Robert - a few thoughts on your nice summary.

1)In a pending paper, "A Consistent Definition for EROEI", Mulder, Lillies and Hagens point out that in situations where a co-product is used in the energy harnessing process itself (bagasse for sugarcane ethanol as an example), the traditional EROEI formulation does not account for the opportunity cost of the precursor energy input and thus overestimates the EROEI of the process.

The above graphics from that paper show the same process (cellulosic or sugar cane ethanol) measured in two ways. The bottom diagram shows traditional EROEI = energy out / energy in. The top graphic indicates that the intermediate step biomass K2 (the bagasse) has an energy opportunity cost as it could be used for other energy uses. This 'loss' of availability has to be considered, which translates to EROEI = (Eout +(E lost-Ein)) / E lost.
From our paper:

What does this imply for the EROI of cellulosic ethanol? Drawing on a review conducted by Hammerschlag [11] of four net energy studies, we averaged the energy inputs and outputs to produce estimates for system energy flows for cellulosic production. Flows follow Figure 3a with the exception that the available energy from Biomass A (the lignin) is higher than the required input to the ethanol processing system, thus yielding an additional energy output. Estimates are as follows on a per liter of ethanol basis:
Energy In = 5.3 MJ.
Energy from Biomass A = 32.5 MJ.
Energy into the biomass processing system = 29.0 MJ.
The surplus energy from Biomass A that is outputted = 3.5 MJ.
Ethanol production (Biomass B) = 23.6 MJ.
Using the intuitive definition, the EROI measure would be Eout ( = 23.6 + 3.5 = 27.1 MJ) divided by Ein ( = 5.3 MJ) for an EROI of 5.5, significantly higher than soy biodiesel or starch ethanol. However, using equation (1), we have:

EROI = 27.1 + (34.3-5.3) / 34.3 = 1.7

where E lost = 5.3 + 29.0 = 34.3 MJ. This value is only marginally better than reported EROI measures for starch-based ethanol [7]. A similar exercise shows that the high EROI numbers for Brazilian sugar-cane based ethanol, which uses the bagasse as an intermediate input, are also overestimations.

As you rightly point out Robert, the bagasse is probably being used for its best use, but in a different economy it might be used in many other energy technologies; heat, biogas, electricity, etc. that would have higher social efficiencies. So the bagasse has to be considered an energy opportunity cost, and if not counted as an input it will overstate the EROEI. This is relevant if we would change how society used energy. There would be less need for high energy surplus liquid fuels if things were done more locally, or with more electricity, etc.

2)You are absolutely right about declining EROEI forcing our hand. We can 'grow' with lower net energy, but only if the smaller energy surplus is offset by some mix of a)conservation b)efficiency or c)move to lower energy footprint infrastructure.

This all boils down to an acceleration of pulling in resources, both energy and non-energy inputs, in order to continue the ICE mode of transportation - a path chosen for efficiency and ease many decades ago. The more we try to generate liquid fuels with low energy gain, the faster we will use water, natural gas, corn, coal, etc. - the things that have NOT been in shortage heretofore.

I think as soon as there are more limiting inputs than just liquid fuels people will start to internalize the biophysical angle on this story. After all, dollars are infinite, but high density, easily transportable energy is not.

The problem with thinking within EROEI is that although it's a good method to evaluate systems on paper, it isn't a wide enough scope to understand whether it's a good idea in the real world. These are some items from an essay I wrote a while back on evaluating renewable energy systems.

Factors for Evaluating Renewable Energy Systems

• EROEI Energy Returned On Energy Invested which is the system energy output over construction and operation energy input. This is the term that is usually used in isolation when comparing energy systems, ignoring the rest of the factors.
  
• Location Independence of the generation system. The construction energy of transport infrastructure and
  loss of energy during transmission is a major factor in total system feasibility. The closer the renewable power generation system is to the consumer, the more efficient the total system is. If the system is used to manufacture energy transport media, the distance the energy product needs to be transported is also important.
  
• Scalability and Availability of construction materials and input media. If the required construction materials are rare or require a lot of energy to locate and process, this affects the efficiency of the system. If the system is built from common and recyclable materials the system will scale well. In the case of energy media manufactured from organic sources (like ethanol, bio-diesel and bio-mass),the scalability and availability of these sources is important. If the organic input media is a waste product and it may be converted into a usable energy product without a large environmental impact, the scalability is less important than the use of an otherwise wasted product.
  
• Reliability: If the system output is intermittent (i.e.only producing power when there is direct sunlight or the wind is blowing) either an energy storage system needs to be incorporated or the system is limited to supplementary power generation. There is a limit on the percentage of intermittent electrical power generation that may be tied to the electrical grid before it becomes unstable.
  The guideline from the utility companies is at around 10% intermittent generation to maintain grid stability.
  The other portion of reliability is related to serviceability and generally the less moving parts and simpler the system the less chance that a
  component or the system will fail.
• Serviceability: If the system is serviceable and individual components can be repaired or replaced the whole system has a better
  energy efficiency than systems that are not serviceable and need to be replaced completely at the end of there usable life span.
• Environmental Impact: Although most renewable systems have a lower impact on the environment than fossil fuels, structures like
  hydroelectric dams usually require major disruptive changes to waterways and the local environment. The manufacture of the components may also have an substantial environmental impact and in the case of converting an existing waste product to fuel there may be a positive environment change.
• Aesthetics and architectural design of the system are also very important to society.
  
• Transportability: The ease at which an energy transport media can be safely transported and stored as well as the energy density of the media.
  
• Implementation: The amount of effort required to convert traditional fueled systems to the renewable product.
• Efficiency of Consumer Engine:
  The total system efficiency is affected by the engine used to convert the energy transport media to work by the consumer.
  
• Complexity of technology and whether the system requires highly specialized equipment to produce and whether this equipment is
  available to the general public.
  
• Intellectual Property ownership and other political factors affecting whether the technology can be
  replicated by the community or will be controlled by agencies that will arbitrarily set the market price once the system is in place.
  
• Security: Large centralized power generation systems and processing/refineries are more vulnerable to major attacks than interconnected community systems. The Internet is a good model of a distributed system limiting single points of failure and is very difficult to completely disrupt.
  

I clearly get the relationship of energy in to energy out and how much of the energy out is net but the source of the invested energy gets problematic with plants.

Question for Robert and Nate if you happen to know the answer.

When studies are done with renewable energy sources (particularly biomass, corn, vegetable oils, etc.) do the calculations of total energy invested include solar energy or just human manipulated energy (which by definition must be almost all fossil energy at present)?

I often can't find this distinction in the equations and it would seem to make a difference. If for instance 50% of the total energy required to make corn grain or soybean oil ("the crop") comes from light energy being converted to carbon energy via photosynthesis than your definition of EROEI might not allow direct comparison to fossils fuels.

The bottom line of net energy analysis, of which EROEI is a subset, is that it attempts to ground decisions in biophysical principles. The unfolding international credit crisis should give clues that we can't base long term social decisions exclusively on measures that rely on fiat currencies, where debt and credit can be created with no relationship to physical foundations. Yes its messy to work with and explain compared to dollars. But it's also more real.

Robert--excellent summary. As someone who dabbles in discussing EROEI now and then, it certainly is a topic that needs grounding in a unified understanding of what the terms mean and why it's important.

Two issues for further thought:

1. "Boot-Strap" EROEI. To what degree does the higher EROEI of past energy (e.g. the "easy" oil days) distort our present EROEI calculations? If we use 100:1 energy to produce long-lived capital goods (mining equipment, power plants, pipelines, smelters, etc.) that are themselves used in the production of current energy, does this make our calculations of present EROEI artificially high? For example, if the energy input required to make a combine harvester used in ethanol production had an EROEI of 50:1, but that same combine harvester could only be manufactured today using energy with an EROEI of 20:1, how does that distort our calculations of the EROEI of the resulting ethanol? Does this cause us to make incorrect decisions today about what is sustainable or more efficient, because our decision making assumes a level of embodied energy in durable capital goods that is no longer available?

2. The infinite regression problem: How do we account for the full spectrum of inputs for EROEI calculation? Do we draw the line at the actual fossil fuel used in the direct production of energy (as in your Brazilian ethanol example above)? Do we include the fossil fuel used to produce the metals, concrete, road infrastructure, etc. required in its production? Do we include the energy needed to grow the rice to feed the sailors on the merchant vessel that transported the machine tools that made the machinery used? This can be regressed infinitely, but doing so creates an impossible accounting task. Any practical line that is drawn for accounting purposes is, by definition, under-inclusive. Is there a methodology in place to estimate how much energy input is being ignored (and how can this be known?)? I have suggested using market price as a proxy for comparing two different energy types, but this is admittedly VERY crude and full of many holes. It seems logical that there is a much greater unaccounted-for tail in complex processes like LNG than there would be in collecting firewood from your woodlot, but to what degree? If we accept that the unaccounted-for tail varies among types of energy, how are we controlling for this in our comparisons of the EROEI of different energy choices?

Maybe the problem with EROI is that it does not include the time factor. For example for ethanol production if time is included you then have the total amount of input energy over the growing season and the various conversion efficiencies. So for corn its all the energy from solar, oil etc input to produce a energy output every six months.

Looking at it this way its obvious why oil is so great since its harnessing solar input that represents thousands of years with secondary inputs on the same scale as for corn or sugar cane.

What it really seems to me is that the energy input outside of primary solar collection is probably fairly constant and the problem is the energy density of the carrier is much lower.

Or to put it a different way its the same amount of work/day to drill one oil well that produces 10,000 barrels of oil a day as it is to grow say 100,000 acres of corn. However the oil well is invested in up front while the corn requires continued investment i.e drill a new well every year for a tenth of the return.

Even in oil you have the same problem say the well just produces a few barrels a day.

It just seems to me that by including time in the measure you can sum the total energy costs and its pretty obvious that biofuels are far more expensive on the input side vs oil.

In fact it looks to me that equating growing corn to having to drill a new oil well every year probably is not far from the truth. And notice that sugarcane does not do much better summed over the entire year. Intuitively it makes sense that biofuels are not close to competitive or they would have continued to have been used in the past.

BTW Mr. Rapier is in India this week, he probably won't respond to comments.

It's probably worth mentioning that the Brazilian model of burning bagasse is not "unique." The bagasse was going to be burned anyway to produce the sugar from the sugarcane. That the sugar is then converted to EtOH is just an additional step that would not be taken if sugar was all we were trying to produce.

Most of the sugar mills we've been to in Florida and Louisiana are self-sustaining (or nearly so) for energy requirements (electricity and heat) but it does require some degree of balancing to accomplish. The extra steps to produce EtOH from sugar requires additional energy which, as pointed out, does not necessarily require additional fossil fuel to accomplish, just management of the heat balance.

The economics argument does tend to get a bit squirrely (what if the oil well pump is powered by nuclear power or solar power are just to variants I've encountered). But your point is sufficient in that eventually we end up with an unbalanced situation where it no longer makes asense at any level to keep expending energy to produce "nothing."

Worse yet, people don't get how fast "growth" can sneak up on you an the natural constraints that exist. Last night as I attended a candidates forum for county commissioner it was pretty clear that most of the people don't have a clue about this AND the ones that do struggle with saying the words "perhaps we should just say no to growth." In particular with our drought situation, the idea of growing more and expending every increasing levels of energy for lower quality water does not register (No, they haven't figured out how to make it rain more).

I hadn't realized just how much confusion there was over this calculation so I agree it's important to provide repeatability. Imagine having 10 different calculations of the mean and saying they were equivalent. So defining EROEI (and agreeing to the definition!) is definitely a crucial first step. However, in assessing viability, other statistic(s), including terms for nonenergy inputs must be used to address the impacts of a renewable energy source on these resources as well. Baby steps though.

Robert, thanks for raising this very important issue again. As I’ve pointed out numerous times at TOD, for example
here, I think the impact of declining EROEI is grossly misunderestimated, to borrow a term. Society only functions on the net energy left over after we expend whatever energy it takes to ‘get’ our gross energy - same as a fox hunting mice. If the fox expends more calories than it acquires from its prey, it won’t live long. Even if it expends nearly as many as it gets, it won’t have enough left to provide for its normal bodily functions. This is the scary slope we are sliding down, and as with all factors surrounding peak oil and resource depletion, understanding it will only add a tool to our belt when it comes to preparing for and dealing with it, insofar as that’s possible.

My best understanding is that early oil had an EROEI of 100:1 or 50:1, where the input energy is so small 1-2%, that it hardly mattered, and where a doubling of required input was hardly noticeable. But once EROEI descends below 10:1 which is more the ballpark we’re in today, the input energy matters a lot and a doubling of required inputs is disastrous.

I’d love to see TOD put its collective effort to nailing down as best we can just what the net energy situation is out there for the major players – remaining conventional, deep water, polar, tar sands, ethanol, natural gas, coal, etc. The sooner and better we understand how this compares to the huge net return of the early ‘straw in the sand’ oil the industrial economy and green revolution exploded based upon, the more fully we’ll grasp the true nature of our predicament.

The EROEI is a very interesting concept that gets the people to be more aware of the problem of dwindling resources of ever lower quality, but has several accountability and conceptual problems.

The first, as Memmel has mentioned, is that it does not include any (f)t. And this is important, because EROEI degrades with time, as exploitation of a given source of energy degrades with the exploited finite amounts. It also happens, for instance for biofuels originated in land cultivation, generally taken for granted as “petrol station rates” (i.e. on 24*7 ready basis and increased supply every passing year), which force the land to produce without rest.

The second problem of EROEI is that in a complex society (and for sure this is a complex society), the energy input costs are generally simplified in all the EROEI studies (at present under the camouflage of “Life Cycle Analysis”) in economic to energetic equivalences. As the economy is today pure flying paper, it is very difficult to properly assess real ENERGY values in a given input to produce and output. There are many hidden energy costs in the economic equivalences and some times, these are quite relevant.

Among the tenths of studies I have seen of EROEI’s or energy paybacks or Life Cycle Analysis, many are dark grey in their data and authors feel very disgusted if you ask for details. They always refer to known economic/energetic equivalences, and when researched, in many cases, are quoting in circular form to few known gurus of the payback periods, without discussing them. Or they simply answer that it is not simply possible to break down to third or fourth derivative the energy contents of every single step of the multiple steps to put a unit of energy at society disposal.

They are only partially right, however. The chain of energy expenses (energy in) to produce a net amount of energy to the society, are in most of the cases in this complex society, the result of a value chain of an incredible length. The process to take a litre of gasoline to a remote place in, for instance, Abidjan, goes through hundredths of complex activities and process, all of them spending energy. But this brings another important subject that puts many EROEI’s studies in quarantine. It is the concept of the weakest link in a long chain. That is, some processes of the long chain are ESSENTIAL to bring a source of energy to society. Perhaps the simple, isolated analysis of the energy content of the single link delivers a small quantity of energy required. But if this single step/link of the chain fails, the whole chain may be at stake. And this is the case of many single processes in having a source of energy at the disposal of the society. If a continuous supply of nanofilters is disrupted for a given time, the whole manufacturing of six nines purity silicon wafers in a 100 MW/year solar PV factory, may be at risk of having to stop completely. How to assess this dependency? The nanofilter factory may not spend much energy in producing just one, but the whole sophisticated factory (they can not be produced in the corner shop in Mumbay or Nuackchott) may spend a lot of energy and may stop or disrupt one day, for a single blackout in the manufaturing area. Or an embargo or a blockade.

And last but not least, the numerator of some sources of energy is in many cases overstated and given for granted. For instance, all the Life Cycle Analysis I know for solar PV plants are given for granted 25 years lifespan. In my experience of three years analyzing over 30 MW solar plant installations, this is more than doubtful, to say the least.

First, no one manufacturer, gives a guarantee for 25 years. The highest guarantees are for 10-12 years, to the best of my knowledge. Many of the other parts of solar PV plants (inverters, piece parts, movable parts in the case of plants with trackers) have 3 to 5 years guarantee. Many would answer that cars are given 5 years and may last 10.

But when you ask the authors of some LCA how they are so sure of 25 years for the numerator, they all invariable answer that they know some panels that have lasted 30 years. Or that this is the standard for the industry. This is a mystification. The calculations have to be made on a sufficient sampling volume in a real world, rather than on personal experiences of skilled hobbyists. I also know many modules that were wrong from the unloading from the vessel. Some others are subject to vandalism in many countries (the samples in the roof of universities, under controlled and secured parameters, are not to be extrapolated). Many others are stolen. Spain has increased the insurance rates considerably, due to this effect (and this is energy, extra and unplanned energy). Or they force the plants to increase to unexpected levels the security measures (more energy in), by doubling fences, having patrolling forces or special night lighting and surveillance systems that decreases substantially the real net energy delivered. And we have far (in levels, probably not in time) from being in a severe economic crisis that might boost crime rates. Some others are subject to fast salinization in areas close to the sea. Or their tempered glasses damaged by sand storms acting like sand paper. I would suggest to think in that to those happily proposing the Sahara desert as an adequate place for energy shipments to Europe. Some others have processes of expansion/contraction in desert areas at peak temperatures, that make insulations systems to fail and then water finally enters into the modules, damaging them.

The costs of repair and maintenance are in many cases understated. I have seen many maintenance contracts that for sure will not allow plants to last for 25 years. Costs of maintenance are generally linked to Cost of Living, which is a variable (energetic) factor. The inflation or stagflation could boost these expenses (both in terms of economic and energy costs)

Evolution of technologies is making sometimes difficult to many to find, in few years from the cutover of the plant, proper replacements of a single damaged module with the same characteristics fitting in an array. For a professional, this might be solved. For many others, that have invested in solar farms in Europe, this will force them to replace the whole array.

The companies in themselves, are promising in many cases warranties beyond their own average lifespan durations, as per the data in the sector, or committing much beyond the social capital backing the operations; or installing as intermediaries or thirds parties or OEM doubtful agreements, with manufacturers in the other side of the world that may not honour the contracts signed by the local representative or vice versa. All this will have a negative impact in the so easily assumed 25 years duration.

The number of boards blown in inverters or meters broken due to spikes or micro-cuts is sometimes much higher than planned and programmed, specially where the grids are less evolved and spares are more distant (that is in 90% of the world). In Spain, fourth country in producing PV modules and in installed power (over 600 MW already feed in), the appearing figures of the annual production average is far below of the “estimated yearly generation” of the contracts signed for those given parallels, except in several professional cases, happening the opposite. And this is mainly due to lack of proper maintenance (a diode may cause 25 kW of installed power to be idle for six months) or not compliance with the maximum guaranteed response times. The fact that a maintenance agreement covers this for the first 3 or 5 years should not give enough comfort to both promoters and LCA analysts. Life, real life, not theories.

This is the real world outside. Not what a handful of experts believe or conclude after few lab experiments under controlled conditions. If you could only calculate the number of modules and wafers that went down to the garbage in China before they could pick the beginning of the learning curve, you would be amazed. Even this will never be disclosed as an energy expense attributable to the solar PV industry. Nor the thousands of transatlantic flights to get Memorandums of Understanding or Letters of Intent for technology transfer, or shipments of row materials, etc. etc. Including the never accounted in the “energy in” failed business trips to the purpose.

EROEI is a very good thing as a concept, but still lacks refinement to allow us to discern if some renewables will see the light in significant volumes.

Pedro Prieto

"What is done to arrive at the 8 to 1 sugarcane EROEI is that they only count the fossil fuel inputs as energy. Boilers are powered by burning bagasse, but this energy input is not counted. (Also, electricity is sometimes exported, and credit is taken for this). For a true EROEI calculation, all energy inputs should be counted."

Did we started counting the solar input required to create all that oil? Or at solar power plants?

No EROEI account counts all energy inputs. First law of thermodynamics (to say nothing about the second) guarantees that no ernergy generator can have a EROEI grater than 1 when you count all the inputs.

So, again, why should we count solar inputs maskeraded as bagasse?

Robert,

I completely support the gist of your calculations and your argument. However the term EROEI on its own is bit of a minefield, in which the essential point that is being made is easily lost, or is easily spun to distort the underlying reality.

To cut a long story short my suggestion is that wherever it is meaningful to do so, the calculation and discussion is of ‘fossil fuel EROEI’, and that this is stated explicitly, taking into account all of the fossil fuel inputs that directly or indirectly are required to deliver a unit of fossil fuel output or its equivalent.

To illustrate the problems of being more general, if solar power is involved - does the energy in include all of the solar energy falling on the plant? In the case of nuclear energy, does the energy in include all of the energy released by the fusion reaction? etc. etc. In the case of biofuels, do you use all of the solar energy falling on the field?. In most cases one obviously does not use these broader definitions of energy, but using the term 'energy in' without, constraining it in some way is perhaps too lax.

'Fossil fuel EROEI' is what people should talk about, or some other well defined other qualification of EROEI. IMO the term 'EROEI' is best never used on its own, unless carefully defined in context.

On the separate point of where all of this is going, I add my voice to those who are only temporary 'doomers', in terms of energy resources - IMO the fossil fuel energy crunch will belatedly be followed by a cornucopian outcome, where the worst case solution (in terms of financial cost) is the electrification of all land transport and other land-based requirements for energy, together with the generation of most electricity from concentrated solar thermal (CST) plants in low latitudes, shipped as needed to larger latitudes over high voltage DC transmission lines.

IMO, there is already ample evidence that this can be done, without any further technical breakthroughs - the (soluble over time) problem will be scaling up.

My best guess is that within a couple of years we will see at least one country or region commit to a 10GW (fossil fuel equivalent) program of 24/7 CST, probably in one of the middle east net oil exporting countries with lots of cash and not enough electricity. My further WAG is that within about five years there will be 100GW worldwide of committed CST projects . The economists will be right in the long term: market forces will lead to the replacement of an expensive and constrained supply of (fossil fuel) energy, with a cheap and unconstrained supply of (non-fossil fuel) energy, but only after an currently unpredictable degree of painful shortage.

It would be an interesting calculation, to see what fraction of the financial surpluses being generated by the large net oil exporters over the next en years, would be needed to fund the complete conversion of the planet to CST plus a transmission system.

Before I get dumped upon again by some hard-core doomers, my views above relate only to the cornucopian supply of energy. I am NOT suggesting that there are no other crunches coming, or that such a cornucopian supply of energy is entirely a good thing, in human hands.

Thanks again Robert,

Mike

Homo semi-sapiens

EROEI is a very useful tool when it comes to pure research. My primary concern is that stated EROEI tends to be variable based on whether or not someone is for or against a given energy source. For example, in the case of sugarcane ethanol mentioned above, many who are most concerned about fossil fuel inputs will state the 8:1 figure. While those who are most concerned about all energy will give a much lower figure.

It's a real furball when you start to look at corn ethanol, for example. Some people claim that it's a net negative. Others state that the EROEI is greater than 2:1. The factors are hugely variable ranging from if the ethanol is transported by truck or train, if the inputs to distillation are coal, natural gas, or electric, how efficient the harvesting method is and a hundred other widely swinging variables. Various rather in-depth scientific papers support a wide range of views and they may all be correct given the assumptions underlying the data.

Meanwhile the US produces 520,000 barrels of ethanol per day and imports less oil because of it. At this point, EROEI is starting to become a little academic as the fuel source is pretty huge now and new economies are starting to make its production more efficient as time moves forward.

"Net Energy" for whom?

What is the unit of survival subtracted from the environment?

(The Universe as a whole appears to operate with 100% efficiency.
Entities subtract from That transact across the defined boundary.)

What is a relevant unit of survival that must obtain its
net energy by investing less than it gets back in return?

Within the political economy, the greatest return is from fraud.

Successful fraud obtains more than any other kind of investment.

Thus, our investment bankers are the most successful defrauders.

Energy can not be created out of nothing,
but, money to buy control of it seems to.

Consider energy producers versus energy parasite/predators.

(With relative scale differences, predators are parasites.)

This gives rise to Murphy's Law on an astronomically scale.

Human beings act as robbers in their environment.

Civilization is a system of organized robbery.

Physical robbery evolved into symbolic fraud.

Triumphant frauds direct decisions to invest in energy production.

Consider how much energy successful parasites
invested to gain control over energy production.

However, too much of that success by a parasite kills the host.

Those in the camp of "the only thing that matters is economics"
pretend that their predator/parasite behaviour is a production.

Indeed, it is true that a parasite invests energy
in order to take control of the host's energy ...

And so, I return to the first question,

"Net energy" for whom?

What is the true unit of survival?

At the present time, most of our decisions are
being made by the most successful parasites, &
the producers have no way to shake them off ...

When the ratio of energy invested to energy returned gets worse,
then deeper problems of the ratio of producer to parasite shows.

In stable ecology it tends to balance out to
almost 50/50 producers versus parasites.

Inside the human ecology, inside the natural ecology,
the changes in our industrial ecology, driven by the
decrease in the ratio of net energy availabilities,
will reveal the social polarization between the
energy producers versus the energy parasites.

Abundance of energy we indulged in, to allow us
to support the populations of way more parasites.

When the net energy ratio goes through transition,
the social effects are going to drastically shake up
the foundations of human ecology, which is built
on industrial ecology that we took for granted.

We are going to be forced to reassess
what genuine units of survival are ...

At the present time, the bullies' bullshit social stories
are the songs and dances done by the best parasites,
to promote themselves as the true units of survival, which
are the only correct measures of economic developments.

Obviously, significant changes in the net energy
are going to change everything else profoundly.

The Universe as a Whole continues to have 100% perfect efficiency.

However, the entropic flows within human civilization
shall go through turbulent times, and that turbulence
is going to shake up the political economy to prevent
it being able to continue to get away with huge lies.

Civilizations were controlled by lies and coercions,
running established systems of fraud and robbery.

Our parasites were able take for granted the health of their host.

Decreasing returns on energy invested by producers
will feedback to effect the parasites that controlled
what the producers decided was worthwhile to develop.

The death controls made and maintained the debt controls.

Vicious spirals of death engines drove the debt engines.

Energy invested through violence and dishonesty
provided the biggest return by robbery and frauds.

The energy producers are primary.

However, the energy parasites took control of the producers.

The presumed units of survival have become totally insane ...

All the real energy productions are regulated by
a fundamental fraudulent financial accounting.

What we have now is a global electronic fraud,
that is backed up by mass destruction weapons.

What is the energy return on mass destruction weapons?

To what degree can the parasites control producers
by being able to kill the producers, and how far can
the ability of the producers become impaired before
that feeds back to have effect on their parasites?

Socially, the most important impact of net energy
is going to be in the relationships between those
who were the energy producers vs. the parasites.

The grand spirals in the flow of using energy are
from industrial, to human, to natural, ecologies.

When our industrial ecology is forced to adapt
to changes in its enjoyment of "net" energies,
then the changes go via non-linear functions
through the human and natural ecologies ...

Some of the deepest problems are that parasites
are the wrong units of survival to worry about ...

Without accounting systems that have a frame of reference
that work around the truly necessary units of survival,
then all of the problems created by original frauds
will end up have "solutions" being proposed that
are merely wrinkles in old fraudulent systems.

Decreasing net energy problems eventually
must force the change of state in systems.

At the present time, all of the actual solutions
being proposed and implemented are directed to
be within the frame of reference of parasites.

When those fail to work well enough,
eventually, the decreasing reality
of available net energy production
will drive radical state changes.

When the ratio of net energy falls far enough,
then the changes will no longer be linear ...

A drastic convergence of the interests of
the energy producers and energy parasites
will be driven through some revolutions.

Nothing less than different units of survival,
using different frames of reference, to measure
the relative "efficiency" of systems, are needed!

Not sure where I got this image from but I find it very useful.

I think it might be useful to differentiate between "direct EROEI" and "indirect EROEI". Indirect EROEI (including all energy inputs, no matter how indirect) will always be negative, otherwise the laws of thermodynamics are violated. So really it becomes a question as to where we draw the line in deciding how far back one goes in calculating EROEI.
Rgds
WeekendPeak

RR's post again makes the logic error he is so famous for: leaping from a valid use of EROEI in the case of comparing oil with oil or similarly using $RO$I which is also valid to then making the unwarranted leap to comparing the energy inputs in the form of fossil fuels to the energy output is the form of ethanol. Can't do that! The same is true of using energy inputs from fossil fuels to produce electricity. They not comparable because they are not alike. The EROEI of electricity is less than ethanol and less than 1 by a significant amount. Electricity production with negative EROEI has been going on for over 100 years and now we find out it is impossible. Why do RR and other EROEI believers not take on electricity production since it has a lower EROEI than ethanol? Is it because everyone uses it and could not live without it? Apparently ethanol seems strange and alien to those outside the Midwest who produce and use it every day. Here in North Iowa we have been using E10 for 25 years. The economy is booming. The ethanol plants can hardly get rid of the stuff. If ethanol is such a disaster we should have had some indication by now. It is those who have rejected ethanol who are experiencing the recession and the financial meltdown of the house of cards economy.

Gasoline and ethanol are not alike even though they may look the same, may be used similarly and even mixed. Ethanol is renewable and despite all the hocus pocus numbers about energy inputs that are supposedly greater than ethanol energy value, I can not verify any of it in my farming operation. As far a I am concerned the energy inputs assigned to ethanol are a lie. If they were true how, for example, is my 1982 JD 4440 accounted for? At energy costs when I bought it 25 years ago or today? Over how many years are those energy costs written off? Every year? Hopefully it is over a fixed number of years. Then is it ever paid for so that the following year there are no energy input cost for the building of that tractor? There are so many fallacies with EROEI that I have trouble countering all of them. But the idea that resource utilization can be based on EROEI to the point that price does not matter is nuts.

Price matters. It is a critical factor that can not be left out.

Also the idea that fossil fuel inputs are a big cost in producing corn is pure myth. They are important but not the most costly. Land costs, seed and fertilizer, machinery and taxes are all larger. If the energy inputs for ethanol are so great they must be occurring in the refining process. Since ethanol plants are paying $5.00+ for corn and selling the ethanol for about $6.50 in rack prices plus DGGs, where is the expensive fossil fuel input coming from? That $1.50 margin has to include labor, management, maintenance, depreciation, taxes, profit and no doubt other costs. The blender collects the 51 cent tax credit not the ethanol plant. There is no room for the large fossil fuel inputs at the ethanol plant or it would have to close.

RR then proposes that it makes more sense to use the natural gas inputs to ethanol directly. He ignores completely the fact that the automobile infrastructure is set up for liquid fuel and not natural gas. This is not a small matter that can be given short shrift. It is a critical fact of life. Are we to believe that it is easy and cheap to switch millions of cars to natural gas and build the necessary infrastructure?. He also ignores in bemoaning the natural gas inputs to ethanol that ethanol's (carcinogenic) predecessor, MTBE, was made from methane (natural gas). All that is going on is that the natural gas is now being used in ethanol production instead of MTBE.

If you are going to do such analysis, how about doing it with eMergy.

A tool:
http://sourceforge.net/projects/emsim/

eMergy
http://en.wikipedia.org/wiki/Emergy
http://dieoff.org/page170.htm
http://www.greatchange.org/footnotes-emergy.html

A few points:

1. All energy production systems are subject to many constraints - available and potential resource, availability of co-inputs and specific rare elements, capacity constraints, etc.

2. EROEI is probably the key indicator we should look at in determining "where do we go from here?", subject to the above constraints.

3. The infinite regression problem may not be as difficult as thought. As you include more types of activities in the backward regression of inputs, the more you are headed towards an average of the world's overall economic activity. Somebody should do a sensitivity analysis of evaluating primary, then adding secondary, and tertiary inputs and see how much it tends to converge towards the global average of economic activity. Some forms of energy production may be significantly different in energy intensity at the secondary level, but once you're past the tertiary level, I doubt there will be much difference as compared to using a BTU/monetary unit average in the analysis.

Now drop the EROEI to 1.3. We now have to produce a total of 43.33 – an excess of 33.33 - to get the 10 we need to run the economy (Out = 43.33, In = 33.33; EROEI = 1.3 = 43.33/33.33; Net = 10 = 43.33 - 33.33). Thus, the requirement from dropping the EROEI from 20 to 1 down to 1.3 to 1 requires a production excess of (33.33/0.53), or over 60 times the high EROEI case.

Very weird analysis.

Who CARES about producing the maximizing amount of 'net energy'? Nobody does that(well,maybe con-men do--doing the least and getting the most).

You only need a finite amount of energy output for the minimum amount of invested.

If you need 10 units of output energy in an EROEI of 1.3 system, you need to invest
an additional 10/1.3=7.692308 units. At some point there must be 10+7.692308=17.692308 units so you can provide the investment and get the finite return of 10 units that you want.

If you have a EROEI of 20 system
for the same 10 units of output you need to invest .5 units. At some point there must be 10.5 units so you can get 10 units of output.

So how have things changed going from a EROEI of 20 to an EROEI of 1.3. For the same amount of 10 unit output the 'investment' has increased by 15.38 times(7.69/.5) but in terms of overall energy 'effort' it has only gone up 168%(17.692308/10.5).

It's obvious that lower EROEI's will require more basic energy to begin with but not an exponentially greater amount of energy.

More resources will have to be invested and more raw materials will have to be processed.

With a slightly positive net energy gain EROEI of 1.1, we should expect that around twice the resources would be required to maintain a given output.

And this is what we see happening in Alberta,etc.

(Y'all can go back to worshipping EROEI now.)

In order to discuss EROEI I will make use of a concept which I call the working reserve of energy. In order to run our economy we need stock piles of fuel in form piles of coal, tanks of refined petroleum fuel, pipelines full of natural gas, piles of uranium rods, etc. Economic producers (including energy producers) withdraw fuel from this stockpile and use it to produce economic output. Withdrawals can be direct or indirect. Indirect withdrawals take place when one producer draws out fuel and then manufactures a product which another producer purchases and uses in their own process. Energy producers differ from other businesses in that in addition to withdrawing fuel from the reserves they also put fuel back into the reserves. If the economy is running in a steady state then at the end of the effective lifetime of the fuel reserves the reserves will still be full, since the energy producer with have put back just as much energy as the total withdrawals during that time period.

Below I show the working reserves of two different economies represented as a series of Xes. The Xes in front of the vertical line represent the fuel used by energy producers and the Xes to the right of the vertical line represent the fuel used by the rest of the economy.

Economy 1: X|X (EROEI=2)

Economy 2: X|XXXXXXXXXX (EROI=11)

I have chosen examples with EROEI= 2 and 11 respectively. Can we not conclude that it is obvious that to lowest order economy 2 is ten time as productive as economy 1?

Before attempting to answer this question consider the working reserves of a third economic system:

Economy 3: XXXXXXXXXX|XXXXXXXXXX (EROEI=2)

This economy has EROEI=2 as does economy 1 but the working reserves have been expanded so that the total energy available to sectors of the economy other than energy production is equal to 10 unit just as from economy 2 (I will return briefly to the question of how such an expansion of reserves could take place. For now I merely assume that it has taken place.) What can we conclude about the relative economic merits of economy 2 and economy 3? I maintain that this question cannot be answered without taking account of the non-energy related costs of keeping the reservoir filled.

In an attempt to justify this assertion let me use the following fanciful illustration. Suppose a wizard appears who can produce energy by magic. At the winter solstice he can perform an incantation at the end of which the working reservoir is filled with 11 units of energy. In order for his spell to work 1 unit of energy must remain in the reserve as a seed. Notice that it makes no difference if the ‘seed’ energy disappears and 11 new units of energy appear or if the ‘seed’ remains in place and 10 new units of energy appear. The economic effect is the same in either case.

Now suppose a second magician appears who can also work a spell at the solstice which will cause 20 units of energy to appear in the reserve. However, he needs 10 units of seed energy. Again it makes no economic difference whether or not the seed energy disappears or not. I maintain that the second magician can support the same level of economic activity as the first.

Of course this example is nonsense since we must work to put every unit of energy into the reservoir. However, this example makes clear that we must account for the non-energy related costs of filling the reservoir. If energy could reproduce itself exponentially in a vacuum without reference to other production resources (such as labor) then even an energy source with a very modest EROEI could support an arbitrarily large amount of economic production.

So now I return to the question of how to compare economy 2 to economy 3. Robert seems to be maintaining that the energy consumed by energy producers (i.e. the energy to the left of the vertical bar) is a measure of the total effort they are expending in the energy production process, so that if the producers of economy 3 consume ten times as much energy as the producers of economy 2 in order to produce the same amount of net energy then their energy must be approximately ten times more expensive. This assumption has some degree of justification. If we knew that one sector of the economy used ten times more energy than another sector we would guess that it was also consuming a lot more of other resources such as labor, capital equipment (which is partly embedded labor) etc. So that if we make the assumption that non-energy related costs are roughly proportional to energy consumption then Robert’s conclusion can be justified. But without some assumption about the non-energy related costs of filling the working reserve we can make no progress in our economic evaluation.

Finally a word about growth of the working reserve. In order to grow the reserve we must dedicate a fraction of our total energy to the task of making more energy which is larger than the replacement fraction of the energy source in question. So if EROEI=2 and we dedicate 54% of our energy to producing more energy we could grow our energy supply (both the working reserve and net energy) by 8% per year. Of course such growth assumes that non-energy related factors of production such as land, labor etc. are capable of supporting such growth. A lot more could be said on this subject, but anyone reading this post has probably fallen asleep a long time ago.

It is certain energy may be obtained from fermenting grain and distilling alcohol, yet the inputs being played with were of very high strategic value. They were a person's MRE's (combat Meal Ready to Eat/DOD). With worldwide grain stocks especially low it is not advised to trade meals for fuel produced from a commodity with highest and best economic usage gained from feeding people. To adhere to the 2005 Energy Policy Act requirement of 7.5 billion gallons of ethanol prodcution by 2012 might require much grain, sugar, or a change in legislation to avoid catastrophe. 7.5 billion gallons divided by 2.7 gallons per bushel means 2.7777 billion bushels of corn will be needed. The total grain harvest in the United States (wheat + corn) was about 16 billion bushels. 2.7777 is about 16 percent of our grain. 7.5 billion gallons is about 179 million barrels of ethanol. The United States uses about 20 million barrels of oil per day. Using 16 percent of the grain will only supply about 9 days worth of fuel. Whether you get 1.3 or 1.4 EROEI with corn ethanol is of little consequence, you start to starve off the population without lowering the cost of gasoline. We do not have facilities for large scale production of cellulosic ethanol, one report I read estimated it cost $300. a barrel to make the stuff.
Brazilian ethanol exports in 2007 were about 3 billion liters. That was about 18 million barrels of ethanol. The world used more than 85 million barrels of oil a day. Brazilian sugar based ethanol exports for all of 2007 might have sustained world oil needs for about five hours. The situation might get worse beyond 2012 the 2007 Energy Bill requires 36 billion barrels of ethanol with a cap of 15 billion barrels from grain. That might mean 32% of our grain harvest, our entire export capacity eliminated, and a need for massive imports. Some of out friends, trading partners, and allies required United States grain imports for their livelihood and survival.

Brazilian ethanol exports 2007 -- half year:
http://www.dtnethanolcenter.com/index.cfm?show=10&mid=63&pid=35

The end of fossil fuels might require some birth control or abstainence in order to thrive on remaining solar, nuclear, hydroelectric, biomass, tidal, geothermal, wind, etc. Oil is unique in its energy content. A few generations ago people were seeing the newly invented steam locomotive for the first time. It was fueled by wood or coal. Trade and travel was greatly facilitated by this overland transportation system.

I am not convinced about the viability of cellulosic ethanol or its supposed EROEI. Have read production cost estimates from 80 cents a gallon to $300 a barrel excluding fixed costs.

Have read about using wood pellets for wood burning furnaces. It this were done, more heating oil might be converted to diesel, and more natural gas available for public transport.

http://www.pelletsystems.com/faq.html

Am not sure where Bush got his ideas about cellulosic ethanol. I do not believe he had much support from scientific advisors, but suspect he had some autocratic notion to micromanage a system he was not familiar with.

This is a draft version and needs some review of the EROEI values, but I hope it'll make it easier to understand the concept of EROEI/Net energy.
Of course no one is postulating to replace all of our energy sources with corn ethanol and I used the world total net energy just as an example to show that we need to think about EROEI (also changing with time) when discussing our energy future. I would love to see revised calculation that Luís de Sousa did for the 'Olduvai revisited 2008'.

This graph needs a review of the numbers and EROEI values and I will post a final version later on if anyone finds some errors that need to be changed.
Thanks

Fascinating essay, Robert, and I agree completely.

Oh, your prediction was safe and sure. The ethanol whores have arrived on cue. But ignore that for a moment and consider something else.

I ask you now, when you see this sort of behavior in front of your very eyes, even while we watch the energy crisis moving forward, does it not make you question your fellow human being a bit more deeply? Perhaps the problem is not simply mathematics and technology at all. Perhaps the problem is homo sapiens himself?

I assert that the problem facing humanity in this energy crisis has never been technology. The problem is what you are seeing from Practical/x, from kdolliso, from majorian, and from others of the same ilk. Human psychology is the problem, not technology.

If this is true, and if the behavior you are witnessing is common, what would be your personal guess as to the probability of success for homo sapiens mitigating this energy crisis without facing serious negative repercussions of some sort?

Quite honestly, I am a doomer, Robert, not because of technology at all. I am a doomer primarily because of people like Practical/x, majorian, and kdolliso. If the world were full of people such as yourself, Professor Goose, Nate, Stuart, and others who write here at TOD, I would be giddy beyond belief. But it's not. The world is mostly full of Practicals, marjorians, kdollisos, and even far worse. That's the problem and that problem will ensure that every possible public boondoggle that can be imagined will be attempted. And after all these boondoggles fail, just remember who to "thank"... if someone else has not "thanked" them first.

Unfortunately the Sugar Cane Ethanol Systems, which burn their Bagass for heat are a total disaster.

For every kilogram of organic matter taken off a farm another kilogram of organic matter has to be added. The alternative is chemical fertilizer, usually Gas or Oil based. The Sugarcane Ethanol industry will not survive longer than half way down the Peak-Oil graph. This may yet be even less than 20 years.

Pretty short term thinking to say the least.

I learned very early and painfully that you have to decide at the outset whether you are trying to make money or to make sense, as they are mutually exclusive.
- R. Buckminster Fuller GRUNCH of Giants, 1983

The concept of applying a scientific EROEI calculation to something like US corn ethanol and thinking that calculation is going to allow for better decision making is a little ridiculous and in the end not worth getting worked up about.

The US corn ethanol blender's subsidy was a way to get around NAFTA agricultural subsidy rules, it never had anything to do with EROEI calculations, and never will.

Maybe I have been wrong in criticizing EROEI for comparing energy apples and oranges. Lets take another case where things are alike in many ways and that energy in the form of body weight is one of the possible ways to determine which is superior.

Men and women. Men in general weigh more and therefore men when compared to women are superior. We can clearly show from statistics that men contain more energy than women. They are bigger and in general stronger and can do many things women can't do because of their strength. I therefore postulate that men are superior to women based on EROEI.

What is wrong with this? We know it is false. Society knows it is false and recognizes it with such things as separate sports for men and women. It also recognises that men and women have a critical difference and that of course is sex and accommodates it with different rest room facilities.

So what is the critical difference that makes women superior to men?
It is the sexual ability, with men's help, to be renewable by reproducing themselves. This is no small thing that can be given short shrift and dismissed as worthless as in the EROEI argument against ethanol.

The fact that ethanol is renewable outweighs gasoline's high EROEI number which may be valid if comparing gasoline with gasoline or a similar energy form such as oil. Once oil has done it's part in fertilizing the ethanol egg it is done. And someday it will die because it is finite and can not replace itself. Meanwhile ethanol can renew itself with another sperm donor and live again.

Might be a weak analogy, but perhaps fitting. Ethanol and gasoline can not be compared using EROEI because they are different. Even though men and women are similar in millions of ways, they are different in important aspects. These aspects obviously outweigh the similarities making comparing them as regards energy inputs and outputs false. EROEI does not apply to unlike and unlike even though they are very similar and look about the same and do the same work.

Why are you leaving solar energy input outside the equation (I know, because then you would always get a ratio of 1)? But bagasse is just solar energy lost in the system. You do not compute the energy used by the plant to grow.

My takeaway is that EROEI, while thoretically significant, in practice is useless at least until the calculation methodology is standardized by a competent and internationally recognized body.

The oft-cited Brazilian EROEI is really a cousin of EROEI. What is done to arrive at the 8 to 1 sugarcane EROEI is that they only count the fossil fuel inputs as energy. Boilers are powered by burning bagasse, but this energy input is not counted. (Also, electricity is sometimes exported, and credit is taken for this). For a true EROEI calculation, all energy inputs should be counted. So what we may see is that the EROEI for sugarcane is 2 to 1 (hypothetically) but since most inputs are not fossil-fuel based the EROEI based only on fossil-fuel inputs is 8 to 1.

Does any of this energy account for the labor of the manual workers who toil 12 hour days in the cane fields to make Brazilian ethanol? Food and water are the main inputs here, how much energy is that? Is it negligible? Is it a fairly large amount?

What if corn ethanol was produced by corn that was hand harvested and shucked by minimum wage workers instead of by combine? Would that improve the EROEI?

The case of Brazilian sugarcane ethanol deserves special mention. It is often quoted as having an EROEI of 8 to 1. I have even repeated that myself. But this is misleading, and I have to give credit to Nate for challenging me on this.

Unfortunately, he's wrong, and now so are you. The reason is:

Boilers are powered by burning bagasse, but this energy input is not counted.

Bagasse is not an input; it's a product.

Your model is:

• Invest 1 btu to get 11 btu of sugar cane.
• Burn 3 btu of sugar cane to get 8 btu of ethanol.
• 8 btu output / (1+3) btu consumed = 2:1 ratio

That is wrong, as we're interested on the return on energy invested, not on energy consumed. The correct calculation is:

• Invest 1 btu to get 8 btu of ethanol.
• 8 btu output / 1 btu input = 8:1 ratio

Consider what would happen if the amount of bagasse burned was different. Your model:

• Invest 1 btu to get 19 btu of sugar cane.
• Burn 11 btu of sugar cane to get 8 btu of ethanol.
• 8 btu output / (1+11) btu consumed = 2:3 ratio

Your model would say the process consumed energy, even though I could put in 1 btu and come out with 8 btu, which is a clear gain. The correct calculation - which depends on only inputs and outputs, and not what is done internally with non-output products of the process - correctly shows that there is no change in the energy return of the process. The only change is the efficiency with which the available energy is turned into ethanol.

If it helps, think of the same reasoning being applied to stocks:

• Invest $1 in a stock that rises to $19.
• Sell the stock for $8.

Is the correct calculation...

• $8 output / ($1 invested + $11 wasted) = 2:3 ratio = $4 loss

...or...

• $8 output / $1 invested = 8:1 ratio = $7 profit

Obviously the latter. The same is true for calculating energy return on energy invested: only the inputs and outputs matter, not the internal intermediate steps.