there next to "let them eat cake". Damn, where did I leave my magic wand?

We don't get "similar attributes" at declining EROI. We certainly do not get lower carbon intensity - short of photosynthesizing hydrogen or uranium. Like I said, magic wand. What we will get is rapidly increasing environmental degradation across all resource bases as we try to combat declining EROI. And the more we do, the worse it will be.

The short, medium and long run challenge is planning the path down. While there is still some ancient sunlight. What's the paradigm? 1/8 the energy we have now in maybe 20 years? What would be the EROI at that point? Crunch out what kind of economy and environment we can have.

cfm in Gray, ME

I think this is too pessimistic. Plug-ins and full EV combined with wind energy and nukes is a great solution and substitute for most transportation needs.

I like this chart to understand the difficulty of scaling energy sources to meet current need. Wind and Nukes make up a tiny % of total energy use (see position on left compared to USA total energy on far right).

And this does not even deal with energy quality issues. Such as the difficulty in replacing the energy density of oil in the modern transportation network.

Well its a nice looking graph but it doesn't show us anything about how effective the usage of energy is/ Consider for a moment if Nuclear turned out to be 5x as efficient in a role providing energy for transport for example -the nuclear bubble could easily cover for a drop in imported oil if this where the case...

Ones thing is for certain, we will look back on our present time as being one of vast inneficiency and since productivity is related to the amount of something you get out for a given input won't our future be one of much higher productivity? Come to think of it isn't increasing productivty one of the core definitions of economic progress?

Nick.

The core definition of progress, according the current economic orthodoxy, is an increase in total productivity. If increases in efficiency lag behind increases in the cost of energy, then the correct label for the situation will be economic contraction. Of course the current economic orthodoxy is functionally insane. The core principle of intelligent economic activity should be ecological modesty. If improved efficiency helps us to live an ecologically modest lifestyle then let's go for it. But if we actually have to give up wealth in order to live within the ecological budget of the earth, then only a zombie moron would say, "Give me my 3000 square foot home, my plasma screen televsion, and my personal automobile or give me death."

I think this is too pessimistic. Plug-ins and full EV combined with wind energy and nukes is a great solution and substitute for most transportation needs.

Which, of course, totally misses the point. Fulfilling your myopic "transportation needs" does less than nothing to solve the much larger multi-faceted problem of the whole world going down the backside, so to speak.

Then again, millions of equally clueless sapiens sitting in their shiny new "plug-ins" with no food or water will quickly solve the overpopulation problem, so maybe that's not such a bad thing after all. Long run or otherwise.

Cheers,
Jerry

"I think this is too pessimistic. Plug-ins and full EV combined with wind energy and nukes is a great solution and substitute for most transportation needs."

Dryki, I think waterpump found your magic wand. BLING!lol

Let's not be so quick to judge waterpump's lack of pessimism.

http://s.wsj.net/article/SB121746229279198963.html?mod=most_emailed_da…

It's not lack of, it's misplaced pessimism.

I personally believe that all these "new tech's" and devices are real and doable. I have personally seen some knock you on your ass amazing devices that if developed would have a profound effect on the area of their focus, and yet for too many reasons to list here will never see the light of day. One of the biggest reasons was TPTB couldn't/wouldn/t give it their ble$$ing (not that they had a clue as to the viability).

I just understand that the constraints we face are much bigger than anything we can invent.

The issue is a socioeconomic, cultural problem that is not even the 800 lb chimp in the room. IT'S THE ROOM ITSELF!

Could you please be more precise and specific? Why wouldn't a plug-in hybrid, full EV combined with a wind boom and more nukes (and perhaps some more coal use if needed) work?

Well, actually, they will work. The sooner we slam into the wall the better because there will be bigger pieces left for us bottom-feeders. Not everything will be gray-gooed. I'm starting to understand that a managed, steady decline is likely to be far more devastating - and all-consuming - than a fast crash.

Just for yucks, I reviewed the charts and assumptions in "Limits to Growth: the 30 year update" last night. Yuck. A pain in all the diodes down my left side. I had to put the book down fast.

Any assumption that we can fix or replace any portion of our infrastructure, where that assumption depends on infinite supply of something - fish, petroleum, wood pellets, phosphate, clean water, human ingenuity - they are all wrong. Everything is limited, even the human ingenuity (Tainter). The quality of all resources is declining - another double whammy.

To paraphrase Reagan, Obama and Souperman2, "tear down the room".

cfm in Gray, ME

How do you define "work"? Do you mean, is it possible to build one electric car and power it from wind/nuke/coal?

Or do you mean, replace all the energy provided by 20 million barrels per day of oil (and 20 tcf natural gas), and all the services provided by 200 million+ cars/trucks, ships, aircraft, on a time line of 20 years? Because that is the real challenge.

There are technology issues and rate of growth issues.

From Energy use in the US

Wind and Solar are too small to even display on this graph. The nuke industry is overrepresented here because no new nukes have been built in a very long time. Coal may already have peaked as an energy source (depends a bit on the Illinois basin) Energy Watch Group Coal Report Summery

I agree about misplaced pessimism. For energy we already have the technologies (nuclear, wind and hydro turbines, etc) to produce a high enough energy return to maintain a form of civilisation. This civilisation is unlikely to involve drive-thru KFCs, but then we managed without them for a couple of thousand years before, so I guess we could cope. In terms of total TWs of energy, we cannot perform an instant switch over to the same level of energy use we have at present, though we don't actually need to because: a) fossil fuels won't disappear tomorrow, and b) the greater use of energy efficiency and conservation. However, this time factor is important as the forced reduction in energy use IN SOME NATIONS due to lower available imports (plus lower net energy) will happen too quickly to adjust to without significant pain. But we also have additional ecological overshoot problems - limits to other resources (fresh water, minerals, cropland), ecosystem collapses due to biodiversity loss, and a climate that is rapidly warming to an extent last experienced on Earth 3 million years ago. This is all exacerbated by a human population growing by a quarter of million souls each day (a new Dallas + Boston each week; or a new Glasgow + Edinburgh + Aberdeen each week [I live in Scotland!]). Yet even each of these might be overcome, for example if we instituted a strict one-child policy, urban permaculture, electric rail & cycle priority, waste materials recycling, rainforest protection, fishing controls, land and wealth redistributions, etc, etc. But these won't happen, and that is the reason I'm pessimistic: these are inter-connected problems with a new level of complexity that require a higher level of critical thinking, but our brains have just not quite evolved far enough to consistently deal with this. It could happen, but the probabilities are that things will get tough for most and nasty for some (and that is without any Black/Grey Swans of nuclear weapon launches, disease pandemics, etc).

Misplaced pessimism again, GreenE. Doomers shouldn't project their own shortages of brain power onto the entire population.

You do realize that certain algae will photosynthesize hydrogen?

I came in contact with a hydrogen producing cyanobacteria last semester at Uppsala University. We had a series of experiments in the labs at the department of photochemistry and Molecular science. During our experiments we never surpassed 1 % efficiency sunlight to hydrogen and our professor Peter Lindblad told us that the bacteria isn’t going to be a viable energy source for many years to come. We also did some experiments with artificial photosynthesis but that technology is very immature (it doesn’t produce any hydrogen) but has a great potential.

You do realise, that the full hydrogen cycle - using any method is several times less energy efficient than a full chemical battery cycle (ref: Ulf Bossel)?

You do realise that replacing the gasoline infrastructure with a hydrogen infrastructure is more expensive than replacing it with an electricity infrastructure (ref: Ulf Bossel, Wilson & Burgh)?

You do realise that it took 50+ years to build the gasoline infrastructure, oil peak is probably 0-7 years away and transition to any new infrastructure will take c. 15-25 years minimum under a crash program (ref: Hirsch & Bezdek)?

You do realise that paper technologies just tested in the lab are not the same as mass-manufacture, mass-installed, mass-scaled and mass-sused infrastructure?

One could go on, but it should be obvious to anybody that there are high uncertainties on the way from here to algae hydrogen paradise.

It may happen, but it's unlikely to be within three years, unlikely to save us from a net liquid fuels decline in the near future and unlikely to 'save' us on it's own due to scaling issues.

And that again does not guarantee that the world will succumb into chaos (a reminder for those inclined to do dichotomic thinking and incapable of probabilistic reasoning).

I am glad to see energy quality is finally entering into the discussion of energy analysis here at TOD. Odum used a simple table to define quality mappings in terms of Fossil Fuel Equivalents (FFEs) for various forms of energy. This is expanded somewhat by the table of Solar Transformaties at dematerialism.net. By adding in other dimensions such as transportablity, carbon intensity, availability, and the others you have listed here we could start to get at a decent method for comparison. For example, solar photovoltaics may have very low EROI, but the fact that they convert the lowest quality energy to one of the highest needs to be taken into account when evaluating our options.

I appreciate that we could all be better informed on net energy analysis. I've read a number of the articles at eroei.com and a number of them (Costanza and Hall, I believe) used input-output analysis. I would like to learn more about this, and any other methodologies the community can point me to.

I recommend starting with two papers you should be able to get at your local university library in PDF form.

Hall C, Efficiency of Energy Delivery Systems: I, An Economic and Energy Analysis, 1979, Environmental Management, Vol. 3, No. 6, pp. 493-504 (there are 3 parts. Get them all.) They do an EROI of a Coal power plant and contrast it with insulating buildings. This gives you a good working example to understand.

NET ENERGY ANALYSIS Handbook for Combining Process and Input-Output Analysis, Clark W. BULLARD, Resources and Energy 1 (1978) 267 313. 0 North-Holland Publishing Company

This second paper contains (almost) all the tables and charts to compute net energy. They are the only IO tables I know about for all sectors of the US economy.

IMHO, the most important resource on this question is the work of H. T. Odum, briefly mentioned in the article above.

His book "Environment, Power, And Society For the Twenty-First Century: The Hierarchy Of Energy" was updated and re-published just last year. The entry for this title in the bibliography above has not been updated to reflect this. Understanding Odum's work is crucial if you want to know why solar, PV in particular, is not going to be the answer everyone thinks it is.

I also highly recommend his book "A Prosperous Way Down", a brilliant summary of his thinking published late in his career, not long before he passed away. I think it's being re-published this summer.

Cheers,
Jerry

Would you be willing to offer a summary of his premise in regards to solar PV? Does his argument provide any different perspective on the usefulness of CSP?

Thanks,
Bob Fiske

He does not mention CSP technology specifically, but this passage sums up his premise in regards to solar in general:

Concentrating Solar Energy

As explained in Chap 4, solar energy is inherently dilute. By the time it is concentrated to fuel status, its net eMergy yield is small. Because of the success of industrial agriculture, people assume that net eMpower of solar production can be increased by more intensive farming or forestry practices. this is wrong, as proved by Steven Doherty (1995) in his analysis of forest production in Sweden, Puerto Rico and the United States (fig. 7.18). The more often a forest is replanted and harvested the less net yield. Very high yields come from forests allowed to grow a long time without much effort by society. In other words, the net eMpower of solar energy depends on time of growth.

Many transformation steps are required to process and concentrate dilute solar insolation to high-quality electric power using organic photosynthesis of the chloroplast, which is the green plants photovoltaic cell. With the intent of skipping steps, hardware photovoltaic cells have been researched for decades, trying to generate electric power from solar energy with net eMergy, which would make them economical. But these designs ignore the energy hierarchy law (chapter 4) that requires many calories of available energy at one level to make a few calories at higher levels. Figure 7.19 compares electrical current generation from silicon solar voltaic cells with that from a wood power plant operated on old-growth logs in the Amazon. Evaluations that claim net yield from solar cells leave out the huge eMpower required in the human services for manufacture, distribution, support, connections, operation, management and maintenance.

The greater the human population, the smaller the area of forests remaining, and the less time is usually allowed for growth. The global net eMpower of solar energy decreases with population. As populations have increased, times between shifting agriculture farming have decreased, which reduced yields.

Where a dilute renewable energy has to be concentrated to support society, either eMergy is used to concentrate the energy spatially or time is allowed for the energy to accumulate in a broadly accumulated storage. There is an eMergy equivalence between accumulation of available energy over time and the work of concentrating energy in space. Self-organizing systems do both (chap 4).

Cheers,
Jerry

Solar is clearly the long-term solution. Concentrating thermal or PV in the near term with the waste heat stored for local heating or cooling use, and high efficiency Optical Rectenna in the intermediate future. As much as possible distributed to the point of use, with backup from large CSP stations or nuclear or coal-with-sequestration and transmission as required.

We can sit around and put out the depressed results of thoughtless naval-gazing, or get started on solutions, and promoting and supporting them in everything we do.

That EROI and "size and rate of delivery of surplus energy" are both important, and the fact that both are incredible difficult to predict for many kinds of energy production in the future, due to optimizations, black swans, etc. and due to present difficulties to read today's "true" EROI in any given system should open the eyes to the reader for the only conclusion possible:

We don't friggin know.

It was mentioned the example of hunting and gathering and farmland. I think that such transition was probably looked upon as a path downward. It meant more hard work, less EROI. And yet, it gave mankind clear advantages. The same could be said that it was what happened in the transition from wood to coal. Wood was cheap and easy to chop and burn. Coal had to be digged up. And yet, it was after the transition to coal that we witnessed the industrial revolution.

These are examples on how some myths that were created or "born again" in the context of peak oil (such as Devon's Paradox, another idiocy spread around many peak oil sites, but gladly forgotten in here) are simply false in the forecasting of the future of energy production and consumption. The fatalism that feeds itself from these concepts should be denied and frowned upon.

It was mentioned the example of hunting and gathering and farmland. I think that such transition was probably looked upon as a path downward.

I do not think it were an either or choise. I live in Sweden where farming has been done in parallell with fishing, hunting and berry picking into modern times. The transition has allways been seemless from areas where farming is lean and gathering is significant to areas where farming is fat and gathering in the form of hunting were a reserved past time for rich land owners.

I am quite sure that everybody wanted the fat land where you often had good years with a huge yield and getting more fat land were an incremental process. The well off already had it, the not well off tried to fertilize, pick stones, etc investing manny lifetimes in providing next year and the next generation with a better farm. Some could of course choose between farming and gathering but almost all niches were already claimed.

I think there are some new directions quantitative energy analysis needs to take;

1. EROEI and payback of integrated systems

It is glib to talk of values of say 20 and 0.5 years for wind power without mentioning the wider system. That system could include storage, new transmission line and sometimes-idle replicated plant and fuel-burn backup. Does the systems integrated EROEI still make the magic number 10, the edge of the 'cliff'?

2. can we really live with low EROEI?

I wonder if a sub 10 EROEI world is nasty brutish and short. On the other hand in a high EROEI world we have unregulated entertainment, a varied diet and personal mobility. Working out that cutoff point will decide what local and global population should be.

3. per-capita energy investment

What is the individual's share of fuel refining and electrical generation infrastructure? Is it $0.5m or $5m? I have no idea, either in dollar terms or megawatt hours of embodied energy. Knowing that figure points to the steepness of the required investment curve to replace fossil energy. For example a plug-in car for every family manufactured and powered by wind and solar. I suspect some time paths will take decades, not the few years some like to think.

2. can we really live with low EROEI?

Theoretically, we can live with an EROEI of 1.001, as long as the following things are taken care:

1. Most of work is automatized. EROEI of 1.001 in complete human labor is hell on earth, we would only have time to work for our energy. But if 99.999% of such work is by robots that feed themselves by the closed system, then it is better. This is why recent coal mines have less EROEI but are far better than older ones: While they spend more energy in robotic and mechanical tools, they use less of our human hours, so we can write in blogs and discuss poker rather than digging up coal. Theoretically, if the system could be completely automatized, there is only one limit that should not be passed through: EROEI=1.

2. The EROEI itself is reliable, that is, it doesn't cross the threshold of 1 time to time.

3. The transition is complete.

The last point is by far the most important. We should keep in mind that the panic that TOD has towards EROEI only comes about because we come from a high EROEI energy market, and perhaps we will be forced to go towards a low EROEI energy market too fast. This is where it gets tricky, because we are still building our low-EROEI infrastructure with high EROEI energy, and the transition is turbulent and may indeed cause troubles.

Apart from it, though, in a pure abstract sense, low EROEI is only worse all else being equal, when it is clearly not. If the energy producing process is mostly mechanical and robotical, it means we have a multitude of "slaves" working for us. I can hardly see that as "bad".

But if 99.999% of such work is by robots that feed themselves by the closed system, then it is better.

No, it is not. Using your 99.999% number, that would require an "economy" 100,000 times bigger than what we currently have to net out the same "return". We've already hit resource limits with our mere puny human economy.

cfm in Gray, ME

that would require an "economy" 100,000 times bigger than what we currently have to net out the same "return"

You're obviously misrepresenting what I said. First, you deny that this is what happens now, most of the tasks to get energy out are not man-powered, they are machine-powered. Man is increasingly only needed to supervision and maintain the machines at work, etc. Second, I was talking in a pure abstract sense, and about energy, not any other resource. As you are aware, renewable energy is there for the taking and is, practically speaking, infinite.

Your assumption that

We've already hit resource limits

shows your fearmongering source code quite well.

As you are aware, renewable energy is there for the taking and is, practically speaking, infinite.

The infrastructure - your robots - required to harvest it is not free at all. The infrastructure for lower EROI energy sources is generally going to be much more extensive and expensive than for petroleum - that's almost the definition of "high value" and EROI isn't it? Benefit - cost to "produce". [I couldn't find the chart in past Oil Drum article showing how lower EROI energy sources start to take up more and more of the economy, sorry.]

Everything is energy, even the Earl Grey tea I just made in my replicator. I'd not disagree with that. Where I find fault is the idea that we can build our way out of low value energy sources by having several orders of magnitude more of them.

Yes, the implications of resource limits do scare the hell out of me. We have a planetary Income Statement and a planetary Balance Sheet. They don't work now because our scale of operations is too big. Increasing our scale of operation will only make matters worse. The logical response would be reducing our scale of operations to what the renewable traffic will support (eg solar) and using capital (fossil) only to increase the harvest of the renewables.

That humankind has a measurable impact on the environment is sufficient to prove the limits are not only real but that we have hit them.

cfm, not in Gray, ME

It is glib to talk of values of say 20 and 0.5 years for wind power without mentioning the wider system. That system could include storage, new transmission line and sometimes-idle replicated plant and fuel-burn backup. Does the systems integrated EROEI still make the magic number 10, the edge of the 'cliff'?

Does it include the energy costs of the hairdressers of the engineers? Where do you stop in whole systems analysis?

I agree with this comment and the following ones, dezakin, you're quite correct in your assessment.

I agree, the whole system needs to be examined from energy source through to use. I would think this would be possible via IO tables. I should really learn how to calculate those.

Another idea is to take a chart like the energy flow from Lawrence Livermore

https://eed.llnl.gov/flow/02flow.php

And then trace the amount of energy either lost (in a engine or transformation) or required as embodied energy (to create a car or truck needed to use the fuel source) to get some idea how much energy is getting to final use. Then proposed solutions could be examined to see how they change the final energy balance.

Doing whole systems analysis is just silly. Eventually you come up with EROI of exactly one, because all of civilization uses exactly as much energy as it produces.

How does taking a plane ride to the other side of the world just for fun, or watching Bevis and Butthead on a 60" plazma TV, contribute to energy production?

Anything can be taken to a ridiculous extreme, but that's not what's being discussed here.

How does taking a plane ride to the other side of the world just for fun, or watching Bevis and Butthead on a 60" plazma TV, contribute to energy production?

Its what you have to pay the employees to build and operate the power plants. The problem with whole systems analysis is there isn't any bright line to stop at, and it makes comparisons between different systems often meaningless.

Doing whole systems analysis is just silly. Eventually you come up with EROI of exactly one, because all of civilization uses exactly as much energy as it produces.

No, because that does not imply that the energy required in production is equal to the consumption. That would be absurd; the lowest exergy energy sources like coal would not be used so ubiquitously around the world if the energy investment were equal to the energy gain, because there would not be any financial incentive to do so.

Think of the rapid empirical growth in global primary energy consumption: that would not have been possible with a whole system EROI of 1.

If you're not talking about all of civilization, which uses exactly as much energy as it produces, you're being arbitrary in where you draw the lines of necissary for production. There is no bright line for whats required. When you calculate EROI, you include the energy cost of the cement kiln certainly, but do you include the cost of the fuel that the workers use to drive to the cement kiln? Do you include the energy cost of the construction of the cement kiln, or the embodied energy of the cars of the workers at the cement kiln? Likewise do you include the embodied energy of the pumped storage dam that is used to load level the intermittency of wind power? Or the embodied energy of the maintenance vehicals of the pumped storage facility?

Theres no bright line of where to stop in whole systems analysis, which is why if we talk about EROI at all we shouldnt mess about with it.

Think of the rapid empirical growth in global primary energy consumption: that would not have been possible with a whole system EROI of 1.

Well, the global growth in energy consumption has historically been around 2%, so that would put whole systems EROI at about 1.02 in a given year.

Theres another problem with EROI, the timeframe isn't specified. Theres a collection of loose definitions and fuzzy thinking that prevents us from actually making meaningful predictions.

If you're not talking about all of civilization, which uses exactly as much energy as it produces, you're being arbitrary in where you draw the lines of necissary for production. There is no bright line for whats required.

That is absurd spuriousness. We do not harvest energy for the sake of it; it satisfies non-energy harvesting related needs. If EROI of an energy harvesting system = 1 then there is no demand because there is no product, no service rendered; and with that, there would be no demand for the energy system itself. Evidently that is not the case.

It is like saying a farmer wants to irrigate his land because he wants to irrigate it. And after that, he wants to irrigate it more because he wants to irrigate it more? Rediculous!

Just because civilization uses as much energy as it produces, doesn't mean it ultimately uses all that energy to produce that energy. We have already seen the fallacy in the argument here: if your position were correct, there would be no incentive to produce any energy, and no energy would be harvested. The purpose of generating energy is to satisfy demand for it. This demand is only in part to continue the process of energy harvesting, and the causality is in fact spurious, as that particular demand is a result of where the rest of the energy is going: it is used for our objective and subjective needs (for which there may be no fine line), which have nothing to do with harvesting energy.

Thus, there is a bright line for what's required. It's everything, except that energy for which there would still be demand if our particular energy harvesting system would not exist. Clearly, there would be demand for cutting one's hair whether one is employed in a nuclear plant or a bakery. All of the things you mention clearly belong in the EROI equation, as this energy demand would be totally unneeded without the energy system.

Well, the global growth in energy consumption has historically been around 2%, so that would put whole systems EROI at about 1.02 in a given year.

Spuriousness really confuses you doesn't it? The fact that EROI is not equal to 1 should have woken you up already, but since you insist...

This is easily refuted by looking at the causes of primary energy growth: It is in fact entirely related to increasing affluence and population and changes in technology. People want more. They don't want energy. That's absurd. They want what they can make with it, and what they want has absolutely nothing to do with harvesting energy. Abundant cheap energy is an enabler in the model of modern economies, and so may have caused an increase in affluence. But that's an academic issue as abundant cheap energy is not in itself a demand. And of course there's increase in population. Again, cheap energy might have at least partially enabled more population growth (eg by indirectly reducing mortality). That is not the same as saying cheap energy is the root cause of population growth. There is an overarching 'demand' to have children. Charles Darwin will tell you all about it. As for technology, if a windmill or nuclear plant or whatever energy system is improved by using only a small part of the embodied energy and materials, your position would be that this has not the slightest effect on EROI?

Time to dust off and open up your statistics textbook and look up 'spurious correlation' in the causal relationship section. Cheers.

As for technology, if a windmill or nuclear plant or whatever energy system is improved by using only a small part of the embodied energy and materials, your position would be that this has not the slightest effect on EROI?

I hope you enjoyed your little rant, because it entirely missed the point.

My position is that doing whole system analysis of EROI doesn't yield useful data because there is no bright line of where the system ends and the consumer begins.

Actually, it's you who is missing the point. Completely. The EROI of society is not what you should calculate as it has no relevance. The EROI of energy generating systems is what matters, and if you actually read my post again, there is a clear line between what's required for the energy generating system and what isn't.

It is as if you didn't read 90% of my post. The purpose of EROI analysis is to look at how much energy input is required for one unit of energy output. Yes, you need to consider all things, but that doesn't mean there is no boundary. If you think this is incorrect, then answer the following questions:

If I turn on my AC, will this make the coal mine more efficient/effective? Or how does that help the windmill churn out more kWhs? When I take my motorcycle and drive to the library to read Shakespeare, how does that help the oil rig pump up more oil?

Please read it again and this time try to understand the overall message. Which, between the rant, is actually there. It's a pretty basic message really, don't know why it's so difficult to understand for you.

Actually, it's you who is missing the point. Completely. The EROI of society is not what you should calculate as it has no relevance. The EROI of energy generating systems is what matters, and if you actually read my post again, there is a clear line between what's required for the energy generating system and what isn't.

No there isn't. If you need to hire a worker at a coal plant, he clearly has an energy cost. You either measure the energy cost of the food to feed him, or the energy cost of the air conditioning that keeps him productive, or the energy cost of the health services he requires to maintain productivity. Or you could not include the energy cost of the coal worker at all, and assume that the coal plant runs itself.

Its why I think whole systems energy analysis is kinda silly.

I agree, the whole system needs to be examined from energy source through to use. I would think this would be possible via IO tables. I should really learn how to calculate those.

The work of H. T. Odum has already greatly advanced this concept. His Energy Systems Language is a symbolic representation of complex systems arranged in order of the energy hierarchy that is common to all systems, and at all scales.

The language is similar in concept to the Systems Dynamics language first developed by Jay Forrester at MIT, but the one really crucial difference is Odum's explicit recognition of energy flow as the fundamental basis around which all systems self-organize. This has come to be known as the "maximum power principle", first proposed by Lotka.

I highly recommend Odum's book "Environment, Power, And Society For the Twenty-First Century: The Hierarchy Of Energy" which was updated and re-published just last year, but the entry for this title in the bibliography above has not been updated to reflect this.

Cheers,
Jerry

Odum's book is indeed a must-read.

BTW, Odum is/was particularly scathing in his treatment of PV solar. Unfortunately, his terminology makes him difficult to quote at any length without a flurry of explanatory footnotes. But here are his conclusions on solar cells:

Evaluations that claim net yield from solar cells leave out the huge empower required in the human services for manufacture, distribution support, connections, operation, management and maintenance.

[page 209]

No wonder PV solar still costs the earth (30 years on).

OK -- one footnote: 'empower' means 'embodied energy' (I think).

Did Odum do a study to determine the energy used in the "manufacture, distribution support, connections, operation, management and maintenance" of PV panels, or is he criticizing the lack of detailed studies at the time and asserting theoretical conclusions about the ERoEI of PV's?

Odem's book listed in the references was published in 1971 well before the advent of modern high powered PV panels. Typical of studies from the 1970's and 1980's authors incorrectly assumed short lifetimes for PV panels which lowered the ERoEI. We now know that they last at least 30 years, but we still do not know from experience how much longer. E. A. Alsema and others have done studies (table in PNG format) and performed calculations although they appear to have ignored some of the embodied energy, such as the energy needed to construct the PV factory and transportation.

Thanks for the reference. I will put in an order for a copy.

I had read his "Modeling for all Scales" which was simple but excellent. One of the most interesting points was the idea that power may be maximized by oscillating systems rather than steady state ones. A prairie grows a large biomass, then it catches fire and burns back to the ground and starts over. Or predator/prey models. A pattern that happens over and over. I thought it fit well with the Hindu idea of "Creative Destruction". They are, after all, one of the longest lived sustainable civilizations.

That's exactly right, the idea of "pulsing" in which assets are accumulated over time and then quickly consumed is a common theme in Odum's work and he gives examples on a number of different scales, including human civilization.

He further establishes a logarithmic relationship between scales in which pulses at larger scales take longer to accumulate assets and thus produce a larger corresponding spike in consumption. Our current frenzy of fossil fuel consumption and the resulting industrial civilization is just such a spike, and one that we are probably at the top of now.

Even more interesting is his idea that pulses at larger scales provide a type of input or feedback to systems at smaller scales which in turn stimulates what he calls "transformity", a concept which is indeed very similar to creative destruction.

I also recommend his book "A Prosperous Way Down" which I believe is being re-published this summer.

Cheers,
Jerry

Boof, you write:

I wonder if a sub 10 EROEI world is nasty brutish and short. On the other hand in a high EROEI world we have unregulated entertainment, a varied diet and personal mobility. Working out that cutoff point will decide what local and global population should be.

Yes, I think the point is that EROEI could be minimal but living standards high in a low-population world (because net per capita energy ‘allowance’ would be high), while on the other hand the EROEI ratio could be fantastic (say 200:1) and yet we could all be starving if the world population was 100 billion.

After a mass die-off leaving only 100 million survivors I suppose an EROEI ratio of 1.5 to 1 would be quite satisfactory.

The formula is:

Gross energy returned minus gross energy invested divided by total population equals net per capita energy consumed.

After a mass die-off leaving only 100 million survivors I suppose an EROEI ratio of 1.5 to 1 would be quite satisfactory.

What nonsensical vitriol. Just like Devon's paradox was a cult some years ago, it seems as if EROEI has taken its place. It's pure doom porn propaganda. Open your eyes, go see the sun, smell the flowers. You are suffering from Kunstlerian disease. Yeah, it's that bad.

What few understand about Jevon's Paradox is that it's about economics, not about energy in specific. That matters for energy efficiency, as almost all of the energy efficient solutions have higher capital costs than inefficient ones. This creates a gap that mitigates the effect of Jevon's Paradox. The articles on this website don't illustrate this clear enough, which leads to fearmongering that energy efficiency is no solution. Typically, it's the nuclear enthusiasts that have an agenda to promote the Jevon's Paradox. But on energy efficiency, it's mostly fallacious. It's a shame that Jevon's intellectual property gets abused like that.

I do not understand what effect it is that you think will mitigate Jevon's paradox. The market does not give a damn about energy efficiency; All it cares about is cost efficiency. If energy costs start to dominate other costs then the market will focus on energy efficiency. However, a system of production which defines economic 'health' as manufacturing and selling as much stuff as possible will always attempt to leverage increased efficiency into the production of more toys, luxuries, etc. If cost efficieny improvements run out of gas (An apt metaphor don't you think?) and we have to sacrifice superfluous production in order to invest in a relatively expensive renewable energy infrastructure, then we will have a hell of hard time coming up with the resources for such an investment within a system of private finance capitalism.

That is why I've been advocating strong gov't standards and financial intervention. Strategic policy, after all, is one of the main tasks of the government.

What do you not understand? Capital costs. It is curious that you say you don't understand, considering you actually give the answer. It is exactly as you say: market forces are based on cost. High efficiency equipment, buildings etc are almost always substantially more expensive than the inefficient ones. Double glazing costs more than single glazing. Heat pumps are more expensive than resistance heaters. This incremental capital costs must be considered. You don't have to believe me. It's in recent literature (Mizobuchi 2008):

Abstract

Technological progress is one of the means of reducing energy usage and carbon dioxide (CO2) emissions. However, this reduction, in turn, leads to a reduction in the real cost of energy services per unit, which results in an increase in the demand for energy services. Therefore, a reduction in the anticipated CO2 emissions caused by a technological improvement might be partially offset in response to the cost reduction. Previous studies have referred to this effect as the “rebound effect.” A large amount of empirical evidence on the rebound effect exists; however, most of these studies assume an exogenous improvement in energy efficiency, and thus, capital costs that may decrease the magnitude of the rebound effect are not taken into account expressly. This paper extends the scope of the research conducted by Brannlund et al. [Brannlund, R., Ghalwash, T., Nordstrom, J., 2007. Increased energy efficiency and the rebound effect: effects on consumption and emissions. Energy Economics 29, 1–17] in terms of two aspects: (i) considering capital costs explicitly as additional capital costs and (ii) adapting an iterating procedure, and estimating the rebound effect, using Japanese household data. As a result of our empirical analysis, we conclude that the rebound is approximately 27%. However, we also find that ignoring additional capital costs leads to an increase in the rebound effect. In the case of Japanese households, the magnitude of the rebound effect increases to approximately 115%. Moreover, our simulation study shows that only a one-time iteration of Brannlund et al. [Brannlund, R., Ghalwash, T., Nordstrom, J., 2007. Increased energy efficiency and the rebound effect: effects on consumption and emissions. Energy Economics 29, 1–17] may lead to a biased result.

A rebound effect of 27 percent is quite good, considering how cheap per kWh energy efficiency is. But when you don't consider the aforementioned capital costs, you'll get a 115 percent figure, so it looks like it's completely self negating. But you can't ignore those costs anymore than the mortgage cost when you buy a house!

All that you are talking about is how Jevon's paradox will run out of gas when the growth economy runs out of gas. A day is coming when instead of double glazing all of our office buildings we will abandon many of them because we do not need and cannot afford the services being provided there. Yes, finite resources will limit the rebound effect, and eventually we will need to leverage efficiency just to put a floor under economic contraction, but it will a sweeping social and politcal transfomation to allow effective allocaton of resources in a stagnant or shrinking economy. The point of Jevon's paradox (as I see it, anyway) is not that we are going to get richer forever, but that we will try to do so until cold, hard, necessity forces us to do otherwise.

I'm not saying infinite growth is going to be enabled by an acceptable rebound effect. Yes, we do need to fix that silly attitude. But that's a different subject!

The point is: end use efficiency works quite well, and the sceptics are wrong.

Yes, efficiency would well at reducing demand on resources if the goal of continuous economic growth were abandoned. As far as I know neither Jevons nor anyone else who cites his paradox has ever been idiotic enough to deny this claim. The point of the people who doubt that efficiency can save us from social and economic disaster is that not the slightest sign exists that we are willing to abandon constant growth as our primary economic goal.

The point of the people who doubt that efficiency can save us from social and economic disaster is that not the slightest sign exists that we are willing to abandon constant growth as our primary economic goal.

Hey, I have no argument with those people. Just with those who claim Jevons + multiple iterations rebound effect completely negates the savings of end use efficiency. You would be surprised how popular this argument is among various doomers and in particular nuclear absolutists.

2. can we really live with low EROEI?

We have already done that. Life were not nasty brutish and short for most people living here before industrialization and electrification. They used biomass and some mechanical hydro power with low EROEI and a majority of the population were working with energy in the form of farming and forestry. But they were poor and death were allways close with high infant mortality, few effective medical procedures and famine were a real risk. But I do not think they were living bad lives.

The same resources could sustainably provide much better living conditions due to more efficient farming technology, more efficient use of biomass and electricity making it possible to gather, transport and utilize hydropower, windpower, power from burning biomass, solar power and nuclear power. And we do not even need second half of 20 century technology to have it much better then before the electricity age.

One key for living with low EROEI is making durable investments with the energy you got. Both that and efficiency of numerous endavours is greatly enhanced by solid state tecnology for power handling, communications and so on. There is no physical reason hindering us from making computer chasises and components that are used for a hundred years with easy repair. Its not done since it do not make sense when technology advances fast.

I do not think the key innovation for humanity is the internal combusion engine and finding oil and other fossil fuels but understanding and utilizing electricity. Being able to change a multitude of resources into light, heat, mechanical movement, chemical processes, communication and computation changes everything.

The key for this kind of adaptations ought to be if the local society can handle change giving people opportunity and and spare time to adapt instead of being weary for outbreaks of violence, monetary breakdowns etc. If individuals have lots of "social capital" and care about each other and their state reflects this we get an ability for personal and market adaptations to lower energy use or a change to new energy sources and new kinds of growth.

Nate,
thanks for the review of the fundamentals. While i do not understand all the nuances of these principals i generally understand the constraints they present for what might and might not work as we make the transition to an uncertain future. while these constraints do not offer great hope for a pain free solution they will hopefully prevent massive subsidies to politically motivated hair brained schemes such as ethanol. Now is the time to really husband the remaining fossil fuels and use them effectively and efficiently. Seems to me that we need to prioritize the things needing to be done and allocate the remaining high quality fuels for those purposes. I read much discussion on TOD about the alternative transportation modes, EV, and really wonder if individual modes of transportation will be that great a priority in the future.

Its a big mess, and most people are barely aware there is a problem outside of immediate energy and food inflation.

We need an accurate accounting of what resources we have, both the amount, the quality (e.g. the cost), and the realistic flow rates. We also have to determine what our long run objectives are -to continue to compete for pecuniary goods will end badly for all involved, including the 'winners' - so we should be figuring out the ends before we start using the 'means' to their highest purpose. Otherwise it will be 'Drill Now, Pay Less for a Month and Pay Dearly in the Near Future'

The large problem of course, is an analysis like the one above benefits everyone but no one in particular, e.g. there are no funds or think tanks that presently have the inclination or charter to do it.

Hey Nate,

I just listened to your interview with Jason Bradford on GPM about the Maximum Power Principle. I'm starting to appreciate the time / flow aspect of all this. In the interview, you indicated that in nature, systems find a balance between maximum efficiency and maximum power. In Odum's writing, he states that the pattern of winning systems is that they use some portion of high-quality energy available to them to raise the quality of more abundant, lower quality energy for their use. I'm wondering what your thoughts are on how these two extra complexities play into the discussion.

Great article Nate!!!

I think many people are underestimating the effects of declining coal quality on energy output. As you know coal prices have risen dramatically over the last year, especially met coal. We are having electricity shortages around the world. Many countries have stopped exporting coal. This problem seems like it could be more pressing than declining oil production. When a utility buys thermal coal they don't buy tons, they buy BTU's. This is why Appalachian coal trades as such a premium over powder river basin coal because it's higher BTU content. Similar to peak oil where the best reserves with the highest energy content are used first, the best and highest energy content coal is used first. Northeast utilities are starting to test powder river basin coal to make sure they can burn it. This means further transportation for a lower quality coal. This is a downward spiral.

Thanks,
Don

We also have to determine what our long run objectives are...

Nate, I couldn't agree more and it is something I have harped on now and then. Realistically, I don't see it happening. My guess is the future will be along the lines of Jeff's Rhizome Communities, Amish-style communities where the good of the community is more important than the individual, extended family/affinity groups or, perhaps, some form of lifeboat community. Unfortunately, I believe that these options will only be considered after everything else has failed.

Todd

Todd: Ive read Jeffs thoughts on rhizome communities
and was facinated..he says in his talk about them...

(While this theory of rhizome warfare is undeveloped and largely untested as a complete package)

I know of a society that practices as a cohesive group
in a rhizome fashion and has done quite well for
several thousand years.
Trouble is,they dont defend themselves with a rhizome
military. They go on the offensive with a hiarchal
military and oppress others.
I wont mention who these people are,for fear of being
labled and anti-semite.I should note that Palistinians
and Moroccans and all Arab peoples are semitic peoples.
Since Ive stated (and quite factually so) that all
Arabs and many groups are semites...I cant be accused
of anti-semitism.

Correctly speaking can we accuse you of anti-judaism? :)
BTW Palestinian correctly refers to the people of Palestine, including Jewish Palestinians. Only modern laziness and the needs of various groups (especially European Jews) to differentiate between groups has caused the word palestinian to de facto mean non Jewish arabs (about half the Israeli Jewish population is arab).

"We need an accurate accounting of what resources we have, both the amount, the quality (e.g. the cost), and the realistic flow rates."

Let me add an observation that I made just this last few weeks.

Near the farm shop where I spend a lot of time(repairing electronics,driving grain trucks and many other aspects of a big farming operation) I watched a nearby area that belongs to a near relative of mine. He had hired two dozers,a couple of trackhoes and some other equipment to clear about 10 acres of woodland along a creek.

They were working at it every day for about two weeks and just finished the other day. What I observed was that they pushed down huge nunbers of large trees in to dozer pushup piles and burn them over several days.

All that timber and wood gone totally to waste and contributing heavily to the carbon and other particles entering the atmosphere.

They did this to increase by a few acres some of his land that he could plant more corn on. I reckoned it might take him 10 years or longer to get the payback for the cost of the equipment.

Now at the same time I was following some videos and data on usage of biogas stoves. Both for cooking and heating and other purposes.

The video (utube) showed that with just a handful of wood chips enough heat could be produced to cook a meal!!!!

So just how much energy , in the form stored in that timber, get totally wasted just to increase a few acres of corn acreage? A huge, massive amount by my reckoning.

This is sinful. Apparently the 'sod buster' regs have been thrown in the trash by the USDA and other ag units of the USA Farm programs.

What a pity. We are decimating our last standing resource just to make more dollars on the runup of corn prices. It makes little sense to me to waste our country heritage and last fallback of resources to use to weather the oncoming chaos.

Myself I have two huge red oaks given to me free that had blowed down in the last big windstorm this spring. I intend to harvest every piece of wood I can for this winter I make the changeover to cooking and heating with wood. All to be ready to survive the future.

Watching timberlands being burned for crops is hard to understand.

We in effect are 'eating our seed corn' so to speak.

I see this happening massively all over this area of Western Kentucky. Huge streams of smoke and huge piles of burning timber. All being dozed down and burnt as fast as they can make it happen.

Just where are the ag watchdogs? We are the idiots mindsets that do this?

Ohhh..they say...a cottonwood tree will suck up huge numbers of ground water...so the worker next to me who was a chainsaw timber cutter tell s me but I ask him how much soil is lost to wind erosion do to no timber/trees in the fence rows to shelter the crop lands?

Mhhhh.he says...never thought of that...he response to my insulting timber cutters was this "Let them wipe their butts with plastic."

Referring to 'tree huggers' I guess.

All over this USA stupid things are being done to our environment such as to make it more and more for those who make it thru WTSHTF and need something to harvest or shot game in. Or camp in. Or whatever.

All the hardwood nutbearing trees are about gone now. We have woods full of 'weedy trees' such as the dreaded sweet gums and maples. Yielding nothing for cattle,hogs or other stock to live on when we try to revert to what our ancestor/frontiersman/pioneers used.

All scalped away for the ag values. Massive fields will revert to weeds and brush. It will take a looooong time for the woodlands to come back. By then there might not be a human left to leave a footprint any more.

Note: The biogas ref was posted by Nephilim a couple days ago. This payday I will place and order for my biogas cook stove. Maybe two or three of them.

Airdale-I intend to try to subsist and survive if the loggers and farmers don't cut it all down or burn it all up. I lived with wood heaters and cookstoves as a youngster. I intend to again.

We've developed a fat strain in this culture that is too Proud of its Ignorance.

Ignorance is Bliss, they say.. but Pride cometh before the fall.

Good Post, Airdale. Who are the Ag Watchdogs? I'd say you're one of them.

Bob

>3. The unprecedented expansion of the human population, the global economy, and per capita living standards of the last 200 years was powered by high EROI, high energy surplus fossil fuels.

The unprecedented expansion of human population occurred among the people who use little to none fossil fuels.

That banging sound is of the malthusians getting a kick on their asses.

"The unprecedented expansion of human population occurred among the people who use little to none fossil fuels."

US example - - figures approximate
1770 about 5 million, agrarian, no heat engines.
1860 about 30 million, 30,000 mi. railroads, wood-steam economy.
1905 about 90 million, 240,000 mi. of rail, coal-steam economy.
1950 150 million, less rail, a lot of roads, coal-oil economy.
Now 300 million, less rail, a lot more roads, airports, coal-oil-gas-nuclear economy.

Including the original peoples living in current-US areas in 1770, do you really think population would have grown more than 10X without high energy use?

How should I know and in any case the US population is 5% of the total. The population of the world didn't grow to 7 billion because the US uses a quarter of the oil. The population of the world grew to 7 billion because people who live on a dollar or two a day kept having more kids.
Western Europe and Japan use lots of oil by non-North American standards and their population is declining.

robert2734 -

You are correct, but only partially.

The population of 'those people over there' was able to grow to the level it is now, largely because they were able to stay alive (albeit quite wretchedly in most cases) due to improvements in agricultural yield made possible by inexpensive ammonia-based fertilizers and ag chemicals, which in turn were made possible by inexpensive fossil fuel. Without such, I doubt the population today would even have hit 3 billion.

So, in an indirect sense, the West, while have a low birth rate of its own, had inadvertently become the enabler of highly prolific Third World peoples.

Q: What do you get when you feed a million starving Africans?
A: Two million starving Africans.

Well, that requires more detailed analysis than I have time for. Third world farmers living on a buck or two a day don't use a lot of inorganic fertilyzer. That's one reason why they can't compete in price with first world grains. Arguably they could have bought or be donated lots of western food but the population density of India and China was high long before the industrial age. Because of the food per acre of rice.

That the world's high population is due to fossil fuels is an assertion.

Third world farmers living on a buck or two a day don't use a lot of inorganic fertilyzer.

This is demonstrably untrue. Synthetic fertilizer use is very high in 'third world' countries today, especially those such as China and India who are most often accused by Americans as being too prolific with their birth rates (even though China's fertility is way below that of the US).

Well done.....check and mate!

Extensive literature studies exist on the subject of plant nutrition, fertilizer-yield relations, and economics of fertilizer use. It is yet very difficult to derive yield response curves for countries or regions. The major reason is that the use of nutrients is not uniform. In particular in developing countries only a minor group of farmers use synthetic fertilizers, while the majority produces at a subsistence level based on crop rotation, recycling of crop residues, organic wastes and animal excreta.

http://www.fao.org/docrep/w5146e/w5146e09.htm

China has a 6% natural growth rate (2004). The USA has a 1% growth rate and half of that is immigration.

http://www.allcountries.org/china_statistics/4_3_total_population_and_bi...

Population growth in China. Looks like China's population doubled between 1950 and 2000.

http://www.medizin-ethik.ch/publik/family_planning.htm

Look, when you confront people with facts which speak against the idea of a mass "dieoff", you disturb their fantasies of sitting on their ammo crates gunning down hordes of cannibal suburbanites. That upsets them, and is mean.

The doomer will be happy to know I have no opinion on whether or not there will be a die off. Plainly we are damaging our environment more and more every year. Going back to pre-fossil fuel subsistance farming is not a pretty picture but could probably be done. Most of the indiginous people who lived in North America in 1770 weren't farmers. Most of the pale faces were.

China has a 6% natural growth rate (2004). The USA has a 1% growth rate and half of that is immigration.

Total fertility rate, which is a leading indicator of population growth is around 1.3 children per family in China vs about 2.3 in the US. I don't have access to the figures right now but I think your quote of 6% population growth in China is way off. They have probably the lowest total fertility rate in the world right now, along with Italy and Japan.

China has a 6% natural growth rate (2004). The USA has a 1% growth rate and half of that is immigration.

You can't even read a graph. It's 6 per thousand, not 6 per hundred. 6% per year? Are you insane?

USA has 10 per thousand, which means that China indeed has less growth than USA. And if you check the graphs, you'll notice a quite interesting bit. The urban areas are the ones which have less growth (0). If we take that fact and combine with the fact that they are increasingly urban, it means they are due to even less growth.

The figure of 6% growth for China is off by an order of magnitude. You must've slipped a decimal.

Data from:
http://earthtrends.wri.org/searchable_db/index.php?theme=8

From the same database, returning to the original argument about fertilizer use:

Sub-Sarahan Africa went from ~575 thousand metric tonnes in 1964 to ~2348 thousand metric tonnes in 2002. Approx. fourfold increase and I think most of Sub-Saharan Africa is considered 'third world'.

Also, although countries in Sub-Saharan Africa currently have the highest fertility rates in the world, they are dropping fairly fast.

For those who like to crunch data and wonder what it means, you might notice the inverse correlation between calories available per capita and fertility rate. It seems that, unlike yeast, adding more food does not cause more babies per child-bearing woman, for humans.

It's not demonstrably untrue when the rebuttal uses China as the example. China isn't 3rd world and hasn't overall had a high birth rate in comparison to the rest of the world for the past millenium or 2.

The population of the world grew to 7 billion because people who live on a dollar or two a day kept having more kids.

Not quite. It grew because they kept having the same number of kids, but fewer of the kids died before having their own kids. Mortality dropped dramatically, and fertility has not yet dropped to match. A big part of the credit for the mortality drop goes to massive aerial DDT spraying programmes.

Your main point holds. Prof. Cleveland's point 3 is a little overstated. In principle, fossil fuels are not necessary in agriculture, and most of the population increase could have happened without them. The necessary innovations--the microbe theory of disease (leading to water disinfection, and hygenic waste disposal), plant and animal breeding for yield, surveying and water pumps (leading to irrigation and drainage), fertilisation and soil management, pest and crop disease control--all started before widespread use of fossil fuels.

High energy flows are only needed if we want to sustain large urban populations. So the answer to kebu77's question is "yes, but more of it would be rural." See pre-industrial China or Tokugawa Japan for examples of high population densities without fossil fuels.

The "global economy", now, and "per capita living standards"... those we could not have done without fossil fuels.

I have been trying to study this issue with reference to the Pickens Plan; wind + natural gas + whatever. The following post may have embedded errors. It garnered only one response.

http://push.pickensplan.com/forum/topic/show?id=2187034%3ATopic%3A503093

It is not at all clear that coal has a higher EROEI than modern solar PV: http://mdsolar.blogspot.com/2008/01/eroie.html

Coal seems to do about half as well. Perhaps the problem is that mouth-of-the-mine figures for coal are being compared to delivered-to-the-user figures for solar.

Chris

It is not at all clear that coal has a higher EROEI than modern solar PV ..

This may well be true (at least for Nevada, though not for Iceland -- for solar much depends on latitude and weather) but once you factor in the price per unit of energy input the picture changes. Coal is still pretty cheap, so even with a lower EROEI it will do better than (still expensive) PV solar.

In the real existing world, it's not EROEI that counts, but MROMI (money returned on money invested). That's why PV solar still belongs to the state-subsidised 'gadget' end of the energy spectrum.

Coal only cheap if you don't have to pay for the deaths due to coal fumes. Or clean up the strip mines afterwards.

Robert2734,

Of course I didn't factor in externalities. I could add a dozen more.

On the other hand, think of all those roofers who die when installing PV panels. I don't know what the fatality rate is per Terawatt/hour but it's certainly greater than zero.

12.5 deaths per terawatt hour (no slash) from rooftop solar panels. Still better than coal. Of course we could go to bigger roofs or put solar panels on the ground.

http://nextbigfuture.com/2008/03/deaths-per-twh-for-all-energy-sources.html

I'm amazed that you were able to respond to that with a precise number and a link in only 17 minutes. The internet is truly a wonderful thing.

It would have been wonderful, if it wasn't for the gross deception.

If you read through the article and comments on Nextbigfuture, you actually will not find a single reference that details PV deaths. Brian has made the inference between rooftop deaths and solar PV deaths. That is gallingly anti-scientific. In fact, one of the most important purposes of science is to unravel inferences, not to make them.

An inference is an hypothesis, not a conclusion. Brian presents a plausible hypothesis, but nothing more.

I agreee that the estimate is completely bogus. Solar installation is not roofing and it increasingly uses more lifting machinery making it even more dissimilar.

Chris

Oh dear! And I was just being facetious, not bogus. Mea culpa -- my apologies. Honest. I should have added a smiley face after the roofer death scare. Actually there are so few roof solar panels installed the world over that it's unlikely whether any roofer has suffered an injury greater than hitting his thumb with a hammer.

But I'm being facetious again. Still, relative risk has to be taken into account if or when PV solar scales up from 0.1% to 1% or 10%. And compared with other energy sources, nuclear still has a very good record in terms of death per Terawatt/hour.

Still waiting for grid parity ...

Oops, I see you guys were dissing Robert, not me. Thanks for the data, Robert, BTW.

I knew it was a SWAG when I posted it. Does anyone have better numbers?

(Dark Charlie ?) -

Well, these days I'm not so sure how strongly the financial world qualifies as being part of the 'real world'. What with all these dodgy financial 'instruments' that are causing so much consternation and the notional trillions invested in vaporous derivatives, I'm not so sure the financial institutions have that strong a grip on what is real and what is not. Their track record in that department is not particularly good.

Now to get back to your main point that it's money returned on money invested that really counts, I agree on one level but disagree on another.

It is well to recognize that some of our financial orthodoxies have numerous built-in assumptions and biases that came about in another age. The time value of money being one example. Is it carved in stone somewhere that a dollar invested in something vital and useful has to return a dollar plus some gain a given years hence? Your answer is probably, 'then why would anyone invest in that thing?' Well, what if at some point nothing is going to provide a 'satisfactory' financial return, do we stop spending money on those things that will enable a society to continue?

Nate Hagens has delved into this general subject far more deeply and in a far more sophisticated manner than I ever could. But I will close by saying there seems to be something serious wrong with our whole concept of time-value of money. And some of the things that may be wrong with it are the very underlying assumptions. Or should I say 'presumptions'?

Joule,

Thanks for your comments. You write:

Now to get back to your main point that it's money returned on money invested that really counts ...

I was simply describing how people behave, not prescribing how they should behave. All this has very little to do with high finance and hedge funds and derivatives. It's about Mr and Mrs Ornery shelling out a lot of money, now, to buy what they consider to be a pig in a poke. People say: cut the EROEI crap 'cos I'm not a rocket scientist. Just tell me what it costs. And if PV solar is so smart, why isn't it cheap?

I'm still waiting for grid parity. Like waiting for nuclear fusion, you need a lot of patience.

Dark Charlie -

Well yes, I would behave in the exact same way because I am part of a financial game that I have to play whether I want to play it or not.

For example, we have lived in an old house for the last 30 years. I have not upgraded much in the way of insulation or super windows or the like. Why, because there was always the question of how long we'd be at this place and whether making such an investment was the best use of very limited capital. Well, my 'bet' was wrong: I should have made those investments, but the rules of the financial game dictated otherwise (remember $20 oil during the Reagan 'Morning in America' years?)

As I think Nate Hagens has pointed out many times, there is a built-in bias that discounts the value of the future far more than it really should. I suspect this bias is built into our genes, which from an evolutionary standpoint are not that old and are very present-oriented.

Of course this gets into the question of whether the price of something accurately reflects its long-term intrinsic value. The answer that the right price is what people are willing to pay at the moment totally ignores a whole host of other questions having to do with values, real or peceived.

I'm sure there's some rich narcissistic idiot out there who'd pay $1million for Marlyin Monroe's soiled panties. (Great conversation piece at parties you know.) But is that really the same thing as saying that $1 millon can buy you 8,000 bbls of oil @ $125/bbl?

So again, there are some real intrinsic problems with what we call money and the way that money interacts with the physical world.

Joule, you write:

As I think Nate Hagens has pointed out many times, there is a built-in bias that discounts the value of the future far more than it really should. I suspect this bias is built into our genes, which from an evolutionary standpoint are not that old and are very present-oriented.

Ethics and 'should-ing' is not my strong suit. I really don't know what people should do. Should we minimalise our 'future discounting' so as to take account of our descendants in 1000 years' time? Or is it enough to discount down to our putative great-grandchildren and stop there? These normative questions are scientifically unanswerable.

As to the evolutionary dimension, I reckon that it is precisely because we are very present-oriented that we are around today. Evolution selects for people who look after themselves and their immediate relatives and tribe, rather than giving priority to the long-term fate of the human race in its entirety.

So we're done for. Or as Georgescu-Roegen put it "the destiny of the human species is to choose a great but brief, not a long and dull career."

"It's better to burn out than fade away"

Neil Young

http://www.youtube.com/watch?v=Seb0ay0ccF4

It's called oppertunism. Our government is supposed to guard ourselves in many ways from this phenomenon, but in stead it indulges into it no less than Mister Bean does.

Most people here have read the bipartisan energy bill recently. Releasing the Strategic Petroleum Reserve. Great oppertunism Uncle Sam!

It is shameful that politicians are allowed to create national energy policy. There should be a collaboration of universities, engineers and scientists to revoke any upsurge of silly ideas and populistic measures like releasing the SPR to 'slightly decrease prices'.

I rather enjoyed reading about the complexities of
EROEI and was seriously brought up to speed.
The latin term for (all things being equal) threw me
for a loop for 3 seconds untill I googled it though.
I only wish that Joseph and Janice Sixpack would have
a explanation they could grasp.

I posted the comment as a needed correction to the article. Cutler has a very nice paper on the EROEI of coal at the mouth of the mine but that number, which is high, probably needs to be reduced a good bit when we consider coal in use. On the other hand, the boost in EROEI for solar power has been dramatic over the last few years and it is still improving.

On costs, First Solar seems to be at about $3.50/Watt right now: http://www.semiconductor-today.com/news_items/2008/JULY/FIRSTSOLAR_17070... so one would expect fairly rapid adoption at that price point.

Chris

Photovoltaic systems have associated costs which are often not mentioned. Moreover, determining if these costs are included in the summary numbers that folk cite, can be nearly impossible to determine. My experience (see bio) is that solar costs, per watt-hour consumed, for a system sufficient to run a modern and efficient household, is more than the costs for commercial power -- even when the initial system cost is discounted. Granted, a per home setup does not benefit from the economies of scale that can be realized from a centralized system located in a desert. Nonetheless, costs for handling the daily intermittent nature of the energy source, for handling the seasonal variation, for conversion of the energy to a useful form, and local infrastructure all need to be included in the EROI calculations. When one adds these costs to the Investment component of EROI, the numbers are not so high....

As I have posted many times, EROEI is a fallacious concept because it tries to do several things that are impossible:

1. It tries to evaluate forms of energy without regard to price. This is futile. Price matters. Price is relevant. There is no logical justification for omitting it. Important factors can not be left out of an argument just because the presenter doesn't want to or can't deal with them. If they are left out the argument is false on its face.

2. It treats all forms of energy as having the same utility. This is contrary to fact. Some forms of energy are more useful than others and disregarding this is a major error of EROEI. Electricity is more useful than natural gas for example. Or ethanol is more useful than corn and natural gas. Changing from a less useful to a more useful form of energy makes sense even if the EROEI is negative.

3. EROEI by its very nature attempts to compare apples and oranges. This is a hard point to get across. While the numbers may look real, they are in fact false because things that are different can not be compared with any validity. For example is oil a better fuel with a high EROEI than ethanol with a lower EROEI? Oil is not renewable and ethanol is. Comparing the EROEI of the two leaves this out. It is a logical fallacy to do so. Important relevant information can not be left out. If it is, the argument is false.

Calling EROEI an important concept with all these and other faults stretches credulity.

This is futile. Price matters. Price is relevant. There is no logical justification for omitting it.

Price does a great job of assessing ABOVE ground availability of resource but a terrible job of pricing long term scarcity. At what point in the past 9 years would you have said the price of crude oil was giving the 'correct' market signal to planners on its rise from $10 to over $125?

For example is oil a better fuel with a high EROEI than ethanol with a lower EROEI? Oil is not renewable and ethanol is. Comparing the EROEI of the two leaves this out. It is a logical fallacy to do so. Important relevant information can not be left out. If it is, the argument is false.

Ok - You have a choice. You have to run your own world - Cornucopia - you have millions of citizens that are used to high energy lifestyles -you are president (and also a large landholder, not that that should matter). You can choose between 1 million barrels of oil or 1 million barrel of ethanol -both given to you as a gift. Which do you prefer?

(Answer- you take the oil because a)it has higher embodied energy and b)the corn ethanol that you would 'renewably' make the following year would also need natural gas or coal, and billions of litres of water, in addition to having huge environmental externalities, specifically the problem of nitrogen runoff into your water systems. To grow corn renewably, WITHOUT fossil based pesticides, WITHOUT fossil based irrigation systems, WITHOUT fossil based soil amendments would give rise to a very high standard deviation of yield (in addition to using tons of non-energy resources - In the millennium between 500 and 1500, Britain suffered a major “corrective” famine about every ten years due to variable crop yields - there were seventy-five in France during the same period - we forget how variable our major 3 crops can be without the oil/gas to keep them coming back)

(Answer- you take the oil because a)it has higher embodied energy and b)the corn ethanol that you would 'renewably' make the following year would also need natural gas or coal, and billions of litres of water, in addition to having huge environmental externalities, specifically the problem of nitrogen runoff into your water systems. To grow corn renewably, WITHOUT fossil based pesticides, WITHOUT fossil based irrigation systems, WITHOUT fossil based soil amendments would give rise to a very high standard deviation of yield

But isn't the EROEI concept trying to numeralize this? I don't understand your point. If FFs aren't renewable, it doesn't matter their EROEI, because even if they have one of 100, it's a hundred of nothing in the long run. Ethanol's problem isn't their EROEI, because with an EROEI of 1.7 it means that we have to have an energy production of ~ 2.5 times what we end up really using, and we haven't the space, the water, the soil to do so in the hundreds of millions of barrels per day. That's the real problem, not EROEI.

Price does a great job of assessing ABOVE ground availability of resource but a terrible job of pricing long term scarcity.

EROEI analysis is even worse, for it says that saudi oil is a hundred times better than renewable ethanol, in the long run, which is patently false (and no, I'm no advocate of ethanol, I'm just stating facts).

Luis: Yes-comparing the EROEI of renewable and non-renewable sources is illogical.

Since a given complexity of a system cannot be maintained as the net energy available to it falls, then I think EROEI is a valuable metric in assessing the longer-term outlook for the human system in particular. It is already a given in broader ecological studies. I understand the differences in opinion over how it can be computed, but I don't understand the differences in opinion in why it is important to know.

Comparing apples and oranges making sense depends on the goal you have in mind. For instance you can compare the calories per gram or vitamin C concentration put unit.
Net Energy is a very important concept but only when certain goals are considered. It not only applies to different forms of energy but also the better use of that energy. Natural gas can be used for many purposes. Its hydrogen content can be used to make fertilizer. But the yield per pound per acre goes down as more is applied. It can be used to generate electricity. But this electricity is more expensive than average. It can fuel a car. It can heat your house. It can be used to manufacture fiberglass insulation so you need less natural gas in the future. But as the layers of fiberglass get thicker less natural gas is displaced per inch.
Now Pickens is arguing that it is better to use natural gas to fuel a car than to fuel an electric power plant. He believes that wind power can be reliably used for peak power demands. It is part of the Drain America First Disease our politicians are infected with. More work can be done by generating electricity, especially in a combined cycle, than in fueling road vehicles. 15% to 20% of that fuel would be burned in vehicles that are not moving. Natural gas also has a fossil carbon advantage over coal fuel electricity.

Anyone who believes that EROEI is good parameter for doing net energy analysis please answer this question: If one variety of grain yields five pounds of seed at harvest for every pound of seed planted and a second variety yields twenty pounds of seed at harvest for each pound planted, then which variety is economically superior? I maintain that this question cannot be answered on the basis of the information given, even to zeroth order. Seed does not reproduce itself in a vacuum. You cannot walk outside your door, throw a basket of grain into the air and have a large pile of grain appear six months later. Other resources such as land, labor, irrigation water, etc. have to be invested, and the economic value of the plants in question cannot be determined without reference to these other resource costs. For example the efficiency with which land is converted into grain is given by:

Land Efficiency = fS×GY

Where fS is the fraction of the harvest left over after the seeds necessary for planting next year's harvest have been subtracted out, and GY is the gross yield of grain per hectare. The closer fS is to 1.0 (which would correspond to EROEI = infinity if we were talking about the ratio of energy output to energy input rather than grain output to grain input) the better, but high values of GY are also important. The ratio of grain output to grain input (or energy output to energy input) is not an economic efficiency. The ratio of net energy output to energy input (=EROEI-1) could be proportional to an economic efficiency if you assume proportionality between energy input and the net consumption of some other resource used in the energy production process.

If one variety of grain yields half a pound of seed at harvest for every pound of seed planted, I think we can fruitfully discuss the futility of planting this seed. I agree that EROEI isn't the whole story.

Obviously zero return is a limiting case, but there is no need to use the ratio of output to input to analyze this limit. For example, as the net grain output approaches zero, then fs and the land efficiency of grain production also approach zero. Also the land cost of net grain production (the amount of cultivated land required to produce 1 net unit of grain = 1/(fS×GY)) approaches infinity. I find either of these statements to be as least as informative (if not more so) than saying that the output to input ratio approaches 1.

Roger - We are on the same page here. The problem you point out is endemic to net energy analysis AND monetary analysis. Non-energy inputs must be accounted for in both, but they are not. The reason why is they have not mattered in our recent memory as much as dollars or energy have.

We are working on it...;-)

If you have a framework to account for such things please feel free to write it up as a guest post.

And for the record, I am not a proponent of using EROI for net energy analysis, primarily because it ignores quality. But I am a proponent that people acknowledge that energy production requires energy (and other) inputs - dollars are just an intermediate step - our gas tanks will be empty long before the printing presses stop printing.

EROEI FROM BIODIESEL. Forgive me if I missed it. But in most EROEI discussions I see biofuels all lumped together. Surely EROEI from biodiesel would differ significantly from that of Ethanol. Can anyone offer some thorough illumination on this or direct me to some resources?

Here's an unsatisfactory answer; the EROEI of biodiesel is not enough. First you need fat or lipids which can be low cost or 'free' in the case of byproduct animal fat or waste vegetable oil. If the veg oil is purpose made such as palm oil there may be unquantified factors such as soil exhaustion and loss of forest carbon capture. Then there is the use of methanol as a catalyst. I'd guess about 5-7 megajoules per litre of 35 MJ/L biodiesel is in effect an energy subsidy from methanol usually made from natural gas. I suspect biodiesel (not the Fischer Tropsch or hydrogenated types) has an EROEI in the range 2-5 but there will never be enough to go round.

http://www.archive.org/details/Myths_of_Biofuels

EROEI discussed at assorted points.

What do the people of TOD think of nanotechnology ... the ability of nano machines able to turn most anything into gas or diesel or grey goo at the atomic level?

Seems like the EROI for self replicating machines that make plastic, tires, fertilizer, etc. would be pretty good.

Nano CO2 + H2O -> asphalt + O2 anyone.

my 2¢,

I think that we will get some pretty cool nano machines able to do things that we can barely conceive of but not for a very long time. Off hand I'd say if we get fusion power in x years then we will get nanobots in 2x years.

Fusion power has been 40 years away for 40 years now. If our shortsighted civilization makes it through the energy, environment, economic troubles we are having right now and emerges as something respectable then I'd put fusion power at 100 years out and nanobots at 200 years out. But honestly, these are just wild guesses, who can say when we will make a break through.

As for

Nano CO2 + H2O -> asphalt + O2 anyone.

Chemical reactions either produce or require energy, even with a nanobot catalyst there is still an energy cost to be paid somewhere.

I'm waiting for the scientist and engineers working with thermodynamics to develop the free lunch. If it can be scaled up then all of our worries are over.

Whilst the idea of nanobots has alot of appeal (make fuel, clean up the enviornment, repair the human body are some of the touted uses) I am still worried.
Why? because some pimply geek who has tired of infecting my computer with a virus may move on to infecting nanobots to screw with me (Big Brother and terrorists will also do this).
That's the problem with technological solutions to our problems, most people see only the good possibilities (cornucopia?) and not the downsides.

EROEI is less clear than looking at the energy surplus and the efficiency with which we use energy.

If EROEI=(eo/ei) then surplus energy per product unit (eo-ei)/eo=(1-(1/EROEI)) where eo,ei are usable energy.

Obviously, any energy system must be net energy positive and have a EROEI of at least 1 by definition. Beyond that the energy surplus drops off rapidly such that the energy surplus per unit of an EROEI 100 product is only double the EROEI 2 product.
(1-(1/(2)))=.5 surplus per unit versus (1-(1/(100))=.99 surplus per unit; .99/.5=~2. Ethanol w/coproduct gets an EROEI of 1.7 with a surplus of .41.

Once a surplus has been turned into an energy product what is critical is how efficiently we use it. So a car using
an IC engine at 20% efficiency burning a EROEI=100 petroleum
could be replaced by a fuel cell car at 50% efficiency burning ethanol at an EROEI of 1.7, without noticable effects.
i.e. .98 x .2 <= .41 x .5

I heard on TV that currently the US is twice as efficient in using energy today as it was in 1970. EROEI experts state that in 1940 oil came out of the ground at an EROEI of 100 , today it is something like an EROEI of 10 with a surplus 90% of the EROEI of 100.
i.e. 1 x 1 <=.9 x 2

In fact, if all energy were derived from some fuel like tar sands with an EROEI of 3.5 we would still have 40% more energy surplus than in 1940.
i.e. 1 x 1 <=.71 x 2

I honestly can't make any sense of this. It appears to be complete gibberish to me. Take this:

(1-(1/(2)))=.5 surplus per unit versus (1-(1/(100))=.99 surplus per unit; .99/.5=~2. Ethanol w/coproduct gets an EROEI of 1.7 with a surplus of .41.

So, you suggest a surplus of .99 at an EROEI of 100 to 1 versus a surplus of 0.41 at 1.7 to 1. Doesn't sound like too much difference, eh?

Turn it around. I have 1 BTU of energy to invest. If I invest it into the 100/1 option, I end up netting 99 BTUs. If I invest in the 1.7 to 1 option, I end up with 0.7 BTUs. The difference is over two orders of magnitude. That's a pretty big difference, nonsense metric notwithstanding.

The basic problem of EROEI is that things that are different can not be compared/added/subtracted/multiplied/divided or whatever. If they are the result is silly nonsense.

Energy is a commodity just as metal is a commodity.

We can not take 1 joule of oil and add 1 joule of electricity plus one joule of corn and then say we have 3 joules of energy which indeed we do, but it is silly nonsense.

Nor can we take one pound of aluminum and add a pound of gold plus a pound of platinum and then say we have 3 pounds of metal which we do, but it is meaningless.

The differences of the components while all of the same class make it impossible. This is what EROEI attempts to do. It is stupid. It is nonsense. It is useless.

Those who think comparing, adding, subtracting or whatever different things makes any sense should think again. This is an important principle of logic. The numbers are meaningless if the logic is wrong. The logic of EROEI is wrong.

The numbers are meaningless if the logic is wrong. The logic of EROEI is wrong.

Your problem is that you think ethanol and oil are so different. They are not. In the case of oil, you have ancient sunshine converted into biomass and processed by the earth. In the case of ethanol, you have a lot of inputs of this ancient sunshine, combined with a little bit of this year's sunshine and processed in a factory. That 'little bit' of this year's sunshine doesn't make the two that much different.

X;

A commodity like metal is not a useful comparison to energy, if you want to talk about avoiding Apple/Orange analogies. It would be a little more applicable if the pound of steel that it took to get you your pound of Aluminum was actually considerably consumed and lost to us in the process, or as with the current debate on energy sources, was almost completely consumed from the task.

As it stands, of course, some Metals ARE consumed in the processes of extracting metal ores, as they also are expended in extracting energy supplies- and in doing just about every industrial process we engage in, but that is simply another Cost Benefit Analysis, one where the depletion of the metal tools and supplies (and the energy costs of producing those metals and tools) is weighed against the output of the desired product.

But the amount of metal expended in any of these economically answerable processes is going to be more akin to the 100:1 or better EROEI of our good-old-days of crude production than the much lower energy returns we're talking about today, or that process would financially fail. If you proposed a process in which it took the consumption, the ONE-TIME USE, FOREVER of a dollar's worth of Steel to Yield 1.7 dollars worth of Aluminum, do you think that business plan would get any investors, or would it have to depend on government subsidies, due to the inviolable requirement that we keep our Aluminum supplies flowing? Would we be able to hold an economy that survived on Aluminum ('liquid fuels') together, or would we have to find a different answer to this WhiteMetal Dependency because the 1.7:1 return of that process wasn't good enough to sustain itself?

Best,
Bob

I honestly can't make any sense of this. It appears to be complete gibberish to me.

I'm turning EROEI into net energy surplus per unit of output.
This makes sense because we use the net energy output to do useful work.

Take ethanol. Shapouri(USDA) finds that the net energy out of corn ethanol w/ coproducts process is ~31430 btus per gallon. Let's say brazilian sugar cane ethanol has an EROEI of 8 or 66,789 btu's per gallon. That's better--213%. The energy profit of the highest possible EROEI= infinity cannot possibly be more 243% more than corn ethanol with coproducts; 76330/31430=2.43

The next step is to use the energy profit to do work; that depends on the efficiency of how we use it.
Let's say that we take the corn ethanol above and burn in a 50 mpg hybrid car and the brazilian ethanol in a 20 mpg SUV. Who is getting more value per gallon?
Obviously the hybrid is 2.5 times more efficient than the SUV. So the comparison becomes 31430 x 2.5=78575 > 66789.

Actually, the driver of the hybrid is objectively better off on corn ethanol than the SUV driver even on a theoretical ethanol with an EROEI of infinity!

So, you suggest a surplus of .99 at an EROEI of 100 to 1 versus a surplus of 0.41 at 1.7 to 1. Doesn't sound like too much difference, eh?

There is a finite difference and it's not very big.

Turn it around. I have 1 BTU of energy to invest. If I invest it into the 100/1 option, I end up netting 99 BTUs. If I invest in the 1.7 to 1 option, I end up with 0.7 BTUs. The difference is over two orders of magnitude. That's a pretty big difference, nonsense metric notwithstanding.

No. You can't compare an EROEI of 1 to and EROEI of 100 because at an EROEI of 1 there is no 'energy profit' at all.
So compare an EROEI of 1.1 to an EROEI of infinity. In this case the energy profit(1-1/EROEI) is .0909 versus 1 or the EROEI of infinity is 11 times larger (per 'gallon') than EROEI of 1.1.
Your idea of subtracting EROEIs would indicate that there is an infinite difference--infinity-1.1=infinity and the energy surplus can't be greater that the energy in a gallon of fuel.

The message is that EROEI is not so important and low EROEI can be compensated by greater efficiency in use of energy.

Over time efficiency continually rises so it compensates for 'inferior' fuels.

What doesn't rise is the quantity of high EROEI fossil fuels which are being depleted.

You make tons of sense. Don't mind RR, he's kinda glued to the EROEI concept and simply cannot accept such a simple debunking of its idea in such a simple manner. It makes him look too dumb.

The message is that EROEI is not so important and low EROEI can be compensated by greater efficiency in use of energy.

Exactly. I think you rather explained it very well and I thank you for that.

Turn it around. I have 1 BTU of energy to invest. If I invest it into the 100/1 option, I end up netting 99 BTUs. If I invest in the 1.7 to 1 option, I end up with 0.7 BTUs. The difference is over two orders of magnitude. That's a pretty big difference, nonsense metric notwithstanding.

That would be very important, if money did equal to energy, like what Savinar uses to tell his readers. But it does not, so you are the one talking gibberish. I'll show you why, by simply adding efficiency measures, which is only but a small part of what should be added to the case in point.

Case A (Eroei=100)

You have an economy running with 1000 Btus. 10 Btus are reinvested in the economy so it keeps going. You are left with 990 Btus "for the economy", living with 10% efficient vehicles. This means that the actual used energy is 99Btus.

Case B (Eroei=2)

You have an economy running with 1000 Btus. 500 Btus are reinvested in the economy so it keeps going. You are left with 500 Btus "for the economy", but this time, we have 30% efficient vehicles. This means that the actual used energy is 150 Btus, which is 50% higher than in case A.

Mind you that I was discussing EROEI = 2, which doesn't seem to be the case of renewable energy, only ethanol of these first generations have such a bad math.

If this doesn't debunk EROEI for once and for all, I don't know what will. But I guess people will just keep on banging it like they did with Jevon's.

Errata: Whenever it is said:

...are reinvested in the economy so it keeps going.

should be read

...are reinvested in the energy production so it keeps going.

Sorry bout that.

You make tons of sense. Don't mind RR, he's kinda glued to the EROEI concept and simply cannot accept such a simple debunking of its idea in such a simple manner. It makes him look too dumb.

Ah, the gratuitious insult. The first sign of someone trying to compensate for a weak argument. And that's interesting about the 'simple debunking', considering half his post was devoted to something I didn't say. I am happy that you are so easily impressed.

500 Btus are reinvested in the economy so it keeps going.

This is where you and majorian both missed the boat. Those 500 BTUs aren't just laying around. You have to work to get them. You have to spend time, energy, and effort. If I can pump oil out of the ground at an EROEI of 100/1, I can run a lot of the economy with little effort. In your first case, you only had to produce 10 BTUs to run the economy. In the second case, you had to spend 50 times the BTUs - and the corresponding effort - to get the BTUs to run the economy. Failure to recognize this is your glaring blind spot. But probably worse is this:

You are left with 500 Btus "for the economy", but this time, we have 30% efficient vehicles.

And all you had to do was triple the efficiency of the vehicles? Who knew it could be that simple. But why couldn't you triple the efficiency in your first case? Of course you could, which makes this a pathetic imitation of a debunking. High efficiency is not limited to a low EROEI case, which is why it is irrelevant. If we improve the efficiency, we also impact the high EROEI case. That you don't recognize this is sad.

Then again, it always seems to be the case that those so intent on debunking EROEI demonstrate that they don't really understand EROEI. Your post is a perfect example, and majorian has a history of this. We have been around and around the case in which he failed to account for his energy inputs (i.e., the energy he used to create his energy was 'free', per the math he was using; thankfully he has abandoned this line of reasoning).

Back to the drawing board.

Ah, the gratuitious insult. The first sign of someone trying to compensate for a weak argument.

Or alternatively, the simple recognition of a reality. Probably you won't read my answer, but that's TOD's fault for providing a new post every 12 hours, not mine.

This is where you and majorian both missed the boat. Those 500 BTUs aren't just laying around. You have to work to get them.

And this is where you are simply drowning yourself. There is no thing whatsoever as an economy starting from scratch. We are living nowadays with energy, and every new energy production system will feed itself from the current energy production system. Even the first oil rigs had to feed themselves with something coming from the economy. What you fail to recognize is that the 50x the energy required of my second example, which should be read as an extreme case, and not exactly a forecast of things to come, are offstetted by simply bringing on efficiency to the system.

You do so by dismissing efficiency gains. Yet, the European Union uses about half the same Btus to produce the same dollars as the US. You can talk about "driving less", we could talk about the difference of cars used in europe and in USA, etc. The fundamental truth is the same: Europe uses less oil than USA, period. Simply put, there was a lot more incentive for higher mpg cars in europe than in USA, and that's the main reason why in USA the inefficiency is so great.

But why couldn't you triple the efficiency in your first case?

Are you this easy? In my first example, oil was sold at 9$ per barrel and gasoline cost 1$ per gallon. In the second example, oil is at 200$ barrel and gas costs 8$ a gallon, because it is taxed. The wonders of the market are amazing, aren't they?

.... demonstrate taht they don't really understand EROEI

Stop patronizing. I understand maths quite well and your own definition of EROEI is simple: it's bullshit. You keep banging on your EROEI = !00 is 99 times better than EROEI = 2 and you only show your ignorance or unwillingness to admit basic facts. Back to drawing board? Let me ask you a simple question.

In a society with an energy production system EROEI of 100, and 27mpgs cars, if it had to go down to EROEI of 5, what mpg would have the cars to be in order to spend exactly the same amount of available energy?

Answer. It would have to be a 33 mpg car. Disregarding that we are not exactly in a stage of E=100 and I don't think we'll reach a stage of E=5, it is rather an unexciting number.

In a E=2 doom porned society, same car would have to be a 53 mpg car. Now that starts to be a higher number. Even so, Ford Focus is going out with a 73 mpg car. And that's 2008 for you.

Drawing board? For the EROEI concept perhaps.

I'm turning EROEI into net energy surplus per unit of output.

The key is how much energy you invested, and how much you ended up with. That's it. That's what EROEI tells you. It gives you an indication of how much energy and effort it takes to make energy. At 100 to 1, it doesn't take much to make the energy to run society. At 2/1, it takes a great deal of effort to run society. Efficiency is of course important, and can reduce the amount of energy you need. But you are underestimating the efficiency improvements required to compensate.

Work the problem out this way. You know you need 21 million BOE per day to run the economy. Tell me how you get there with the 100 EROEI versus the 2/1 EROEI. Tell me how much your efficiency has to increase to compensate.

No. You can't compare an EROEI of 1 to and EROEI of 100 because at an EROEI of 1 there is no 'energy profit' at all.

Right, and I didn't write 1. I wrote the same 1.7 that you used. So the rest of the lecture is irrelevant.

I'm fairly certain you're just being sarcastic but I'll
oblige you anyway.

Using your oil based economy of 21 mbpd;

21 mbpd equivalent at an EROEI of 100 would require a base of 21 mbpd x (1-1/EROEI of infinity)/(1-1/EROEI of 100) or 21.212121 etc. mbpd of EROEI 100.

21 mbpd equivalent at an EROEI of 2 would require a base of
21 mbpd x (1-1/EROEI of infinity)/ (1-1/EROEI of 2) or 42 mbpd of EROEI 2.

Therefore the required improvement in efficiency so as not to notice a difference in functionality would have to be by 42/21.212121=~1.98, about doubling the efficiency.

Most of that has to do with the ways we squander energy, living in
poorly insulated homes, drive cars with oversized engines doing 0-6 in 5 seconds, etc.

You subtracted an EROEI of 100 from an EROEI of 1 and got a EROEI of 99, to criticize my concept. That doesn't make any sense from a net energy viewpoint.

Let's work on through this. In Case 1, we had to produce 21.2 units of energy to net 21 for running the economy. Let's assume that gets converted into usable work at a 25% efficiency rate. Therefore, we end up with 5.3 units in the end.

We can do two things in Case 2. No increase in efficiency, and we need to produce twice as much energy to net out the same. In this case, we produce 42 units (which - even if possible - will require an incredible effort) to net 21, and we end up with the same 5.3 units. This is bad.

Second, we double the efficiency and continue to produce 21.2 units. But our EROEI has fallen to 2/1. Therefore, our net is down to 10.6 units, which means as you say that our efficiency must double to end up with the same 5.3 units. But can you appreciate what you are saying here? Double the efficiency across the entire economy? Our electric motors, our combustion engines (and there is room to improve there), our petroleum-derived heating - it's a tall order. It reminds me of when Ross Perot was running for president. They asked how he was going to balance the budget. He said something along the lines of "The CBO has stated that there is about $2 billion of waste because of inefficient processes. I will eliminate that inefficiency, and there you have an immediate $2 billion." So then my follow-up is "How are you going to do it?" And "Can you demonstrate examples where it has been done according to your methods?"

Remember, you aren't talking about doubling the efficiency of a combustion engine. You are talking about the entire economy. Everything. I don't think you appreciate that. It's like saying "All we have to do to start terraforming Mars is put 100 people up there and get them started." There are numerous technical challenges that are assumed away in statements like that.

Further, as I pointed out above, you can't couple the efficiency increase with only the lower EROEI. It would also apply to the higher EROEI. That's another reason this is a nonsense example.

You subtracted an EROEI of 100 from an EROEI of 1 and got a EROEI of 99, to criticize my concept. That doesn't make any sense from a net energy viewpoint.

Um, no. I didn't have an EROEI of 99. I had a net energy of 99. I invested 1 unit, got 100 back. The EROEI is 100. The net energy is 100-1.

I will also make two observations. You dropped the EROEI of 1.7 for 2. I presume you realize that things get dramatically worse at an EROEI of less than 2, so you did that so you would only have to 'double' the efficiency.

Second, I still don't think you understand EROEI. When I wrote that you were writing gibberish, I was thinking of things like this:

The energy profit of the highest possible EROEI= infinity cannot possibly be more 243% more than corn ethanol with coproducts; 76330/31430=2.43

That is nonsensical. If you have an EROEI of infinity, you have an energy profit of infinity. If I invest 1 unit to get 10,000, my energy return is a lot more than 243% greater than corn ethanol.

Let's work on through this. In Case 1, we had to produce 21.2 units of energy to net 21 for running the economy. Let's assume that gets converted into usable work at a 25% efficiency rate. Therefore, we end up with 5.3 units in the end.
We can do two things in Case 2. No increase in efficiency, and we need to produce twice as much energy to net out the same. In this case, we produce 42 units (which - even if possible - will require an incredible effort) to net 21, and we end up with the same 5.3 units. This is bad.

You assume 25% efficiency. Would that it were! Our real efficiency as far as accomplishing tasks is far lower..around 10% efficient. Great increases in efficiency are possible if we redesign how we do things. You're ridiculously rigid on the ability to increase efficiency.
Instead you insist that we need to produce more energy to make up for falling EROEI, the world doesn't work like that!

Second, we double the efficiency and continue to produce 21.2 units. But our EROEI has fallen to 2/1. Therefore, our net is down to 10.6 units, which means as you say that our efficiency must double to end up with the same 5.3 units. But can you appreciate what you are saying here? Double the efficiency across the entire economy? Our electric motors, our combustion engines (and there is room to improve there), our petroleum-derived heating - it's a tall order.

If we double out efficency at 21.2 our total IMPROVES(not falls) from 5.3 to 10.6 and therefore with an EROEI of 2 we end up requiring half the energy we had before.
Yes, I do understand that we do need to double the efficiency in how we use energy! You view this as an impossible goal but you have to open your mind.
High efficiency compact fluorescent lighting is less than 1/2 the wattage of normal lighting. Houses could be vastly better insulated than they are reducing heating and cooling plant size and energy input at the same time--R2000 houses require half the energy of standard building code designs, cars are easy--I know a 50 mpg hybrid is twice as efficient as a regular 25 mpg car, certain conveniences are just energy wasters, more durable appliances would save energy,etc. The biggest savings will not be with new energy technologies as it will be with reducing how we use energy--what is more efficent a microwave or a gas range?
Is it more efficient to dry clothes outside on a clothesline or in a clothes dryer?
We have to live more energy inefficent lives to make this happen. Instead we use energy to satisfy our cravings instantaneously.

So then my follow-up is "How are you going to do it?" And "Can you demonstrate examples where it has been done according to your methods?"
Remember, you aren't talking about doubling the efficiency of a combustion engine. You are talking about the entire economy. Everything. I don't think you appreciate that. It's like saying "All we have to do to start terraforming Mars is put 100 people up there and get them started." There are numerous technical challenges that are assumed away in statements like that.

You're being very silly. It is a well known fact that Europeans
are about twice as efficient as Americans(per capita boe). Are they suffering incredibly? I think plenty of American would do fine living a European lifestyle. I believe it is widely accepted that today the US is twice as efficient as it was in 1970.

Further, as I pointed out above, you can't couple the efficiency increase with only the lower EROEI. It would also apply to the higher EROEI. That's another reason this is a nonsense example.

The point is to maintain our current net energy level involved in doing real tasks. However, if it ain't broke, why fix it (by putting in energy efficiency measures)? Why bother increasing efficiency
if energy is cheap (high EROEI world)?

Um, no. I didn't have an EROEI of 99. I had a net energy of 99. I invested 1 unit, got 100 back. The EROEI is 100. The net energy is 100-1.

You like to argue. That's not the definition of EROEI;
(eo-ei)/ei=EROEI-1, not eo-ei=EROEI.
http://en.wikipedia.org/wiki/EROEI

I will also make two observations. You dropped the EROEI of 1.7 for 2. I presume you realize that things get dramatically worse at an EROEI of less than 2, so you did that so you would only have to 'double' the efficiency.

Yes, they are worse but not by much. The net energy of 1.7
versus 2.0 is just ~20% less i.e. .411/.5=.82.

Second, I still don't think you understand EROEI. When I wrote that you were writing gibberish, I was thinking of things like this:
The energy profit of the highest possible EROEI= infinity cannot possibly be more 243% more than corn ethanol with coproducts; 76330/31430=2.43
That is nonsensical. If you have an EROEI of infinity, you have an energy profit of infinity. If I invest 1 unit to get 10,000, my energy return is a lot more than 243% greater than corn ethanol.

Really? A gallon of ethanol has 76330 BTUs in it. I make it in your EROEI=10000 process putting in just .0763 BTUs to make a gallon of it. What is the net energy per gallon? What is 76330-.0763 btus? ~76330, right? Or can there be more than 76330 btus in a gallon of ethanol?
If I make it in a 1.7 EROEI process what is the net energy per gallon? 76330-44898= 31432 btus.
So the EROEI=10000 process yields 76330, just 2.43 times the energy of the EROEI=1.7 process at 31432.

Instead you insist that we need to produce more energy to make up for falling EROEI, the world doesn't work like that!

Show me. Just show me an example of where a society has doubled its overall efficiency of energy usage over a relatively short period of time. Good luck.

We have to live more energy inefficent lives to make this happen. Instead we use energy to satisfy our cravings instantaneously.

It is a fact that we must increase our energy efficiency. But it is a big leap from increasing efficiency with higher mileage vehicles and fluorescents, to doing so across the entire economy.

It is a well known fact that Europeans are about twice as efficient as Americans(per capita boe).

That’s completely inaccurate. They use half the BOEs. They also drive about half the miles per year. That’s not efficiency. At least if that’s what you are using to refer to efficiency, we are using different definitions.

You like to argue. That's not the definition of EROEI;

I knew you didn’t know what EROEI was! That’s not accurate. Someone has recently edited that Wikipedia article, and what they have in there is inaccurate. The definition by which corn ethanol has long been measured is the same one I have been using: EROEI = Eout/Ein. Try here:

http://www.eroei.com/articles/the-chain/what-is-eroei/

Really? A gallon of ethanol has 76330 BTUs in it.

This goes back to your incorrect definition of EROEI. It is a fact that an EROEI of infinity will yield an energy profit of infinity because either your output number must be infinity or your input number must approach zero. Either way, the profit is infinity.

It gives you an indication of how much energy and effort it takes to make energy.

Wrong. It tells nothing about effort. It only tells about how much energy. Old time coal mines had a higher EROEI than present day big machinery diggers. You aren't really saying that today we put more human effort (the only one really important) than back then, now are you? EROEI doesn't say a thing about effort. I'd rather have a EROEI = 2 energy system built out of completely automated process than an EROEI = 10000 where I'd only have my muscles labor to dig it out. Former = utopian society, latter = slavery society.

Get now, why EROEI is not by a long shot the only "kid in town"? There are many other important variables that will contradict any decision merely based on EROEI.

But you are underestimating the efficiency improvements required to compensate.

You are the one underestimating the effects that a very cheap energy supply has made in society. Right now we are witnessing the USA demand dropping by a million barrels of oil per day since 2007, which accounts for 5% of all oil used. That's a 5% decrease in consumption derived from increased efficiency and demand destruction in only one year. Clearly the market is putting efficiency measures in the top front priorities of companies and individuals.

Good insights in these 10 points.

CarbonROI and exergy have been mentioned already. Specifically, it may be worthwhile to talk about EROOI - Energy Return On Oil Investment. How much oil investment is required for an energy system, considering all aspects?

Another important point regarding EROI is to differentiate between 'overnight energy costs' and variable energy 'running' costs of an energy system. EROI is an aggregate of these two energy costs, but they are quite different. With PV and fission, it's possible to come up with a similar EROI figure without being largely incorrect, but most of the energy for PV is upfront whereas for fission the brunt of the energy costs are variable. The PV energy system would have somewhat of a tendency to 'breed' ie have high overnight energy investment, whereas the nuclear fission energy system would breed less (unless it's a breeder reactor!) but would be more 'parasitic' in terms of variable energy costs.

A shift to a lower EROI energy system means that more of society's productive resources are devoted--directly and indirectly-- to delivering the same amount of energy. That energy thus cannot be used for other purposes, notably consumption goods. Energy used to make a drilling rig or wind turbine cannot be used to manufacture iPods or provide medical care.

Aside from significant environmental costs, energy invested in extracting fossil fuel does not necessarily in and of itself reduce total available energy as long as there is plenty of surplus fossil fuel available. One can simply extract extra fossil fuel whose net energy can then be used in the ongoing extraction process.

To alleviate confusion on this subject, I think cost of extraction needs to be split up into its component costs, such as energy cost, human labor, money, opportunity cost and so on. It's perhaps not very useful to use the concept of EROEI by itself, as this particular quantity creates very different problems as total energy availability decreases.