## An EROEI Review

Introduction

I can be a very persistent (some might say hard-headed) person. If someone doesn't understand something that I think is important - and readily understandable - I will often continue to explain it until I am sure they either understand it and won't admit it, or they are incapable of understanding it. Because the topic of EROEI continues to be misunderstood (especially by those in the camp of "the only thing that matters is economics"), I will once again try.

Nate Hagens and I have discussed this subject at length on a number of occasions. He has written extensively on it, and I don't pretend that this essay can hold a candle to his magnum opus - and in my opinion best ever EROEI essay written at TOD - A Net Energy Parable - Why is EROI Important? (There's your dopamine fix for today, Nate.) This is just a little review of why I think EROEI matters.

EROEI Basics

There are a couple of important EROEI equations. The first is that EROEI = Energy Output/Energy Input. In other words, if we have to spend 10 BTUs (Input) to extract and refine 100 BTUs of oil (Output), then the EROEI is 100 to 10, or 10 to 1. Digressing for a moment, I recently had a conversation with someone who suggested that this is completely different from finance, where \$105 returned on a \$100 investment is a 5% return, not 105%. As I explained, the situation is the same. EROEI is a ratio. If I divide the \$105 I get back from my \$100 investment, then I get an output/input ratio of 1.05, but my return on investment is 5%. Likewise, if I input 100 BTUs and output 200 BTUs, the EROEI is 2 to 1, but the rate of return on my energy investment is 100%.

The second important equation concerns the net energy; that is how much energy was left after the energy input is accounted for. This equation is Net Energy = Energy Output - Energy Input. In our previous example, the net energy is (100 BTUs produced - 10 BTUs input), or 90 BTUs.

A couple of points here. First, the break even for EROEI is 1.0. In that case, you have input just as much energy into the process as you got back out. In some cases, that may make economic sense. For instance, if you input coal BTUs but got back out ethanol or diesel BTUs, then you have converted the coal into something of greater value. This is a source of the "only economics matter" argument. But this misses the larger point: EROEI is going to have a huge impact on economics, because it shows that in order to maintain current net energy for society, energy production must accelerate as EROEI declines. It isn't that planners are looking to EROEI to make their decisions; it is that a declining EROEI can indicate what those decisions will inevitably be.

However, if you input one transportation fuel and got another transportation fuel as output - as is mostly the case with corn ethanol (natural gas, diesel, and gasoline in; ethanol out) - then you are really just spinning your wheels. In a case like this, it would make more sense - given all of the negative externalities - to use the inputs directly as a transportation fuel. Funny that the shills will suggest that CNG infrastructure is lacking; these same shills are screaming for E85 pumps. Somehow countries like Brazil and India have managed to build out an impressive CNG infrastructure - yet we are being asked to believe this is not practical in the U.S.

Net Energy can also be negative and yet still make economic sense. But an important point here is that society can't run for long on an EROEI of less than 1.0 or on a negative Net Energy. Doing so is equivalent to withdrawing money from a bank - at some point you have to make some deposits - or at least stop the withdrawals.

The EROEI of Brazilian Ethanol

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. 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.

That isn't to say that the 8 to 1 is an invalid measurement; just a different one. We need to bear that in mind when making comparisons. What is overlooked by touting the EROEI of 8 to 1 and skipping over the true EROEI is an evaluation of whether those other energy inputs could be better utilized. For instance, that bagasse that doesn't get counted could be used to make more electricity instead. Probably in the case of sugarcane, firing boilers is the best utilization. But the lesson from this digression is to be careful when people are touting very high EROEIs. They probably aren't really talking about EROEI.

Calculations

Now for some calculations that show the challenge of energy production if the EROEI of our energy sources continues to decline. In the early days of oil production, the EROEI was over 100. Now, it has declined to somewhere between 10 and 20. So let's look at the implications as the EROEI declines from 20. Here is what it takes to get 10 units of energy (gross, not net) at various EROEI values.

A 20 to 1 EROEI takes an investment of 0.5 energy units to get 10 out

At 10 to 1 it takes 1 energy unit to get 10 out

At 5 to 1 it takes 2 energy units to get 10 out

At 2 to 1 it takes 5 energy units to get 10 out

At 1.5 to 1 it takes 6.67 energy units to get 10 out

At 1.3 to 1 it takes 7.69 energy units to get 10 out

At 1 to 1 it takes 10 energy units to get 10 out

So, dropping from an EROEI of 20 to 1 down to 1.3 to 1 takes over 15 times the energy inputs (7.69/0.5) to output the same amount of energy.

Net Energy

But here is where many miss the plot. Look at the net energy.

At 20 to 1, an investment of 0.5 units got 10 back out. The net is 9.5 units.

At 1.3 to 1, it took an investment of 7.69 units to get 10 back out. The net is 2.31 units.

At 1 to 1, an investment of 10 units got 10 back out. The net is 0 units - all you have done is converted one energy form into another. (And of course at less than 1 to 1, you have actually lost usable energy during the process - clearly an unsustainable process).

If we wish to net 10 units, then at 20 to 1 we have to produce a total of 10.53 units (you are solving 2 equations here; EROEI = Out/In and Net = Out - In; For EROEI = 20, the solution is Out = 10.53 and In = 0.53). For an economy that requires 10 units of energy to run, we need an excess of 0.53 units to net that 10. (And if you want to pick nits or do the calculation yourself, 10.53 is rounded from 10.5263157894737).

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.

Running Faster to Stay in Place

Therein EROEI illustrates clearly the challenge we face. As EROEI declines, energy production must accelerate just to maintain the same net energy for society. At an EROEI of less than 2, the amount of energy required to net our current energy usage far exceeds even the most optimistic proposals for our production capacity. Others have concluded much the same: The status quo can't be maintained if EROEI continues to decline. But by understanding the implications of EROEI, we can see this coming, and perhaps(?) start to change the status quo.

Yet I say with confidence that some will comment and still not grasp this concept. If they did, they would understand why a falling EROEI is reason for concern - and that concern is why I can be persistent over explaining the implications.

Previous Essays on EROEI/EROI

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.

So what you are saying is that if you burn biomass A and B together in a power plant and use the electricity to power a BEV, then that could (depending on the efficiency of the plant, transmission and batteries) be more efficient than using the energy in biomass A to convert biomass B to ethanol and run the car on that? Interesting.

Yes, This is the ridiculous thing about the obsession with liquid fuels. An internal combustion engine with an optimistic efficiency of 30% has an EROEI of 0.30 whereas you could expects a BEV to be 0.8+. The whole thing is based on the continuation of ICE based transport which are the "installed base" creating inertia in the re-engineering of the system. The justification is "Range", evidently though 80%+ of trips are under 40k's we require ranges which match liquid fuel cars, this is clearly untrue.

There is some truth in the old joke "God managed to make the world in seven days because (s)he had no installed base"

There are some signs of sanity in the asylum though, I see VW have totally dismissed Hydrogen and are delaying their entry into the hybrid fad as long as possible, VW and Toyota must be licking their lips at their prospects in the US in the coming years

Neven MacEwan B.E. E&E

The whole thing is based on the continuation of ICE based transport which are the "installed base" creating inertia in the re-engineering of the system.

Which is silly, because the useful lifespan of a light-duty vehicle is ~17 years and 50% of the lifetime mileage is driven in the first 6 years.  Designing infrastructure with a 50-year lifespan to suit ephemeral vehicles is letting the tail wag the dog.

The justification is "Range", evidently though 80%+ of trips are under 40k's

The PHEV is the solution to that.

I see VW have totally dismissed Hydrogen and are delaying their entry into the hybrid fad as long as possible

Good and bad, respectively.  Hybrids are no fad; the PHEV is an evolutionary path to the pure BEV as battery technology improves and prices fall.

Well, the problem here is the boundary of the system. When you have a system and moving the boundaries you get different results for the same indicator referred to the same variable then it means that there is something wrong going on... In this case what is wrong is the indicator itself. EROEI is an easy indicator but should be used always the same way. In fact, it changes simply moving the boundary. Then this means you have to decide: using it as in the first case (arrows generated within the boundary and used in the processes within the boundary must remain in the boundary) or as in the second case (arrows must exit and then go back inside if they are meant to go in a process within the boundary).

If you assess a system using LCA, for example, you don't have these problems. Moving the boundary would generate the same results...

Nate, I'd be very interested in reading your paper when it is released.

I'm curious how you derived some of the figures you have in your example. I can't replicate what is often offered as energy balance of a (theoretical) cellulosic ethanol plant when tracking the mass balance of the plant.

Take 1 kg of switchgrass for example.

It's 42% cellulose, 31% hemicellulose, and 27% lignin (including 0.7% ash).

From the cellulose, assuming 100% recovery, the stoichiometric ethanol yield of 51%, and 75% fermentation efficiency of glucose, you get 0.16 kg (0.20 l) of ethanol, 0.21 kg of CO2, and 0.05 kg of other mass (additional bacteria body mass; dilute solids)

From the hemicellulose, assuming 100% recovery, and 50% fermentation efficiency of xylose, you get 0.08 kg (0.10 l) of ethanol, 0.15 kg of CO2 emission, and 0.08 kg of other mass.

The balance is 0.27 kg of lignin, at 21 MJ/kg energy content, or 5.7 MJ. Biorefinery direct energy requirement for cellulosic ethanol production is 28 MJ/l-output (EBAMM 1.1), or 8.2 MJ to produce the 0.30 liters from the 1 kg of switchgrass input.

My question is, how does this 5.7 MJ of lignin per kg of switchgrass input provide all the processing energy in the plant (including drying the lignin, which is in solution when separated) and generate enough electricity to export 1.9 - 5.4 MJ/l of electricity? (Range in Hammerschlag)

If you zero out the lignin "credit" in the biorefinery in the EBAMM model, the EROI drops to 0.88, including the 4.8 MJ/l "credit" for some undefined byproduct.

Anaerobic digesters use wet biomass to generate methane which can then be used by the biorefinery instead of natural gas(fossil methane). An Iowa engineer figured that a distillery's entire energy needs can be met by digesting the cellulose and lignin portions of the corn kernels.

The problem with ignoring the energy costs of the biomass can easily be seen when you are working with wood. (I have heard people in the cellulosic ethanol field say that they prefer wood to switchgrass, because it is much easier to transport and store.) If you use a huge amount of wood to power your process for converting wood to cellulosic ethanol, you will have a high return on the fossil fuel inputs, but you are likely to have a very expensive process, since wood has other uses.

Nate,

It is customary not to count the renewable energy input in such calculations. About 2000 times more energy in sunlight falls on a cane field than ever comes out as ethanol. So, roughly, EROEI=0.0005 if the renewable energy in is counted. It seems to me that you are beginning to venture in this direction with your modification. I suppose you could say that the bagasse is processed so it is no longer just sunshine, but then, how do you count the wind that dries it so that it can be burned? I think you are OK counting ethanol burned in a truck to bring the cane to the plant as an energy input, but I'm not sure that counting the biomass after squeezing it is right.

Chris

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.

Some good points, Rohar1.

Let me add a scenario. Let's take a situation where the world market is Saturated with Sugar (pretty much like the present.) BUT, Country A (Brazil, say) has hundreds of acres lying fallow which Could be used in Sugar Production.

Let's do something different. Let's SEPARATE the process of growing the sugarcane, EROEI-wise, from the process of making ethanol. In other words, let's assign the cane it's own btu number, and a number for the EROEI of producing the cane. And, yes, let's consider the Solar Energy as a freebie. Would this help?

All good real-world considerations.

It's also important to realize that one cannot simply chain together EROEI calculations in a purely mathematical way. If that were possible, one could end up with the following infinite progression:

1 unit energy -> process producing 1.5 EROEI -> 1.5 units energy

chain this together a few times and you would get:

1-> *1.5 -> 1.5-> * 1.5-> 2.25-> * 1.5-> 3.375 giving a total of EROEI of 3.375 (or however far you want to take the thought experiment)

Giving the impression that if you chain up a number of ethanol plants and consider the whole system, you get way better than 1.5 EROEI. What is wrong with this picture?

What wrong is that the equation utilizes ALL of the net energy from each step as input for the next iteration. Civilization, society, industry or a single organism trying to survive needs to access a portion of that net for other functions. That's why it makes a HUGE difference as we shift from 100:1 easy oil, when our industrial economy could utilize 99 barrels of oil to build stuff and bustle around like bees on ecstasy, to energy sources in the 10:1 range, where the non-energy producing part of the economy only gets 9 barrels to buzz around on for every 1 needed for re-investment in producing more. And that's why we won't be running an industrial economy (or probably any kind of civilization) on 1.3:1 ethanol, or any other low single digit EROEI source. Now some folks, like posters below who insist that \$ matters more than EROEI, or that EROEI is some kind of religion that we worship, may not agree, but to me, this is a simple concept that gets grossly misunderstood or more often just ignored. We're not talking about the efficiency of a system or a process, per se(so engine efficiency is not comparable to EROEI). We're talking about how many barrels of oil (or of ethanol, or any other energy SOURCE) it takes to get more, leaving the balance for other uses - like growing food, heating homes, and transporting people and stuff. Once it takes all - or even most - of the energy just to get more energy, that is, as EROEI approaches unity, industrial society is screwed. I'm not here arguing whether that's a good or bad thing, but it will be a big thing. Some also try to debunk EROEI by comparing it to the generation of electricity. But that is comparing the conversion of one form of energy that is a source (coal, for example) into another form of energy that is a carrier (electricity). The electricity is tremendously useful to us, yes, but electricity itself is never a source for humanity - it is always generated from something else. Ultimately, there are only two sources of energy for humans - the sun (fossil fuels, solar, wind, hydro) and nuclear decay. I'm not a physicist, or anything close to it, so perhaps there's really only one ultimate source, but that's beyond the practical point I'm (very windily, I know) trying to make. As for where to draw the boundary in analysis, I say apply KISS. Picture a broad plain, a tribe of humans, a barrel of oil. They want more. They invest that barrel into the infrastructure to extract more from the ground. The work that one barrel does produces ten more. They take one and repeat the process, and have 9 left over to party with. This goes on for some time. But then the source rock gets stingy. Now they only get 2 barrels for each one invested. Party slows down. Big chief says, my father rode a camel, I flew a jet, son, you can still drive a car, but your son, when that one barrel allows us to extract only one barrel, will again be riding a camel. OK, I give up. It's a simple concept, I suppose folks will either get it or they won't. But we'll all be living by its impact, as William Catton laid out clearly way back in '80 in "Overshoot: The Ecological Basis of Revolutionary Change." (Oh, and sorry, ET, I know you're not one who misses the point, I merely took the opportunity of your hypothetical scenario to launch into my little rant...)

What wrong is that the equation utilizes ALL of the net energy from each step as input for the next iteration.

But that is exactly the point of my post. If we theoretically take ALL the energy output in a multi-staged process and apply it once again to the same process, we get, theoretically, an infinitely increasing ER on a given EI for the entire process. Obviously this cannot be even remotely real even if the math works out.

The larger point is that reality checks are always a good idea. When I see EROEI figures for solar PV of 10:1 bandied about, and look at the actual price, I know the figures are bullshit. Same with wind power.

Not sure that's true, and panel photovoltaic competes with me and my concentrating photovoltaic, partly. Mostly panel photovoltaic competes with distribution in a financial sense.
Most of the cost of photovoltaic is labor cost. Your are paying for the Ford F150 to haul the roofer around. In China the roofer costs less and travels by tram. Does that mean that panel photovoltaic has a higher EROEI in China?

When I see EROEI figures for solar PV of 10:1 bandied about, and look at the actual price, I know the figures are bullshit. Same with wind power

We are on the same page ET.
My take on that situation is: Have the renewable-manufacturers utilize their own HOME MADE energy in all their necessary sub-processes (or as many as possible at least) and see where that bring them. Not far I’m afraid…

In the future when fossils are gone, we will be back to square-one and that is not a sophisticated square(!) I can see good old fashion windmills, various “easy” to make waterwheels some sort of sterling/steam-engine/generators and such driven by combustion
I have serious trouble to see modern WT-Nacelles and PV technologies made and maintained in that scenario, and by then their EROEI issues will be clear as the sun by midday.
In my mind we should develop “simple technologies” today, which are not focusing efficiency – BUT rather on simple functionality and easy to maintain demands (as good as it gets sort of thinking).

Let the Non-Engineer, also, expound a bit on "Civilization."

Successful ones tend to be made up to some degree by "Successful" people. Successful people tend to NOT be "Wasteful" people.

Will a Non-Wasteful Person ignore a fallow, but fertile, field as a source of energy just because it's a little harder to get energy out of than a barrel of "easy" oil? Even when the "easy" oil is getting harder?

I think that depends on what you mean by run the economy. Since oil is used at a practical efficiency of somewhere around a percent or so as long as we define it's use as that of personal transportation (for the most part) we have quite a ways to go in terms of smaller more efficient vehicles and to a less extent better drivetrain efficiency. If we define it as the transportation of people and tons of steel/plastic, then it's efficiency of use increases, but that's somewhat disingenuous since we could use even larger vehicles, say semis with 40,000lbs in the back, and see even higher efficiency of use because ICE efficiency tends to increase with load. What I'm saying is that we should look at efficiency from the point of view of consumption, not just efficiency for the sake of efficiency.

You wrote a hell of a lot of unneccesary words to get your (one line) point across.

"Once it takes all - or even most - of the energy just to get more energy, that is, as EROEI approaches unity, industrial society is screwed."

And THIS is the problem with the understanding of EROEI being propounded here.

We're NOT going to get down to unity. Not even close.

Wind power, wave power, hydro power, Solar power. Even growing vegetables.
All of these have EROEI of anywhere from the low single digits to the high twenties.
(Look at the footnotes on the original post).

Thus while it is true to say that we will have to produce MORE INFRASTRUCTURE and use a larger share of our economy to produce energy than we did before it is patently UNTRUE to say we are inexorably sliding towards an unproductive 1:1 situation.

There is a FLOOR under us and it's the lower limit of renewables.

Now taking this to it's LOGICAL CONCLUSION: Even if the return on energy invested is only 20% then that means you only have to build five wind turbines or wave generators or hydro plants or solar panels to get one FREE ONE each year.

Now by compound interest of EROEI that means that at 20% you double your installed base approximately every four years. If from that 20% you use 10% for other things than building your infrastructure you double your installed base every eight years.

So back to the point: We need to build INFRASTRUCTURE.

Even if the return on energy invested is only 20% then that means you only have to build five wind turbines or wave generators or hydro plants or solar panels to get one FREE ONE each year.

It also means that 80% of society's energy-production effort would be devoted just to obtaining more energy, and a mere 20% for the other things we need to do (like growing food).  If you can't re-invest all energy to increase your installed base, you're screwed.  On top of that, the source has to scale to nearly 5 times today's gross production for the same net.

Industrial society can't handle EROEI as low as 1.2.  I'll bet that anything less than 8 is going to cause plenty of pain.  Fortunately, most of our options are a lot better than that.

EP,
I agree with your point. But consider it a little more.
Even at 1.2, if they use half of the energy for other things (and we'll NEVER get that low) then it only takes 8 years to double the installed base, 16 years to quadruple the installed base etc.

Now go back and look at the actual EROEI numbers on the original post.
Wind, Solar etc are WAY better than 20%. And we STILL have a bunch of oil to get us kickstarted.

Even at 1.2...

... you have 80% of the effort of society devoted to obtaining more energy.

Not unlike the times when 80% of people worked on farms.

You don't quite grasp how enormous a dislocation that would be.  Industrial society needs more of a surplus than that.

EP,

I do understand the idea of using 1.2 I used it as an illustrative example because it's easier for people to understand 4 windmills gets you one free than it is to understand 320 windmills gets you 160.

I said "we'll NEVER get as low as that". If people just take the time to read the links at the bottom of the original poster's post (as I have) you'll see that the WORST of the renewables is nowhere near as bad as 1.2

Anyways, what's the matter EP? Have you become a doomer all of a sudden?

I do understand the idea of using 1.2 I used it as an illustrative example because it's easier for people to understand 4 windmills gets you one free

The problem is that the claimed EROEI for corn ethanol is greater than this, and it doesn't scale at all (neither does it include non-energy losses like topsoil).  Using that as an example implicitly approves one of our most disastrous "energy" policies.

Have you become a doomer all of a sudden?

Hardly.  Just reminding everybody that there are a lot more ways to screw up than to get it right.

not to be a doomer but:

1) i am uncertain how wide of boundaries those NREL EROI figures are - there is a good deal of infrastructure they may take for granted that is subsidized by oil

2) high EROI is great, but only part of the problem - we need high EROI that matches our current infrastructure. If we already had PHEV transport, rails, etc. then i would say that higher EROI solar would make oil a dinosaur. But clearly that is not the case. We need high energy gain consistent with what society is dependent on, OR high enough EROI to transition social infrastructure into a new era without too much pain

What's wrong with it?

Nothing, really. The only issue is that each cycle takes a full growing season, and it assumes that all of the production from the previous cycle is put back into the next cycle.

This is nice if you are bootstrapping a new infrastructure while society runs on some other source, but reality means you have to use some of the surplus outside the system that's normally defined when considering EROEI.

Reality therefore looks more like:
Ein*EROEI-Eext->Enext
or:
1.0*1.5-0.5->1.0

You are expanding the sytem the whole time. For oil, you are drilling more wells and building more refineries. For biofuels you are putting more fields under cultivation and building more distilleries. All the time you are not getting any net energy for other uses. Once you stop your expansion and start using energy elsewhere, you are back to your original EROEI. I think that if you think it through in this manner, you'll find that you never get more than the original EROEI even if you cease operations and take all the product from your last harvest for use elsewhere.

Chris

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.

Excellent list and spot-on. It takes a comment I was going to make and expands it quite a bit.

That comment was that while the "quality" of energy is frequently discussed, I haven't seen it described in a simple way. That could be useful; seems like up until now energy has been valued mainly by cost of extraction and processing, and not by it 'intrinsic worth' to hominids wishing to perform 'magic'.

And the term 'magic' is used by me here because that's sort of the ultimate standard: a substance with infinite energy that anyone could pick up and use with no investment and store & transport at zero cost, causing no harm to the biosphere. We don't have any such stuff, but clearly some energy carriers approach that ideal more closely than others do, and where they fall on that line would be useful to consider.

The listing is good and more complete than my top-of the-head one, which was:
energy density
ease/cost of storage at earth-surface temps and pressures
Moving it around: threshold costs, complexity costs, etc
what stuff can currently or in theory be done with it
level of complexity investment to utilize it (ie, chain saw vs. fission plant,)
Investment thresholds for obtaining and using the energy carrier from where it starts (ie, gathering firewood vs. deep offshore oil drilling)
toxicity to the biosystem, in extraction, processing, or from use
safety
reliability
etc

It'd be nice to be able to assign a "quality coefficient" to different sorts of energy, even if it wasn't perfect. Clearly, kerosene is closer to being "magic" than is burning cowpies, since you can fly a jet halfway around the world on it nonstop, etc.

This is the complement to EROEI which is needed....

Great post, and continuing kudos to Nate for his work as well, can't want to see the next batch of stuff.

The problem is that 'quality' as defined by our current socio-political system is not the 'quality' that would be long term desirable or sustainable. We should set aside EROI for a moment and determine what type of society we can achieve post cheap oil - what infrastructure looks like. What the ecosystems look like. etc. This will then change the definition of quality - though I expect liquid fuels will always be valuable. But if transport fuels take up 1/10 as much % of our fuel mix in 20 years than they do today, the definition of 'quality' will have changed.

Next determine how much energy gain we can expect, not for next year but for next 100 years. This would require an analysis of best uses for the remaining high quality fossil stocks in order to turn them into renewables that could support the type of infrastructure in #1

Then we use net energy analysis as an allocation tool of how to properly allocate our energy stocks and flows into productive society.

We're kind of going about it backwards now - assuming that 'quality' is given by current conditions, and then bickering about which fuels have the better EROI, quality adjusted. Its the fixed cost nature of our current system that is the bugaboo. The barriers to change are so large that we will keep seeking liquid fuels without noticing we are destroying our life support systems to procure them

(p.s. Rohar -that is a nice list - all important things - tho energy surplus (via EROEI) is a biggie. Many of those things are also not accounted for in our present market system either - so 'energy analysis' as we speak of it has to include ecology and externalities.)

nice website too - if you want to write a guest post on that SHPEGS project let me know

The problem is that 'quality' as defined by our current socio-political system is not the 'quality' that would be long term desirable or sustainable.

So true. I actually find the quality of undrilled oil & pristine environment higher than jet fuel, perhaps why I didn't work out long-term as a doodlebugger. My "quality" comment had only to do with one of the confounding factors of having a conversation about energy with present-day humans, which is often unavoidable. BTU's are a pretty gross metric.

Its the fixed cost nature of our current system that is the bugaboo. The barriers to change are so large that we will keep seeking liquid fuels without noticing we are destroying our life support systems to procure them.

Well said. We should probably be thinking more in terms of Planetary Choices Created / Planetary Choices Foreclosed (PCC/PCF ?) which would treat energy as a sub-category, and for that matter human activity as a sub-category. I'll try thinking up a way to sell that & get back to you....

Elsewhere in the comments H. T. Odum is mentioned, as are the concepts of eMergy and Lifecycle Assessment (LCA) as analysis tools. Essential to understanding energy (according to the wikipedia bit on eMergy) is the concept of transformity or quality of energy. Elsewhere this appears to be related to the concept of exergy [Gibbs].

EROEI seems a useful concept specifically when addressing the dropping productivity of oil or other liquid or coal production. But I think the energy quality issue needs to be incorporated to avoid the twisted explaining away of Brazilian sugarcane EROEI.

Also, it is critical where you draw the system boundary in determining net energy, as the poster about LCA mentioned. I want to add the concept of energy yield [Mollison, Holmgren] to the discussion, that is, the net energy out of a system when all the systems energy needs are met. This is not, on the surface, different from net energy, except that it explicitly identifies the boundary / scale of the system as being a key determining factor.

Odum [The Energy Basis of Man and Nature] states that not all BTUs are the same- some have the ability to do mechanical work. This may be what the "economic value" folks have in mind. Odum proposes a Fossil Fuel Equivalent (FFE) as a way of converting all types of energy, as measured by heat (BTUs, calories, etc.) into a common base quality energy.

1 FFE =:

• 10,000 uncollected solar radiation calories
• 2000 sunlight calories
• 20 gross plant product calories
• 2 collected wood calories
• 0.33 elevated water calories
• 0.25 electricity calories

These were written in 1976 so the conversions may be somewhat different today. But it clearly shows that the analysis of return and net energy needs to be broadened.

• Odum was a genius and I have learned a great deal from his work, and his students. But eMergy is something I just can't internalize-it complicates things even more.

The graphs I post do not twist EROEI of sugarcane at all - they just show that some energy is used to process it that could have a different use.
In the end, all we are trying to do here, with ecological economics, EROI, net energy etc. is to have more of a biphysical/ecological basis for our decisions. How we do that is of course important but I think we are still at the stage of convincing people it should be done.

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.

"When studies are done with renewable energy sources (particularly biomass, corn, vegetable oils, etc.) "

I'd be careful about equating "renewable" with biofuels. People often get confused about this, and forget that "renewable" includes wind, solar, geothermal, wave, etc, which have high E-ROI.

"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)?"

They exclude solar energy, just as the E-ROI of oil excludes the "free" BTU's in the oil. Otherwise, E-ROI could never be positive.

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.

My last blog (http://questioneverything.typepad.com/question_everything/2008/03/whats-... ) covered this topic in an attempt to show how net free energy should be used as a monetary standard, similar to the gold standard in purpose but physically relevant in practice.

On another note, I will remind readers that topics like net energy and ERoEI should be fundamental to energy systems design. To that end I am developing a Master's of Science in Energy Systems Engineering at the University of Washington Tacoma, Institute of Technology. We are developing relationships with the local utilities (city and regional) to focus on renewable energy sources, transport, and consumption issues. The Governor has recently signed a bill that will increase funding for energy and environment programs and this project is rising in the priority list. Oil at \$110/barrel hasn't hurt the attention factor either! In the near future we will be looking for qualified commentary (Nate take note), ideas and eventually faculty. If you have any interest in this project, please contact me at: gmobus AT u PERIOD washington PERIOD edu and I will be happy to send you a copy of the proposal.

Regards

George

"debt and credit can be created with no relationship to physical foundations."

Not really. Money (debt and credit) has to be in balance with actual goods and services. If it's not, you get inflation.

What the Fed is doing right now is attempting to ensure that we have enough money, to prevent deflation.

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?

As Jeff's questions illustrate, while EROI is a simple concept to grasp, it starts getting really tricky once you go past direct inputs and outputs and start trying to get a more comprehensive (and accurate) grasp by considering indirect inputs and outputs. It is tempting to conclude that these muddy the waters too much and to just exclude them, drawing the line at direct inputs and outputs. Unfortunately, there is a problem with that approach.

The indirect energy inputs might be quite significant for one energy resource, and quite insignificant for another, so ignoring these might result in misleading conclusions. For example, the EROI for stranded NG at the well might be quite high. Obviously, the energy required in transport infrastructure to "un-strand" that NG would be considerable, and would lower the EROI substantially. Ignoring these considerations opens the door to claims that the world has more abundant energy resources than it really does. After all, NG appears to be so abundant that we are just flaring it off! Without looking at the broader picture, we open ourselves to incorrect conclusions, wrong-headed public policies, and suboptimal investment decisions.

Unfortunately, trying to account for all of the imbedded energy inputs (especially) and outputs associated with the production of a particular energy resource can be a nightmare. We probably do need some standardized conventions and standards to simplify the whole thing. Otherwise, we will be talking past each other continually.

In any event, I think the most important take away is that the way oil and liquids production is portrayed is very misleading; we are in much worse shape than is portrayed by the various curves purporting to show where we are where we going. While we will never reach a perfect and completely agreed upon portrayal of net energy, we need to recognize that the net energy curves have or will have a much steeper descent than the gross energy curves.

This analysis also, by the way, implies that the importance of conservation is understated.

Jeff,

Excellent observations and questions. See my response to Nate above. These kinds of questions need attention and answers. In the end, energy is the currency of the economy. An accounting system does need to reflect the true costs of work done.

George

I seem to remember that Howard Odum addressed some of these issues. He also resorted to dollars as a proxy energy value for those 'infinite regression-type items' such as administrative energy costs and so on.

As I recall, EROEI and Net Energy were widely discussed back in the 1970's and early 1980's. That's when Herman Daly started ISEE, the International Society for Ecological Economics, which I joined soon after it started. Howard (T.) Odum and his brother, Eugene, both contributed quite a lot to the debates of the day. I still have copies of Howard's books, "The Energy Basis of Man and Nature" and "Environment, Power and Society". They were both quite good. Amazon Books shows some of Howard's titles as being available.

Those early efforts didn't carry on much into the 1980's, especially after Ronnie RayGun became President. Then too, the Saudis' flooded the market with oil in 1986 and the country (the World?) went back to Happy Motoring/BAU. We burnt up all that oil, so now we get to be slaves to OPEC! I guess that's our reward for our collective short sightedness.

E. Swanson

Hi Jeff,

On the market price technique, I think it makes a very good sanity check to know if the EROI is reasonable. For instance if solar PV generated electricity is much more expensive than wind generated, then it is unlikely to be higher EROI.

But the price technique is going to suffer from shortage driven spikes or taxation issues. NG could be produced at an energy loss if the tax incentives are good. Interest payments are a form of taxation on an energy source that penalizes capital intensive sources and biases the price. Royalty payments have the same issue.

"On the market price technique, I think it makes a very good sanity check to know if the EROI is reasonable. For instance if solar PV generated electricity is much more expensive than wind generated, then it is unlikely to be higher EROI. "

Not really. PV has much higher profit margins than wind (precisely because of the kind of "shortage driven spike" that you mention), and much more expensive labor. This is, in fact, an illustration of why E-ROI is different from \$-ROI. Heck, if we could equate the two, we wouldn't need E-ROI.

While I agree that \$ROI is different then EROEI, I don't think either of your examples supports the assertion that market price isn't a valuable tool for comparative EROEI between energy sources. The "more expensive labor" that you propose demonstrates the greater embodied energy required to bring this more expensive worker up to the level needed. Getting an engineering degree, for example, represents a lot of embodied energy. Second, I think your theory of "shortage-driven spike" is wrong: when I ran my own numbers on PV using market price as a proxy for EROEI in 2004, the numbers work out essentially the same as they do now in 2008. If a market isn't capable of spinning up production in 4 years to meet a "shortage-driven spike," then the reality is that there is something else (such as poor EROEI) that is actually constraining production.

"Getting an engineering degree, for example, represents a lot of embodied energy."

I don't understand how we can equate metabolic energy expended on knowledge work, and extrasomatic energy. A college campus doesn't consume much energy beyond environmental stuff: lighting, HVAC. I just don't get equating professional training with industrial process heat.

"when I ran my own numbers on PV using market price as a proxy for EROEI in 2004, the numbers work out essentially the same as they do now in 2008."

Sure. Costs have dropped dramatically, but prices haven't budged.

"If a market isn't capable of spinning up production in 4 years to meet a "shortage-driven spike," "

It has raised production. In fact, production has at least tripled. The problem is, demand has risen even faster!

A university consumes a huge amount of energy. In a solar society it would all have to be gleaned as "surplus" from agriculture. Simply supporting the "scholar caste" requires a large amount of emergy. Information is among the most emergy intensive items. Unfortunately, the marketing department of the typical multi-national corporation is right there with the university. The best exposition I've run across is in Hornborg, "The Machine".

cfm in Gray, ME

"A university consumes a huge amount of energy"

In what form?? I see the basics of residential living, and offices: food, lighting, HVAC, computers. That's not huge.

"In a solar society it would all have to be gleaned as "surplus" from agriculture."

????

Not if you use solar in the form of CSP & PV, wind, nuclear, wave, geothermal, etc.

"Simply supporting the "scholar caste" requires a large amount of emergy."

Again, how do we equate metabolic labor energy with estrasomatic energy (heat, electricity, propulsion from FF, nuclear, solar, etc)??

The shortage is in refined silicon. In the past the solar industry was using scrap from the electronic industry but now it is starting to get its own dedicated supply. That has meant building factories. A number of panel fabrication plants are not running at full capacity because they still can't get enough silicon. This is one reason why CdTe is doing so well even though it is less efficient. I think if you look at the price for that and figure half or more is going into expanding capacity you'll come up with a different conclusion.

Chris

When I worked at a wafer fab, wafers for chips were a hundred bucks and reject wafers for solar cells were one buck. That was fifteen years ago so prices have changed.
All the solar power subsidies have done is increase the price for reject wafers. It's not a subsidy to the solar power industry, it's a subsidy to the electronics industry.
There is one good point to the solar energy boondoggle. We are unburdening the power distribution network during hot, sunny, clear days. This is when they need it the most. Solar panels as energy don't pay off. Solar panels as network supplements have more than paid for themselves by reducing the burden that leads to blackouts.

Another good thing is that it should be at an EROEI of 30 next year: http://www.nrel.gov/docs/fy05osti/37322.pdf
That is a little higher than for oil and gas. The development of thin film solar is pushing silicon to be come more efficient as well: http://pesn.com/2007/05/02/9500469_RSI_Silicon_wins_MIT_contest/
Thus, while a small quantity of panels were maufactured with too much silicon using scrap, The bulk of the panels will be manufactured under very favorable circumstances and won't need subsidies. Perhaps it is time to end oil and gas subsidies?

Chris

Ah, thanks for digging up that NREL document.  The most recent version I'd seen had all references from 2000 or earlier.

Interesting that the old predictions have mostly panned out.  This ought to quiet a lot of nay-sayers.

I think some of the old numbers were speced for 300 mph winds or so. Once you have to insure a utility installation, actual risks get weighed and you go with something less than the worst case. With rooftop, it does not make sense to build the panels any stronger than the roof because if the roof goes, so do the panels anyway. I would guess that that is the main change, together with frameless panels, in the balance of system numbers. I'm guessing we'll be seeing EROEI=50 in the Southwest by 2013 or so as the 40% efficient silicon starts to roll out.

Chris

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.

Well, that settles it; we'll just use oil.

Oh, . . . wait a minute . . haven't a lot of people on this blog been saying that oil is going to start running out, soon?

You know, one point in the favor of that corn field is that there's no reason to think it won't keep producing until the next glaciation gets here.

You know, one point in the favor of that corn field is that there's no reason to think it won't keep producing until the next glaciation gets here.

Actually, there are plenty of reasons. Clearly you are not a farmer, and appear not to have understood the EROEI message either.

In order to grow, plants need excess sunlight, sufficient warmth, stable climate, unpolluted air, unpolluted water, N, P, K, lack of predation, lack of disease, sufficient excess energy to plant, harvest the crop and deliver to market etc. Any one of these can be the Liebig minimum that brings the EROEI <1.

I thought that westexas' ELM concept was relatively simple but almost every day now I realise 'plain vanilla' ELM massively understates reality for any country expecting to import oil. EROEI even for conventional oil (as more and more comes from expensive production) has massive implications for the 'net energy' of the 'net exports'.

I don't know, Xeroid; did you ever carry a gallon jar, wrapped in a burlap bag, full of water out to your father as he was plowing behind a pair of horses?

You do realize that we have corn fields in Pennsylvania that have been producing corn for 500 years, don't you?

My grandfather yes, his farming methods were more or less sustainable. He would be truly amazed at modern tractors with several hundred horse power.

Unfortunately the type of industrial agriculture now practiced generally doesn't use horses or recycled organic manures.

Current agricultural practices are unsustainable and can't function forever. Inorganic phosporus, just for one example other than oil, will soon become a limiting factor in the yield of any crop anywhere in the world.

Most civilisations fail eventually because their agricultural system fails - since the last ice age some 26 or so civilisations have come and gone, ours is just the latest.

other than losing topsoil, depleting water resources, increasing costs of inputs like fertilizer and pesticides, killing the oceans and rivers with runoff, using food for fuel when there are hungry people in the world, causing inflation of food costs domestically

yeah, other than those, no reason to think we can't just keep producing ethanol that does not contain as much energy per gallon as gasoline...and may be barely positive in EROI

yay government subsidies!

"haven't a lot of people on this blog been saying that oil is going to start running out, soon?"

No. Nobody has said that. Everyone will agree that oil & gas will be the fuel for the next decade(s). And it never "runs out". But there is a shift going on in globalist power: from the West and North to the East & South. Less and less will be used in the WnN, more in the SnE.

You know, one point in the favor of that corn field is that there's no reason to think it won't keep producing until the next glaciation gets here.

How's that White Paper coming?

Because I look forward to your justification of the above quoted statement.

Maybe I justify it by the fact that, due to the increasing use of no-till farming - that's almost 80% of corn land, now - we are INCREASING TOPSOIL in many parts of the Midwest.

No till still uses fertilizer, pesticides, energy to plant and harvest and mow.

we are INCREASING TOPSOIL in many parts of the Midwest.

How many acres fall under that statement? And how many acres have still-depleting topsoil? And how depleted are they?

My wild guess is there are 1000 acres still depleting for every acre where no-till methods are increasing topsoil, that the topsoil in the latter is being increased by a generous millimeter per year, and that the average soil depletion is several inches...but hey, don't let reality stand in the way of your boundless optimism.

memmel, I agree that time is the missing ingredient in these calculations, though I would phrase it a bit differently. Robert hints at the issue in his article:

EROEI is going to have a huge impact on economics, because it shows that in order to maintain current net energy for society, energy production must accelerate as EROEI declines.

When you try to quantify that acceleration impact in relation to actual economic measures, time naturally enters.

Robert's definition of EROEI is missing a critical piece - this is what it should be: EROEI(process, t) = Energy Output/Energy Input for a given process in time t and comparing EROEI only makes sense when you normalize to the same time interval t.

But the problem is there are two different energy investment time-scales in most processes: the capital investment phase (the energy that goes into building a nuclear power plant, say, or exploring and drilling an oil well, or preparing a field the first time for agricultural use), and the production phase (energy that goes into growing and harvesting bio-fuels, energy that is used in running the oil wells and transporting the fuel to market, the energy cost of mining uranium, etc). The time-scale for capital investment is on the order of decades, while that for production is typically months.

What that means is, a given EROEI that agglomerates both components of energy investment doesn't tell you, economically, how fast you can ramp things up. If the capital investments are already made and you just have to ramp up the production side of things, then you can do that quickly with relatively little input energy. But if the capital investments still need to be made, that's going to be a huge up-front energy input: where's that going to come from? Obviously you have to pull it out of current production.

So the time issue is critical, and missing from the discussion here, to make it relevant to economic and societal impact.

Thanks thats what I'm trying to say. On the oil side you have photons harvested over thousands of years vs in one year. This buys you a lot of "time" if you will in the EROI equation.
As you state once you start adding in EROI/unit time then oil blows away anything else by a huge margin. This means to me at least that our current EROI calculation are probably very optimistic since including times seems to indicate that oil is like 1000:1 or more EROI/t vs corn.

Again this makes sense since pre oil economies generally only grew by expanding the land area under control and at that grew at a fraction of the rate that oil based economies expanded.

So your pretty sure the real answer is probably 1000:1 for a oil based economy vs alternative energies its just a matter of expressing it correctly. So the answer to the EROI equation is known from the past. I don't expect technology to have a big impact since the limit is photon harvested per unit time and this is basically a constant. Only nuclear energy offers returns comparable to oil.

And at least for our current lifestyles its not pretty. I'm a huge fan of renewable and don't believe we should use nuclear in a wasteful manner but at least to me any chance of maintaining a lifestyle even remotely like we have today is probably impossible. I'm not saying that we all live in abject poverty arguably the Romans had a better life in many respects vs modern man but it was quite different.

One more illustration of how time enters in. Suppose you have a process (like biofuel production) that has energy input E_IN at the start, and then after time 'T' produces E_OUT at the end. For a given output energy production rate (r barrels of oil equivalent per day, say), the total energy needed to be produced over time 'T' would be the product of T and r, i.e. E_OUT = T * r.

If E_OUT = EROEI * E_IN, then the input energy accumulated over the production period before it can be replaced by some of the output is E_IN = T*r/EROEI. You could think of T/EROEI as the length of time on average before the system reaches breakeven, though the full time T is needed to produce the output in this simple model.

Now, suppose we're plowing all our output energy into a feedback loop to grow this particular form of energy supply. All sources of economic growth are fundamentally based on loops of this sort. From an initial start at time t=0 with an initial supply of energy E_IN(0), then at time T we have E_IN(T) = EROEI*E_IN(0), at 2 T we have E_IN(2T) = EROEI^2*E_IN(0), E_IN(3T) = EROEI^3*E_IN(0), etc.

I.e. we have exponential growth E_IN(t) = E_IN(0) * exp(a t), where a = ln(EROEI)/T

Two processes with the same EROEI but different production periods T will have different realizable growth rates, with the shorter period process able to grow faster. And note that even having a very high EROEI does not make a very slow process economically better than a faster process with relatively low EROEI.

It's this limiting growth rate, I believe, that is the more important term, rather than any raw EROEI number.

This is excellent.

I also believe we need to add in the construction time. That being the time from when an new unit of energy production begins to draw energy out of the economy until it starts generating power. Add that to the time from first power generation until energy payback is reached. Then you have the maximum growth rate without going net energy negative.

Right and its obvious that cheap oil blows the doors of renewable energy sources using the above concepts. Its orders of magnitude type differences.

Another way to look at it is that everyone using renewable energy would need ten acres of prime farmland to support their lifestyle and worse somehow the crops need to be harvested with minimal human input. Considering all the issues you need about 40 acres of "real" land to accomplish the task. Its no wonder that 40 acres was chosen for US homesteading since it represented and amount that allowed a person to be "wealthy".

Also it makes sense that someone farming for profit and support a family probably needs 300-1000 acres to really make money and support a non-farming population. So the base production/population distribution levels using biofuels are probably about the same as the 1800's when we reached peak biofuel usage in the US or in the 1700's for Europe. I just don't see why these numbers have changed much. So this 40 acre min biofuel requirement seems to be inline with oil giving close to a 1000 fold boost vs biofuels.

This to me says that the current EROI calculations are very optimistic since they leave out time.

I'm a bit surprised that more people don't look at the energy levels in pre-oil based society since it seems to make it clear that no way and hell are we going to maintain our current society under those energy constraints.

Another thing I think EROEI leaves out is the "quality" of the incoming energy. Having some process consuming large quantities of low-grade energy (waste heat) isn't nearly as bad as having the process consume high-grade energy.

If I have to invest 500BTU of corn to get 100BTU of ethanol, it looks bad, but had I invested even 50 BTU of electricity to get the 100BTU of ethanol, its worse.

Maybe it would help if we expressed EROEI as a percentage when speaking to financial/managerial/executive types, like bankers do money. They already understand the concept of rate of return on investments.

The concept of EROEI as a ratio apparently is confusing to them.

However, we have a quirk in our "currency" - not all BTU is valued equally - we have cheap BTU (sunlight, waste heat) and expensive BTU (electricity, petrol) - with petrol being proven a finite supply.

I can understand Robert's frustration with dealing with non-engineers, as I had trouble communicating with those whose expertise was people skills, not real-world physical phenomena. My frustration in dealing with them led to my early retirement, which was just as good as my blood pressure was taking the hit.

As the quote on the top of my page reminds me:
“It's difficult to get a man to understand something if his salary depends on him not understanding it.”
—Upton Sinclair

but had I invested even 50 BTU of electricity to get the 100 BTU of ethanol, its worse.

Depends again on the hows and purpose.

You can't drink electricity.....

As I recall, it was 160 acres. 40 for woodlot, 40 for hay, 40 for pasture, 40 for cash crops.

"..no way and hell are we going to maintain our current society under those energy constraints."

Very well put. Keep 'm coming, m

I think you're on the right track with making comparisons over a set time interval, but I feel like using just time is too specific - it doesn't account for capital that may be tied up in the process. For example, a given farming technique might require minimal labor (time), but tie up large amounts of land, which is limited. Maybe instead of standardizing for time intervals, you want to standardize for opportunity cost?

I'd say that the opportunity cost type issue is a sort of output of EROI calculations coupled with capitol investment. So I don't think its used in the EROI calculation itself.

Maybe its a constraint ? For example one solution is for everyone to have their own personal nuclear reactor, large window mill or large pv array but our society simply can't afford it.

So I think opportunity costs type calculations work in tandem with EROI.

The problem I see while reading about EROI is that neither time nor capitol requirements (opportunity cost) are considered in a consistent way(I believe this has been the gist of your argument, yes? That time needs to be considered in tandem with EROI in order to make meaningful comparisons?). Perhaps these three factors (EROI, time, capitol) could be combined in a mathematically rigorous fashion into a sort of Index of Usefulness? If the relationship were made explicit there would be less room for hidden assumptions and useless argument.

Just an observation/musings:

Biological processes exhibit exponential growth -oil is a result of a biological process.

Renewables are a result of a man made factory approach -at best production line.

An ideal energy creation process / source would use some of the energy captured to produce more energy capture systems or devices -i.e. it would be self-replicating as well as providing useful energy. The time variable for replication would probably depend on the fraction of usable energy exported vs the replication energy usage; faster replication would mean less energy output per generation but greater numbers in a given time.

OK, I'm not sure where I'm going with this now but a concrete example might be that a PV production line and all its inputs would be created and powered by PV generated electricity...

Nick.

Human economies exhibit exponential growth too. Look at any growing market - look at the PV industry itself, or wind. Exponential until it reaches natural limits of course - the usual "S" curve.

And fundamentally, the reason for the exponential growth is the same - feedback loops, where we still need humans in the chain. But economics isn't autonomous and independent of human control just yet!

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 numbers are a little difficult to come by, but the work of Cleveland (the man, not the city) estimated a 3.5% annual decline in EROEI for oil.

For a rough overview, if you took 1930 as a starting date and EROEI of 100:1 to start, and then constructed a simple table to calculate the changing EROEI year by year at 3.5%, the result is that in 2060 you fall below 1:1, at which point for all practical purposes the oil industry ceases.

Hypothetically, were total oil production to remain at current levels all that time, it would not matter because the oil produced in 2060 would all go to discover, drill, pump, transport, refine, etc., and none would be left for our use otherwise. This is hardly an exact picture because it assumes that all the cost (EI) is incurred in the same year as the return (ER), which is not the case, but it hopefully hits home the idea that deteriorating EROEI is far more controlling of our future than is peak oil itself.

As you note, in the early years of this change in EROEI curve the move is relatively flat, but as we progress down the curve the year to year change becomes steeper and steeper. It is not a straight line. If you additionally construct a curve factoring in the decline of oil production at a modest decline rate starting in 2011, as an arbitrary date, the curve for the combination of the two still gets you to 1:1 in 2060, but the drop off is even steeper after 2011 than it would have been for EROEI alone. If you are looking at the Hubbard curve alone to give you a picture of the future, you are looking at the wrong curve.

We are very late in the game. I seriously doubt that even if there were a viable solution that there are sufficient energy and other resources to implement a conversion even at today's EROEI for oil; each year we don't find solutions, it becomes even less possible to implement them because of deteriorating EROEI for oil.

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.

We have to draw the line somewhere: What kinds of energy counts as invested [this is the hard one], and what kind of energy counts as returned [obviously only usable energy].

Because otherwise EROEI is, as you say, completely pointless since it will always be 1.

I guess it is not obvious, but EROEI is concerned with conversion of unusable energy into usable energy. A barrel of oil underground is not usable, whereas a barrel at the surface is. It's not a closed system. "Investing" means we use some of our usable energy to bring unusable energy into the pool of unusable energy. The unusable energy does not count as investment.

The boundaries and definitions may seem unclear, but EROEI is a consistent and logical formulation.

EROEI should not be confused with energy efficiency in a closed system, which will always be < 1.

I agree, it makes sense not to count the bagasse if the question is whether we want to evaluate the sustainability of sugarcane ethanol as an energy source. Any meaningful calculation of EROEI must involve a "free" sources of energy. The essential question is how much energy is necessary to harvest that energy and hence how much net energy is left to run your civilization. To consider whether a particular "sustainable" energy source is in fact sustainable is of course complicated by whether or not we can transition to it (e.g. from using fossil fuels as an input) to not using fossil fuels. I emphasize that this is a transition process; we will not be able to point at any current sustainable method because they all use materials, labor, etc that currently depend on FF.

Very spotty connection in India right now, so I will try to knock out a few very brief replies.

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

You didn't count the solar input in the case of bagasse either. All you counted was the bagasse that was burned. In the case of oil, you counted the portion of oil that was burned. In other words, in neither case do you count the solar energy; just the embedded solar energy that got consumed in the process.

I hope that's clear now. This is an apples to apples comparison.

I guess the question, then, is: Would we grow sugar cane just to get the bagasse to convert into electricity? If the answer is no, then bagasse is a "freebie."

My hunch is that no one would grow "bagasse" if there wasn't a co-product - ethanol, or sugar.

If you actually followed the argument here, you would realize that nothing is a "freebie."

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

Well, nerd, that makes at least two of us. It happens that I am working night and day on solar thermal for deserts, and just between you and me, making a hell of a lot of progress, real fast. Fun, too.

I live in a local pit of gloom-- rain and fog out the window just now, but that HVDC will light up my life with desert sunlight once removed, and I can even quit using that plie of wood that is presently heating my house, spouse, water, and baby chicks.

Trouble is, as being widely noted, if us naked apes get too much energy, we are gonna ruin this planet for sure, so maybe for the good of all I had better just go back to the wood stove and quit playing with all that ever so fascinating solar hardware.

There's always that auto trans for bikes- almost guaranteed harmless--I think..

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.

This issue is cost, not whether or not CSP and a global HVDC grid are technically possible. It is technically possible to remove CO2 from the atmosphere and chemically combine it with hydrogen produced electrolytically from renewable resources to produce hydrocarbon fuels. That does not mean that such a process can support the same ton-miles of transportation as are currently supported by fossil fuels.

Roger,

IMO there is sufficient ground to expect that the cost for CST generated electricity will become competitive with new fossil-fuel powered plants (at today's fuel prices) fairly soon, and that after that the cost of CST will continue to decline. To quote Vinod Khosla "At 1 GW scale plants we believe these will start to be competitive with coal power plants in the US in the next few years even without carbon sequestration." and Vinod is putting his money where his mouth is.

Mike

Homo Semi sapiens

Mike,

I am aware of Vinod's statements, and I hope he is right. However, Solel ,which runs the CSP plants in the Mojave desert, has announced plans for a new 150MW CSP installation in Spain at a cost of \$7000/kW, and the Spanish government has guaranteed a price of \$0.31/kWh. Maybe Ausra's linear fresnel technology will beat the pants off Solel, but I will reserve belief on this matter until they start delivering large scale plants at the expected costs. There is also the small matter of the hemispheric super grid which will be required if CSP is to supply reliable year round power.

"at a cost of \$7000/kW, and the Spanish government has guaranteed a price of \$0.31/kWh"

Is that adjusted for Purchasing Power Parity? IOW, is that a straight currency conversion (which would mean that it's too high)?

"There is also the small matter of the hemispheric super grid which will be required if CSP is to supply reliable year round power."

That's only if you were to depend on 100% solar, which no one is really proposing, as a practical matter. Stuart's recent analysis of such a grid was intended to address a worst case scenario.

The numbers (quoted directly in \$U.S.) come from this announcement published in November of 2006 when the U.S. dollar was stronger than it is today. How are you planning to compensate for the winter/summer solar variation in the long term if not via a super grid? I was responding to claims of eventual cornucopian supplies of cheap solar energy and not to proposals for short to intermediate term provision of peaking power in the Southwest and California.

The subsidy is € 0.21/kWh, which is really equivalent to \$.21, not the \$.31 you get with the standard currency conversion.

http://www.thegreenpowergroup.org/pdf/renewable_policy_Spain.pdf

You have to adjust for purchasing power & currency conversions in these things. This seems to be a chronic, enormous blindpot for TOD, especially when it comes to evaluating the effect of oil pricing on supply - oil suppliers really don't think in terms of dollars so much.

" How are you planning to compensate for the winter/summer solar variation in the long term if not via a super grid? "

Again, it's not sensible to try to power the grid 100% with solar. Wind is stronger in winter, and at night - it's a perfect synergy. Add nuclear, and a small amount of biomass for backup (1-2 weeks per years), some demand management (including a lot of PHEV/EV's charging when needed, and some V2G), a fair amount of long distance transmission (but not a worldwide super-grid), a modest amount of pumped storage and you're good to go.

I am well aware of the various possible energy storage technologies and load management techniques. What I am not aware of is a detailed analysis of the costs of putting together an integrated system which is capable of providing 365 days/year, 24 hour/day electrical services similar to that provided by today's predominantly fossil fuel system. Apparent Stuart is not aware of such an analysis either since in his essay Powering Civilization to 2050 he writes:

I have not been able to construct a believable story about how current electric storage technology can scale to the required magnitude in a timely way, and thus this approach, as far as I can see at present, faces a critical bottleneck.

Since you claim that we are 'good to go' with respect to intermittancy, please present your detailed analysis of the costs of delivering reliable grid power by the scheme you have outlined above.

"I am not aware of is a detailed analysis of the costs of putting together an integrated system which is capable of providing 365 days/year, 24 hour/day electrical services similar to that provided by today's predominantly fossil fuel system. Apparent Stuart is not aware of such an analysis either "

Well, no. No serious professional organization is going to tackle this, because it isn't needed for many decades out. At the moment ISO's are satisfied with projections that (for instance) kwh market share for wind can be up to 10-20%, depending on area, with current grid/technology, and see no need for further analysis when higher market shares are somewhat distant. French nuclear has demonstrated that nuclear can provide roughly 75% of a grid's power (it could provide 100%, but again, it would be sub-optimal cost-wise to handle peaks).

"I have not been able to construct a believable story about how current electric storage technology can scale to the required magnitude in a timely way"

Sure. He appears to have been addressing a common notion, that the only solution to intermittency is storage. This is similar philosophically to the approach he took to the problem of solar intermittency, in which he analyzed just 1 solution (long-distance transmission aka geographical dispersion), taken to an extreme(a world-girdling grid), in order to deal with a worst case scenario. No sensible real-world planning scenario would assume one solution, just as it wouldn't assume just one source of generation (such as 100% from just nuclear, or just solar, or wind, etc).

Variance isn't as hard to deal with as some imagine: demand now has enormous variance, with which the grid deals successfully, and generation sources have their own variance (even nuclear), with which the grid must deal. As things scale up, the ratio of variance to mean power falls quickly. For instance, a single wind turbine may go to 100% name-plate power, but as a practical matter a wind farm won't go above 85% (meaning, if you decided to throw away that peak power, you wouldn't raise costs noticeably). Wind and solar are negatively correlated, both diurnally and seasonally. Solar is very nicely correlated with demand (with the exception of a small late-afternoon offset, largely due to artificially flat residential rate structures).

I would project an optimal solution as roughly 25% nuclear, wind & solar each, with the balance from hydro, wave, geothermal, and roughly 10% gasified biomass. Load balancing would come from geographical dispersion, source synergies, biomass peak generation for prolonged but uncommon outages, and roughly 50% of demand from interruptible/modulatable sources (with EV/PHEV's being the largest single source, at very roughly 20% of total demand), V2G and some storage. I would estimate a system cost about 25% higher than FF's.

Alan Drake has presented his own scenario. Stuart presented his, which was feasible if expensive. Please note that costs and optimal solutions will change a great deal over the next few decades, and so such projections are really only useful to reassure ourselves that our future is liveable, not for anything practical.

An ideal analysis would require quite a bit of time and data to simulate the dynamics in detail. An intermediate analysis might involve the variance profiles for every source and load, including diurnal, weekly and seasonal variance.

This is the kind of thing I do for a living, and unfortunately, my work is calling - I'm impressed that people like Stuart and Robert can spend their free time to do really detailed analyses for free, but I can't, sadly - I can only hope to address the high points. I'll try to add more later, but if you have more specific objections, I'd be happy to address them.

Thanks for the detail response. Your write:

Variance isn't as hard to deal with as some imagine: demand now has enormous variance, with which the grid deals successfully, and generation sources have their own variance (even nuclear), with which the grid must deal.

Variance is not hard to deal with when the majority of generation is powered by stored chemical energy which can sit around for indefinite periods and be then be used at whatever time of the day or time of the year that we please. Citing the current success of the the grid in dealing with load variance as evidence that dealing with variance will not be all that difficult when the contribution of chemical potential energy has been reduced to 10% of the total begs the question which I am asking.

Well, no. No serious professional organization is going to tackle this, because it isn't needed for many decades out.

Given the natural gas supply situation on this continent and given the fact that some analysts are now saying that coal supplies may peak in less than thirty years, I think that your claim that there are 'many decades' of elbow room is questionable. I think in particular that a long distance power transmission network needs substantial forethought and planning. You claim that the need for such transmission will be 'moderate', but without a detailed model how can we know what the requirements really are? Pumped storage will have high up front capital costs and will need advanced planning. Even if real cost estimates cannot be made we could at least be mapping the solar and wind resources and seeing how well they really do complement each other on a regional basis, and estimate how much energy storage and how much long distance transmission will be needed. I am not saying that this is your job, but it ought to be somebody's job today and not twenty years from today. Until I seem some numbers related to how much storage and how much long distance transmission will really be needed I do not have any confidence that your estimate of 25% greater costs than FF has any basis in reality.

I have to agree with Nick: any projection of future grid power architecture is only useful as a thought experiment and a rough feasibility assessment. The more detailed such a study would be at this point, the more irrelevant it would be once the grid is built up. After all, it's not like we have some grand top-down oversight and planning in this area (I wish we did!); it's completely left up to capitalism to solve these issues, and in a highly local way, relying on the individual decisions of hundreds (?) of ISOs and their investors and customers.

In my view, a plausible solution would involve just about everything you can name, esp. say 20 years out from now. I assume we'll have some functional utility-scale marine generation systems by then, along with "universal" or "enhanced" geothermal power everywhere (not just in thermal vent zones). I assume that wind will continue to grow by around 20% per year. In time--and I'll grant that it may take quite a long time--I expect appropriate renewables to assume the baseload generation role now primarily served by nuclear & coal.

Add to this CSP systems with their own thermal storage, which is already a commercial reality and set to increase as aggressive investors are jumping in. Then add a little pumped storage capacity everywhere geography permits.

At the non-utility scale, I anticipate better storage solutions, be they some sort of battery, or thermal storage, or my personal favorite, flywheel technology. I don't see any reason why homes & businesses could not store, say, 12 hours' worth of power. Throw VTG into the mix, and we might have a very significant buffering capacity.

Add to that residential solar PV to the degree that Japan has done it. Then add ubiquitous micro-wind turbines, even the little vertical axis rooftop units.

Then add in your smart grid technology, demand response systems, smart meters, and conservation incentives.

All together, I think it's at least technically possible that massively distributed grid power production and storage could do the job, without needing all that much in the way of long-distance transmission, let alone globe-girdling HVDC lines. I suspect that small and distributed system would be faster to deploy, and ultimately cheaper, anyway.

But it's far too early to make specific projections of what it will all look like when complete. The only marching orders we need now are "get busy and do everything you can."

Good thoughts.

V2G/VTG has astonishing potential: the total peak generating capacity of the current 210M light vehicles (at 125HP each)is in the range of 21 terawatts, or 21 times our current US peak grid capacity!

Of course, dynamic scheduling of charging will be much easier to do, and has enormous potential in it's own right - imagine 420GW (if they all charged at the same time) and 10 TWhours of charging that could be moved where needed to smooth out variance.

it's completely left up to capitalism to solve these issues, and in a highly local way, relying on the individual decisions of hundreds (?) of ISOs and their investors and customers.

Making decisions in a decentralized way works well if resources (and in particular energy resources) can be shipped to wherever they are needed with relative ease. Such will not be the case with solar and wind energy unless we build a super grid. If your local region has three weeks of cloudy weather and local wind does not make up the deficit, then you are in trouble. I am not too worried about storage on a 12 hour time scale, although I suspect that energy that resides in an electrochemical battery will never be cheap by today's standards. However, longer time periods are troublesome since all of the technologies which seem have some chance of achieving reasonable cost have relatively low energy densities.

Getting a majority of our energy from sources that are not renewable or transportable would be huge paradigm change. If we were starting from scratch I would not be that worried, but we have a large existing infrastructure and a pattern of population density that is dependent on the existing paradigm. Trusting that private finance capitalism will carry us through the transition without major financial and social dislocations seems naive, particularly so if energy costs in a post fossil fuel world rise significantly.

"If your local region has three weeks of cloudy weather and local wind does not make up the deficit, then you are in trouble."

Not really. First of all, this would be very rare: when it's cloudy, it's almost always windy. If it did happen, it would be straightforward to deal with it.

First, such conditions would be forecast, and end-user prices would start rising several days before. Consumption would start falling, and power from normal surplus production as well as moderate imports would start filling storage (primarily EV/PHEV's, but also utility-scale storage, such as flow batteries and pumped storage). Utility maintenance, especially on nuclear plants, would be deferred. The 25% of capacity from nuclear would be as normal. PV & wind would still have some production, perhaps 10% of normal, so production would be at about 30% of normal (25% +2.5% +2.5%). Consumption would fall to perhaps 80% of normal. The 50% gap would be filled by standby bio-mass fired turbines, which, like gas turbines today, would be cheap to build and have on standby.

But, you might ask, how do we get 50% from a source which only provides, on average, 10% of our KWH's? Because it would be used rarely. Remember, wind & solar will produce above average 50% of the time. If their distributions were independent, both would be below average 25% of the time. But, because they're negatively correlated, both might be low 10-15% of the time. So, backup generation (or large imports) would only be needed 10-15% of the time, and represent 7.5-10% of kwh's.

At that rate of utilization, cheap standby generation would be much cheaper than a super-grid, or massive utility-scale storage, which is why standby "peaker" generation would be the preferred, optimal solution.

Make sense?

That makes quite a bit of sense.

However, "making sense" is far from the last word.  It should be checked against the real world (which is the last word).

I set about to do this once; I collected megabytes of radiosonde data from weather stations around the world, hoping to be able to determine just how much potential there might be in some of the high-altitude wind energy proposals.  I fell apart at the data-analysis stage, because many of the fields in the data records were missing or ambiguous and I didn't have good tools for putting it in order.

Hope you can get further than I did.

"That makes quite a bit of sense."

Thanks.

As you say, data conversion & cleanup can be 90% of a project.

I'm afraid I won't have time for such a project soon.

Not really. First of all, this would be very rare: when it's cloudy, it's almost always windy. If it did happen, it would be straightforward to deal with it.

Do you have some data to support this statement? In California where I live the wind blows hardest in the Summer when there is not a cloud to be seen for weeks on end.

"" when it's cloudy, it's almost always windy." - Do you have some data to support this statement? In California where I live the wind blows hardest in the Summer when there is not a cloud to be seen for weeks on end."

I saw research finding that when wind slowed in S Cal that conditions were consistently good for solar - that's an analogous negative correlation, but not what we were talking about with wind being around during stormy/cloudy weather. I'll see if I can find what I've seen that talks about that specifically.

It does sound a bit like a summertime positive correlation between wind and solar, though given the CA peak summer demand, that would likely be a good thing.

In general, wind is modestly stronger at night, and during winter, but the relationship does vary regionally.

I would expect that energy source mix would also vary regionally. I would expect that california would emphasize solar, and of course, have a bit more wave energy and geothermal than inland.

Well, I can't argue with the idea that it would be desirable to have someone attempting such long-term planning. Such long-term planning is difficult: technology and pricing will change (for instance, a big portion of demand will be EV/PHEV's, which don't exist now, and PV pricing will crash), and alternatives are mired in resistance by related industries who might be expected to do such planning. For instance, demand/load management and distributed generation (PV, net-metering, etc) are generally resisted by utilities, because it doesn't fit their regulated cost-reimbursement framework, which is now based on capital expenditure ("build plants and sell KWH's, and we'll guarantee your income").

"Variance is not hard to deal with when the majority of generation is powered by stored chemical energy which can sit around for indefinite periods and be then be used at whatever time of the day or time of the year that we please."

I think the ISO's and utility planners who have to do this day-to-day would disagree. That's one reason why they often make pessimistic noises when faced with renewable intermittency: they don't want anyone to make their already hard jobs a little bit harder.

" Citing the current success of the the grid in dealing with load variance as evidence that dealing with variance will not be all that difficult when the contribution of chemical potential energy has been reduced to 10% of the total begs the question which I am asking. "

Well, I would note 1) that nuclear is 20% of the grid now, that it stores energy just as well as FF's, and that I was projecting a total of 35% for both nuclear & biomass. Now, it's not optimal to load-follow with nuclear, but that can be done if needed, and it's presence alone does reduce supply variance. And, 2) really, what timeframe are we talking about here? FF's will be around for a long time (see below), which would give time to put more emphasis on nuclear if necessary, and 3) I didn't present that as a proof, but as an illustration as to the dynamics of what we're dealing with: variance is nothing new for utilities.

"Given the natural gas supply situation on this continent"

Yes, that deserves good planning. I would note that it's not clear what gas will do: it may be just fine. For instance, Hubbert predicted US natural gas would crash by 1990, and instead it has continued to do quite well. OTOH, such experience is nothing to rely on...

"some analysts are now saying that coal supplies may peak in less than thirty years"

Sure, but they're saying that in the context of abundant and relatively cheap alternatives. We have enough coal for much, much longer should other energy sources become badly supply-constrained. I had a detailed discussion about this with David Rutledge on a recent TOD post, and we came to agreement on this. In fact, I think renewables (wind & solar, primarily) & nuclear will indeed provide abundant and relatively cheap alternatives, which will be badly needed to handle PO and climate change, so coal is likely to peak fairly soon (at least in the US), but that will be because of demand constraints, not supply.

" I think in particular that a long distance power transmission network needs substantial forethought and planning. You claim that the need for such transmission will be 'moderate', but without a detailed model how can we know what the requirements really are? Pumped storage will have high up front capital costs and will need advanced planning. "

Yes, I agree. Good long-term planning would be very desirable for such things.

" we could at least be mapping the solar and wind resources and seeing how well they really do complement each other on a regional basis"

Much of that has been done, and very nicely too - I'll try to dig that out for you. hmmm. While I was looking in my notes for it, I noticed this, a source dealing with geographical dispersion and variance reduction with scale: http://www.stanford.edu/group/efmh/winds/aj07_jamc.pdf

"Until I seem some numbers related to how much storage and how much long distance transmission will really be needed I do not have any confidence that your estimate of 25% greater costs than FF has any basis in reality.

Well, sure, how can you without supporting detail? Here are some thoughts: only a portion of production will need to be shuttled around, or stored (so that this overhead would be spread more thinly than it might appear at first glance), and transmission & storage, while significant, aren't overwhelmingly expensive. Recent TX and CA projects estimated about \$.25/watt (or about 16% of wind project costs) for long distance transmission to bring wind projects to market, and pumped storage is in the range of less than \$.01/KWH - see, for instance, Ludington MI, which has been in operation timeshifting nuclear output for 30 years.

Thanks for the detailed response.

I would note that it's not clear what gas will do: it may be just fine. For instance, Hubbert predicted US natural gas would crash by 1990, and instead it has continued to do quite well. OTOH, such experience is nothing to rely on...

I think renewables (wind & solar, primarily) & nuclear will indeed provide abundant and relatively cheap alternatives, which will be badly needed to handle PO and climate change, so coal is likely to peak fairly soon (at least in the US), but that will be because of demand constraints, not supply.

My big concern is that if natural gas crashes and renewables costs remain high compared to coal then the pressure to build more coal fired power plants will be very high. As far as I am concerned the real costs of new nuclear will not be known until a series of new plants are actually delivered, an event which may be the better part of a decade away. I am also concerned that electrification of services that are now provided by oil will not be able to proceed fast enough and at a low enough cost to stave off economic pressure in this sector of the economy. Futhermore, electrifcation of services now provided by fossil fuels will place increased demands on electricity supply.

In my view we would be better off to stop striving for growth (at least in the short to intermediate term) and instead concentrate on maintaining decent levels of ecomic services with maximum efficiency. I realize that the chances of this advice being followed are indistinguishable from zero, but I cannot help wishing that we had the social intelligence to pursue this path. Once you do not 'need' growth for economic health, you increase your flexibility in dealing with resource constraints.

duplicate

"we would be better off to stop striving for growth"

I agree with your priorities, but I think we can reduce CO2 emissions, and deal with PO, with less drastic measures.

"renewables costs remain high "

Actually, wind at about \$.07/kwh is competitive with both gas (at or even near current prices), and new coal, which is much more expensive than old coal plants (at least in the US). Even now, wind was 20% of new plant in 2007, and looks it will be 30% in 2008.

"I am also concerned that electrification of services that are now provided by oil will not be able to proceed fast enough and at a low enough cost to stave off economic pressure in this sector of the economy. "

Yeah, it will likely take 5 years for plug-in's to get to 10% market share of new light vehicles, and another 5 to get to 50%. The US, as well as the rest of the world, is going to be under a lot of stress in the meantime. The easiest solution is mandatory car-pooling, whose only cost is inconvenience. Doesn't seem too likely at the moment, though...

"Futhermore, electrifcation of services now provided by fossil fuels will place increased demands on electricity supply. "

In an ideal world, electrification would proceed a lot more quickly than it is. It will likely take 10 years for building HVAC and light vehicle electrification to cause noticeable increases in utility demand. In that period efficiency regulations for appliances, AC, heat pumps, transformers, etc, could dramatically reduce consumption - the Current Occupant was scarily timid about such regulation, and there's much more low-hanging fruit.

Time-of-day metering (mandated by the 2005 energy act - check with your utility for availability: PGE is rolling it out, and SCE shouldn't be too far behind) would reduce peak demand, and essentially eliminate the need for new plant construction. Then we could concentrate on replacing FF plants with renewables.

duplicate

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.

I read that the U.S. produced about 6 billion barrels of ethanol per year. That is about 391,400 barrels per day. If the U.S. will produce its full 7.5 billion barrel requirement that will be closer to 500,000 barrels per day. The amount of oil + products we have been importing is little changed at about 12 million barrels a day last year. Energy usage has been between 20-21 million barrels a day over the past two years. There is some evidence demand slacked off a bit dropping it down towards 20 million barrels a day; perhaps due to higher prices more than ethanol production. Increased imports this past month compared to a year ago have been used primarily to rebuild stockpiles. Total crude plus products was near the middle of the 5 year average range for this time of year with stock inventory levels in an uptrend.

From the US Energy Information Agency:

US ethanol production January and February of 2008:

January: 500,000 bpd
February: 520,000 bpd

http://tonto.eia.doe.gov/cfapps/STEO_Query/steotables.cfm?periodType=Mon...

Also from the Energy Information Agency STEO report:

"Consumption. Total petroleum consumption of liquid fuels and other petroleum products averaged 20.7 million bbl/d in 2007, up only 10,000 bbl/d from 2006 (U.S. Petroleum Products Consumption Growth). Consumption of liquid fuels and other petroleum products is projected to grow by 40,000 bbl/d in 2008, a downward revision of 100,000 bbl/d from the previous Outlook. After accounting for projected increases in ethanol use, U.S. petroleum consumption falls by 90,000 bbl/d."

Robert Marston said,
"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."

BY JOVE, I THINK HE'S GOT IT!!! :-O

RC

"Meanwhile the US produces 520,000 barrels of ethanol per day and imports less oil because of it."

This may be true, but consider that the EROEI refers to energy, not just energy in oil. So hypothetically, if the ratio is less than 1:1 for corn ethanol, it may save oil, but is nevertheless an energy loss, not an energy gain. So is this a good idea? When you consider that if the current EROEI for oil is somewhere broadly between 10:1 and 6:1, which means that we are gaining 900% or 500% for each barrel of oil spent (EI) depending on what the real EROEI is. For corn ethanol at even 2:1 then the gain is 100% for each barrel of oil invested. (I assume for comparative purposes that the EI is all oil.)

The whole purpose of corn ethanol is to replace oil derived fuels. If oil can keep 900 or 500 vehicles on the road at 10:1 or 6:1 then corn ethanol can only keep 100 on the road at 2:1. And if you take a more conservative 1.3:1 for corn ethanol, then only 30 vehicles are on the road. We know how many people are on the planet now, so how many can be supported by corn ethanol being substituted for oil based fuel?

We lament our dependency on foreign oil when we should lament our dependency on any oil. I suppose that were we to become heavily dependent on corn ethanol, then we would lament that dependency also, particularly after a few years of crop failure from drought, pests, or disease.

Of course, Robert, yet another good thought provoking post on your part.

"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 ...

"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

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.

You got it from my computer!
Actually - that is an old version of something I uploaded to TOD a long time ago - but there is a mistake -it should read X /(X+Y) = % of Total Energy Available to Society.

The pink curve vs the purple curve looks a little like our total liquids vs crude oil curves at the peak areas (just look at the 3/19 production update curves here at TOD to see the similarity) if you take conventional crude as being what we have been used to for many decades with EROEI over say about 20. A sharply increasing amount of conventional crude is being used to manufacture low EROEI "resources" like the tar sands, shale, ethanol, and the deepwater reservoirs. This image would be just like our commonly seen projections by the USGS, CERA, and company if you would take the black Y* area, turn it 90 degrees counterclockwise, and tack it up to the peak showing decades of climbing reserve production from here on.

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.

"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."

Right. The happy motoring American way of life is non-negotiable. It must be kept no matter what. Including if the people of some countries have to pay for it in more than one way.

http://www.washingtonpost.com/wp-dyn/content/article/2008/03/11/AR200803...

"In January, to cite one example, Afghan President Hamid Karzai appealed for \$77 million to help provide food for more than 2.5 million people pushed over the edge by rising prices. He drew attention to an alarming fact: The average Afghan household now spends about 45 percent of its income on food, up from 11 percent in 2006."

Ban Ki-moon, March 12, 2008. The New Face of Hunger.

Maybe I should repeat from yesterday's post:

The problem with biofuels in general (except again with sugarcane ethanol, since nobody would grow sugarcane in prime land for grains or oilseeds) is that, as the crude oil price rises, the diversion of agricultural production out of food and into biofuels continues until reaching a temporary equilibrium state with LOWER food production volumes and consequent higher food prices so that the profitability of food production becomes again competitive with that of biofuel production.

Now, the geology-driven dynamics of crude oil production guarantee that, in the absence of a worldwide voluntary reduction in crude oil demand in line with the future peaking and subsequent decline of its production, the prospects for the crude oil price are of a relentless rise. That, through the biofuels-food arbitraging mechanism based on profits per acre/hectare, will drive the world into successive new equilibrium states with higher biofuel production and lower food production. Obviously the process will eventually stop before 100% of the food gets turned into fuel. But along the way a large number of poor people wanting to eat will have been outbid by the rich and middle class wanting to fill their tanks.

And there is yet another important side of the biofuels issue that is overlooked most of the time: turning an ever greater share of US corn to ethanol (and then soybeans to biodiesel) will cause in a few years the halving of US agricultural exports in volume and their doubling at least in dollars (i.e. at least quadrupling agricultural prices). That will substantially reduce the US current account deficit and give the US a significant strategic advantage.

The US has certainly the right to follow that path. But they also have the duty to tell the world openly that they will do it. Like: "Along the coming years and decades our food exports will become progressively lower in volume, and the same will probably happen to total world food production. It is conceivable that they could be half their current volume in 10 years. People, and particularly poor people, should have it in mind when making procreation decisions."

Dropping a nuke on a city is not genocide if its dwellers are given a week's notice.

Nitrogen fertilizer(typically natural gas, often stranded(cheaper)) is the biggest input into growing the corn, followed by diesel for farm machinery.

Production of corn ethanol consumes some 50 000 BTU/gallon of ethanol. That's a lot of energy and it currently comes from in part electric power and in part natural gas or coal, but a lot of it can in principle come from fairly low grade heat opening up the possibillity of using solar energy or waste heat from nearby industry.

Why is it that you cannot replicate the trick used by cane ethanol and harvest part of the corn stalks and use them for providing the energy? Would it really change soil errosion all that much?

Soylent,

your pdf is from 2002. A lot has changed since then. It currently (with the more modern technology) takes between 30,000, and 35,000 btus to produce a gallon of ethanol. This includes raising - and, fertilizing - the corn, making the fertilizer, and processing the corn to make ethanol.

You have to allocate a certain amount (40%) of the fertilizer, diesel for tractors, etc to the coproduct, distillers grains, since corn is, primarily, cattle feed, and the remaining distillers grains accomplish 40% of the primary task - putting pounds on cattle.

100% of the processing energy is allocated to the primary product, ethanol. You could, possibly, justify allocating a small part of the processing to the distillers grains since the DDs that are produced are quite a bit more efficient at putting weight on cattle than the original corn is; but, why bother? It would start another argument over a small amount of input.

Anyway, here are some numbers.

It requires about 25,000 btus of nat gas to make the fertilizer for one bushel of corn.

We average 151 bushels of corn per acre.

We use about 8 gallons of diesel to grow an acre of corn (this is an old number from the U.N. Thanks to more, and more, no-till farming this number is probably quite a bit lower now; but, on a per-gallon basis it's so low as to be insignificant.

The newer plants get about 2.8 gallons of ethanol from a bushel of corn. We get about 30% of the bushel back in the form of distillers grains. The distillers grains, fed in a 30% ratio, will give about 10% More weight gain than a diet of straight corn. I put these two numbers together to come up with 40% of the corn feeding ability is returned in the Distillers Grains.

SO, we multiply 151 (bu/acre) times 2.8 gal/bu and get 422.8 gallons/acre. Now, we recover 40% in DDs, so we multiply 422.8 x 10/6 and get 704.66 gal/acre.

Okay, let's go back to fertilizer. 25,000 divided by 2.8 x 6/10 = 5357 btus of nat gas per gallon of ethanol.

A little over 1,000 btus of diesel per gallon of ethanol.

A modern plant, according to Poet, will use about 22,000 to 24,000 btus of nat gas to produce a gallon of ethanol.

So, we have: 5,357 + 1,000 + 24,000 = 30,357 btus, more or less, to produce a gallon of ethanol. And, yes; our plants are starting to use biomass for process energy. Corn Plus has signed up several refineries, I think, to use their "syrup to heat" technology, and Poet is building a plant that will use the lignin from the fractionation process, and the corn cobs from the field to produce heat. Corn plus has replaced about 50% of it's nat gas with gassification of it's syrup. This brings them, I believe up to about 4:1 FOSSIL EROEI.

I think you should include transportation energy since the corn doesn't magically get from the field to the ethanol plant and then to the E85 gas station or refinery where they mix it with regular gas. Have you read Fermenting the Food Supply by Stuart Saniford ( http://www.theoildrum.com/node/2431 ), I think increasing our corn ethanol production is a bit silly. We will do more harm for our economy then good, due to higher livestock prices, milk, cheese, the list goes on and on, so we can do what, try to save 10 cents at the pump which won't even offset the price of oil. That is money that would be better invested in wind, solar, geothermal, nuclear and energy storage research.

I don't see how anyone but someone connected to the ethanol industry could logically disagree

-Crews

It currently (with the more modern technology) takes between 30,000, and 35,000 btus to produce a gallon of ethanol. This includes raising - and, fertilizing - the corn, making the fertilizer, and processing the corn to make ethanol.

You know, for a retired insurance salesman who is only interested in ethanol, you seem to think you know an awful lot about it. I mean, we have actual plant surveys from the USDA that contradict your numbers, but hey, who are they to argue with a retired insurance salesman?

To put this into perspective, the numbers you give above would provide an energy return of better than 2/1. Show me any independent confirmation of this. I think you are only counting the BTUs that went into fermenting the corn, distilling the ethanol, and drying the DDGS. But prove me wrong. Show me the data. Show me the breakdown of energy inputs, so we can compare them with past surveys.

This brings them, I believe up to about 4:1 FOSSIL EROEI.

Always banking the claims as promises. Always doing mental gymnastics to try to justify this farce. That's why I have never taken seriously your claims of being a retired insurance salesman. Who knows, maybe you did that once. But your behavior suggests that your aren't doing that now. It would be as if I consistently defended ExxonMobil at every turn, while claiming to be unrelated to, or having no investments in the oil industry. Who would believe that?

I'm assuming, Robert, that the USDA lumps all of the Old, and New plants, together, to obtain an average.

Maybe, I just think our country's going to need this source of energy in the coming years; and, I'm afraid that some bad information being propagated by different people, for different reasons is going to do great harm to this industry, and, as a result, to my grandkids' country.

BTW, I don't know if you've noticed; but, I advocate, also, for solar, wind, waste, wave, and hybrid vehicles. I believe the originators of this blog are correct in that we're going to be in a mess fairly soon. I don't think we have the luxory of waiting for the PERFECT solution. I firmly believe that we need to work like the dickens with what we've Got NOW. We can make improvements, as we go.

As for my "knowledge:" Like I said, I read a lot.

the remaining distillers grains accomplish 40% of the primary task - putting pounds on cattle.

There are limits to how much DDG can be fed to cattle without making them sick.  Cattle are evolved to eat grasses, not grains; even corn gives them problems.  This places a cap on the total "coproduct credit".

SO, we multiply 151 (bu/acre) times 2.8 gal/bu and get 422.8 gallons/acre. Now, we recover 40% in DDs, so we multiply 422.8 x 10/6 and get 704.66 gal/acre.

You're making up fictional gallons there.

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!

It always seems to be a waste of my time to argue with the corn farmer formerly known as Practical. After all, you benefit above all others from these policies. I am in India observing people who are starving to death while we turn food into fuel. I have little patience for your arguments.

A couple of points. First of all, you seem to misunderstand what EROEI is. I am using it validly. You are trying to redefine it, and then accuse others of making invalid arguments based on your new definition (which is to treat fossil fuel inputs differently; sorry, you are no longer talking EROEI).

But this is why you are a complete waste of time. You are simply a liar:

Why do RR and other EROEI believers not take on electricity production since it has a lower EROEI than ethanol?

There is no other way to slice it than you are a blatant liar when you make that claim. Your stupid electricity argument has been rebutted every time you made it. Yet you have the gall to claim that we do not "take it on." To me, this indicates a character who would rather lie to justify lining his own pockets than to honestly address arguments.

But here it is, one more time. You can't use coal in the applications that you use electricity for. Simple as that. If you could plug your toaster into a lump of coal, your argument would hold water. You can't, so it doesn't.

He ignores completely the fact that the automobile infrastructure is set up for liquid fuel and not natural gas.

Completely? That will be news to a lot of people who have CNG vehicles or bus fleets. I have seen lots of them in the U.S. You know, Brazil isn't so stupid to use their natural gas to produce ethanol. They actually have a much larger CNG fleet than we do. Here in India, where they make a lot of ethanol, they use natural gas in CNG vehicles - not in making ethanol. So somehow Brazil and India have managed, but the U.S. is just too backward to phase them in. Again, sounds like an argument from someone who is lining their pockets as a result of these policies. These are arguments that are easily shot full of holes, but maybe it makes you sleep better to make them.

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.

That's a non-sequitur. As long as natural gas is being made to use an oxygenate that is truly serving a needed purpose, that's fine. But current computerized engines don't in general need oxygenates. And MTBE was being produced from natural gas to be used as a primary fuel. Furthermore, if you think that the natural gas that is now being used was only the gas used in MTBE production, you probably ought to check your facts. But that's never been your strong suit, has it?

Rapier is right on this question. Our natural gas distribution network accesses a significant part of the population. We could be running vehicles on natural gas very quickly if we had a decent storage system.

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

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.)

That's the point Robert wrote that people would miss. It matters a huge amount, because the scale of the energy infrastructure needs to be increased enormously just to get that 10 units. Instead of using 1 unit input to get 11 by sucking it from a straw in the ground - and leaving net 10, we need another order of magnitude input to net the 10. Instead of the infrastructure scaled to handle 11, it has to handle an order of magnitude more. Everything else being equal, we churn through the reciprocal *more* of the energy resource as return falls.

Perhaps someone more wizardly than I can do a graphic showing gross energy to maintain a constant net energy as return falls from 100:1 to 1:1. It's worse than a hockey stick. The size of the economy necessary to support energy infrastructure goes infinite at 1:1.

I didn't express that very clearly, sorry, can someone help with that?

cfm in Gray, ME

Exactly and in my opinion once time is correctly included then oil in EROI/t is more like 1000:1 vs 2:1 for biofuels. So not only are you right but its two orders of magnitude not one.

You don't even have to do the math to see this. Imagine someone in the 1700's with access to fertilizer living a 20th century McMansion/SUV lifestyle powered by energy and food etc produced on there own farm. How big does that farm have to be ?

Depends.

Do they get a 1 MW Wind Machine?

I would have thought it would be the other way around. Oil took millions of years to create. Corn only takes a few months.

Oil took millions of years to create. Corn only takes a few months.

Ok, what is the time weighted value of the photons that created the oil VS the corn?

Euan's graph here and Nate's graph above illustrate the precipitous decline quite clearly. IMO, these should be as well utilized as the basic Hubbert curve itself, for as you point out, Hubbert decline itself does not begin to paint the full picture of what we face. As for explaining it, my hat is off to Robert, but the resistance to his and others' efforts within this very thread, let alone out in the world of decision makers, bodes ill for any meaningful grasping of the grave importance of this relatively simple concept. Alas...

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.

I'm afraid you must have messed up your math majoran..

in order to get 10 return units from a 1.3 ratio system you must expend a minimum of 33.3 units.. 33.3 units IN so you get 43.3 ( 33.3 * 1.3 ) units OUT so a return of 43.3 - 33.3 = 10 units returned.. in your example 17.69 units * 1.3 will get you 23 units, for a return of 23-17.69 = 5.307 net units returned.. not 10 units.

for a units system of 20, you would have to expend a minimum of 0.5 units to get 10 units out or spending, so therefore if we look at the minimum amounts of net energy requires before we input it into the system to get more out, we divide the minimums 33.3/.5 to get around 60.. so it will take you 60 times net energy to get the same net energy return of 10 units to power your car or whatever you want to power. This also means that with for example ethanol with an EROEI of around 1.3 will cause you too have to have a production base 60 times larger than that of an energy production base of something like oil with an EROEI of 20.. I don't think there is enough land, water or anything for that.. Which means as you probably already know that our lives are going to have to change to something completely different.

I think you were confusing the energy put in with net energy or something or other..

-Crews

I'm afraid you must have messed up your math majoran.

He has, and I have explained it to him before. He is treating those secondary, tertiary, etc. inputs as free. That's why backcalculating the EROEI and net energy from his numbers gives the wrong answer. But then again, I don't suspect he is that interested in getting to the truth.

Haha Robert, I suppose he's not, by the way I am jealous of your India trip, hope your having a good time you lucky bastard. Hope you you smell like bagasse forever, ; )..

-Crews

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

I had you in mind when I started writing this. Sorry in your case I failed. Your argument was wrong the previous time you made it, and it is wrong now. I pointed out before what you are missing. It seems to me that you are trying really hard to do the calculation incorrectly. But as I pointed out, some people can't get it, and some won't get it because they don't want to get it.

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.

This is just pathetically, absurdly wrong.

Funny, you don't sound sorry. :->

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.

I'll try again. If I have a process which outputs 100 barrels of oil for one barrel invested, then that's the same as a process that one barrel of oil transforms muck into 101 barrels of oil. If the process produces 100 barrels of oil for 50 barrels invested then that is the same as 50 barrels of oil transforming muck into 150 barrels of oil. Therefore if I have a process which outputs 100 barrels of oil for 100 barrels of oil invested then that is the same as 100 barrels of oil transforming muck into 200 barrels of oil.

The problem is that when you "invest" energy into a process, that energy isn't recovered in the form of net energy. The energy invested is dissipated in the process and cannot be recovered (2nd principle of thermodynamics). That is why you cannot revert things as you do. If you invest 1 barrel of oil to obtain 100 barrels, that means the barrel you invested has been used to make mechanical energy, heat and others which will dissipate and cannot be recovered.

With a 2:1 EROEI, when you extract 100 barrels of oil, you will have to put 50 barrels aside to produce the next 100 barrels. Thus you will net out 50 barrels only because the ones you've put aside will be burned (ie used, then dissipated in the extraction process) away, not to be seen again and not sold for profit.

That means that for 50 barrels invested you don't get 150 barrels but 100 barrels with a net of 50 barrels if you want to continue to work. (net energy=EROEI-1).

At an EROEI of 1:1, if you invest 100 barrels, you can extract 100 barrels, with a net of 0 if you want continue extracting which you won't do because you are no fool. In that case you burn your 100 barrels in engines and stoves to extract that darn next 100 barrels.

But of course you know all this, so why do you try to argue ?

"With a 2:1 EROEI, when you extract 100 barrels of oil, you will have to put 50 barrels aside to produce the next 100 barrels. Thus you will net out 50 barrels only because the ones you've put aside will be burned (ie used, then dissipated in the extraction process) away, not to be seen again and not sold for profit."

Sorry No.

The assumption you are making (and it's rife here on this board) is that the ONLY POSSIBLE INPUT is barrels of oil. That's a crock. There are multiple possible energy inputs that can be used to extract oil. Thus as long as we have energy coming into the system from outside and it can be tapped, we can keep every single one of the 100 barrels.

Another common fallacy I often see is that of natural gas and the oil sands:

In Alberta they are currently using natural gas to power turbines to heat the water to separate the tar from the sand. Thus the argument is that syncrude will rise in price concurrently with natural gas prices. Well, no. We can substitute out natural gas for nuke to heat the water. Or windmills. Or Hydro. Or a bunch of Mexicans running on a treadmill.
We need ENERGY input not OIL.

Jeeez.

Don't try to distract readers with idle logic. I replied to marjorian who used oil instead of BOE to make his point. But the energy problem related to EROEI doesn't change.

"Don't try to distract readers with idle logic. I replied to marjorian who used oil instead of BOE to make his point. But the energy problem related to EROEI doesn't change."

1. NOT idle logic. Just logic.
2. The energy "problem" related to EROEI does not indeed change but the incorrect picture painted here should be cleared up.

EROEI stands for energy return over energy invested. We're not talking about oil or barrels of oil. We're talking about ALL forms of usable energy. With me so far?

Some people through in concepts such as "the second law of thermodynamics" without understanding the whole concept. They are making the statement that in a closed system energy at the end is always less than energy at the beginning.

That isn't the complete statement. There is the additional part "without energy being added or subtracted".

So: to clear things up. Energy is being added to the closed system (Planet Earth) on a continual basis by the sun. Useable energy is sunlight and derived sunlight.

Oil is derived sunlight. So is wind and wave.

THUS under the concept of EROEI, if you are trying to get barrels of oil out we have all that sunlight, all those waves and all that wind to get it out.

We do not run EVER out of the ability to get oil out until we have run out of the ability to wind turbines, solar panels, wave power generators. Our ability to build these things is constrained by the amount of resources required to build them. That does not ONLY depend on oil.

If you ARTIFICIALLY constrain the concept of EROEI to ONLY include barrels of oil where you are NOT ALLOWED to use any of the other useable energy sources then sure. But we DO in fact have other useable sources thus the problem we have boils down to one thing and one thing alone:

INFRASTRUCTURE.

Do you really believe that solar, wind et al don't have an EROEI ?

With what do you build your infrastructure : prime matters and ... ?

Of course I believe in EROEI. I have a bachelors in physics. But I also have an mba. I understand both sides.

The issue being muddled here is when we talk about "barrels of oil equivalent".

Barrels of oil are a dimishing resource and it is difficult for most people to get into their heads that some of those "barrels of oil equivalent" are being CONTINUALLY ADDED to the system whereas others (the actual OIL) are being burned up. This is the problem, not the concept of EROEI itself.

Thus: to answer your question. Yes solar, wind etc do have an eroei but since it is not like oil where you burn a barrel to get more barrels the problem does not arise.

You do not build a wind turbine then burn it to make five more. The original wind turbine is STILL THERE. Thus UNLIKE OIL you get a compound interest effect.

If you are going to use terms with the word INTEREST in them then make sure you understand the full concept.

EROEI is much more like the investment term of principal + interest than it is like using barrels of oil to get barrels of oil.

If people could understand that we wouldn't have this dumb debate about us using barrels of oil to get barrels of oil. It's ridiculous.

You do not build a wind turbine then burn it to make five more. The original wind turbine is STILL THERE.

Not necessarily, in a practical sense.  Machinery wears out.  Metals corrode.  Even composite blades suffer creep and fatigue.  Eventually you have to spend energy to rebuild or replace these parts.

If there is useful embodied energy left in the system at the end of life (certain for metals, less certain for fiber composites and electronics), that's part of the equation too.

Actually EP,
In a practical sense there certainly IS energy still there.
Over the course of twenty years (a reasonable planning period) the vast majority of windmills would still be there and still producing energy. Thus we would have the compound growth of installed base for that entire time. Moreover, increases in technology would create better and better windmills with time thus increasing EROEI as we went in this case. This is economies of scale.

During the same period of time a purely oil based EROEI would end up with diminishing returns as TOD is pointing out.

But we DON'T have a purely oil based EROEI and THAT's the point.

No, the initial point was that marjorian said that the energy input into a transformation process was recovered at the end. I replied that the energy input in the sense of EROEI is dissipated and not recoverable for other processes.

If I understand you, your original point is that we can apply higher EROEI renewables to extract oil that would have and EROEI of 1, say, and still have oil because of this. We don't run out of oil because we burn it up to get oil.

I think that this is a fine point, but I don't think that it owing to the sources being renewable, just higher EROEI. I won't be all that surprise to see refineries starting to get their process heat from wind and solar. There was a proposal for that in the eighties: http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6823722
and it probably makes economic sense now. Wind turbines are becoming common on offshore oil rigs. Here is a company that works in that market: http://www.provenenergy.co.uk/windturbines_oilgas.shtml

But, compensating for the decline of the EROEI of oil won't compensate for its declining availability all that much I think. On the other hand, one can make oil directly using wind or solar power so that in places where we actually need it like aviation, there is not too much of a worry. You just want to have a good use for the process heat: http://mdsolar.blogspot.com/2007/12/jet-fuel.html

Chris

"Barrel of oil equivalent" is an energy unit, and can be expressed also in joules, watts etc. EROEI applies to energy "production" (or conversion from primary "free" sources, be they renewable or not), not infrastructure. Hence the discussion with majorian who tried to show that the energy invested in a conversion process is recovered, which it clearly is not, you do agree with this ?

Now the problem you write about is the place of the real renewables (wind, solar, wave, tidal ...). I fear that we still have a problem : will the renewables have a fixed EROEI forever or will their EROEI decline as goes for the EROEI of everything which is made with finite ressources. The very fact that there is an EROEI for solar and wind, shows that there is a limit for the energy you can recover with a solar pannel, a turbine generator in a given setting. Yes, solar pannels need maintainance, replacement, they can break, they wear out. So does every compound in the energy delivery and regulation system. All the devices need materials to be built which need an amount of energy to be extracted, transported etc ... . Will this amount of energy stay fixed, decline or increase ? You decide, but until these issues are solved, I believe that we have a problem. I really hope that this can be resolved but it will take time and probably some huge paradigm shifts.

Still, declining EROEI in our current society is my worst nightmare.

I think you may be missing the point - to compare the amount of energy in Barrels of Oil Equivalent.

"If the process produces 100 barrels of oil for 50 barrels invested then that is the same as 50 barrels of oil transforming muck into 150 barrels of oil"

Hmmm, ok, how about this. I have a ten story building in manhatten. I knock it down and build a 20 story building in the same spot. So, by your logic, I should now have a total of 30 stories to live in. Trouble is, I just keep reaching the roof when I try to get to floor 21. Where have the extra ten stories gone? are they underground?

Surely transforming my 10 story building into a 20 story building is the same as turning an empty plot into a 30 story building. I don't understand, help me understand please.

You've almost got it!
As you say, you actually produced 30 stories.

But let's just keep to energy.

In the case of energy, it comes from nature.

Let's say nature holds invisible
units of energy locked inside it and we use energy invested to unlock it.

We have a ratio EROEI which tells us how much energy invested we need per unit of output, or Einv=Eoutput/EROEI.

We send it to the process where it is destroyed and it magically turns potential energy Ep into usable energy at the ratio of EROEI+1, or Ep=(EROEI+1)*Eoutput/EROEI.

But this is exactly the same as total of the energy we get out of the process, so we set them in the equality(EROEI+1)/EROEI=1+1/EROEI. And the algebra checks.

If you graph x=EROEI versus y=Ep/Eo you get a function 1+1/x WHICH I HAVE SEEN FLOATING ABOUT HERE. This tells you how much feedstock you must process per output.
The process requires asymtopically more feed(potential energy) when the EROEI dips below 1--the zone of negative net energy gain, the amount of Ep/Eo is huge but above 1, Ep/Eo flattens out to 1 as you go to infinity. This is why net energy gain is not tremendously important above an EROEI of 1.

Plug in an EROEI of 1 and you find that you end up extracting 2 units of potential energy for each unit of output energy; at EROEI of 10 you find you will extract 1.1 units of potential energy to get 1 unit of output energy and at EROEI of 1.3 you have to extract 1.7692308 units of potential energy to get 1 unit of output.

What EROEI tells us is that the amount of energy extractable from nature must be very large to get justify a low EROEI if it is above an EROEI of 1, a big change in EROEI will only involve a small change in feedstock(EROEI).

It seems I'm still a minority(who is correct). :->

What EROEI tells us is that the amount of energy extractable from nature must be very large to get justify a low EROEI if it is above an EROEI of 1, a big change in EROEI will only involve a small change in feedstock(EROEI).

What EROEI tells us is that the amount of energy extracted from nature must be very large to justify a EROEI below 1 but if the EROEI is above 1 a big change of EROEI will only involve a small change in feedstock.

(I know..it's too wordy) Just look at a graph of y=(1+1/x). I can't figure out how to download images here. :(

I am very ashamed when I see the major editors having to reply to such mischievous threads. So I will take a little time to answer naively this ridiculous argumentation. I know "don't feed the troll", but I just answer for the record, giving the right elemental calculations and hope that no one wastes any more time on this.

By definition Net energy = Energy out - Energy in. This is the definition of *net* (look it up and don't twist the words). Everything follows from here. Let's define Eout as "energy out", Ein as "Energy in", Enet as net energy. Enet=Eout-Ein Ok ?

Now EROEI = Eout/Ein still per definition. When expressed as x:1 you have Eout=x and Ein=1. Still Ok ?

Since Enet=Eout-Ein, Enet=Ein(EROEI-1) and since in the expression x:1 Ein=1 we find that Enet=EROEI-1 (and not EROEI+1 as majorian has written).

Besides majorian, why are you doing this ?

If you graph x=EROEI versus y=Ep/Eo you get a function 1+1/x WHICH I HAVE SEEN FLOATING ABOUT HERE.

That formula should be 1+1/(x-1), or x/(x-1).  You may not be able to derive this formula yourself, but any test would have shown you that the one you had was wrong.

at EROEI of 1.3 you have to extract 1.7692308 units of potential energy to get 1 unit of output.

Wrong.  An EROEI of 1.3 requires 4.333 units extracted to yield 1 unit net; the other 3.333 must go back to feed the process.

You may be intelligent, but you are essentially innumerate.  You post numbers which are obviously wrong to anyone with a basic grasp of arithmetic, over and over again.  You are either too lazy to check your numbers even when you have the formula, or don't have the ability.  Either way, it results in you posting a huge heap of utter nonsense.

If there was a means of forcing you to put down a deposit for every number you post, and forfeit it to the person who corrected you, I'd be at the front of the mob demanding it be done.  Your posts actually make people dumber for having read them.

It seems I'm still a minority(who is correct). :->

One of the traits of the incompetent is that they cannot recognize their own errors.

All due respect EP (I believe you are the best poster on this board) I think that you have unintentionally continued to propound the myth.

You said "An EROEI of 1.3 requires 4.333 units extracted to yield 1 unit net; the other 3.333 must go back to feed the process."

Remember, that not all available energy is gone when it is used up. That is true of oil, gas and other fossil fuels. If we use energy which is being continually replenished from outside the closed system then we DON'T NEED to use the other 3.333 to feed the system.

THIS is the crux of the problem. EROEI is a perfectly reasonable concept. Failure to understand the difference between non-renewable barrels of oil equivalent and renewable barrels of oil equivalent in the overall process of producing energy is leading us to the FALSE conclusion that once the low EROEI OIL is used up we're screwed.

We're not. We have a full tank of sunlight. And it's refilled every morning.

not all available energy is gone when it is used up. That is true of oil, gas and other fossil fuels. If we use energy which is being continually replenished from outside the closed system then we DON'T NEED to use the other 3.333 to feed the system.

If that energy remains available, it should be counted in the output and the EROEI increases.

If we are talking about systems like corn ethanol (where these dismal numbers come from), the energy input goes to cultivation, fertilizers and other chemicals, and mashing/distillation.  The ability to get anything useful out of this energy is gone; there is no practical way to recover any of it for further use.

It's a perfectly valid point you make about the sun continually adding barrels of oil equivalent to the closed system of earth. But how many barrels per day of useful energy is that? It's insignificant compared to what get's shuffled around within the closed system. If we had the infrastructure in place to capture a big percent of our energy use, we could factor it in. But we don't and won't for a long time.

majorian, you seem to be taking no account of past or future production of energy, instead using one isolated energy cycle. Let me try to explain, using rounded figures.

You're right that an EROEI of 1.3 takes 7.5 units to produce 10 and that 17.5 units would need to be produced to get 10 units of useful energy plus another 7.5 to produce the next 10. However, the next 10 won't be enough to produce the 10 units needed by the economy and the 7.5 units needed for the next cycle. It would produce only 2.5 (10-7.5)units of energy for the economy, with the other 7.5 needed for the next cycle.

This is why Robert was including the net energy also. Note that this doesn't mean that only 13 excess units are needed in the last cycle, to produce the 17.5 needed in the current cycle (at an EROEI of 1.3). To produce 13 excess units, that means producing 23 units, in all (the 10 we need for the economy plus the 13 needed to produce 17.5 for the next cycle). As you can see, working this back, you find that you need more and more, until you reach point where the combination of EROEI and net energy produces the amount required to keep the process going (of 10 units usable by the economy). This will result in needing to produce 43 units altogether, which was the result of Robert's formula.

So your limited calculation is flawed as it cannot possibly keep up those 10 units needed by the economy, except for 1 isolated cycle, where the inputs were free.

Phew! That took some getting to!

Not sure if you mean the post was a bit drawn out or that there have been a lot of posts, in response to majorian, that didn't really spell out his mistake.

However, the fact that majorian has not responded to the pointing out of his glaring error probably means that he doesn't care, because he doesn't want to know about realities.

...or because he's just a troll. All talk and no listen.

Gee, I'd better respond to all the brilliant stuff posted against me.
I was a little shocked at the venom but then I guess TOD is evidently not quite the place I thought it was.

I was also trying to put an into my reply the way some people do but I haven't figured it out yet.

Oh, well.

I am amazed that nobody here seems to understand the practical value of EROEI (at least my interpretation of it:Ep/Eo=1+1/EROEI).

Unfortunately low EROEI will really mean that we will have to go thru conventional oil must faster than would have been with convnetional oil.

For example, let's assume the Alberta Tar Sands have an EROEI of 3 using natural gas. There is a proposal to gasify bitumen instead of using natural gas.
Gasification is about 50% efficient. What is the new EROEI?

We know 1.1 barrels of bitumen is converted into 1 barrel of syncrude, so for this example we will consider the output of 1 barrel of syncrude coming from 1 barrel of bitumen.

Let's say we require 30 barrels of bitumen(syncrude) out. That means we need to invest 10 barrels equivalent of syncrude in.

Please don't have a heart attack on account of me mixing apples and oranges.

Since by gasification we are destroying input, we need to double our input from 10 barrels to 20 barrels to do the exact same job as natural gas. Then we will need 30 barrels output plus 20 barrels reinvested=a total of 50 barrels. Since Ep/Eo=(1+1/EROEI), then 50/30=1+1/EROEI so EROEI=1.5.
Notice that bitumen production(mining) had to be raised from 30 barrels when using natural gas to 50 barrels, a 66% increase(50/30).

It's a good thing that these resources are so large because we need to burn through so much of them to get the same output as conventional oil.

For what we typically think of as unconventional oil, huge contiguous deposits of hydrocarbons(Alberta, Colorado Oil Shale or Orinoco Super heavy) adding production may not be a problem as much as for things like superdeep oil or EROEI where large areas must be drilled with a lot of luck.

What would be the EROEI of coal fired electricity with CCS? An average ton of coal makes 2000 kwh of electricity. Somebody has given the EROEI of coal to electricity to be something like 9.

Let's say that CCS requires 317kwh per ton of carbon dioxide or 1160 kwh per ton of coal(carbon) to capture and sequester the gas by the amine method, which can be retrofit to conventional coal plants.

If the EROEI is 9 then Einv is 2000kwh/9=222kwh. So we add in the 1160 kwh to produce a total of 1477kwh.

The EROEI is 1.45(2000/1477) and we now must mine 1.69 tons of coal; 1+1/1.45=1.68955.

Before you start moaning, this site says scrubbers reduces the EROEI of coal-fired electricity to 2.5.

http://www.eroei.com/eroei/evaluations/net-energy-list/

This isn't going to be the same with IGCC because the efficiency of IGCC is higher and the cost of CCS is lower
at 710 kwh per ton of coal/carbon.

Another idea is oil shale recovery by Shell's toaster method at Mahagony. Basically you need to heat a big cube of oil shale for 2 years and you get out a certain of shale oil and some gas. I think somebody has said that with the retort method and rich 30 gallon per ton oil shale rocks you get an EROEI of about 3.5, so let's assume that Shell's heater will do the same. If that heat is provided by coal-fired electricity then that will require 1/2 ton of semibituminous Wyoming coal per barrel of
shale oil:5500000/(3.5x3412x1500)=.31,
1 ton of coal for 3.25 barrels of oil. This is a lot better than CTL which produces at best 100 gallons of gasoline per ton of good quality bituminous coal.
If we also 'amine' sequester CO2 at the lignite coal-fired plant as above with an EROEI of 1.2 then you'd still be at 2.7 barrels of shale oil per ton of Wyoming coal.

Perhaps I should look at the EROEI for EOR/CCS.

After all these years of praising TODers praising EROEI to the skies, who would ever think that they had no idea how to USE it. (:-~

Muaaaaaaaaaahhhhh!

I was also trying to put an[image] into my reply the way some people do but I haven't figured it out yet.

let's assume the Alberta Tar Sands have an EROEI of 3 using natural gas.

Is that a remotely valid assumption?  Sources I can find say closer to 5:1.

Not even close.  Cold-gas efficiency for existing gasifiers is at least 74% when operating on coal; for bitumen, it would be higher due to the higher H/C ratio.  Waste heat from the gasifier is more than sufficient to power the oxygen plant via a steam turbine (1825 MMBTU/hr = 534.5 MWth, and the off-heat would be about 188 MWth or 56 MWe @ 30% efficiency).

What is the new EROEI?

You'll never find it if you start from erroneous premises.

You are really wrong. Your equation :

Ep/Eo=1+1/EROEI resolves itself into Ep=Eo+Ei. This cannot be since Ei is DISSIPATED in the production process.

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.

I didn't fall asleep. I liked your example. And as you've written about for a long time, the main problem we face with scaling a fuel like ethanol is we are short sightedly just trying to get more "X", without understanding how much water, land, soil, GHGs, biodiversity, chemicals, etc. this will take to accomplish. Non-energy inputs on lower quality fuels will loom large.

We all need to collaborate and make a cartoon on Youtube or such.

But without some assumption about the non-energy related costs of filling the working reserve we can make no progress in our economic evaluation.

Indeed. And one critical cost is the time to produce one unit of net energy. If we find that a certain energy consumption per unit time is required for a society to maintain a desirable standard of living, then the available energy producing processes will be encouraged to scale to meet that requirement based on net energy produced per unit time. It follows that net energy per unit time (also per unit labour, per unit of environmental damage, per unit of other limited resource) is an important point of comparison.

The other, important, side of the coin is maximizing units of quality of life produced per unit of energy consumed (per unit time).

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.

"Oil is unique in its energy content. "

Not really. It's pretty convenient, and it's been very cheap, but it's pretty straightforward to replace (with renewably generated electricity). Not as fast as we would like to replace, but straightforward.

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.

Ahhh, but the wood has to be processed into pellets.

http://www.sredmond.com/vthr_index.htm

This does not need any more processing beyind chipping.

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

<img src="http://blah.blah.blah/thing.jpg" width="80%" >

I don't know why, but I am unable to edit the first comment with the full rez image.

A very attractive graph. I am guessing that the bar heights represent how much gross energy production would be needed to create a net energy of 385 with that source of power?

Yes, that's the idea

That graph would be scary if it weren't for the fact that all of those can be scaled up significantly with the exception of the fossil fuels.

Actually, PV, nuclear, and wind needs to be adjusted for the 3:1 advantage they possess, because they produce electricity, not heat.

We count heat inputs for FF, but we count electricity outputs for PV, nuclear, and wind, which is 3x as valuable.

For instance, the US uses 39 quads of FF to produce 13 quads of electricity. If you go from FF to PV, nuclear, and wind, you'll count 13 quads, not 39.

It's confusing, but it's something to keep in mind.

That's correct but for example some coal is used for heating some for electricity and some is burned in CHP plants, so that's a bit more complicated. Also gasoline and diesel engines get different efficiency, so we would need to take a lot of different data to get a result that would take into account the useful energy. The basic concept is:
with Net energy = constants if EROEI -> 1 then Total Energy Output -> infinity. You can't run society with an energy source with EROEI near one.

I think it would be worth it to have an inset bar for hydro that shows it is getting tapped out but that it works as
an energy input to run some of the others since it's EROEI is high. Maybe start it above the yellow line. Nick is
correct that the back end scale has to be larger for things that have poor conversion to the form of energy that we
actually use. For biofuels this is the mechanical energy to turn wheels, for nuclear this is electricity since the
scale is too large for much CHP. You might also want to use the best numbers available for each technology since the market ought to drive out the lower values included in the average. For solar you might want to use this link:
http://www.nrel.gov/docs/fy05osti/37322.pdf
I compare solar and nuclear prospectively here:
http://mdsolar.blogspot.com/2008/01/eroie.html

Some of the sources you list don't have a chance of covering world net energy use and some could not grow quickly enough to do so in 30 years. I wonder if shading the bars could be used to indicate their potential in this respect? That way hydro could fit in in the same way but with it's potential scale indicated in a different way.

Chris

Well, my point was that wind, solar & nuclear will come in at well below 400-450 MJ, more in the neighborhood of 200.

I see what you mean. The figure 385 Exajoules is really a before conversion to work (in the case of the fuels) or electricity (in the case of nuclear) number. Wind and PV solar don't need to come up to that level at all to replace the other sources. For the US break down they only need to do about 37 EJ out of 103 EJ since they don't have all that lost energy. Nuclear would have to come up a little higher though since it is not 36% efficient.

Source: EIA through Wikipedia

I think that would be worth modifying the figure for. A seperate yellow line for wind and solar makes sense. This is just sketched in but what do you think?

Might want to group nuclear over with the other thermal sources.

Chris

That makes sense. Of course, then you create other problems, by making the outputs looks dissimilar when they aren't, but I think it's worth it. At worst, it creates a teaching opportunity.

The first figure says "Net Primary Resource Consumption" and the label on the yellow line is similar. How about
a new label for the lower yellow line that is something like "Real Energy Use" or something that can indicate that
waste has been avoided?

Chris

Mdsolar ->
That's a very interesting graph, shows the whole picture. I wonder if we could create a loop from the useful energy to the inputs to show the effect of EROEI and how much is left for the society for other, non-energy purposes.
It would be nice to combine this with a functionality similar to the Gapminder, so you could track the changes in efficiency, EROEI and the useful energy level over time. Create alternative scenarios with different energy mix.

Twice now I've thought of a song I think sung by Eddie Murphy at the end of one of the Shrek movies that did not seem appropriate for kids about large posteriors in connection with your plot. With low EROEI, you kind of have this picture of people not being able to fit through a doorway because of what they are dragging behind them. There might be a cartoon there.

I think that schematically you could fan out the left hand inputs based on EROEI and try a few 2030 and 2050 scenarios using different mixes. One might have biofuels at their maximum potential, another with electric transportation covering 95%. Electricity might be generated thermally or directly as with hydro. One thing you don't really notice, because all the electricity generation goes in together, is that very little of the hydro energy is lost, just transmission and distribution while 70% of the nuclear and 60% of the coal is lost. This was the modification I was suggesting for your graph. If you make it explicit that some sources provide electricity directly and don't need to meet the current input levels of energy, then, even with a lower EROEI, the scale needed to provide them (portions above the yellow lines) can be smaller than for sources that provide lossy energy.

One of the saddest things about the top figure is that it shows than more energy is lost from the electric power sector than is input from coal and gas combined. Surely we can do better than that.

Chris

Slight correction, since I had to chase down the source of that top chart (attributed to EIA via Wiki) for one of my projects. The source was actually Lawrence Livermore Lab. It's available in both english and metric units at: https://eed.llnl.gov/flow/02flow.php

The number for cellulose ethanol is grossly wrong; for net energy of 385 EJ and EROEI of 6, source energy would be 385*(6/(6-1)) = 385*1.2 = 462 EJ.

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.

Robert and Greyzone and the like,

I am only 19 years old, I have researched peak oil, climate change and the overall sustainability of our society with an unhealthy obsession for 3 years. I am in college now and am sophomore majoring in Industrial Engineering and hopefully will get a Master's in Business Administration in a 5 year program, graduating by 2012, god forbid, all with the goal of starting a business which will create as much geothermal, solar, wind and renewable energy as much possible. Along with making solar water heaters, electric vehicles and electrical storage, ammonia solar/wind generating systems, graphite energy storage and whatever the hell else I can think of that may help. I have accepted the fact that many bad things are going to happen and I can't save everything or everyone. Therefore, my goal right now is to find a good region to live and do as many things as I can and hopefully create a bubble of a sustainable Prof Goose Staniford Nate idealized type society based on those ideals where we take into account carry capacity, negative externalities, EROEI, sustainability, energy and all the things other people can't seem to fathom.

frankly though I also realize such a thing is likely just a dream and the economy will be so bad I will probably never find a job, or get to start a business. I will probably get to see society and the world tear itself apart in resource wars and economic collapse. I'll probably see rape, murder, riots, famine, starvation on scales that the world has never seen or imagined. I will probably never live the plush comfy adult life that most of you old folks have lived and are living but just a strange perversion of it. I will soon likely have a fully developed hatred of those who have squandered away me and my children's future ( I would be ecologically responsible and not have 9) in greed for profit and pleasure with no respect to the future. Believe me, If/when this life comes to bear I'll be "thanking" plenty of these people who impeded a better world. What else will there be to do? I have barely seen the world, and now that I finally understand it better, I've got to admit I'm not too impressed. Nevertheless, I will hold onto my illusions of hope until they fail me completely and all is lost and I'll keep on trying to create my "bubble" until then.

Hopefully there is, a future of green pastures, horses, wind turbines, solar panels, happy gardeners and a paradigm shift away from the past, but then again there probably just be a big fat Malthusian correction. The more I see limitless bounds of ignorance and denial the more reality keeps pushing me back, with images of Paris Hilton, talk of the new restaurant/super-target/shopping mall in town and the disregard of all things real. It all makes me take a very long lonely sigh, like a man with very long stare, watching a horrible train wreck in very very, slow motion. But until then, when the train completely de-rails I'll be working on the "bubble." Anyone looking for a bubble?

Excellent post Robert good work, sometimes you really have to beat'em over the head with it.. I think you a doing a wonderful thing in laying the foundations for understanding and change..

-Crews

get a Master's in Business Administration in a 5 year program, graduating by 2012, god forbid, all with the goal of starting a business which will create as much geothermal, solar, wind and renewable energy as much possible.

Look upthread for the info about eMergy and work to figure out how to express things/invest with that model as part of your business decision model.

Eric Blair,

Thanks that is a good idea actually, I been reading different comments about eMergy which I gather so far has to do with EROEI analysis. I will definitely taking a look, I think if business took a more logical analysis approach to business then they would be looking forward more than 2 years into the future doing stuff like EROEI they would be forced to innovate more than the cork in the boat approaches they use now.

Thanks,
Crews

For what little it's worth, Crews, I am in awe of the depth to which you grok the situation so early in life. Best of luck in your pursuits. Just knowing what you do gives you an advantage not only over your peers, but over 99% of the population. Flexibility, adaptability and practicality shall be invaluable as well.

ditto that.
but don't waste your time with the MBA. That time would be much better spent learning skills about energy - the business opportunities will follow - MBAs are just rubber stamps to get you interviews at the best firms, like Bear Stearns, Citi, etc. I used 4 classes out of my 20 at University of Chicago MBA later in life - 2 were stats classes, 1 on risk and 1 on international economics. But given what you 'grok' already, MBA is waste of time. Find a network, perhaps through TOD to work on these problems and your career and life will shape themselves. Just my 2 cents.

Thanks Nate,

I am doing Industrial Engineering because I think it would have the best skills suited to do engineering from a business type stand point, I really would like to take some statistical modeling classes because I'd like to contribute more to theoildrum.com like Staniford does, with these complex logistic curves and Lorentzian models. I would love to be more networked through TOD and involved more in general, maybe I create an article or two that could be guest posted. I am putting together a slide show about peak oil, directed towards city councils that I would hope regular people could download off TOD and could present to their city council kind of like what Gail has done. Anyway maybe I'll shoot you an e-mail Nate, I really appreciate your 2 cents. It's kind of lonely at my age group because no one really likes to talk about these things that matter nor do they understand them, but I am trying to fix that.

Thanks,
Andrew Crews

I agree the most evil thing humans can do is deliberate ignorance.

Allowing for a 30 year age difference, Crews reminds me of myself.

The differences during 30 years is that we have seen
our real society "adapting" to more "information" ...

We have seen the magnitude of deliberate ignorance,
based on dishonesty, backed up with violence,
controlling our civilization ...

A difference between Crews and I is that he has been able to
jump forward to get to the same position I am in now,
but it only took him three years to get there,
instead of the 30 years it took me.

Like every other kind of exponential growth,
children are forced to grow up faster now ...

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.

alekarac, you would be referring to this energy...

The energy is there, don't worry about that, but then we are back to the old question, and that is why use plants, why not use the sun directly with conversion devices (thus explaining Robert Rapier's interest (and mine also)in concentrating mirror solar technology. As one commentator recently said about ethanol, "it's trying to suck sunlight through a corncob", and poster on TOD recently called it "a way of converting natural gas to a liquid fuel and using our food supply to do it."

This is one reason that using biofuel, and particularly ethanol, as an example to explain EROEI is a bit of a strawman argument, because it is taking the absolute worst of all possible alternatives and using it as a model of what "renewable" energy can return. Of course, it in no way explains the volume of energy available directly from sunlight and the varied forms in which it can converted and used (low temp heat, extreme high tempeture heat, electricity by way of PV, etc.

RC

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?

And that is the point I'm trying to make here:
As long as we can add to the gross energy input by means of renewable exogenous sources such as wind and solar then we essentially get some FREE inputs once you take the building of the infrastructure into account.

It's exactly the same as the PHEV when they erroneously say that the car gets 120 mpg.

Well, looked at one way, it DOES get 120 mpg because only one gallon of gasoline was used.
Looked at another way it uses more than a gallon of gas energy equivalent.

My argument is that this is just perfectly ok because ultimately as long as we build the infrastructure we keep getting this free tank of sunlight every single day.

So I say this: the doomers can retreat to their basements while the rest of us get busy building the infrastructure to power the future going forward.

Now that we have identified and analyzed the problem to death, can we finally get down to SOLVING it?

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.

• 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.

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

The reason I think it is correct to do it this way, is this is the same methodology that gives us the 10/1 numbers for gasoline refining. When we refine gasoline, the fuel gas that we use to run the process is also a product - of the refining process. If it wasn't counted in the EROEI equation, we would say that the refining process is 50 or 100 to 1. But we don't distinguish between those inputs that are a product from those that were imported from outside the process: All consumed inputs are calculated, regardless of whether they were a byproduct of the process. So when you count up all of the consumed energy, it takes about 1 BTU to refine 10 BTUs of oil into gasoline. That would be consistent with counting the bagasse.

Robert,

I'm not sure that analogy works. If we were to build a solar still (EROEI >> 20) and use the bagasse for compost, we would only count the energy needed to make the still as an energy input and not the sunlight that boils off the ethanol. We might account for this as an energy conversion efficiency and with renewables this certainly can affect EROEI. A solar panel that needs the same energy input to produce but is twice as efficient in converting sunlight to electricity will have twice the EROEI, but the change comes in the output, not the input.

In the present case, Nate wants to count an opportunity cost. He would say, build the solar still and then send the bagasse out to be used as charcoal and EROEI has gone up because you are now getting both ethanol and bagasse charcoal as outputs. The missing charcoal is the opportunity cost. But, I'm thinking that the bagasse is probably too close to the original sunlight to be counted. The problem with biofuels is the inefficiency of land use because they use plants to gather solar energy rather than EROEI which can be fairly high if other inputs are minimized as with surgarcane ethanol. Even Brazil's castor bean program, which uses marginal lands, still faces this problem. It seems to me that we should not be thinking of biofuels as an energy source, but rather as a sequestration method. Turning the bagasse into charcoal and putting it in the soil should be the main goal with whatever ethanol that is produced seen as a marginal benefit. The solar still will still give an overall EROEI of 8 or so. Switching to sucrose rather than fructose in our beverages might be a better use still than the ethanol, but we can still put the charcoal in the soil.

Chris