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U.S. energy transitions in one graph

The views expressed are those of the author and are not necessarily those of Scientific American.

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To understand what the future of United States’ energy mix will look like in the future, it’s useful to look back at its energy history. This one graph from the U.S. Energy Information Administration tells us a lot about how we have consumed energy in this country:

U.S. consumption of primary energy sources from 1776 to 2012. Source: EIA.

There are three themes that run through U.S.’s energy history:

  • We go through energy transitions regularly, largely out of necessity (running out of forests or whale oil (Peak Whale) or with the discovery of a better fuel source;
  • We tend to diversify our fuel mix as time goes on (again, finding new, better fuel sources) by adding new fuel sources more than we retire fuel sources;
  • We tend to decarbonize as time goes on (from carbon-intensive wood to coal to petroleum to natural gas).

The twentieth century saw an explosion of fuels: natural gas was heavily developed, coal reemerged as an electric fuel source, nuclear fission was harnessed for electricity generation while renewables like solar, wind, and hydro grew as well.

We can make an informed guess about the future of the U.S. energy mix and assume that these three themes will continue. It’s likely that we will continue to decarbonize (which we are seeing some with fuel switching to natural gas from coal and an increase in renewables, notably wind generation).

As for the first bullet point, there is an important nuance between past transitions and present day. The impetus to fuel switch was more observable in many cases in the past; one could look out and see a dwindling supply of trees in a forest, or run out of whales.

Energy transitions driven by climate change and carbon emissions are based mostly on indirect observations or anticipated outcomes (rising sea levels, melting glaciers, insects and other biological proxies), rather than, say, stepping outside and “seeing” more carbon in the atmosphere.

David Wogan About the Author: An engineer and policy researcher who writes about energy, technology, and policy - and everything in between. Based in Austin, Texas. Comments? Follow on Twitter @davidwogan.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. M Tucker 5:49 pm 07/8/2013

    Gee, whale oil doesn’t seem to make the list. I wonder why? How expensive was whale oil when it was used? Where there other oils that were also used at the time? When did whale oil use end? What was going on in the US at the time?

    I wish people would stop bringing up whale oil.

    Wood still seems to be at nearly the same level as its historic past maximum.

    I guess the idea that “one could look out and see a dwindling supply of trees” really didn’t apply to using wood for energy.

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  2. 2. Chryses 9:44 pm 07/8/2013

    Cool graph. I’d have liked to see the sum plotted.

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  3. 3. David Cummings 7:00 am 07/9/2013

    I look forward to the day when solar energy tops the chart.

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  4. 4. sault 11:06 am 07/9/2013


    Since coal, oil and gas are just highly-distilled solar energy, it already does. Problem is, it takes millions of years for the distillation process to work and it operates a million times slower than the rate at which we harness it. Oh, and releasing millions of years of stored CO2 in mere decades messes with our climate too…along with all the other nasty elements like sulfur, mercury and various radioactive elements that accumulate in the fossil fuel deposits.

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  5. 5. sault 11:09 am 07/9/2013

    Hey, “other” renewables are outpacing petroleum during a similar part of its history!

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  6. 6. tuned 12:14 pm 07/9/2013

    A fearsome new study released in major news sources. 100% credible.

    National Geographic
    Published July 8, 2013
    Life expectancy in northern China was 5.5 years shorter than in southern China in the 1990s, and a health risk disparity lingers today, a difference almost entirely due to heart and lung disease related to air pollution from the burning of coal, a new study shows.

    The research, published Monday in the Proceedings of the National Academy of Sciences (PNAS), not only adds to the large body of evidence on the risks of small particle pollution, it provides the most precise measure yet of the health impact of smoke from combustion

    Link to this
  7. 7. OgreMk5 2:53 pm 07/9/2013

    I’m not sure I see your three themes in the history of US energy… unless you’re basing it on more than that graph.

    Theme 1: I see no transitions. Everything that has ever been used for power is still in use. The biggest change was the upsurge in petroleum use, but that was over a 45 year period. I’m not sure I’m willing to call that a ‘transition’, especially considering that natural gas and coal also increased during that period. How exactly are you defining ‘transition’?

    Theme 2: Since the 30s, the big three have stayed the same. OK, in the 50s we added nuclear, but even at it’s peak, it was still lower than coal over 100 years prior. And 35 years ago we added “other renewables”, which is almost up to 10% of the power supplied by petroleum.

    I think we must be using different definitions of diversification. In my stock portfolio, 45% of one stock, 40% of another stock, and 5% of 8 different stocks is not diversified. If something happened (say a massive, long-term refinery shutdown, coal-miner strike, or pipeline break), then we would lose about a 1/3 of our power. That’s not diversified.

    Theme 3: We aren’t decarbonizing. We’re introducing non-carbon dioxide producing power sources, but while renewables have grown from zero to almost 5 QBTU, all two of the three fossil fuels rose more than than (gas about 10 QBTU, oil more than 5 QBTU, and coal about 2 QBTU) renewables. That’s an increasing trend of carbon producing techs, not decreasing.

    I wish your trends were true, but I don’t see any support for them here.

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  8. 8. waltvdk 5:46 pm 07/9/2013

    Wood is carbon neutral, not more carbon intensive. Any wood not burned will eventually rot and return all its’ carbon to the atmosphere. When I harvest dead wood from the forest (I live in northern BC) it makes way for new trees to grow and trap carbon. The only real trend I see in the chart is a continuous growth in use of non-renewable sources. Wood is one of our renewable sources, although admittedly not practical for most people.

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  9. 9. 'RikS 6:34 pm 07/9/2013

    Please use SI units.

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  10. 10. DaRaco 1:36 pm 07/10/2013

    Encouraging in many ways – coal down, nukes down, renewables growing rapidly. Once the fracking bubble bursts (soon) then renewables will grow even faster.

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  11. 11. OgreMk5 2:05 pm 07/10/2013

    As much as I hate fracking (and believe me I do), natural gas is one of the best possible fossil fuels. Unlike coal or fuel oil, it can be used in turbines which can power generators directly. That means there’s no waiting period for a couple hundred thousand liters of water to boil under pressure.

    There was a report recently about how ERCOT (Texas) was using natural gas fueled power to supplement wind and solar because of it the very low ramp up period. A natural gas station can go from cold to full power in minutes instead of days like coal and fuel oil. Then (also unlike coal and oil) can shut down a few hours later when no longer needed.

    If we can’t have nuclear, then NG is a good (not great) supplement to renewables.

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  12. 12. smfullman 7:03 pm 07/16/2013

    I think that chart would be more effective if it were arranged to show the percent of total energy consumption for each energy source. Something like this: (only found data back to 1973)

    Link to this

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