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77 comments on EROEI Short #1: Boundaries & Calculations

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Roger K on August 23, 2007 - 12:15pm

Todd,

I was not trying to present a realistic calculation of energy balance. I was trying to conceptually illustrate the proper method of accounting for energy balance in determining the economic quality of energy. In a real world energy calculation of course embedded energy must be accounted for. Indirectly it counts as a fuel purchase such as I discussed above.

Your claim that I conflating energy and economics puzzles me. The underlying ideas expressed in my post are quite simple, though possibly I did not express them as clearly as I could. Energy provides services. Suppose you buy a tankful of gas and use it to travel 300 miles. The economic quality of that tankful depends on the amount of economic effort that was required to extract the oil, refine it, and transport it to the gas station. If for example it took 10 labor hours to produce a tankful of gas from conventional oil compared to 30 labor hours to produce a tankful of gas from oil shale, then clearly the gas produced from conventional oil is superior. This is common sense, not left field philosophical theorizing. The ideas expressed in my post are not any more complicated than this. Energy balance calculations just account for the excess resource costs due to the consumption energy during the production of fuel.

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Todd on August 23, 2007 - 4:02pm

Roger,

Thx for responding. Ok, quoting you, "The economic quality of that tankful depends on the amount of economic effort that was required to extract the oil,...". Emphasis added. Economics has nothing to do with EROEI.

And, "If for example it took 10 labor hours to produce a tankful of gas from conventional oil compared to 30 labor hours to produce a tankful of gas from oil shale, then clearly the gas produced from conventional oil is superior." It may be superior (and, no, differential labor hours is not common sense) but that isn't what EROEI is about. It is how much energy is required to produce so many joules compared to how many joules you had to expend to get them. And, BTW, I've done energy balances for chemical plants so I am not unaware of how to do them.

Let's look at on-shore and ultra-deep water drilling. It may take more "labor hours" drilling on-shore but the infrastructure for deep water drilling is massive, e.g., it requires horrendous amounts of energy before drilling even begins! Yet, on a bpd basis, the off-shore field could look excellent on the basis of "labor hours" alone.

I am totally lost by your last statement, "Energy balance calculations just account for the excess resource costs due to the consumption energy during the production of fuel." Excuse me? So, drilling, et.al., don't count when it comes to EROEI, just the energy used by a refinery? Now, I may have misinterpreted this so maybe you want to clearify it.

Todd

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Todd on August 23, 2007 - 4:09pm

As an aside, the Yahoo Energy Resources forum has beaten EROEI into the ground for several years but has yet to find common ground.

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