Sunday, July 27, 2014

Renewables have higher ERoEI than fossil fuels

One the central claims of the peak oil/energy decline movement, is that renewable sources of power have extremely low ERoEITherefore, it is claimed, renewables are no substitute for fossil fuels, because they cannot provide enough “net energy” to power civilization. In support of this claim, energy decline adherents often post graphs like this one, showing that renewables (especially solar PV) have low ERoEI compared to fossil fuels. More recently, Hall and Prieto have published a book, Spain's photovoltaic revolution, in which they claim that the ERoEI of solar PV in Spain is only 2.45, which is far lower than the ERoEI of fossil fuels.

In fact, those claims are entirely wrong. Renewables have ERoEI ratios which are generally comparable to, or higher than, fossil fuels. Although peak oilers reach a different conclusion, that is because they are carrying out the calculation incorrectly. They are ignoring or not including massive waste heat losses (generally 60% or more) from combustion engines which drastically reduces the ERoEI of fossil fuels. Those waste heat losses provide no energy services to society, and should be counted as losses, but are wrongly counted as "energy returns" by peak oilers. Furthermore, peak oilers are ignoring or not counting other large energy losses of fossil fuels. Those omissions exaggerate the ERoEI of fossil fuels relative to renewables. When the calculation is carried out correctly, renewables have higher ERoEI ratios than fossil fuels.

In other words, the notion that renewables have ERoEI ratios which are lower than fossil fuels, is simply mistaken. It arises from performing invalid, apples-to-oranges comparisons, or from not counting energy losses of fossil fuels.

Fossil fuels have very low ERoEI ratios

Take this graph as an example. It compares the ERoEI of solar PV for electrical power, against the ERoEI of coal and gas for heat. That comparison is invalid, because it’s an apples-to-oranges comparison. Thermal power plants (like coal-burning plants) waste approximately 2/3ds of their energy as waste heat. Waste heat is radiated out into the atmosphere from the power plant, and provides no energy services to society. This massive energy loss from fossil fuels is not counted in that graph of ERoEI, thereby artificially inflating the ERoEI of fossil fuels. If we subtract the energy losses from conversion of thermal energy to electricity, then the ERoEI of fossil fuels declines by approximately 2/3rds relative to solar PV. Conversely, we could also increase the ERoEI of solar PV by approximately 3x, thereby providing an energy quality correction. As a result, the ERoEI for thermal power plants which generate electricity is approximately 2/3rds lower than the graph indicates, or (conversely) the ERoEI of solar PV is approximately 3x higher.

It’s simply meaningless to compare the ERoEI of electricity generation from renewables, against the ERoEI of heat from fossil fuels, because heat is an extremely low-quality kind of energy which is far less capable of performing work. This is an elementary principle of thermodynamics. In order to convert heat to work, we must lose the vast majority of that heat as waste. For example, the vast majority of energy from fossil fuels is simply rejected as waste heat from power plants or internal combustion engines, and so shouldn’t be counted as an “energy return” in ERoEI calculations.

In general, the ERoEI of fossil fuels is extremely low. Natural gas may have an ERoEI of 10, but that falls to 5 when considering the massive waste heat losses emitted from natural gas turbines (generally less than half of the energy in gas is converted to electricity). Coal may have an ERoEI of 30, but that declines to 10 when considering that coal power plants lose approximately 2/3rds of the energy of the coal as waste heat.

The ERoEI of oil is particularly low because it's used in inefficient internal combustion engines inside of vehicles. Most car engines lose about 80% or more of the energy from gasoline, as waste heat, when you include both engine and transmission losses. As a result, the ERoEI of energy which actually turns the wheels of the car (rather than heating the outside atmosphere) is not 14.5 for oil, as commonly claimed, but only 2.9.

Renewable sources of energy do not suffer from those tremendous losses. Although renewables sources of energy do suffer from power grid losses, those losses are minor (usually less than 5%).

As a result, the ERoEI ratios of renewable sources of power are often much higher than their fossil fuel counterparts. Wind turbines have an ERoEI of 18, compared to 10 for coal or 5 for natural gas. Solar PV panels powering battery-electric cars have an ERoEI of about 7 (deducting grid losses and recharging heat losses), compared to 2.9 for oil in gasoline-powered cars.

Incidentally, the extremely low ERoEI of oil for driving cars and trucks (2.9), refutes the notion that an ERoEI less than 8 would lead to the collapse of industrial civilization. That claim is extremely common in energy decline circles, but it was pulled out of thin air and was wrong to begin with for several other reasons. In fact, modern industrial civilization has been growing for decades (especially China and Korea) with ERoEIs far lower than 8.

Hall and Prieto’s criticism

More recently, a book by Hall and Prieto, has become all the rage in energy decline circles. That book claims that the ERoEI of solar PV is grossly exaggerated. Hall and Prieto adjust the ERoEI of solar PV downwards, by adding all kinds of incidental energy costs. They add every incidental energy cost they can think of, like the energy costs of building fences around the solar farm, and so on. They even add energy costs for things like corporate management, security, taxes, fairs, exhibitions, notary public fees, accountants, and and so on (monetary costs are converted into energy by means of a formula). Sometimes, their estimates of those costs are absurdly high. According to Hall and Prieto, the ERoEI of solar PV is only 2.45 when all those things are added.

Once again, the calculation is incorrect, and the comparison is invalid. Hall and Prieto are adding every incidental energy cost to solar that they can think of. However, such energy costs are not included in the ERoEI calculations of fossil fuels. For example, the ERoEI of oil does not include the costs of security in the middle east, or the costs of pipelines, tankers, tanker trucks, road wear from tanker trucks, construction of gas stations, energy costs of driving to the gas station to refuel, the highway patrol, and countless other things. If those costs were counted, then ERoEI of oil (which is already low, at 2.9, when including waste heat losses) would only decline further.

It's necessary to perform an apples-to-apples comparison here. If we're going to add up every incidental energy cost of solar PV, then we must perform the same procedure for oil. Only then would we have a valid comparison.

If you carry out a detailed accounting procedure for both solar and oil, then the ERoEI of oil will be even lower in comparison, than it already was. The incidental costs of oil are almost certainly higher than those for PV. Whereas oil is a scarce substance which requires massive extraction and transportation costs, silicon is the most abundant mineral in the Earth’s crust (sand, rocks) and does not require expensive or elaborate techniques of extraction or transportation. Whereas oil comes from unstable regions and requires massive security and military costs, silicon requires only a few security cameras. Whereas oil is subject to ongoing transportation costs, silicon needs to be transported only once during the lifetime of the solar cells. In general, the incidental costs of oil are far higher than those for solar PV. As a result, if we include those incidental costs in both cases, the adjusted ERoEI of oil will be even lower in comparison than it already was.

Again, when you perform valid, apples-to-apples comparisons, the ERoEI of solar PV is higher than that of oil or natural gas. Oil for transportation in cars has an ERoEI of only 2.9 (because of waste heat losses), but that is before we include incidental costs such as security, infrastructure, and so on, so oil’s total ERoEI would only decline, and would likely be lower than 2.

Hall and Prieto’s analysis is mistaken in other ways. Their estimate of 2.45 for PV is certainly far too low. They include things like taxes and land leases, which are not energy costs, but redistributions of money. Taxes provide services for society, so they should be counted as energy returns, not energy costs. If taxes in Europe on gasoline were counted as an energy cost, then the ERoEI of oil there would certainly fall to below 1. Also, Hall and Prieto include massive energy costs for premature retirement of solar cells because of rapidly advancing technology, but those cells won't be prematurely retired because they are paid for in advance and almost free to operate at that point, regardless of their efficiency compared to newer panels (newer panels would simply be added for future projects). Also, Prieto and Hall include things like administrative expenses, employees’ salaries, and so on, using a formula for converting dollars to energy which is far too high and is just wrong. You would obtain a far lower figure by 
converting salaries to energy using a more reasonable formula, of dividing the entire energy expenditure of a country by its entire GDP in order to obtain a conversion factor.

A correct calculation of the the ERoEI of solar PV including everything, would be more like 6, not 2.45. You can derive this figure by removing everything from Hall and Prieto’s analysis which is not an energy cost (such as taxes or land leases), and by using a more reasonable formula to convert monetary costs to energy.


In short. Renewables generally have higher ERoEI ratios than their fossil fuel counterparts. When you carry out a valid, apples-to-apples comparison, the ERoEI of renewables is generally better. This is because the ERoEI of fossil fuels is actually very poor--generally less than 5--when you correctly subtract the massive waste heat losses of combustion engines, and also subtract the massive incidental costs (such as security costs) of fossil fuels.

The only circumstance where fossil fuels have a higher ERoEI for renewables is when generating heat for smelting of ores or making cement or glass. That’s because such applications do not take place inside inefficient combustion engines, and so don't require subtracting the enormous waste heat losses of such engines. As a result, such applications still favor fossil fuels. Coal has a much higher ERoEI for this purpose than solar thermal plants, and (more importantly) is much cheaper. However, those uses are only a small fraction of total energy usage. Those uses will probably be the last energy uses which are converted from fossil fuels to other sources of energy, possibly more than 100 years from now.

Not that ERoEI matters much anyway. The whole idea is a mistake. What matters is the cost (in money) of net energy, for an energy source. If the cost of net energy is low, then the ERoEI is just totally unimportant. For example, if it were possible to build a 1 GW fusion power plant very easily out of duct tape for only $10, then it wouldn’t matter at all if it had an ERoEI of less than 2. We could just build more of them, and thereby produce the same amount of net energy as a higher-ERoEI (but more expensive) energy source. As long as an energy source has an ERoEI higher than 1, the ERoEI ceases to matter, and what matters is the total cost of net energy. This is discussed further here.


  1. Hi there Tom!
    Though this is the first time I write a comment here, I have been reading your posts for a very long time now. It is always a pleasure when you add a new post, as I always find them to be very enjoyable and informative to read. Keep up the good work!
    Best Regards
    Jimi (Denmark)

  2. Jimi,

    Thanks for the kind remarks. I'm glad you're happy with my blog. I intend to add some more posts in the next couple of months.

    -Tom S

  3. Some strange claims here, so I wrote a blog post about it.

  4. Hi eclipsenow,

    Thanks for your comment. I'll respond to it here.

    "As I understood ERoEI, the claims were that x amounts of coal or oil or gas delivered y amounts of useful work. That is, x coal delivers y electricity or heating or whatever... They’re measuring what x coal actually does: how much power it produces, how much it heats homes, whatever."

    You're mixing up terms like "heat", "work", and "electricity". They are not interchangeable. The words "heat" and "work" have totally different meanings in thermodynamics.

    ERoEI does not measure the amount of useful work performed. Nor does it measure what "gets done". ERoEI measures the heat in a power plant from burning coal.

    If you wish to measure work, then you can't count waste heat losses. In thermodynamics, waste heat losses are not work.

    For example, moving a train one mile, would be an example of work. That would actually count as "getting something done". Solar power would propel the train 2.7x further than coal, as their ERoEI figures would suggest. In other words, solar power would "get things done" 2.7x more than coal, as their ERoEI figures would suggest, from a given energy input.

    ...If you count waste heat losses as "getting something done", then ERoEI has absolutely no meaning. In that case, the ERoEI of all energy sources would be 1, because of the first law of thermodynamics (conservation of energy). In that case, renewables have ERoEI ratios (1) which are exactly identical to fossil fuels (1), and that ERoEI ratio would never change.

    "That is, x coal delivers y electricity or heating or whatever..."

    No. Electricity is not heat! X coal does not deliver y electricity. It would deliver y heat, but it would deliver 0.3333y electricity, or 2/3rds less than the ERoEI figures would suggest. If x is the energy input and y is the amount of electricity produced from coal burning plants, then y will be 2/3rds lower than what you'd expect from the ERoEI figures.

    For example, if you try to recharge a huge battery from a coal-burning plant, then you would get 1/3 of a joule of energy in the battery for every joule in the coal.

    "Looking at waste heat and then subtracting that off the work coal actually does is nonsense."

    ERoEI is not measuring what coal "actually does"! Waste heat is not work!


  5. "The thermal losses in the process might be terribly inefficient, but y still gets done. The thermal losses might warrant reinventing how they build power plants to capture some of that waste heat for the local houses, but y still gets done. The sheer waste of heat might make you want to pull your hair out, but y still gets done! That’s the point."

    But that's not the point. ERoEI is a ratio, not an event. It is not just implying that something gets done. It implies that something gets done for a given energy input. However, it was calculated incorrectly by the peak oil community.

    "This is not theoretical. There’s so much energy in fossil fuels that even when we use them badly, they still have enough left over energy to run our power grids and move our cars."

    That's beside the point. The point is that the ERoEI of oil is 80% lower than is reported. It's still higher than 1, so it can power our cars, but the ERoEI figures reported by the peak oil community are still quite wrong.

    "For if x coal produces Y work in an inefficient power plant, will not x coal produce 2y or 3y in a really good Combined Heat & Power plant?"

    Sure. You could capture the waste heat from coal-burning plants and use it to heat homes. For that matter, you could capture the waste heat from solar thermal power plants, and use it to heat homes. Or from nuclear plants (the coolant water is not radioactive). You could probably even capture the waste heat from solar panel manufacturing, and use it to heat homes.

    If you are going to count one kind of waste heat, then you must count the others too. Otherwise, it's an invalid comparison. The problem is, peak oilers are counting the waste heat which radiates into the atmosphere from coal plants, as "energy returns", however they are not counting the waste heat from PV manufacture or from solar thermal plants, as "energy returns".

    "Some strange claims here,"

    I'd guess you've been hanging around the peak oil doomsday prepper community for too long. In comparison, my claims aren't strange at all.

    In fact, my claims are quite normal. My claims are fairly obvious implications of calculating things correctly and not ignoring waste heat losses.

    -Tom S

  6. Hi again,
    I think you're playing a semantic game to ignore my point which still stands. I was not speaking technically when I used the word ‘work’: I meant it in the English sense of ‘job’, or ‘getting something done’, which I thought was the main basis of actual ERoEI discussions. Sure some sites might make the mistake of just going on and on about all that heat, and then ignoring the ERoEI losses as the heat is converted to electricity. That happens. But my point was that *IF* an ERoEI discussion about a specific coal plant was conducted correctly, and compared the energy inputs to energy outputs, that conversation would have to find a base energy measure (GJ?) to compare all the diesel and petroleum and thermal and electric inputs (and even food inputs for those desperate to measure the human embodied energy in a system: to which I ask why bother!?) to the electric or heating outputs.

    *IF* a discussion is just measuring coal and oil inputs to sheer heat outputs of a coal thermal plant, then I’m with you! The ERoEI discussion is about useful energy resources IN against useful energy resources OUT (whatever those resources are). So yes, the ERoEI should go down if they’re not actually doing that. That’s wrong. But I contest your assertion that ERoEI discussions are always that off-beat, and I also contest that they have to discuss one type of energy only. Here’s an example from Engineer Poet who clearly shows the ERoEI for a variety of energy services that nuclear power can provide. Note: I know it doesn’t address Lenzen’s first 3 energy inputs in mining and milling and enriching uranium but here it is anyway.

    AP1000 is 42t(steel)/MW(avg)
    Concrete is not given, but 1970’s PWRs were 190 m³/MW(avg).

    Energy required to make steel is 19 million BTU per ton (about 21 GJ/MT).
    Energy required to make concrete is roughly 1.1 MJ/kg, or about 2.64 GJ/m³.

    Major material inputs are (882+502)=1384 GJ per MW of average output. This energy is recovered in (1,384,000 MJ / 1 MJ/sec) = 1,384,000 sec = 16 days. That’s assuming that the energy to build is counted against energy output; if it’s against raw thermal energy, it’s repaid in about 5 days.

    If we assume 16 days, the energy of the materials used in construction is repaid about 23 times per year, or 912 times over the initial 40-year licensing period. It’s pretty obvious that 75:1 is pessimistic, and Stasse’s assertion of 10:1 is delusional.

    Given that the energy overhead of centrifuge enrichment is about 0.1%, the EROI of nuclear power plants must be well in excess of 100.

    The big problem is lawyers; adding lawyers to the process can reduce the EROI of anything to less than 1 in short order. The solution is to shoot them, which diminishes their billing rate tremendously and practically eliminates actions filed.

  7. eclipsenow:

    "I think you're playing a semantic game to ignore my point which still stands. I was not speaking technically when I used the word ‘work’: I meant it in the English sense of ‘job’, or ‘getting something done’, which I thought was the main basis of actual ERoEI discussions."

    Whether you were using the word "work" in the thermodynamic sense, or in the everyday sense, makes no difference here. Waste heat does not accomplish any "work" in the everyday sense either. Waste heat ultimately heats the atmosphere above a smokestack which causes infrared light to beam out into space. It does not perform any useful service in any sense of the term.

    Of course it's possible to build combined heat and power plants which use some of the waste heat to heat homes. In which case, it would be reasonable to count that as "energy returns". However, that does not affect ERoEI of fossil fuels at present, which are rarely used in combined heat and power plants. All that would mean, is that you could increase the ERoEI of fossil fuels in the future (if we wished to replace all the power plants we have, with combined heat and power plants over the next 40 years). Of course, it's also possible to increase the ERoEI of all other energy sources in the future. ERoEI is not referring to future potential, otherwise nuclear and solar would win again, by even more. ERoEI refers to the energy return we get at present, in which case the energy returns of fossil fuels are quite low.

    I don't think we will ever be able to do much with the waste heat generated from cars and trucks. If we attempted to store that waste heat using a thermal mass, and then driving it back home and heating the house, then the thermal mass would greatly increase the weight of the car and decrease fuel economy. I think the ERoEI of oil in cars and trucks is 2.9 and will only decline gradually from there, whereas the ERoEI of solar panels powering battery-electric cars is approximately twice that and will increase in the future.

    "*IF* a discussion is just measuring coal and oil inputs to sheer heat outputs of a coal thermal plant, then I’m with you! The ERoEI discussion is about useful energy resources IN against useful energy resources OUT (whatever those resources are). So yes, the ERoEI should go down if they’re not actually doing that. That’s wrong."

    Then you are with me. In fact, most ERoEI calculations do not subtract waste heat losses, and so are calculated incorrectly.

    I've read a few ERoEI analyses that correctly subtracted waste heat losses from power plants. However, I don't think I've ever read an ERoEI analysis of oil which correctly subtracted the massive waste heat losses from the radiator, engine, and transmission of your car (which total 80%). On occasion, it's possible to use that waste heat to heat the cabin of the car, but that never employs more than a few percent of the waste heat. As a result, the actual ERoEI of oil is very low.

    "But I contest your assertion that ERoEI discussions are always that off-beat"

    I've never seen ERoEI have a legitimate use. When waste heat losses are correctly subtracted, there doesn't seem to be a huge difference between the ERoEI of difference energy sources. They are all around 5-10, except oil which is lower, and hydro dams which are higher. Most of them, however, are in a fairly narrow range. That range is obviously compatible with sustaining society.

    Increasing the ERoEI beyond this range would have little benefit. For example, if nuclear power plants had an ERoEI of 10 and we massively increased it to 100, then that would be only a 9% increase in net energy output for a given number of plants. As long as the ERoEI is higher than 4 or so, only a smallish minority of energy is used to collect more energy, and increasing it more would make little difference.

    -Tom S

  8. eclipsenow:

    "The big problem is lawyers; adding lawyers to the process can reduce the EROI of anything to less than 1 in short order. The solution is to shoot them, which diminishes their billing rate tremendously and practically eliminates actions filed."

    Unfortunately, the problem is not lawyers. The person who coined the term "ERoEI" (Charles Hall) does this procedure constantly. He calculates the ERoEI of solar, but then starts reducing it by subtracting every kind of ancillary cost, like the cost of security cameras, fences, employee salaries, fairs, exhibitions, taxes, and so on. All those are guesses, so he comes up with huge overestimates for most of them, and finds that the ERoEI of solar is actually only 2.5.

    Of course, it's possible to use this procedure for any energy source. Most energy sources have fairly low ERoEI (5-10) to begin with, and oil has a very low ERoEI (3-4, or less than 3 for cars and trucks). With oil, you could reduce the ERoEI to less than 1 if you started counting gasoline taxes, and military expeditions in the middle east, and so on, and came up with huge overestimates of the energy expenditures of those things. Of course, it's not really less than 1, but it's easy to produce a mistaken estimate showing that, by using the procedure which those guys are using.

    Interestingly, Charles Hall counts taxes in Spain as an energy cost in his book about PV. However, if taxes on gasoline in Europe were included in the ERoEI of oil, then it would approach 1 there even before we started adding up all the other ancillary costs. The ERoEI of oil in cars and trucks is only 2.9 anyway, and I think some European countries have taxes of 50% or so on gasoline and diesel, which immediately reduces the ERoEI of oil there to less than 1.5. That's before we start subtracting the thousands of ancillary costs.

    Some energy decline theorists claim that nuclear power is an energy sink! However, France gets 40% of all energy from nuclear power. If it were an energy sink, then France would spend almost all of its imported fossil fuels on just maintaining nuclear reactors, and would have almost no fossil energy left over for cars, trucks, cement making, and so on. Obviously, this is not the case, since France has many cars, trucks, and buses which operate at present.

    -Tom S

  9. ERoEI is only a part of the issue with solar and wind energy capturing devices. Solar and wind capturing devices are not alternative energy sources. For the physical devices – for wind, photovoltaices, solar hot water, hot air panels - the sun and wind are there, are green, are sustained. The devices that are used to capture the sun and wind’s energy are an extension of the fossil fuel supply system.

    There is a massive infrastructure of mining, processing, manufacturing, fabricating, installation, transportation and the associated environmental assaults. There would be no sun or wind capturing devices with out this infrastructure. This infrastructure is not green, sustainable, or renewable. The making of these devices inadvertently but directly supports fracking, tar sands and deep ocean drilling because of the need for this infrastructure.
    I invite anyone cheerleading for solar to view these essays.
    This essay has diagrams and pictures of how we get copper, aluminum, glass, black chrome – the chemicals, heavy machinery, and industrial processes that are necessary to make the devices to capture the energy of the sun and wind.

    And even if you could get around the environmental degradation, the low ERoEI and could amass enough extra energy to reproduce the capturing devices and their equipment, then how about the rest of the STUFF of high tech, high energy society?

  10. Hi John Weber,

    Thanks for your civil and thoughtful post.

    I looked at your website and I think you're making three errors.

    First, you're making the old "fossil fuel subsidy" argument which is incorrect. I've already addressed that argument here:

    Although renewable sources of energy have a fossil fuel subsidy RIGHT NOW, the subsidy is temporary and does not prevent us from transitioning to renewables. The subsidy happens ONCE, as the FIRST generation of renewables are built. Every subsequent generation of renewables will have a renewable subsidy.

    This is the case with every energy source: oil was originally subsidized by coal, which was originally subsidized by wood (charcoal), since early steam engines ran on charcoal. Still, it was quite possible to transition from one energy source to another, because we no longer use wood inside of steam engines at all.

    Your other argument is that manufacturing relies upon complicated procedures that require a series of steps. This is the case whether you are using renewable power or fossil fuels. It's no easier using fossil fuels. There is specialization and compexity in a modern economy, but that's the case using any energy source. It is not an argument for fossil fuels per se.

    Your third argument is that manufacturing requires fossil fuels. However, manufacturing uses fossil fuels as sources of HEAT and ELECTRICITY. Heat and electricity could also be provided by renewables, or by nuclear power for that matter.

    I think your fundamental error here is assuming that current conditions are permanent. You observe that the energy for manufacturing aluminum comes from electricity (mostly) which comes from fossil fuels. However, you are wrongly concluding that that must always be the case. The heat and electricity for manufacturing could just as well come from solar furnaces and solar panels. Obviously, it would take a long time to transition to solar power for manufacturing, but we have far more time than is required.

    Obviously, the first generation of solar plants would have a fossil fuel subsidy, but the subsidy would be temporary. It's entirely possible to use fossil fuels to manufacture solar plants, which are then used to manufacture more solar plants. This is the kind of allocation decision which all capitalist economies carry out routinely. That is how we transitioned from one energy source to another in the past. There is nothing preventing us from doing so again, or from making yet another energy transition to renewables. It will take a long time (decades) but it's entirely possible.

    -Tom S

  11. I couldn't disagree more. You think you are going to mine, refine, process, manufacture, fabricate, transport, install, maintain, replace parts, replace devices and also provide the goodies we want to use the electricity for with renewables? You simply have not done the numbers or understand the global extend of the industrial infrastructure that accomplishes all this including the equipment at a solar energy collecting device manufacturing firm. Just one mining truck 24 feet tall uses one gallon of diesel every 30 seconds and there is a global fleet of them. Better bring a shovel or do the math. Send your stuff to either Charles Hall or Pedro Prieto. We are done.

  12. John Weber,

    You have not provided any refutation or counterpoint to anything I've said. Instead, you've asked a QUESTION ("do you think that...") and then just assumed your conclusion. Then you said that trucks use a lot of diesel, which doesn't support your point at all.

    "You think you are going to mine, refine, process, manufacture, fabricate, transport, install, maintain, replace parts, replace devices and also provide the goodies we want to use the electricity for with renewables?"

    Yes, because it's quite possible to do all of those things with renewables, even now. Obviously, it's a major transition, and it won't happen quickly. However, we have more than 100 years to make that transition before fossil fuels are exhausted, which is far more time than is required. The vast majority of industrial civilization is less than 30 years old, and most industrial equipment is replaced every 30 years anyway.

    "Just one mining truck 24 feet tall uses one gallon of diesel every 30 seconds and there is a global fleet of them. Better bring a shovel or do the math."

    This just doesn't support your point at all. Trucks can easily run off liquid fuels (such as anhydrous ammonia) which can be manufactured from electricity taken from renewables. This is possible now, and is already done on a pilot scale. We have more than 100 years to convert the fleet of trucks to anhydrous ammonia or any number of other alternatives, which is far more time than is required.

    It doesn't support your point at all to just say "there's a truck which runs on diesel." You are claiming on your website that it's IMPOSSIBLE to run an economy on renewables. It obviously doesn't support your claim just to say that a truck runs on diesel NOW. You would have to show that no trucks OTHER than diesel trucks are possible (which you haven't done), or that we don't have enough time to make the transition to alternatives (which you also haven't done).

    "You simply have not done the numbers ... do the math"

    I have done the numbers, and it's clearly possible to generate far more electricity and liquid fuels from renewables than was ever available from fossil fuels. This is something you can easily look up, or calculate. The average solar irradiance is almost a kilowatt per square METER of the earth's surface. Multiply that by the terrestrial surface area of the earth, and then multiply by 0.2 as an efficiency factor, and then compare the resulting figure against worldwide energy consumption. You can quickly determine that it would take about 1% of the Earth's surface covered in solar cells to generate more energy than the world uses.

    The math here is very simple. One number is FAR GREATER than another. Renewable energy is FAR more abundant than fossil fuels ever were. If there are enough fossil fuels to power civilization, then there is certainly enough energy available from renewables to power civilization.

    "We are done."

    Okay. Whether you choose to respond or not, is up to you. However, you've not yet provided any evidence or reasoning to support your claim.

    "Send your stuff to either Charles Hall or Pedro Prieto."

    The work of Charles Hall and Pedro Prieto contains mathematical errors so severe that they invalidate the conclusions. I've detailed that elsewhere on this site.

    -Tom S

  13. From Wikipedia definition of EROEI: The energy returned includes usable energy and not wastes such as heat, although depending on source and application, waste heat is used in district heating and water desalination, these cogeneration plants however are rare, globally, and thus usually excluded in EROEI analysis of energy sources.

  14. Hi gilbert,

    Most ERoEI analysis does not exclude waste heat losses. Here is the definition of ERoEI from Charles Hall, who invented the term and who is cited extensively in peak oil circles:

    EROI=Mean quantity of energy discovered / Quantity of energy used in that activity.

    This definition is taken from Hall's latest paper on the ERoEI of oil, in 2011, entitled A New Long Term Assessment of Energy Return on Investment (EROI) for U.S. Oil and Gas Discovery and Production

    Hall explicitly states in that paper that he is not excluding waste heat losses, and not making an energy quality correction: "Results... EROI for production of the oil and gas industry (with no quality corrections) ".

    Hall and most other ERoEI authors do not exclude waste heat losses.

    Granted, there are a few papers now which avoid the error and which do not count waste heat losses in ERoEI. Perhaps those papers are what wikipedia is referring to. However, those papers show that renewable sources of energy have ERoEI comparable to fossil fuels.

    For example, there was an extensive paper written by Mason Imman recently with an accompanying article in Scientific American (Vol 308, Issue 4). That article examines the ERoEI figures from all papers which the author could find, and EXCLUDES waste heat losses. It reports the following ERoEI ratios for electricity generation (excluding waste heat losses):

    Nuclear: 5
    Solar PV: 6
    Natural Gas: 7
    Coal: 18
    Wind: 20
    HydroElectric: 40

    Imman's paper was the ONLY large-scale comparison of the ERoEI of different energy sources I know about, which does not commit that mistake. It clearly shows that renewables are in the same range as conventional sources of electricity generation.

    There is also an analysis of the ERoEI of solar PV by J Lundin, which performs a quality correction for waste heat losses. Lundin's paper is always very careful to differentiate when he is talking about heat, and when he's talking about electrical energy. He performs a "quality correction" to account for waste heat losses of fossil fuels. The quality-corrected ERoEI of solar PV is ~14, which is similar to mot published ERoEI figures for natural gas.

    -Tom S

  15. I disagree with the notion that EROEI is irrelevant as long as it's greater than 1. If your average EROEI over all your primary energy sources in 1.00001 then according to your theory everything should be fine. In reality that would leave you with very little surplus energy that can be used for anything useful ... unless you litter the planet with an insane amount of units of whatever power source you're using.

    1. "If your average EROEI over all your primary energy sources in 1.00001"

      Typo correction: If your average EROEI over all your primary energy sources is 1.00001 ...

  16. I agree: if a nuclear power plant only produced enough surplus energy to run one light bulb, I don't think anybody would bother building one. Even if it could power, say, fifty homes, still nobody would build one. Even if people wanted to, the various materials to build that many nuclear plants would quickly run out.

    So a power source has to have sufficient EROEI.

  17. @Tom S
    > The average solar irradiance is almost a kilowatt per square METER of the earth's surface.

    No. It's 89,000 TW / 510 trillion square meters = 175 watts per square meter. The earth orbits the sun elliptically, and when it's further from the sun, this figure is even lower. Power generation infrastructure must be built to accommodate this lower power density.

    > Multiply that by the terrestrial surface area of the earth, and then multiply by 0.2 as an efficiency factor

    Real-world solar power plants don't use the surface of the earth as efficiently as a given solar cell uses its own area positioned perfectly perpendicular to a light source. Page 93 of Robert Bryce's book Power Hungry gives solar's power density as 6.7 watts per square meter. Presumably, that's only at the best locations. I would guess that's optimistic, and a more realistic figure would be 1 watt per square meter. That would give us 5 TW, covering 1% of the earth's surface with solar power plants. That's 25% of the 20 TW people use right now, and only 10% of the 50 TW people will use sometime in the future.

  18. Hi hitssquad,

    In that comment I was quoting the maximum solar irradiance, which I grant was too high. That does not include reductions due to tilt of the Earth or absorption by the atmosphere. I typed that comment far too quickly and didn't actually look it up.

    However, your figures are too low. The figure of 175 w/m^2 includes places like Antarctica and the North Pole, where nobody lives and where we obviously wouldn't put solar panels. The average insolation for densely inhabited terrestrial land masses appears to be about 250 w/m^2. It is much higher in the southwestern US, Austrialia, the Middle East, and most of Africa. It's much lower in Europe.

    "Page 93 of Robert Bryce's book Power Hungry gives solar's power density as 6.7 watts per square meter. Presumably, that's only at the best locations. I would guess that's optimistic, and a more realistic figure would be 1 watt per square meter."

    I just don't see how you arrive at those figures. Could you indicate how you derived those figures?

    Even at 200 w/m^2 at 15% efficiency, it's about 30 w/m^2. Furthermore, that's not for the "best locations", but a fairly poor location. That's 30x higher than what you indicate.

    I'm looking around on Google now, and everything I encounter says people typpically get 5 or so full sun hours per day of 1000w/m^2 from their solar panels, and that 15% efficiency is fairly low. That's 30 w/m^2, not 6 w/m^2 and certainly not 1 w/m^2. Furthermore, Tom Murphy on his blog "do the math" (which is how you arrived here, I think) indicates that "At 15% efficiency, our square meter captures and delivers 0.75 kWh of energy to the house" which is 31.25 w/m^2, about what I calculated.

    I grant that we would need access roads, etc, between the solar panels. However, that would not reduce the area of the panels by 97%.

    I think a very pessimistic figure would be 20 w/m^2. The figure for deserts would be higher, about 30 w/m^2.

    I will grant that it would take about 3% of the desert area of the world (not including antarctica) to power the whole world, not the 1% I indicated above. I was not taking into account absorption by the atmosphere. (Details of calculation: world desert area not including antarctica is 25 trillion m^2. 25 * 30 = 750 TW. 20/750 = 0.0267 = 2.67%).

    "and only 10% of the 50 TW people will use sometime in the future."

    I think solar panel efficiency will increase in the future.

    -Tom S

    1. Robert Bryce cites this paper by Jesse Ausubel ("The future environment for the energy business"; p494):

      " equal the output of a single 1,000 MW nuclear power plant [...]
      photovoltaics [...] still need a carpet of 150 km^2."

      Doing the math reveals that's 6.7 watts per square meter. Ausubel doesn't provide a source for his 150 km^2 figure.

      On the previous page of that paper (p493), Ausubel has an info sidebar that says "solar thermal (actual)" produces 3.2 watts per square meter. I think you'll find in general that when you look at the outputs of actual operating power plants and divide those outputs by the actual areas of those power plants, the figures will be far below your theoretical figures. The reason is: life has a way of being messier than theory.

      For example, Ivanpah is 3,500 acres = 14,163,997.5 m^2. From Google: "for the eight-month period from January through August, its three units generated 254,263 megawatt-hours of electricity".

      Google says that's 242 days. That works out to an average production of 43.778 megawatts, or 3.1 watts per square meter. I imagine it would be even worse for December, the one and only month in the Northern Hemisphere that actually counts when rating solar power. I wonder how bad it will be once the mirrors start to get a bit dirty.

      Note that isn't pure solar power. That 43.778 MW was produced with the help of natural gas:

      "Those growing pains included realization that the plant would need to boost its natural gas consumption. The fuel is used with auxiliary boilers that prime the system in the early morning, allowing the plant to begin generating electricity as soon as possible after sunrise; to maintain performance during intermittent cloud cover; and to eke out more energy as the sun fades at the end of the day.

      In its March petition to California regulators [PDF], Ivanpah’s owners said it was only through running the plant that they realized “more boiler steam would be needed than previously expected in order to operate the system efficiently and in a manner that protects plant equipment, and to maximize solar electricity generation.” They added that “auxiliary boilers typically need to operate an average of approximately 4.5 hours a day during startup (an increase from 1 hour daily average originally expected).”

      Under the original certification, “total annual natural gas fuel heat input” was not to exceed “5 percent of the total annual heat input from the sun” at each of the three Ivanpah units. That provision has been struck, and now BrightSource can burn a total of 1,575 million standard cubic feet of natural gas every year. To get a sense of that volume, an average U.S. natural gas-fired power plant might be expected to produce about 200,000 MWh from 1,575 mmcf of gas, according to the EIA."

      So, only about half of that 3.1 watts per square meter of electric power was actually produced by solar. The real figure then is about 1.5 watts per square meter of solar power. My wild estimate of 1 watt per square meter was close.

      ...And before you say photovoltaics vs. CSP, remember that PV cells perform worse, the hotter they get.

    2. Update: this site says Desert Sunlight, a PV power-plant, produced 1 million megawatt-hours of energy in 2014 (114 megawatts average) on 6.5 square miles of land (16,834,922.7 square meters):

      That works out to 6.78 watts per square meter -- pretty close to Jesse Ausubel's figure of 6.7 watts per square meter.

      ...And, again, that's not in December. I'd like to see a December figure for Desert Sunlight 10 years from now, when the system will have decayed somewhat.

    3. Hi hittsquad,

      Desert sunlight was still being constructed in 2014. It was constructed in stages and didn't reach full output until 2015. That might partly account for the low output per square meter.

      Interestingly, it's difficult to find real-world data on this issue. The vast majority of solar plants in the world have less than a full year of continuous operation at full capacity. The ones which have longer experience are usually lower-efficiency thin film technologies.

      I was able to find some data on three solar plants: Nellis solar power plant, Agua Caliente Solar Plant, and California Solar Ranch. Those three have more than 1 year of continuous operation at full capacity. I calculated values of 6.4 watts/m^2 for Nellis, 8.6 watts/m^2 for Solar Ranch, and 8.81 watts/m^2 for Agua Caliente. All three are in fairly good locations, meaning southern California or Nevada.

      In the best locations for solar (like Saudi Arabia) it appears that solar PV plants (not thin film) would produce about 10 watts/m^2, whereas in poor locations such as Germany the figure would be about 4 watts/m^2.

      There is very little information on solar thermal plants, but they appear to be worse. The website for the Genesis Solar plant indicates that it's anticipated to get 300 GWH per year on 780 hectares, which is 4.4 watts/m^2. Bear in mind that the 4.4 watts/m^2 is what they expect, not what they've achieved. No data is available on actual performance.

      -Tom S

    4. Thanks for the data. The EIA seems to have production data. Here's some December 2014 production data for those sites from the EIA (links are in the Wikipedia articles for those sites):

      Agua Caliente: 36,706 MWh / 744 hrs = 49.3 MW
      Nellis: 2,046 MWh / 744 hrs = 2.75 MW
      California Valley Solar Ranch: 27,634 MWh / 744 hrs = 37.1 MW

      December 2014 power density:

      Agua Caliente: 49.3 MW / 9,712,455 m^2 = 5.1 w/m^2
      Nellis: 2.75 MW / = 566,560 m^2 = 4.9 w/m^2
      California Valley Solar Ranch: 37.1 MW / = 7,956,120 m^2 = 4.7 w/m^2

      That seems to average around 5 watts of December power per square meter. That would give us 25 TW of December power, covering 1% of the earth's surface with PV solar power plants. That would be almost half of the Sahara desert.

      Note: Nellis data is for December 2013. The EIA's data set for Nellis ends there.

    5. "That would give us 25 TW of December power, covering 1% of the earth's surface with PV solar power plants. That would be almost half of the Sahara desert."

      That's assuming we have no seasonal energy storage and December solar power must be sufficient to power civilization for that very month.

      For the time being, we would likely use natural gas backup for the few winter months during which solar power is reduced.

      What happens after that, when the natural gas runs out? I don't know, because that's more than 50+ years in the future and there are many technological developments happening now with regard to energy storage, artificial photosynthesis, and so on. If none of those things work out in the next 50+ years, then we may need to overbuild solar so that the worst month (December) provides enough power for that month.

      -Tom S

  19. Hi Bountiful Energy.

    Charles (Hall) has certainly taken oil, shale and tar to task, along the same lines, for its diminishing energy returns. He's rounded Energy Return on Investment to oil down and down and down - citing, I believe, that some 2 barrels are used for every ONE received in every bit of the long road of procurement, manufacture/refining, and distribution of oil to gas. If you search the web, you'll easily find that Hall makes the point that we use at least one barrel, and probably more, in that long drilling/refining/delivering chain.

    I'll quote him:

    "By the time the oil energy is delivered to the consumer, 40 percent has been used and the EROIpou has fallen to roughly 6:1 (including the entire refining, conversion and delivery chain). But it is energy services that are desired, not energy itself, and to create these energy services requires energy investments in infrastructure that carry, at a minimum, large entropic losses. If infrastructure costs are included, the EROIext falls to about 3:1 because two-thirds of the energy has been used; implying that more energy is being spent on extraction, refining, delivering, and maintaining the transportation infrastructure than is found in the end product. Thus by the time a fuel with an EROImm of 10:1 is delivered to the consumer – that is after the energy costs of refinement and blending, transport, and infrastructure are included, the EROIext is 3:1."

    That's from his paper, "What is the Minimum EROI that a Sustainable Society Must Have?" From "Energies" journal, 2009.

    I guess you might want to apply the same logic to your arguments.

    Give solar and wind their best estimated, hopeful, wishful Energy Return - now subtract that all important: MAKE IT USEABLE TO CONSUMERS.

    And you've got the same old long drainage system. You've not done that work, and once you do, you'll winnow your large potential gains down to a less hopeful reality. (Much like is done with shale oil - a trillion barrels as a potential oil resource, versus a proven extracted reserve of a few billion.)

    Electric cars, by the way, come from here:

    That's tons of the most toxic stuff on earth for a windmill, a pile of big electric car batteries, etc, etc. And for every cell phone - about a pound of radioactive and toxic material - thanks very much, Steve Jobs and the Pirates of Silicon Valley. Thanks "free market." Thanks consumer capitalism (without a thought for the future).

    Now, it's all pretty hypothetical at present, because we live inside an internal combustion engine. But I think most EROI discussions miss this point:

    The initial return of oil, over 1,000 to 1 in discovery, in EROI, in every way - was so bloody IMMENSE that it didn't matter what the EROI at the point of use was (car, diesel drill sludge pump, water pump, streetcar system, bus, airplane), because we had SO BLOODY MUCH OF IT.

    That simple equation - let's call it SBM - so bloody much - made all the difference. So compact, so burnable, and SBM. So..bloody...much.

    I love conservation. I hope the world starts to do the same. But I also understand the human species has the foresight of...well... the human species. A funny monkey that thinks about one meal into the future.

    Thanks for the blog and the chance to communicate on these important topics. - Liam Scheff, (that's me.)

    1. Hi Liam,

      Thanks for your thoughtful remarks.

      "I guess you might want to apply the same logic to your arguments... Give solar and wind their best estimated, hopeful, wishful Energy Return - now subtract that all important: MAKE IT USEABLE TO CONSUMERS."

      I have already applied that logic to my arguments. I ignore the transportation infrastructure etc for both oil AND renewables. I am assuming that the transportation infrastructure (roads, bridges, and so on) is no more expensive energetically for EVs than for gasoline-powered cars, in which case it makes no difference when comparing the relative ERoEIs of both sources.

      Even if I were to account for distribution costs, those costs would almost certainly be lower for renewable electricity than for oil. Electricity can be distributed over a grid which was built for other purposes anyway. Electricity does not need to be "refined" the same sense as oil. Solar panels do not require protection using the US military or repeated military interventions in the middle east, all of which have large energy costs.

      "And you've got the same old long drainage system. You've not done that work, and once you do, you'll winnow your large potential gains down to a less hopeful reality."

      Sure, but that "long draining system" winnows down the ERoEI of BOTH fossil fuels AND renewables. In all likelihood, it winnows down fossil fuels more, so the ERoEI of fossil fuels is being exaggerated relative to renewables.

      As long as you perform an apples-to-apples comparison, the ERoEI of renewables is comparable to, or higher than, fossil fuels. Since the ERoEI of fossil fuels right now is sufficient to sustain an industrial society, the ERoEI of renewables is sufficient also. There may be other problems with renewables, but ERoEI is not one of them.

      "Thus by the time a fuel with an EROImm of 10:1 is delivered to the consumer – that is after the energy costs of refinement and blending, transport, and infrastructure are included, the EROIext is 3:1."

      The typical internal combustion engine in a car loses 75% of that 3:1 energy as waste heat, in which case the ERoEI of energy which actually moves the car is below 1. Perhaps Hall is being too pessimistic in his estimates of ERoEI. In any case, the ERoEI of energy which actually moves the vehicle is almost certain to be higher for any EV powered by wind, solar, or nuclear.

      -Tom S

    2. Hi Tom,

      Thanks for your response! I feel like some major costs are being omitted in your more hopeful accounting. You wrote:

      "I am assuming that the transportation infrastructure (roads, bridges, and so on) is no more expensive energetically for EVs than for gasoline-powered cars, in which case it makes no difference when comparing the relative ERoEIs of both sources."

      The cost of roads is immense - Roads rely on:

      Tar, diesel engines, pouring and rolling machines, steel works, foundries, overseas mining, limestone, cement... (and fast food restaurants, though I don't recommend it).

      But it also relies on the idea that 239 million people will be driving cars in this country. (Here's a recent write-up on the now billion internal combustion engines accounted for in the world. And are they even looking at motorcycles, scooters, and small 'irregular' vehicles' that define most of Asia and India? Not that I can tell.)

      And all of that relies on a diesel-driven infrastructure to produce - all of the above.

      Electric cars are a boutique market - with heavy metal batteries sucked out of inner Mongolia (the Bayan Obo district) - we're not getting to a billion cars made out of plastic running on electricity, powered by nuclear plants (built out of steel and concrete by diesel machines).

      The electric car market, also, requires a new build - gas stations plus electric charging, done with a standard plug-in...nation, state, city-wide. I'm not betting on it. Power lines are sagging and breaking across this vast continent, and country roads are now going unpaved....I think the prices are staggering - and without a Spindletop to take us there... well.

      I mean, if we were smart --- and we are not --- we'd be putting electric trolleys on every Main street in Amorica. (Did I say 'but we're not," yet? Because we aren't. We aren't capable of thinking ahead as a species...)

      I appreciate your toothy taking to task of the vaunted EROIs of various carbon-fuels - but I think the point I made is the one that almost no one really understands when discussing energy.

      The return of energy from some wells in the 30s was 35,000 to 1. That and that alone is how we built the 20th Century - and without that kind of return, we live in a much, much, much lower energy world. And with Fukushima and its soon-to-be sisters puking up enough ionizing radiation to even put the "Hormesis is good for you crowd" to silence.... well. I just don't know...

      I appreciate the opportunity to blog-chat about it - I understand you have a strong point of view. That's fine. Just think about what a lower-energy world looks like. I think it looks like one in which we better be within a hundred miles (and maybe 10) of our primary fields and food and water sources; where long-distance happens by train and boat - and is much slower and at lower volume..

      I know it's a heresy to ask Americans to imagine that the future doesn't look like a new iPhone... I think we get to go backwards and downward in the energy use spiral now. And I'll plan for that - and I'll hope that solar and wind pop up and do good work. Better work than anyone predicts.

      It's a nice hope. In the meantime, I'll be working on getting my permaculture design certificate, and writing about this transition.


      Liam - c'est moi.

    3. Hi Liam,

      We might jus be talking past each other here. I think you're making a different argument than the "low ERoEI of renewables" argument which this article was meant to address.

      "Electric cars are a boutique market - with heavy metal batteries sucked out of inner Mongolia (the Bayan Obo district) - we're not getting to a billion cars made out of plastic running on electricity,"

      They're a "boutique market" right now. Then again, cars of any kind were a boutique market 100 years ago. They went from boutique to mainstream in about 30 years.

      "The return of energy from some wells in the 30s was 35,000 to 1."

      Yes but ERoEI isn't very important as long as it's higher than some small number. Don't confuse ERoEI with net energy available to society.

      "without that kind of return, we live in a much, much, much lower energy world."

      No, definitely not. ERoEI has already declined from 35,000 to around 15 today. Yet global net energy production is at least 100x higher _despite_ the lower ERoEI. That's because ERoEI is not very important.

      Really, the ERoEI figure would be more meaningful if it were inverted and subtracted from one: one minus energy invested over energy returned, or 1-EI/ER. In that case we can tell how much of an energy source remains after the energy required to obtain it.

      If ERoEI declined from 35,000 to 15 over the last century, then 1-EI/ER has declined from 99.997% to 93.3%. In other words, it now takes 6.7% of the energy in a barrel of oil to obtain that oil, instead of 0.003%. In other words, the net energy available to society for the SAME initial investment of energy has declined by about 6.7%, relative to what it would have been (not an absolute decline). That 6.7% reduction in net energy is totally unimportant because it has been more than offset by enormous increases in energy investment. If the world generates 100x as much energy now as it did in 1930, then the 6.7% decline in 1-EI/ER means that the NET energy has increased by 93.3x instead of 100x. ERoEI wasn't very important.

      Have a look at this:

      -Tom S

    4. @Tom S
      > global net energy production is at least 100x higher [than in the 30s]

      In 1930, it was around 1.3 TW (converting the approximately 40 quads shown in the graph):

      Today, it's 20 terawatts (EIA global energy figures for 2008 and 2012 convert to 15.0 and 18.0 TW, respectively; extrapolating, it should be around 20 TW today). 20 TW / 1.3 TW is 15.

      Also, even Peak Oil gurus only claim 100:1 EROEI for 1930 oil:

      There might have been one 30,000 EROEI "well" (actually, crude spurting naturally out of the ground?), but one well is irrelevant.

      It's important to recognize that, at least as far back as the dawn of the nuclear age, oil hasn't been used as en energy source (except in Saudi Arabia). It''s been used as a package. That means that, at least as far back as the dawn of the nuclear age, the EROEI of oil has been irrelevant. Its EROEI could be below 1, and people wouldn't necessarily use any less of it, because it doesn't power society. Uranium, hydro, and coal do -- and their EROEI's are 500, 100, and 80, respectively (using present thermal-spectrum reactors to burn the uranium, and using present centrifuge-based isotope-separation):

      All other fuels are subsidized by those 3. A possible exception would be volcanic geothermal in Iceland, but I suspect even that's subsidized by the primary 3.

      3 important points:

      1. Society doesn't run on oil. It runs on uranium, hydro, and coal.
      2. The present EROEI of society's real fuels amalgamates to around 100. Proposed replacement-fuels that rate lower than that require proof of concept.
      3. Wind's EROEI is below 1. Not only can it not replace uranium, hydro, or coal -- it can't even replace itself. Denmark proved this. Despite launching the greatest per-capita subsidy program in the world, trying to power itself with wind, Denmark, and its supposed wind industry, today remain powered by uranium, hydro, and coal:

    5. Hi hitssquad,

      "Also, even Peak Oil gurus only claim 100:1 EROEI for 1930 oil: There might have been one 30,000 EROEI "well" (actually, crude spurting naturally out of the ground?), but one well is irrelevant."

      Sure. I was just granting his point. I don't think the ERoEI was ever 30,000. However, even if I grant his figure, and assume an ERoEI of 30,000 back then, it still doesn't matter.

      Even if early oil had an ERoEI of 1 billion, it would still make little difference. That would lead to an increase in net energy of less than 0.00000000001% compared to an ERoEI of 100. Any ERoEI higher than 5 or so makes increasingly little difference.

      "Today, it's 20 terawatts (EIA global energy figures for 2008 and 2012 convert to 15.0 and 18.0 TW, respectively; extrapolating, it should be around 20 TW today). 20 TW / 1.3 TW is 15."

      Perhaps I should have been clearer. I am measuring output energy, not waste heat. Modern combined-cycle turbines produce about 3x the output of the reciprociating steam engines and steam turbines from 1930. Internal combustion engines in cars have gotten much more efficient. Also, I was assuming we use 25 TW today, not 20 TW.

      Still, even adjusting for that would result in a figure of ~75x the energy production, not 100x. I was throwing out a rough estimate. I didn't bother to look it up or calculate it because it's not really important to the argument I'm making. Even a 15x increase in power production greatly outweighs the 6.7% reduction in net energy imposed by declining ERoEI.

      "It's important to recognize that, at least as far back as the dawn of the nuclear age, oil hasn't been used as en energy source (except in Saudi Arabia). It''s been used as a package. That means that, at least as far back as the dawn of the nuclear age, the EROEI of oil has been irrelevant."

      That's not right, in my opinion. Oil has always had an ERoEI significantly higher than 1 so it is an energy source. An "energy carrier" in your sense would be something which has an ERoEI of 1 or less.

      Oil provides about as much net energy to society as coal.

      A breakdown of energy production by source is here:

      If we adjust those figures for ERoEI (assuming 30 for coal and 15 for oil), their net energy is almost equal. Coal and oil provide about the same net energy to society.

      Even if we subtract waste heat losses and make adjustments for that (engines in cars and trucks are very inefficient) oil still provides more than a third the net energy to society that coal provides.

      Gas is also an energy source, not a carrier. Gas provides almost as much net energy as coal to society, if we use the figures from the graph linked above and adjust for ERoEI and waste heat losses.

      -Tom S

    6. Hitssquad,

      "All other fuels are subsidized by those 3. A possible exception would be volcanic geothermal in Iceland, but I suspect even that's subsidized by the primary 3."

      In my opinion, all forms of the "energy subsidy" argument are wrong. An energy investment does _not_ imply a permanent subsidy.

      Look at this way. Early on, coal "subsidized" oil because the steel and materials for early oil wells were built using energy from coal; now oil "subsidizes" coal also because the trucks and trains for coal mining and transport run off oil. Hydro has always "subsidized" all sorts of things; now Hydro is subsidized by oil which is used to carry the cement to build the hydro dam. Oil "subsidized" nuclear because the uranium is mined using oil-powered machinery; now nuclear sometimes "subsidizes" oil (France has a massive truck manufacturing sector which uses electricity taken from nuclear power plants, and some of the trucks are used to transport oil). Early on, oil wells were "subsidized" by FOOD energy because people were constructing them by hand; now food energy is subsidized by natural gas and oil.

      Nothing is really fundamental here, except for food and the Sun. The economy is a WEB of inter-connected parts which is constantly adjusting and being re-configured. Fossil fuels are not "fundamental" forms of energy because the economy isn't organized as a pyramid. The only really fundamental source of energy is the Sun (and nuclear power is not entirely derived from that).

      Furthermore, nothing is really a subsidy here. A subsidy implies payments in one direction only. If there's energy going back and forth between different energy sources then that's an exchange, not a subsidy. If I pay my grocer for food and he pays me for plumbing services, neither of us is "subsidizing" the other.

      Even when the payments are overhwhelmingly in one direction only, the "subsidy" is TEMPORARY. It's a one-time thing. We bootstrap each new energy source using the prior energy source, that's all. Originally, coal really did subsidize oil. The first oil wells were built using coal energy, and no energy payments went the other way. Now, however, coal is transported using oil. The subsidy happened ONCE and was over then.

      -Tom S

    7. Tom S: "Fossil fuels are not "fundamental" forms of energy because the economy isn't organized as a pyramid. The only really fundamental source of energy is the Sun (and nuclear power is not entirely derived from that)."

      I think this statement is misleading if not outright incorrect. Humans use energy to survive (food from sun), and have built upon that an increasingly energy intensive industrial society. The quantity of energy needed per unit of time to keep a human structure/system/civilization operating is its rate of metabolism.

      Fossil fuels are stored solar energy. Millions of years of stored solar energy. We are using huge quantities of that stored energy to support our current metabolism. It is clear that stored solar energy (fossil fuels) now constitute a major portion of the energy needed to keep our civilization—as currently configured and operating—from 'starving' due to lack of sufficient energy. Thus peak oil (and coal and gas) and its corollary EROEI are very relevant to our future.

      A good analysis of humans' changing use of energy over time is Yadvinder Malhi, 2014, “The Metabolism of a Human-Dominated Planet” (Chapter 8 in “Is the Planet Full”) --

  20. Whoops - I forgot this link.. (Cars on the road estimated)

    1. @Liam

      Cars aren't people. The average American owns more than one car. He only drives one at a time. There were only 212 million licensed drivers in America in 2012:

  21. I just want to say that I agree with you 100%. I am impressed by your impeccable logic, math and reasoning.

    Of course the propagandists for the polluting fossil fuels status quo will attempt to refute it. Your excellent rebuttals to their arrogant attempts to undermine the veracity of your claims is a breath of objective energy science fresh air. I am far less patient than you are when dealing with the fossil fuelers. Your methodical debating skills has been a learning experience for me. It is a joy to see you take fossil fueler arguments about piece by piece. I will try to emulate your patience and fortitude.

    I challenged Charles Hall's SUNY study conclusions and ERoEI pseudo-math in 2012. It went over the defenders of the "high energy density" fossil fuels like water off a duck. Logic and objectivity is not their thing; agenda laced rhetoric is.

    I wish to add something about the toxic brew known affectionately as "gasoline" by the fossil fuelers. Due to all those VOCs and various lengths of hydrocarbon chains in that refinery waste product, incomplete combustion is the norm, not the exception.

    Charles Hall et al, of course, neglected to include that bit of embarrassing inefficiency along with the waste heat issue when they made their calculations for gasoline ERoEI.

    How convenient was leaving that thermodynamic mathematical reality out when comparing gasoline with ethanol? Very convenient. I suspect mens rea was involved, but I can't prove it. Nevertheless, Charles Hall's main sources of funding and all his cheerleaders at the now defunct Oil Drum web site provide more circumstantial evidence that Mr. Hall is not an objective scientist.
    Continued in next comment:

  22. But getting back to ethanol as a Renewable Energy based fuel, far superior to gasoline, I have learned that ethanol's octane rating is higher than that of non-leaded gasoline. More themodynamically important, however, ethanol combusts completely because it has one consistent chemical structure and carries it's own oxygen to aid the process.

    In addition, ethanol has extremely low waste heat because, unlike gasoline, it doesn't produce carbon deposits from incomplete combusiton on the cylinder walls that increase friction and decrease engine life. Unlike an engine running on gasoline, you can touch the block, or the manifold, of an engine running on ethanol with your hand AND KEEP IT THERE without getting burned. This has huge savings implications for engine design that the fossil fuel industry has done it's best to keep from internal combustion engine designers and manufacturers (more on that below).

    As you have stated in so many words, "high energy density" calculations are based on EXTERNAL thermodynamic combustion processes. It is true that gasoline will boil water in an open flame faster than ethanol will. That doesn't have beans to do with automobiles.

    But when INTERNAL combustion is involved, ethanol produces more useful work than gasoline. That has EVERYTHING to do with automobiles.

    But there is more the fossil fuel industry does not want most people to know. Due to the fact that ethanol burns so cleanly and has such low waste heat, a high compression internal combustion engine specifically designed for ethanol would be about 30% lighter (i.e. a lot cheaper) because the metal alloys involved would not have to be engineered to withstand the engine stressing waste heat that gasoline generates. Of course, said internal combustion engine (ICE) could not be approved for running gasoline. Gasoline would trash an engine designed specifically to run on ethanol in short order. The fossil fuel industry would not like that at all.

    A lighter ICE running ethanol would then get even more mechanical energy out of each gallon because less engine weight would need to be moved along with the car an occupants.

    The only way gasoline's higher energy density than ethanol would make it a superior fuel is if cars were run by EXTERNAL combustion processes like a steam engine.

    The Fossil Fuel Industry knows all that. That is why they continuously try to demonize and talk down ethanol biofuel with mendacity and dissembling about "low ERoEI", "water in the fuel" and "corrosion".

    I, and many others, have exposed all that fossil fuel industry self serving propaganda. I will provide links if you so desire.

    Thanks again for your detailed and scientifically objective posts.

  23. But, Agelbert, just how many acres would it take to produce enough Ethanol? Do we have enough? And how much water, fertilizer, and energy (to run farm equipment and distillery equipment) would be needed to produce this? And finally, who's pockets would this fill? Agribusiness? There are many evil companies in this world, besides the oil companies.

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  24. Actually, you got me wrong: I don't like fossil fuels, and think they will not power the world in the future.

    Also, I would tend to discount any discussion of technologies under development. Sometimes they actually apear, sometimes they don't. I have read text books from the 50's, claiming that within the next few decades, nuclear power would make electricity too cheap to meter. Well, it didn't happen. Sometime there are problems with scale.

    My point about the farm equipment etc. was that there would have to be additional crops grown to power them.

    Finally, it does not matter what we call them; some companies do not do the right things. I think that ethanol will simply replace one group of destructive companies with another. Sure, ethanol can be done without ecosystem degradation, but currently it is not. If the companies find it can improve their bottom line to create it in a destructive way, they will. Currently, the best (or at least the most economical) way to create it is to plant vast monoculture of corn, and apply lots of toxic chemicals to them.

    We could conceivably have a small ethanol plant in each town fermenting waste products from surrounding small farms and businesses, but that is not the current trend.

  25. I understand what you are saying. Of course we live in a thoroughly corrupted world. But the fossil fuel industry is simply suicidal. Ethanol is just one of the alternative energy "ports in the storm", so to speak.

    I think those folks at E100 engines and Vision ( would take issue with your statement that what they are doing is contributing to ecosystem degradation.

    Also, any talk about nuclear energy was always a bold faced lie, so comparing renewable energy with nuclear power is not a valid comparison. Nuclear energy was NEVER carbon neutral, no matter how much all the happy talk from the nuclear industry claims. They always left out those pesky details like the energy to mine, refine and machine the cake, then make fuel assembles and then baby sit them for a few centuries after they are "used". Nuclear power is not now, or ever was, or ever will be, a renewable energy source. It is a MEGA deadly polluter.

    Ethanol technology is mature, not some emerging technology. Refinements for algae and duckweed will certainly help, but that is not a valid reason to claim ethanol is not ready for prime time. That has been the fossil fuel industry pitch for over 60 years.

    And ethanol, as the author of this article has pointed out, is just part of a large mix of renewable energy technologies that work NOW, not in some far away future.

    Did you know that the "not ready for prime time" fossil fuel propaganda against PV was manufactured in the 1960's? Congress funded a study in the late 1950's and recommended that photovoltaic cell technology be developed. They recommended funding on a par with nuclear. In that report, it stated CLEARLY that, if PV research was not funded, it could not play a large role in U.S. energy use.

    The fossil fuel lobby can read. PV did not receive even a tiny fraction of what nuclear energy received (and receives to this day!). There was only one concession to PV funding. THAT concession did NOT threaten fossil fuel profits. The funding for PV was restricted to satellites and kept from we-the-people.

    Reagan did it AGAIN in the 1980's. Google "How Reagan turned the lights out on solar power" to understand how stumbling blocks have been consistently and continually placed on PV technology development by the fossil fuel industry for several decades.

    But despite their skullduggery to keep PV out of energy market share, it has finally arrived and it will be instrumental in bankrupting the oligarchs that buy politicians with dirty energy profits. Good!

    When you talk of technology development, you sound like the "most competitive" technology won. That is simply not true! We could develop the bomb in the 1930's and 1940's but we couldn't develop PV when photovoltaic physics was already understood (see Einstein) by 1910!!!?

    Give me a break Mr. Fritz! The foot dragging has been deliberate and massive. And every step of the way, the hemming and hawing about "it's not ready for prime time" has been used as an excuse to strangle Renewable Energy market share.

    The fossil fuel industry does not live in the real world. They are dangerous to themselves and the biosphere. This is not hard.

    Your argument that a plethora of different renewable energy technologies with present, off the shelf, proven low ERoEI performance from ethanol to PV to wind to current to tide to hydro, all with computer controlled load balancing, are not ready to replace the global biosphere degrading fossil fuel infrastructure is just more "not ready for prime time" foot dragging.

    You agree that "things are bad" but then you flip the argument on its head by claiming the Renewable Energy technologies now replacing the crap out there are equally bad. I don't think so.

    Whether you want to admit it or not, your argument is a back door defense of the corrupt and biosphere degrading status quo.

    Mr. Fritz, if you are in a hole, you are supposed to stop digging.

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    2. Whatever happened to fuel from algae? A few years ago there were a lot of articles about it, but a lot of them have disappeared. Here's one that's still on the web:

      "The Power of Pond Scum: Biodiesel and Hydrogen From Algae."
      IEEE Spectrum, April 2008

      The video about this technique was taken down around 2010, and Valcent's web site doesn't mention "Vertigro" any more, only "VertiCrop."

      What happened? Was this another case of the fossil fools finding a way to suppress a superior technology?

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  32. I agree that energy quality is an important issue with EROEI, but that includes looking at the quality of energy produced by alternative energy devices. Intermittent energy doesn't have the same quality as energy on demand has. Current industry has a lot of big furnaces, kilns, rolling mills, running continuously, and it simply would't work to try to do this with intermittent energy, but the expense of storing energy on such scales is so large that nobody has tried to do it. There are also issues of current industry needing to use coke or natural gas for smelting, because of the ease of using the carbon in these fuels to reduce the metal oxides. Using electrolysis is theoretically possible but for producing iron a practical way has not been worked out, though a lot of effort has gone into it.
    I've often thought that the EROEI that really matters the most to us, is food EROEI, which is where Prof. Hall started off. We ultimately want all this machinery to spend less muscle energy getting more food, and getting shelter as needed as well, to avoid excess energy gain or loss to our bodies... If we just looked at food EROEI, and the sustainability of a good ratio, then the calculations avoid most of the problems of applying EROEI to energy conversion devices.
    Energy supply is only one problem, as well. We wouldn't be helping ourselves to go on with business as usual with alternative energy, eroding and depleting soil, destroying forests, sweeping the oceans of fish, producing other kinds of pollution besides what we get burning fossil fuel, and continuing to have diseases become resistant to antibiotics, and of course the current virus is also showing up this problem of masses of people being vulnerable this way, also the crops and animals the people depend on have less and less variety and are also vulnerable.
    I think "Limits to Growth", had it right. People have denied we had limits because we have found our way around limits in the past, but there isn't any cause and effect relationship between what was found in the past and what might be found in the future. People have confused correlation with causation in their expectations of needed things being found. Looking isn't at all a sure way to find imaginary things, but that is what humanity has bet on being true.

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