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The Dirt on Oil Sands

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

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By Scott McNally

With the U.S. Department of State currently reviewing TransCanada’s application for a presidential permit of the Keystone XL pipeline, protests from environmental groups opposing the pipeline have been heating up. The main reason for the opposition to the pipeline is that environmentalists generally consider oil sands to be “dirty” – partially because mining oil sands results in a lot of surface disruption and water pollution concerns, but also because it takes a lot of energy (in the form of burning natural gas) to produce and upgrade oil sands. Therefore, the carbon footprint, and the energy required to produce oil sands, may be higher when compared to conventional oil. I recently spoke at the 2013 Connecting the Dots energy conference at Stanford University, and one anti-Keystone attendee raised an interesting point. He said, “Because you burn so much natural gas upgrading oil sands, you actually use more energy than you get from the oil. The only reason they are doing it is because oil is so valuable and natural gas is so cheap! The energy return is negative!”

That claim was quite alarming. Would Canadians really put more energy into producing oil sands than they would get out? After all, a low energy return on energy invested is one argument against corn ethanol (actually, for every unit of energy you put into growing, harvesting, refining and transporting corn ethanol, you get about 1.3 units of energy out. So it is borderline but slightly positive.).

As it turns out, researchers have been investigating the answer to the oil sands energy return question. That is, how much energy goes into oil sands compared to how much energy we get out? This relationship is generally known as the Energy Return on Investment (EROI), but it can go by many names (net energy return – NER, energy return ratio – ERR, and so on). For conventional oil, this number can range from around 5 to around 30, depending on where you are and how you are producing the oil. The average EROI for oil these days is about 18. That means for every 1 unit of energy you put into locating, drilling, and producing that oil, you get 18 units of energy out. For ‘easy conventional oil’ in places like Saudi Arabia, the EROI is likely much higher than the average, but for ‘hard unconventional oil’, like oil sands, tight oil, or deepwater offshore, the EROI is often lower than the average.

However, a disturbing trend has been uncovered by researchers at the State College of New York. According to their analysis, our global energy return on investment has been getting worse over time. Much worse.

Why is this trend happening? Well as you can imagine in the early days of oil production, we didn’t really know what we were doing. We didn’t really understand geology. In fact, the theory of plate tectonics had not even been conceived yet. However, there was a lot of easy oil around. In many places, it just bubbled out of the ground, and you could literally dig it up with a shovel. Over time, as we learned more about geology and technology, we got more and more efficient at extracting oil, and our EROI kept going up. But then something happened. The rate at which we were producing easy oil outpaced the rate at which we were becoming more efficient. According to the study at the State College of New York, oil produced in 1992 had an EROI of 26, and in 1999, the EROI had increased to 35. But since then, the EROI has been declining dramatically. In 2006, the average EROI was 18 – about half of what it was less than a decade earlier. Now these numbers come from just one study, and while they may not be perfect, they highlight an important trend. Today, we have to go farther, work harder, drill deeper, spend more energy, and turn to unconventional sources like oil sands to satisfy our demand for oil.

So how bad is the Energy Return on Investment for oil sands?

From a societal perspective, surprisingly, it may actually be good. Just in the province of Alberta, Canada, there is about 1.7 trillion barrels of oil. How much oil is that? It is a little bit more than the total amount of oil that humankind has used so far. That’s right; Alberta has more oil than all humans have used to date. In addition, because oil sands tend to be in remote locations, the extraction process has become energy self-sufficient. Energy independent, if you will. In the process of extracting oil sands, you can use some of what you produce to fuel the production process. Therefore, you don’t need to use much external energy at all. You don’t need to pipe in natural gas, use electricity from a power plant, or even take diesel from a refinery to fuel your trucks. According to a recent study at Stanford University, from an external perspective, the EROI for oil sands is a whopping 30, almost twice as good as the current conventional average.

However, from an internal EROI perspective, oil sands are not so good. Even though you are using energy that was internally produced, you are still using energy. If you include this energy in the total, the EROI for oil sands is around 5. And because you have to use more energy to fuel the process, this could mean more carbon emissions per barrel of oil produced.

But – oil sands emissions do not have to be so high. When oil sands are ‘upgraded’, they are actually converted from a heavy tar into three things: a synthetic natural gas, a light, low carbon oil, and petroleum coke. (petroleum coke is a black powdery substance that is mostly made up of carbon. It is very similar to coal.) Much of the natural gas goes back to fuel the process, and the light oil is sold (or blended with heavier oil, and then sold, like in the case with Keystone XL). The natural gas and light oil produced from oil sands have a lower carbon footprint than conventional oil because so much of the carbon goes into the coke. Thus, the total carbon footprint of oil sands all depends on what you do with the coke. If you burn the coke, or sell it to someone that burns it (coal plants often buy coke – it is a good substitute for coal), the carbon emissions will be high. But in some oil sands production fields, the coke is actually sequestered (buried) back in the mine. If this is the case, the oil sands will have a smaller carbon footprint, but will also have a lower EROI, since coke contains energy.

Now, how bad or good you think oil sands are is all a matter of perspective. If you want to reduce oil imports from the Middle East, become North American Energy Independent, and produce more oil to fuel society, than oil sands have a clear benefit. If you are primarily concerned about carbon emissions, we should really get off oil – including oil sands – altogether.

Scott McNally holds a bachelor of science degree in chemical engineering from the University of Texas at Austin. He is pursuing dual master’s degrees in energy resources engineering at Stanford University and in public policy at Harvard University. Scott has previously worked as a renewable energy project administrator at Austin Energy, a project development engineer at Shell Oil Co., an energy and climate research intern at the White House Council on Environmental Quality, and an Oak Ridge Institute for Science and Education fellow at the U.S. Department of Energy. He was originally invited to submit guest posts by Plugged In’s Melissa C. Lott.

Photo Credit:

1. Graphic of oil barrel © by Amiralis and used under this creative commons license.

Melissa C. Lott About the Author: An engineer and researcher who works at the intersection of energy, environment, technology, and policy. Follow on Twitter @mclott.

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

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  1. 1. ronwagn 9:46 am 05/6/2013

    Use the vast amount of natural gas itself. It is cleaner than coal, gasoline, or diesel.Natural gas is the future of energy. It is replacing dirty old coal plants, and dangerous expensive nuclear plants. It will fuel cars, trucks, vans, buses, locomotives, aircraft, ships, tractors, engines of all kinds. It costs far less. It will help keep us out of more useless wars, where we shed our blood and money. Natural gas is the future of energy. It is replacing dirty old coal plants, and dangerous expensive nuclear plants. It will fuel cars, trucks, vans, buses, locomotives, aircraft, ships, tractors, engines of all kinds. It costs far less. It will help keep us out of more useless wars, where we shed our blood and money. It is used to make many products, and will bring jobs that boost our economy. It lowers CO2 emissions, and pollution.
    Over 6,200 select natural gas story links on my free blog. An annotated and illustrated bibliography of live links, updated daily. The worldwide picture of natural gas. Read in 79 nations. ronwagnersrants . blogspot . com

    101+ Useful references on natural gas:

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  2. 2. sault 10:54 am 05/6/2013

    Seriously, SciAm…delete “ronwagn”‘s account. They repeatedly spam the comments section of any article where the words “natural gas” or “fracking” appear with their ready-made rant. Spambots like “ronwagn” do not participate in discussions and they make this site look like a magnet for industry shills.

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  3. 3. sault 11:11 am 05/6/2013

    As for the tar sands, they are just one of many very large stores of fossil carbon that need to stay in the ground for our climate to stay recognizable. If we built our towns and cities so that people had jobs, shopping and entertainment close to their homes, then not everybody would HAVE to own a car and could walk, bike or take mass transit to get places if they wanted. Electric cars can handle in-town driving for most people while hybrids use around half the fuel of a regular vehicle and are great for highway trips. Regional high-speed rail similar to Amtrak’s Acela line can move passengers nearly as fast as it takes to get through the entire process of taking an airline flight. There are many high-speed rail corridors that make sense (Amtrak actually makes money off the Acela line!) and if built, they can save lots of fuel and ease congestion at airports.

    Long-haul trucking is massively subsidized due to the fact that the fuel taxes they pay on diesel doesn’t even come close to pay for the damage big-rigs cause to the roads. Make them pay their fair share and a lot of the tonnage would shift to rail. If we invested in improving our rail cargo infrastructure, we could take even more long-haul trucks off the road.

    I’m probably forgetting a few fuel-saving measures, but my point is we can reduce oil consumption A LOT. If we can eventually cut 70% or so while continuing to develop oil substitutes for industry feedstocks (think plastics and pharmaceuticals), then biofuels cold produce much of our supply alongside a much smaller oil industry. The only problem is that the oil industry is one of the biggest spenders in Washington D.C., so it’ll take a massive popular movement to keep the dangerous fossil carbon in the ground.

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  4. 4. RDH 11:12 am 05/6/2013

    Using the “dirty oil” excuse for blocking Keystone is not smart economics. Nor will it help the global environment. Canada will produce the oil whether we transport it and refine it or not. Why should we not benefit from the added value of the refining process?

    Using energy derived during the development and extraction process is nothing new. Pump jacks at oil wells have been powered by the gasses given off at the well-head (when they are available) for as long as man has been pumping oil out of wells. Natural gas powered motors are nothing new. I wouldn’t be surprised to find the natural gas carburetor was developed just for that purpose.

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  5. 5. curiouswavefunction 11:49 am 05/6/2013

    sault, a suggestion: Instead of repeatedly denouncing ronwagn and issuing calls for having his account deleted, why don’t you instead respond to the actual content of his/her comments, and especially the assertion (documented in other sources) that natural gas from fracking has contributed to lowered CO2 emissions? Your contribution would be much more productive that way.

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  6. 6. Kenj15 12:13 pm 05/6/2013

    Considering the continuing need to USE energy to PRODUCE energy from fossil sources, renewables such as wind energy may have an up-front cost (manufacture of a turbine) but there is NO continuing need for energy expenditure, save for minor maintenance of the turbine itself. It seems that the energy companies could easily guarantee their perpetual existance by investing some of those massive profits in the production of wind turbines and forever reap the profits of electricity sales. I agree with ‘sault’, leave the carbon in the ground.

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  7. 7. sault 12:39 pm 05/6/2013


    “ronwagn” is a spambot that will not respond to any comments and merely posts their cookie-cutter rants over and over again whenever their rss feed or whatever picks up certain terms. I already tried discussing things with them months ago and I got nothing back. “ronwagn” is almost just as bad as the spambots that post meaningless strings of words to get your attention only to have a link to a dangerous or shady website at the bottom of their comment. Except this approach is more sinister as it is specifically targeted at certain articles and the posts are actually coherent, giving them the appearance of being written by a real commenter to the casual reader that doesn’t know any better.

    I mean, just look at the copy / paste errors in the comment! “ronwagn” repeats the paragraph that begins with “Natural gas is the future of energy” twice! It’s totally a red flag that this is not an organic response to this article.

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  8. 8. sault 12:48 pm 05/6/2013


    The current Keystone XL route was chosen by Transcanada precisely becase it was the least expensive design that could achieve their goals of getting more refined fuels to the growing markets of Latin America and Asia. All other routes and methods for accomplishing their goals were more expensive and / or risky. So saying that the oil will get to market regardless is ignoring the higher costs and risks that the other options for producing fuels from tar sands present. For example, a westerly route to ports in BC is experiencing heavy opposition from First Nations peoples and other communities along the proposed route along with potential export terminals on the coast.

    And the only reason why the tar sands make “economic” sense is because all the damages from producing and using the oil are offloaded onto society as a whole for countless future generations. The social cost of carbon is probably around $50 a ton, although even $20 a ton could put the future of tar sands in danger. And all the profits from these operations will be pulled off before the bill comes due to REALLY clean up and fully restore the moonscapes that are being created up in Alberta.

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  9. 9. Soccerdad 1:11 pm 05/6/2013

    Interesting article yet totally irrelevant to the issue of whether Keystone should be approved or whether oil sands should be exploited. The oil will be produced and used. The only question is whether the NER will be even lower because the oil has to be shipped by truck / rail or whether a pipeline will be built into the US or to Canada’s west coast.

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  10. 10. M Tucker 3:32 pm 05/6/2013

    “If you are primarily concerned about carbon emissions, we should really get off oil – including oil sands – altogether.”

    That is why we need to leave it in the ground. In the US we have no way to force Canada to not develop tar sand oil. We have no real way to stop it from coming into the US by existing pipelines, trains, trucks or ships. But we can demonstrate our disapproval and make the oil companies suffer just a little bit by opposing the Keystone extension. Don’t let the perfect be the enemy of the good.

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  11. 11. jgrosay 4:10 pm 05/11/2013

    Few times I understand you, you could rarely understand me. Only when we are in the mud, we understand immediately. Please watch Tommy!

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  12. 12. kienhua68 2:45 am 05/12/2013

    So the net effect, no matter the choice, is more CO2. We may suffer less secondary pollutants with gas than coal or oil. Still the end result will be a hotter and hotter planet. So all this debate is purely for the sake of itself.
    We’ve dug up the past and will likely relive it. Well many of you will as I’ll be gone by then. So stock up on summer clothes and antiperspirant and hope for the best.

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