• Oct 14, 2011
File this one under "ammunition for future debates."

EVangelist Peder Norby, who has been having more fun driving and writing about his Mini E than anyone at BMW probably thought possible, recently wrote a most interesting post comparing electricity usage to produce gasoline to the electricity needed to drive an electric car. The short version: "It takes more electricity to drive the average gasoline car 100 miles, than it does to drive an electric car 100 miles."

Let's go over that again. If we simply count the electricity used to make the gasoline that gets burned in a normal vehicle, you need more juice than you do to move an EV the same distance. Of course, then you need to factor in the actual gasoline used (and the resulting CO2 emissions). Plus, don't forget, it takes a bunch of water to refine gasoline. Put this all together and you've got on hell of an energy efficiency argument in favor of plug-in vehicles. Here are some numbers (get more details in Norby's post).

There is no exact calculation for how much electricity it takes to drill, transport and refine a gallon of gasoline, but the accepted amount is around 8 kWh. So, for 8 kWh, you can go around 22 miles (using the U.S. average; we know you can go over twice that if you drive a Toyota Prius). That means that a gasoline car uses just under 40 kWh to go 100 miles. An EV, on the other hand, uses around 30 kWh to go 100 miles (given 3.3 miles per kWh, which is on the low side for some cars). Even if the exact numbers need to be shifted a bit one way or the other, we're just comparing electricity use here – not the petroleum that needs to be factored in for the ICE vehicle. So, if we were able to magically use all the electricity that is currently spent to give us gas and shove it into automotive battery packs instead, we'd use less energy and no gasoline. So much for the long tailpipe argument. Nissan sometimes uses this argument when advertising the Leaf, but it's not a commonly used statistic. We wonder why.


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  • 92 Comments
      Darin Caggiano
      • 3 Years Ago
      While I don't think the headline is accurate, because a lot of it is somewhat speculative, Darell (evnut) posted about this a while ago with some details I posted on gassavers dot org that appears to have been deleted for some reason. The basic idea is that the natural gas used to refine/extract oil could be used instead in combined cycle plants to provide electricity to EVs and of course the electricity used by extracting/refining oil could also be used directly to power EVs. http://www.evnut.com/gasoline_oil.htm Per gallon of everything (diesel, jet fuel, gasoline), we use what could be ~4.7kWh/gallon of electricity at an EV owners home. This was before Neil brought up the idea of refinery efficiency. We're gonna loose a fair bit of energy with refining because all the reactions involved are exothermic. http://ecomodder.com/forum/showthread.php/how-much-energy-does-take-produce-gallon-gasoline-13545.html http://ecomodder.com/forum/showthread.php/how-much-energy-does-take-produce-gallon-gasoline-13545-5.html#post185641 So adding that brings up the total to ~5.5kWh/gallon, and my WAG was that natural gas flaring added another ~1kWh/gallon, bringing everything up to ~6.5kWh/gallon. This does not include the energy needed to move the oil from the point of extraction to the refinery and the refined products from the refinery to the point of sale, which may bump the tally above ~7kWh/gallon electricity equivalent. At that point an EV like the Leaf could travel about 20+miles on the energy needed just to get the gallon of gasoline to someone is a similar sized vehicle like a Versa. Besides not needing as much electricity generation as is generally assumed due to a drop in gasoline demand, this is also very interesting because it illustrates the differences in how much energy each process requires. A Versa needs ~35kWh of gasoline plus ~15kWh of natural gas/electricity/etc for a total of ~50kWh to travel 33 miles. A Leaf needs ~15kWh of natural gas/electricity/etc to go ~20 miles, which translates into ~25kWh of the same to go 33 miles. The big take away is that even while using the same feedstocks as gasoline, an EV still only requires half as much energy as a conventional car of similar size. Toss in diverse electricity generation that isn't as susceptible price swings, and it seems likely that sooner or later EVs will be more economically feasible than conventional cars. They still have a lot of ground to cover because conventional cars and infrastructure have a lot in the way of sunk costs and production of scale, which are very advantageous, but if EVs can even get close with less in the way of infrastructure and lower production figures then they'll probably succeed conventional vehicles later.
        Spec
        • 3 Years Ago
        @Darin Caggiano
        "A Leaf needs ~15kWh of natural gas/electricity/etc to go ~20 miles," Are you adding in some other factor? The Leaf is much more efficient than that. With its 24KWH battery, it is EPA rated to go 73 miles. So it only takes 6.67KWH to go 20 miles with the Leaf.
          Darin Caggiano
          • 3 Years Ago
          @Spec
          That's it Spec. If we were looking at replacing that with the output of a wind turbine or a solar panel then it would be pretty much at 1:1, but since we're using gasoline feedstocks, natural gas in this case, to instead make electricity we would need to factor in the efficiency of a natural gas power plant.
          Spec
          • 3 Years Ago
          @Spec
          Wait . . . I guess you are factoring the inefficiency of the natural gas power plant?
        Neil Blanchard
        • 3 Years Ago
        @Darin Caggiano
        The one part though is that the electricity used to find/drill/extract/transport/store/refine/store/transport/pump the gasoline *also* has the same generation losses and transmission losses. So, that compounds the embedded energy in the gasoline. Neil
      Dave D
      • 3 Years Ago
      Guys, I found the numbers for Exxon's Baton Rouge "Energy Star Compliant" refinery last year (whatever Energy Star can mean for a refinery anyway). Regardless, that refinery is acknowledged to be the most efficient refinery in the world and simply taking the pure ELECTRICITY kWh used for the volume of gasoline they produced was ~3.0kWh per gallon in the refining process. Just as important, this does NOT include any NG used. They did not publish any numbers on their NG usage that I could find, but I found other sources that allowed me to ESTIMATE that most refining uses about 3x as much energy in NG as they do with electricity in the refining process. Again, I admit this was just estimates based on a lot of clues I could find but no outright published numbers. Also, this does NOT include the electricity and other energy used to create all the chemicals used in the refining process. A refinery is nothing more than the worlds largest chemistry set. And every one of those chemicals used has to be refined and processed with their own set of energy inputs and then shipped to a refinery for use. Also remember, that Baton Rouge plant is the only Energy Star Compliant Refinery. So they are the most efficient. Who knows what the others use?? They sure don't publish the numbers because they don't want anyone to know. Luckily, they were dumb enough to publish the Baton Rouge numbers so they could brag Bottom line, it is hard to find a true apples to apples comparison because it is clearly not in their best interest to publish damning facts so they try not to do so. And to get the whole picture you have to include all the inputs in the entire process. What about the energy required to pump the oil out of the ground and transport it? What about the energy used to pump steam or hot water into the ground to for older wells that need the pressure boost to get the oil out now? I'm not sure it's possible to get a true "apples to apples" across the board because there are so many assumptions to be made and it almost becomes an exercise in lies, damn lies and statistics. But you better believe it takes a lot of energy to get a gallon of gas into our cars. Just as important, it does
        electronx16
        • 3 Years Ago
        @Dave D
        "171, 031 million kWh of electricity.....went to produce 5,119 million barrels of petroleum and oil products" For further numbers resulting in the conclusion that you can leave the oil in the ground and drive in electric vehicles 15% of the distance the gas guzzlers would have gone just on the saved energy that refineries : http://blog.storybridge.org/2009/07/leave-oil-in-ground-drive-electric-with.html
      Peder Norby
      • 3 Years Ago
      Most power trains for gas cars and electric cars have a warrantee of 8 years or 100,000 miles. So I don’t try to calculate the embodied energy cost of either the gas or the electric car, just the fuel source. Gasoline or electricity. As I delved into this subject I was surprised to see how much electricity and energy was required to refine gasoline at the refinery. In my opinion this fact was absent in the national discussion of the benefits drawbacks of electrifying our transportation fleet and the related arguments to emissions. Pre refinery and germane to the discussion is the concept of pumping oil through pipelines. In the case of Alaska it’s pumped from the North Slope of Alaska to the northern most ice-free port in Valdez, Alaska at a length of 800 miles. During it’s journey it crosses three mountain ranges and more than 30 major rivers and streams. That regures a huge amount (I don’t know how much per gallon) of electricity to pump and we are not even at the ocean tanker that takes it to the refinery yet. For the Canadian Tar sands pipeline, it’s a 2000 mile journey via a pipe to get to the Texas refineries. Again that transputation of a heavy raw product will take a huge amoun of electricity to pump pre refinery and then we have the refining process itself. For my car and my house, it’s a 30 foot journey from the solar panels on my roof to my panel to my garage. Cheers Peder
        Neil Blanchard
        • 3 Years Ago
        @Peder Norby
        Hi Peder, Thanks for bringing this discussion to the fore! Tar sands will require an immense amount of natural gas to heat water to then wash the sticky stuff out of the sand. So, the natural gas fracking and extraction and transportation have to be added in. And the millions and millions of gallons of water that will be used and contaminated just to get the stuff out of the sands must also be accounted for -- the drilling and extraction of the water, too. Never mind that this is happening in the middle of the boreal forest which is the largest area of forest on the planet. They apparently have to lubricate the Keystone XL pipeline just to get the sticky tar to flow through it, so the pumping effort must be staggering. And it is acidic and otherwise nasty stuff, so the wear and tear on the pipeline will be a critical factor. Something I learned during the Yellowstone pipeline spill is they cannot just turn it off instantaneously, if there is a leak. The momentum of hundreds of miles of tar/oil in the pipeline would cause a violent rupture if they did this. They must do it relatively slowly to avoid shattering their pipe. And shutting it down for maintenance will add to the energy overhead. Neil
        Ford Future
        • 3 Years Ago
        @Peder Norby
        And the XL pipeline route is across on of the US's largest fresh water aquifer's. The pipeline is NOT DESIGNED to handle this sludge. Therefore, you can expect the Aquifer to get polluted. Another Insane Koch Industries Tragic Investment Disaster for America.
      2 Wheeled Menace
      • 3 Years Ago
      When comparing gasoline to electricity, there are a lot of calculations that need to be made. Here's my take though; an electric drivetrain, from the plug to the wheels is going to waste about 20% of energy, at most. A gasoline engine is going to waste 70-80% of the energy put into it as heat. We only have so much petroleum.. and methods of getting at it keep getting more desperate and destructive. And for electricity, well i do doubt the sun will cease burning, the winds will stop howling, and the streams will stop running... just sayin.
        Dave
        • 3 Years Ago
        @2 Wheeled Menace
        A power plant is going to waste about 60% of the energy put into it.
          j
          • 3 Years Ago
          @Dave
          An internal combustion engine wastes over 80% of the energy put into the gas tank.
          Neil Blanchard
          • 3 Years Ago
          @Dave
          Yes, and the electricity used to make gasoline has this same overhead of embedded energy. Neil
      masteraq
      • 3 Years Ago
      This story has a major error. According to the cited sources, it takes 8kWh of *total energy* to produce a gallon of gasoline, not 8kWh of *electricity*. This 8kWh does not come from electric power plants but mostly from burning off a fraction of the crude oil in the refining process. The assertion that gasoline powered cars consume more *electric power* than electric cars is not accurate.
        Dave
        • 3 Years Ago
        @masteraq
        So, if you burn that 8 kwh of fuel at ~45% efficiency and run it through the grid at 95% efficiency and charge your BEV at 85% efficiency, you have about 2.9 kwh of energy in your battery. About enough energy to travel 9 miles.
          Dave D
          • 3 Years Ago
          @Dave
          @Dave, You're assumptions are completely off base. the 45% is applied when producing the electricity....so that is before the 8kWh are brought into the equation whether those 8kWh are used for refining Gasoline or running an electric vehicle.
          Dave
          • 3 Years Ago
          @Dave
          wrong. read what i am responding to.
        mustang_sallad
        • 3 Years Ago
        @masteraq
        From the source article: It is a simple fact that just the refining of gasoline requires approximately 6 kwh of electricity per gallon of gasoline.
          Dave
          • 3 Years Ago
          @mustang_sallad
          Here is a good breakdown of refinery costs: http://energyalmanac.ca.gov/gasoline/margins/index.php Example: Crude oil cost per gallon: $2.62, Refinery cost and profits: $.51 That means that natural gas, electricity, water, labor, plant construction, plant maintenance, and refinery profit altogether add up to $.51 per gallon. Even if they only paid 5 cents per kwh, that would be 30 cents out of the 51 for electricity. Good luck wth that!
          Dave
          • 3 Years Ago
          @mustang_sallad
          Get it????
          electronx16
          • 3 Years Ago
          @mustang_sallad
          Who says they even pay 5 cents? Wonder what they really pay. Could be another hidden gasoline subsidy.
          Dave
          • 3 Years Ago
          @mustang_sallad
          Actually, the source article contradicts itself: "It is a simple fact that just the refining of gasoline requires approximately 6 kwh of electricity per gallon of gasoline." "In a 2008 report, Argonne National Lab estimated that the efficiency for producing gasoline of an “average” U.S. petroleum refinery is between 84% and 88% (Wang, 2008), and Oak Ridge National Lab reports that the net energy content of oil is approximately 132,000 Btu per gallon (Davis, 2009). It is commonly known that a barrel of crude oil generate approximately 45 gallons of refined product (refer to NAS, 2009, Table 3-4 for a publication stating so). Thus, using an 85% refinery efficiency and the aforementioned conversion factors, it can be estimated that about 21,000 Btu—the equivalent of 6 kWh—of energy are used per gallon of gasoline refined:"
          Spec
          • 3 Years Ago
          @mustang_sallad
          @Dave The probably don't even pay 5 cents/KWH . . . . They often generate their own electricity on-sight with natural gas, coal, or perhaps the crude oil. The amount of electricity is the issue, not the price of the electricity.
        Chris M
        • 3 Years Ago
        @masteraq
        Oil refineries do burn certain undesirable fractions of their oil - to produce heat for the refining process, not for electricity. It is actually cheaper for them to buy electricity at industrial rates than to make their own power.
      Marco Polo
      • 3 Years Ago
      Neil It's evident that you missed the point of what I'm saying (A common fault among the self-righteous, is the assumption of what other say, not what they say.) You are so busy huffing and puffing indignantly, you failed to read the word "currently'', What part of the term 'oil depletion' don't you understand. There is no need to pompously relate that fossil fuel are finite, I already said that! What in your pompous reply, contradicts what I wrote?
      Neil Blanchard
      • 3 Years Ago
      So, if we are in agreement, why the vitriol? Neil
      • 3 Years Ago
      Lost in this torturous discussion of the minutiae of conversion and efficiency rates is the shining advantage of electricity: you can make it yourself. Most Californians can send the electricity they generate with solar panels to the grid, "banking" it for night time and winter. By generating during peak--more expensive--hours and using it during cheaper, off-peak hours, they can actually use more electricity than they generate without having to pay for it. But they are limited to the total electricity they can use in a year. So homeowners calculate how much power they need in a year and install just the amount of solar panels needed and no more, even if the rooftop could support more solar capacity. But If homeowners planned for electric cars, they could add the amount needed to charge the car to the total capacity installed and charge the car for free, minus only the one-time cost of setting up the solar system. Not everyone has the ability to generate their own power with solar or wind, but a substantial fraction of homeowners can and will do so given the added advantage of driving for free. Add to that the growing presence of renewable energy in the grid itself, and you have a compelling argument for electric vehicles.
        Spec
        • 3 Years Ago
        And if you have DIY capabilites, the price of installing a PV system is ridiculously cheap now. Most of the cost is now for the installers. Less than $10K in parts can provide you with electricity for powering your EV for the next 30 years.
      EZEE
      • 3 Years Ago
      Right Wing Extremist Here. Question - not everyone here hate everything, but as a group, everything is hated in some way, and nothing will work for whatever reason people come up with (as proof, fine me one universally happy post on a subject). Anyway, my question is, if all cars switch to electric, and we beef up the electric grid (all with solar and wind plants, of course) wont this be bad for women, the poor, and minorities? We ALL KNOW that power lines cause cancer, and that the racist power companies direct them through poor neighborhoods to kill poor people. So, what about the tens of millions of people that will die of brain cancer from the electromagnetic radiation from these lines (all in poor areas and no where else)? I am mildly serious, seeing as there has been debate on the subject.
        Spec
        • 3 Years Ago
        @EZEE
        You know you are really being a jackass. It is the standard Limbaugh schtick . . . take some tiny minority view and say the entire left believes it. Well, I guess every single Republican thinks the world will end on October 21, right? derp derp.
        Chris M
        • 3 Years Ago
        @EZEE
        To begin with, you've ignored the major premise of the article - with less gasoline being refined there will be less electricity used to make it, more than compensating for increased electricity being used by EVs. Overall electrical consumption could actually go DOWN with EVs replacing gassers. 2nd, we DON'T KNOW that "power lines cause cancer". There was one poorly done survey that seemed to suggest higher incidences of leukemia (not "brain tumors") in areas near power lines - but the survey didn't actually measure exposure to electromagnetic fields, nor did it check for other possible factors, such as lower income, less health care, toxins, or other environmental factors. Other studies that actually measured electromagnetic fields have not found any correlation between field strength and any illness, and follow-up studies on areas near power lines found that when economic and other environmental factors were taken into consideration, there were no differences in cancer rates between power-line sites and similar non-power-line sites. Sorry, no "tens of millions dying of brain cancer due to electromagnetic radiation from power lines" - wrong on all accounts. "Mildly serious" appears to be like "mildly truthful". i.e., not really.
        • 3 Years Ago
        @EZEE
        I guess you didn't get the point of the article. If you are driving a gas car, you are already using more electricity than if you were driving an EV. The question about how dirty is the electricity or does it cause cancer is moot, because driving an EV uses less.
      PR
      • 3 Years Ago
      The reason this argument isn't used often, is that oil and gas companies aren't required to disclose their electricity and water consumption. So they don't, making it difficult to present 100% authoritative numbers. If oil and gas companies WERE mandated to report total electricity and water consumption along with total gasoline production numbers, then it would be simple to present the authoritative numbers, instead of estimates based upon the best science and documented evidence available. If the oil companies, or their defenders think that 8kWh is wrong, they can disclose their total electricity and water consumption if they want. They have that power. If they don't want to disclose their actual numbers, then they can't cry about that 8kWh number.
      • 1 Year Ago
      DOE estimates that energy efficiency of producing gasoline is about 85%. About 21,000 btus of energy is lost for every gallon produced, equivalent to 6 kwh of energy (a kwh is equivalent to about 3400 btus). However the energy consumption is not just electric, it is nearly all oil energy. In other words they start out with about 141,000 btus of energy and wind up with about 120,000 btus of chemical energy - a gallon of gasoline. Some of that may be for electricity to run cooling pumps, and some of that electricity may be self generated. But most of it is fuel to distill the oil.
      Peder Norby
      • 3 Years Ago
      Greetings, I have added a part two that confirms my conclusions that a gas car uses more electricity than an electric car. http://electricmini.blogspot.com/2011/10/it-takes-lot-of-energy-to-make-gas-part.html It's focused on simple easy to read information. Cheers Peder
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