* To establish feasibility, it is necessary to include some items in the energy invested term that are normally not thought of as investments. For example, the cost of sequestering such carbon dioxide as will be produced by the energy technology under investigation should be added to the energy invested term because feasibility requires that our society be sustainable (until astronomical events intervene). In this thought experiment, the support of an alternative energy technology would be the sole concern of every citizen.

Wednesday, December 5, 2012

Missing Components of ERoEI

Let us recall once more that, in a sustainable society, the store houses of natural resources with which the earth and our species are blessed must be retained at more or less steady-state accumulations.  The atmosphere and the land are natural resources as well as the repositories of iron and other metals, the nutrients in the soil, and the atmosphere itself.  This means air and water quality and the infrastructure of primary and recycle processes must be maintained.  Therefore, let us add to the list of energy expenses that must be met to achieve sustainability.  (In this work, feasibility and sustainability mean the same thing.)

1) Sequester carbon, in case fossil fuels are involved in the process - even if only in the start-up phase.  But, in the case of shale oil and gas, the energy costs of carbon sequestration that must be borne by the consumer should be added to the energy-invested term to calculate ERoEI.  Probably, under present-day economic conditions, this can be thought of as a tax, which should be levied.

2) Maintain storehouses of materials that are used to build and maintain the principal process and the secondary processes such a tax preparation, healthcare, etc.

3) Mothball process equipment at the end of its life and restore the plant site to the pristine conditions in which we found it.  Let us maintain Earth as a garden.

4) Desalinate sea water to replace the fresh water used and decontaminate such water as the process renders unfit to drink.

5) To the energy costs of 1 - 4, add the energy budgets of the employees and the appropriate pro-rata portions of those whose services must be charged to the process such as the  health services that keep the workers healthy.  If there are stockholders or venture capitalists who take profits from the process, an appropriate portion of their energy budgets must be charged to the energy-invested term (EI).  Recall that every item that adds to the (monetary) price the consumer must pay for the product has an associated energy cost.  Clearly, salaries, fees, profits, and taxes add to the price.  All computations of ERoEI and/or emergy must be carried out just as they would have been carried out if government subsidies had not existed.  Quite frankly government subsidies are not the best way to defeat market intransigence and they make  our job as analysts harder. Quite possibly there is an energy cost associated with subsidies that should be added to EI.

6) If there is an energy cost due to withdrawal of the land from other uses, it should be added to EI.  I am not quite certain how to calculate this term.  Perhaps the reader has some ideas.  If you do, please leave a comment.

Undoubtedly, additional energy costs that should be charged to the process will come up. Denis Frith renders a valuable service with his extreme skepticism inasmuch as most of his objections to the use of ERoEI suggest a new energy cost for which a methodology must be chosen or invented to meet.  Denis is never quite right; but, the ways in which he errs are not likely to play a role in a world that seems to be hell bent on destruction.  Most people are not interested in being absolutely correct theoretically when the bottom line (survival) is not affected.  Therefore, Denis may do a lot of good and only a little harm.

Here is Denis's latest round of objections to the general utility of ERoEI.  (If there is any repetition, well, Denis does tend to repeat himself.)

ERoEI in even the sound form that Tom has promoted does no more that provide a measure of the effectiveness of an energy supply process. It does not take into account

  1. whether the energy supplied is used for a useful purpose or otherwise. Is all the fuel used by cars serving a useful purpose?
  2. that the supply process produces waste material that has caused such deleterious consequences as climate change and the accumulation of stores of radioactive materials
  3. that the supply process irreversibly divests limited natural material resources, including fossil fuels and uranium

Denis Frith

Here are my comments on Denis’s three points listed below:

  1. This is not the business of the analyst and it should not be.  Can you imagine what most people would say if I told them that the energy they use to conduct their lives or businesses is wasted because I do not approve of what they are doing?
  2. This is included in the energy-invested term by including the cost of sequestration.  Even the loss of space to sequestration can be given an energy value by counting the insolation that might have been harvested but could not be because the space was otherwise occupied.
  3. If the process does consume material resources, the energy-invested term can be increased by the energy cost to recycle not consume, which is always possible except for an insignificant trace amount.  In some cases, this expense is unbearable and must be avoided by choosing different technology.
Tom Wayburn, HoustonTexas



  1. This comment has been removed by the author.

  2. In Item 2 of the post, I claim that the repositories of materials that are needed for the main process under investigation and the ancillary processes that are necessary to the main process could be maintained at their original levels. I wrote as though the recycle problem had been solved and could be achieved without further fuss. This is not the case. Recycling the material in the infrastructure is a tricky business. More research is needed. Here is what I wrote to the critic who raised this point:

    Friction is not a problem. In general, the principal effect of friction is overcome by pushing harder. Let us weigh an engine with serious friction, like the gas turbine on a 747, when it’s brand new and after it is ready to be replaced. I would be surprised if the two weighings gave very different results, that is, I am under the impression that the slight loss of material will not affect sustainability.

    In other cases, the problem should be categorized thusly: (a) Separate the materials that we need to carry out the activities we consider important to our civilization, i. e., the materials we need to produce food and clothing, maintain shelter, render health care, and provide art, music, literature and a few luxuries to take the drudgery out of life, e. g., computers; divide the useful materials into two categories: (b1) the materials that can be recycled and devise the most energy efficient techniques to recycle them; (b2) find substitutes for the materials that cannot be recycled in any way, shape, or manner. (Remember that, even if only the elemental species can be recovered, with enough energy the original substance can be synthesized at the expense of our supply of available energy (enthalpy minus the lowest temperature reservoir to which waste heat can be rejected times the entropy).)

    I expected that you might nail me on recycling pharmaceuticals. I gave it a lot of thought. For now, I am satisfied that pissing on the ground might have to be forbidden. This was done by the Freeman on Frank Herbert’s Dune, a desert planet. Useful chemicals can be extracted from sewage by chromatography for example. Materials that are deemed essential and cannot be recycled for one reason or another will remain a challenge for the time being. But, isn’t it a shame that I can’t write the University of Michigan and explain why this would make a relevant research topic. Since I am an alumnus, they should listen. But, not even a million dollar gift would be an incentive to violate the received wisdom from the ruling class, as they will not admit that it is unnecessary.