New EV Myths and Facts Page

Discussion in 'EV (Electric Vehicle) Discussion' started by efusco, Feb 9, 2012.

  1. wjtracy

    wjtracy Senior Member

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    ...the coal plants use about 1 lb coal per 1 kWhr
    so thats about 0.333 lbs coal per mile if Telsa gets 3 mi/kWhr

    Prius @ 50 mpg is ~0.125 lbs gasoline per mile.
    Therefore if the Porche gets <18 mpg, you are correct!

    These numbers look funny, but 50% coal is national average.
    So for national average, divide the Telsa in half and you have rough CO2 equivalnce with Prius 50 MPG ~= 3 mi per kWhr elec.
     
  2. wxman

    wxman Active Member

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    According to Argonne National Laboratory's GREET model (Argonne GREET Model), the following are well-to-wheel emissions it calculates for a generic mid-sized vehicle based on the current average U.S. electric grid mix (I used a diesel vehicle since that is what I have; haven't check an equivalent hybrid yet - DV = diesel vehicle; EV = (pure) electric vehicle)...


    VOC - 0.091 g/mi (DV); 0.027 g/mi (EV)
    NOx - 0.24 g/mi (DV); 0.28 g/mi (EV)
    CO - 0.579 g/mi (DV); 0.082 g/mi (EV)
    PM10 - 0.054 g/mi (DV); 0.432 g/mi (EV)
    PM2.5 - 0.03 g/mi (DV); 0.115 g/mi (EV)
    SOx - 0.085 g/mi (DV); 0.563 g/mi (EV)

    GHG - 387 g/mi (DV); 333 g/mi (EV)


    Also, based on EIA projections

    http://www.eia.gov/pressroom/presentations/howard_01232012.pdf (slide #27), the following are emission estimates for 2035 based on GREET1_2011...

    VOC - 0.075 g/mi (DV); 0.024 g/mi (EV)
    NOx - 0.219 g/mi (DV); 0.226 g/mi (EV)
    CO - 0.574 g/mi (DV); 0.076 g/mi (EV)
    PM10 - 0.050 g/mi (DV); 0.344 g/mi (EV)
    PM2.5 - 0.027 g/mi (DV); 0.093 g/mi (EV)
    SOx - 0.072 g/mi (DV); 0.422 g/mi (EV)

    GHG - 351 g/mi (DV); 279 g/mi (EV)


    Of course, projections that far in the future are very speculative, so they probably need to be taken with a grain of salt.
     
  3. wjtracy

    wjtracy Senior Member

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    ...correct I am doing ballpark calcs by hand and if you want EPA numbers go to GREET and I think fueleconomy.gov both allow you to get emissions tuned into your vehicle and elec mix.
     
  4. wxman

    wxman Active Member

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    Here's what I get for a generic "grid-independent SI HEV" (HEV) using current U.S. electric generation mix assumed in GREET...

    VOC - 0.199 g/mi (HEV); 0.027 g/mi (EV)
    NOx - 0.204 g/mi (HEV); 0.28 g/mi (EV)
    CO - 3.533 g/mi (HEV); 0.082 g/mi (EV)
    PM10 - 0.053 g/mi (HEV); 0.432 g/mi (EV)
    PM2.5 - 0.027 g/mi (HEV); 0.115 g/mi (EV)
    SOx - 0.080 g/mi (HEV); 0.563 g/mi (EV)

    GHG - 324 g/mi (HEV); 333 g/mi (EV)
     
  5. wxman

    wxman Active Member

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    By the way, manipulating GREET1_2011 at 100% electricity from coal yields GHG emissions of 581 g/mi, significantly higher than even the baseline gasser (451 g/mi).

    NOx, PM10, PM2.5 and SOx emissions would also be correspondingly higher according to GREET.
     
  6. hyo silver

    hyo silver Awaaaaay

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    Does this comparison include the energy that went into making the gasoline? Exploring, drilling, refining, transporting and storing gasoline takes a considerable amount of energy, and also results in significant emissions.
     
  7. SageBrush

    SageBrush Senior Member

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    wxman,

    The difference between the HeV and the DV looks off.

    If the two cars have the same MPG, the diesel will emit ~10% more GHG because of fuel density differences.

    So 90% of the DV's 387 grams/mile CO2 = 348.3 grams/mile if the same mpg is in an HV.
    Since the HeV is reported by you to be 324 grams/mile, this suggests the DV travels 7.7% less on a unit volume of fuel than a Hev.

    Starting from EPA 50 mpg combined for the Prius, the DV should be 50*.933 = 46.65 mpg combined.

    What car is that ? The best I can find on fueleconomy.gov is 35 mpg combined
     
  8. SageBrush

    SageBrush Senior Member

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    Thanks. I have bolded NOx and Sox, in hopes EVangelists will take note. The Prius almost certainly makes EV look much worse.
     
  9. austingreen

    austingreen Senior Member

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    This is one place where mythology gets in the way. You test a car in bad conditions, then compare it to the EPA of anouther car. Or as car and driver noted on some diesels, you test a car in the best condtions then compare it to epa of anouther car. Either way you get badly warped results. One thing is sure, a EV running in the winter in indiana will produce a great deal more CO2 source to wheels than one running in moderate conditions in west texas winter (mainly wind) or seatle summer(hydro).

    That still seems to be a valid point.
    There is a lot here. Certainly some plug ins will produce more co2 than some cars, and this has a lot to do with driving condtions, location, and which car. But somehow the idea is a smaller prius c produces less co2 than a prius is only true under some operating conditions, on others it produces more. But this gives a false dichotomy. Doesn't a prius c and a volt both produce less co2 than a normal car? Can't you choose like dr. innovation has done, and power your volt from low carbon sources? In polluted places like LA and Pittsburgh, aren't tailpipe emissions of dangerous pollutants more important than CO2 emissions from smokestacks?

    I don't think these slam stories are kind at all, they are distorting. There have also been positive stories and editorials that may distort in favor of technologies. Forbes, WSJ, and Businessweek have shown both sides, and have included balanced stories as well as the editorials. The 24hour news stations have been overwellingly distorted in a negative way.

    There is wide republican and democratic consensus that electrification - hybrids, phev, and bev - are a favored way to reduce oil consumption. I don't think that is in anyway in conflict with the facts. The votes by congress to continue oil and ethanol subsidies seems like they favor conventional ice cars above electrified ones. Congress has also kept national gasoline taxes low also favoring ICE vehicles.
    The Keystone pipeline cancellation or postponement is not pro electrification of the car fleet. It in no way advances plug-in or hybrid cars. Likewise the nuke approval only helps if it lowers electric rates, and I doubt it will do this. Both things do support the anti-ghg contingent though, and this is a subset of environmentalists.
     
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  10. wxman

    wxman Active Member

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    Yes, it's a complete well-to-wheels analysis.
     
  11. wxman

    wxman Active Member

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    Since this is a well-to-wheels analysis, upstream emissions are considered. Diesel fuel (ULSD) is more efficient to produce according to GREET (~84% efficient for ULSD; ~81% for gasoline (GREET uses 65% RFG/35% conventional gasoline, IIRC)).

    The assumptions in GREET are...

    Diesel vehicle gets 120% mpgge of baseline gasser.
    HEV gets 140% mpgge of baseline gasser
    EV gets 375% mpgge of baseline gasser.
     
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  12. wxman

    wxman Active Member

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    Argonne National Laboratory has a pretty extensive list of publications that went into the development of the GREET model available at http://greet.es.anl.gov/list.php if anyone is interested.
     
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  13. SageBrush

    SageBrush Senior Member

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    More proof that GREET's HV is well inferior to a Prius, since we know that gassers do not get 35 mpg EPA combined. A more realistic MPG(e) Prius:gasser is about 1.8:1. I used the Chevy Cruze for the comparo.

    For that matter, Prius beats diesel by considerably more than 140/120 = 16%
     
  14. wxman

    wxman Active Member

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    The baseline gasser in GREET is assumed to get 24.81 mpg. Therefore, the default diesel gets 29.77 mpgge, the default HEV gets 34.73 mpgge, and the default EV gets about 93 mpgge.
     
  15. drinnovation

    drinnovation EREV for EVER!

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    It is wells to Wheels. Greet does not include exploration, drilling. It includes pumping, refining and delivery to the station. (I also don't believe it includes service station energy usage, even though that would be part of "to wheels". )
     
  16. hyo silver

    hyo silver Awaaaaay

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    The costs don't stop at the wheels. Are environmental and social costs factored in?
     
  17. daniel

    daniel Cat Lovers Against the Bomb

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    ^ They're stating emissions numbers, not the cost of those emissions. Presumably there is rough equivalence if the same emissions are being produced.

    I'm glad all my electricity comes from hydro.

    My Roadster in Spokane:

    VOC - Zero.
    NOx - Zero.
    CO - Zero.
    PM10 - Zero.
    PM2.5 - Zero.
    SOx - Zero.
    GHG - Zero.
     
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  18. wjtracy

    wjtracy Senior Member

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    AG- Thanks for responding I wrote a long rebuttal which is lost in cyberspace. But I am from Pittsburgh which is way CLEAN now. Different when I was a kid with the steel mills.
     
  19. daniel

    daniel Cat Lovers Against the Bomb

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    Contradicting my earlier statement, street-level exhaust probably has greater health effects than power-plant emissions out in the boonies. But the goal should be to eliminate pollution, and the electric grid is getting cleaner every year, as has been commented elsewhere, and has the potential to be sustainable and very low footprint. And of course, you can put PVs on your roof for 100% emissions-free driving. It's harder to grow your own corn to make your own ethanol, or grow your own soybeans to produce your own biodiesel, and while all available used fry oil should be used productively rather than dumped, there will come a time when it's all being used. And it still has emissions, even though it's carbon neutral.
     
  20. wxman

    wxman Active Member

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    It appears GREET includes at least emissions from drilling, according to this...

    "Your vehicle’s carbon footprint is more than just the tailpipe emissions and includes all the activities that are needed to get the fuel from its source to the car. For example, crude oil drilling, pumping, refining, and shipping contribute to the carbon footprint of gasoline...."

    http://www.transportation.anl.gov/pdfs/MC/586.PDF

    It doesn't mention "exploration", but that would arguably be included in the "all the activities that are needed to get the fuel from its source to the car".
     
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