What I Learned About Energy Use In The Us From My Students

Lynne Kiesling

I asked my freshman seminar to write an essay about energy use in the US in the past 50 years based on this EIA data table showing GDP in 2000 dollars, energy consumption in BTUs, population, and other stuff. Here’s what I (and they) learned from the experience.

Total energy consumption in the US has increased over the past 50 years. The only time it decreased was in the mid-1970s, as a result of the OPEC oil embargo and the resulting economic recession.

However, energy consumption per $ of GDP has consistently, if not steadily, fallen over the same time period. This fact indicates that we get more economic bang for the buck out of each BTU of energy we consume. In fact, BTU/$GDP has fallen by about half in the past 50 years, meaning that it takes half the energy today to generate a dollar of economic value that it took in 1949. Technological change plays an important role in this story, as does the structural shift in the US economy toward production of services and away from manufacturing.

Energy consumption per capita, however, has generally increased, even though population in the US has been growing. This fact suggests that the energy consumption growth rate is generally larger than the population growth rate over the past 50 years. Again, this should not be surprising if you consider the lifestyle changes that have occurred since then — cars, appliances, computers, televisions …

To me the most valuable insight from this exercise is to see how much more economic value we generate today using a given amount of energy than we did a half century ago.

UPDATE: Thanks to David Stone for the link to this Economist article commenting on the current situation of the world oil markets in a historical perspective.

6 thoughts on “What I Learned About Energy Use In The Us From My Students”

  1. I swear, the EIA is one of my new favorite sites on the internet. My work has recently required me to dig into just about everything EIA has for oil (and energy) consumption and production since, well, since they started recording it. They’re great about providing data tables for nearly everything referenced on the site.

    I was intruiged by this when you first mentioned it on the site, and am glad you posted what the question was. I’m not sure which is my stronger reaction: relief that I’ve got to the same answer (and have been using throughout my work since), or jealousy of the students for having access to such a class. I wonder if my job would let me telecommute from Evanston while working on another degree…

    Another source of some interesting raw data is the BP Review of World Energy. Partisan, possibly, but a lot of the data squares with the EIA and IEA stuff.

  2. Robert Schwartz

    Is it not a law of economics that actors will always try to obtain the maximum output with the minimum input? Isn’t it this as true of energy as it is of other resources? Why shouldn’t this continue to be true in the future?

  3. Robert Schwartz

    Is it not a law of economics that actors will always try to obtain the maximum output with the minimum input? Isn’t it this as true of energy as it is of other resources? Why shouldn’t this continue to be true in the future?

  4. Interesting, but is GDP really a good denominator nowadays? Afterall, much of the energy-intensive activities have simply been shifted offshore rather than being eliminated. Is this captured in the data provided? I would guess that some of these activities have even regressed and become less energy efficient after shifting off shore (since reduced labor costs relieve the pressure to reduce costs in other areas) even though they likely had trended more efficient for some time before that. Or maybe the question should be “is domestic energy consumption the best numerator?” Assuming GDP captures expentitures on imports, the energy consumption figure should also capture energy expended to produce those imports.

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