* 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.

Friday, November 30, 2012

Why We Need the Concept of Emergy


The input to the production facility that produces solar cells and their ancillary equipment consists of energy corrected for entropy and material streams and human effort.  The embodied energy or emergy of the material imputs must be added to the Energy Invested term.  Thus, a blog on ERoEI must discuss the concept of emergy.

ERoEI* as a Measure of Feasibility

If we wish to define an ERoEI that will indicate a feasible alternative energy technology if it is greater than 1.0, we must begin to think of society as a system the purpose of which is to keep high-grade energy flowing. Let us begin by defining consumption in terms of emergy with an M. For those who wish to know what I mean by emergy see http://dematerialism.net/emergyunit.htm. Thus, every citizen can be characterized by the community according to how much emergy he or she consumes strictly because he is employed, e. g., commuting costs, clothing costs, and meals away from home, and how much emergy he consumes otherwise.

Suppose, for the sake of analysis, that these quantities can be replaced by the average values in a few discrete strata. Then, the system I used in Chapter 2 of On the Preservation of Species can be resurrected mutatis mutandis for our purposes. It will not be necessary to take advantage of the distinction between personal emergy budget and work-related emergy budget until we begin to furlough people whose work is unnecessary to the well-being of the community. At this point we may employ the notion of the Autonomous Alternative Energy District (AAED):
Let us suppose that a group of people representing all of the trades and professions wishes to support itself completely by relying on a single alternative, renewable energy technology for all of its energy needs. Let us suppose further that all of the natural resources necessary to do this are available within the AAED [and the repositories of such natural resources can be retained at steady state from the detritus of the AAED including superannuated installations of the technology].

Nothing is imported from outside the District whereas energy and only energy is exported. If a man needs a car to drive from his home (in the District) to his job (in the District), the car is built, maintained, and fueled in the District. If his wife is sick the doctor in the District will treat her with medicine made in the District from chemicals produced there from raw materials mined there and subsequently recycled aggressively. The ERoEI of the new energy technology is the total energy produced, ER, divided by the quantity ER minus the quantity EX, where EX is the energy exported; i. e., EX = ER – EI. If the District is able to export any energy at all the ERoEI ratio exceeds one and the technology is feasible – at least. In the case of a single energy technology, the energy produced by each technology can be assigned a transformity of unity and the value of emergy is quantitatively the same as the Gibbs availability, which, at room temperature, is the Gibbs free energy. I prefer to report emergy values in units of emquads rather than quads, emjoules rather than joules, etc. Thus, the units of transformity are emquads per quad, for example.

The actual situation in a self-contained US economy would be virtually identical to that of the AAED if the economy were to run exclusively on the alternative, renewable energy technology under investigation and there were precisely as many physicians, for example, as are needed to supply the needs of those whose purpose in life is to provide energy. Thus, every ancillary and indirect expense of producing energy including the support of the workers and their dependents must be counted in computing energy invested if the ERoEI methodology is to be used to determine feasibility.

In the broader economy, the pro-rated share of each workers energy budget that should be charged to energy invested is easily determined from the pro-rated share of his working hours and the consumption stratum to which he belongs. If more than one technology is employed and the matching problem discussed in Chapter 2 of On the Preservation of Species has been solved, it is not necessary to convert one form of energy to another; therefore, a transformity of unity can be assigned to each form of energy produced. Since, in addition, the fraction of personal energy and work-related energy served by each technology is usually known, this methodology can be extended easily to the more general situation. To distinguish it from the superscripted ERoEIs in Energy in a Mark II Economy and to indicate its importance as the only ERoEI that determines feasibility, let us call it ERoEI*.
 
Tom Wayburn
December 14, 2008
Houston, Texas

On ERoEI as a Measure of Feasibility


Currently, I am trying to convince Charles Hall, Tom Robertson, and the rest of the world that I have solved the problem of computing the ratio of energy returned to energy invested, i. e., ER/EI or ERoEI or EROI, depending upon who is writing the term. My latest effort to state the solution concisely is posted at http://dematerialism.net/eroistar.htm, which has hyperlinks to longer discussions elsewhere. The notion of the autonomous alternative energy district (AAED) originated in a section of “Energy in a Mark II Economy” that was posted at http://dematerialism.net/remarks.htm. In “Energy in a Mark II Economy”, I computed a series of subscripted ERoEIs beginning with the direct production expenses of the manufacturer in the energy-invested term and with each successive ERoEIi including more components. The last is very close to the composition of the energy-invested term for ERoEI* in the AAED that determines feasibility. (Overwhelming sentiment dictated that I change EROI back to EROEI or ERoEI – regardless of the similarity of that term to EIEIO in the lyrics of Old MacDonald’s Farm.)

Note. Actually, energy returned might be confused with net energy returned, denoted ER – EI in my papers except for http://dematerialism.net/emergyunit.htm; therefore, we should be referring to the energy produced. Also, and this is more important, in http://dematerialism.net/emergyunit.htm, I defined EROI so that it is the same as EROI - 1 in http://dematerialism.net/Mark-II-EROI.html and http://dematerialism.net/Mark-II-Balance.html.

In a community that can subsidize a renewable energy technology with fossil fuel, it is especially important to use ERoEI* as discussed at http://dematerialism.net/eroistar.htm because the lifestyles of the participants can be supported by fossil fuel. Thus, the alternative energy technology might be able to produce energy, but the total amount of fossil fuel used by the community would be increased rather than diminished. And, no one might ever know.

Before I ask you to read “ERoEI* as a Measure of Feasibility” copied from http://dematerialism.net/eroistar.htm (with EROI changed to ERoEI), I need to emphasize a few key points:

· One of the correspondents claimed that ERoEI does not account for quality or convenience. That is not true, provided that transformity is applied to the final product accounting for quality and for time and place of production to compute the emergy of the product in terms of a well-defined standard as I have done in my papers on emergy and ERoEI. It is essential to combine emergy analysis with the computation of ERoEI to determine the feasibility and sustainability of the process under investigation.

· The price of energy should reflect the cost of preventing or repairing any changes to the environment that diminish the quality of life of mankind and other species or that compromise the sustainability of the relevant ecosystems including the magnitude of the storehouses of natural resources. The quality of life depends upon aesthetics as well as pure material circumstances.

· The energy-invested term should have an energy contribution corresponding to every monetary item that affects the price even if this reduces ERoEI* to less than 1.0. Research should continue until technologies with ERoEI* greater than 1.0 are found. This approach is mathematically rigorous as opposed to other approaches that merely state that an ERoEI must be greater than some unsupported number such as 3.0 to support the operations of civilization.

Revised April 29, 2011 and December 6, 2012

ASPO Conference Austin, Texas, 2012

 
Yesterday, I attended the ASPO Pre-Conference Workshop in Austin where the recent World Energy Report that predicted that the USA would achieve cornucopian oil output was discussed. Despite general acceptance of Peak Oil by the meeting speakers, some otherwise astute economists who claimed to reject the standard economic model seemed to be pretty much caught up in flat-Earth economics principally based upon money rather than energy. They rejected planned economies and retained faith in market economies with religious conviction. Basically, they were rearranging the deck chairs on the Titanic. But, there I must leave it, as I don't want to be late for today's ASPO meetings.

Tom Wayburn, Houston, Texas