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EVs now cleaner than a 50mpg car for 60% of the population!

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Zythryn, Sep 18, 2014.

  1. Zythryn

    Zythryn Senior Member

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    The Union of Concerned scientists have published a blog with some updates to their study on GHG emissions of EVs compared to gas cars.
    How do EVs Compare with Gas-Powered Vehicles? Better Every Year…. - The Equation

    The average EV, by sales form July 13 to June 14, has improved from .35kWh/mile to .325kWh/mile.
    Carbon intensity of the grid from 2009 (the year the original study's grid data is from) to 2010 actually went up a small amount. However, came down in both 2011 and 2012.

    I am very happy to report that my neighborhood went from 39 mpg (GHG equivalency) to 43mpg.

    Very happy to see that EVs are continuing to get cleaner as the grid gets cleaner AND as improvements are made in the EVs as well.
     
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  2. GrumpyCabbie

    GrumpyCabbie Senior Member

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    As well as the significant improvements to local air quality on city level.
     
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  3. jdenenberg

    jdenenberg EE Professor

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    I believe that this analysis does not take the battery charging inefficiency into account. Including the energy lost as heat during charging would swing the result to favor the 50 MPG hybrid, but then you would also have to include the energy used to supply gasoline (from well to car) to the hybrid as well as the energy used to supply fuel to the electric generation facilities.

    JeffD
     
  4. Zythryn

    Zythryn Senior Member

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    That would be incorrect. They talk about their methodology in the original paper as well as the update.
    The EPA numbers already take into account charging losses.
    The majority of the improvements come from the improvements of the efficiencies of EVs.

    Overall though, this is a perfect example of how EVs get cleaner over time.
     
  5. wjtracy

    wjtracy Senior Member

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    No doubt that %coal in the grid has been dropping so could be true based on 2012/2013 coal useage.
    I too feel there is some over-optimism about EV-CO2 in the Northeast (winter/summer) scenario.
    Not to mention many of these cars are smaller than a Prius, so we are not comparing on cars of equal practicality.
    Maybe I get around to renting a Volt this winter to check if my winter MPGe thinking is correct.
     
  6. Zythryn

    Zythryn Senior Member

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    The EPA numbers do take seasonal variability into account.

    That said, their corrections are an average and may be too much, or not enough for some winters.
    A great example of this is our experience over the last couple of winters. Last year we got less than the EPA numbers. The prior year we got better than the EPA numbers. I attribute that completely to the much colder winter this last year.
     
  7. Jeff N

    Jeff N The answer is 0042

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    Although it's great for the long term that coal is being replaced with natural gas, in the short term (next 20 years) it isn't clear that it will result in lower global warming impact.

    Natural gas drilling is poorly regulated and there is little comprehensive information about methane leaking from the fields. The best recent measurements indicate higher leakage than previously estimated -- high enough that methane's much greater warming effect may overwhelm the reduction in CO2 from coal.

    In the longer term (100+ years) it is still an important improvement as the methane eventually breaks down in the atmosphere. So we shouldn't be complacent due to the faster than expected switch away from coal.
     
  8. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Living in Alabama, I would buy an EV only if it meets my usage needs and is cheaper per mile to operate. Cleaner air plays no part in my calculus.

    Bob Wilson
     
  9. austingreen

    austingreen Senior Member

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    I think those pushing sticking with coal and oil have usurped some of the environmental community and duped them into the idea that natural gas is the new big bad, and isn't well understood. Fracking has been going on for half a century. The amount leaking from fracked wells is well understood, and is being studied further. We do need better regulation, but compare the destruction of mountain top removal to natural gas, and its no contest.

    What will it take to get sustained benefits from natural gas? | Environmental Defense Fund
    Electricity is cleaner with natural gas. plug-ins are cleaner than pure gasoline powered cars except in rare circumstances. cng cars and trucks though may be worse than oil.
    Better regulation is definitely needed, but transitioning from coal and oil to natural gas, wind and solar, is definitely an improvement.

    Given all the coal negatives including mercury and particulates, coal ash, etc, we should be accelerating US reduction of coal.

    Japan and germany for short term economic reasons are burning more coal each year, but we should try to get a peak coal usage in these industrialized countries and China and India, the big burden.
     
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  10. SageBrush

    SageBrush Senior Member

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    I'm surprised to read this from you. Please explain why.
     
  11. SageBrush

    SageBrush Senior Member

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    I don't accept the UCS methodology because it uses average emissions. The proper way to analyze the question is by looking at marginal emissions.
     
  12. -Rozi-

    -Rozi- Member

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    Bravo, You just said out loud what I believe most of this community is thinking quietly. Including myself. Economy first. Ecology is mostly a by-product.
     
  13. hill

    hill High Fiber Member

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    Not only does the analysis take charge loss into account, it does NOT take into account the ultra high cost of importing oil from countries that we've set up dictators in - than the heavy use of military from (what the CIA calls) the 'blow-back'. Nor does it take into account respiratory disease/med costs via pollution caused by carbon fuels. Those less tangible factors are harder to nail down - but they're still huge. So even if the analysis hadn't taken into account charge loss - the result would have still been a huge landslide against the ICE vs plugs.
    Cheaper per mile is often the best formula. We swallowed the plug-in cool-aid after running numbers that counted in PV costs, that basically paid for itself in 6-ish years. Now, if I could just afford that Tesla . . . . . boy, THAT'd sure take awhile to amortize.
    :D
     
    #13 hill, Sep 19, 2014
    Last edited: Sep 19, 2014
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  14. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Well you should :)

    Air pollution - State and impacts (Slovenia) — European Environment Agency (EEA)
     
  15. SageBrush

    SageBrush Senior Member

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    I think (I hope) you jumped the gun. Bob may simply be saying that that his grid is coal heavy. As for your 'quiet majority,' if true it is foolish. The environment IS the economy.
     
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  16. Zythryn

    Zythryn Senior Member

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    Far too complicated, marginal rates vary from day to day, minute to minute as well as by location.
    My understanding is that there are areas that simply turn on wind, or heat up the coal plants that are already running to increase efficiency.
    Doing so would increase carbon more than a NG mix, however it also lowers the carbon intensity of the rest of the power supply.

    Using the average grid carbon intensity may not be perfect, however it is a good approximation.

    What we really need is real time carbon intensity information available to the end user. For purposes of this type of paper though, I see no benifit to replacing one approximation with a more complicated approximation.
     
  17. SageBrush

    SageBrush Senior Member

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    It's been a few years now, but a marginal emissions analysis was done for EVs by one of the US national energy labs. IIRC granularity was sub-state. The important take-home message was that overall EVs looked a lot worse than a regional average suggests.

    This issue of under-utilized wind capacity, e.g. in Colorado, is a political and financial problem. The utilities are using the source they find the cheapest. So coal gets used and wind is allowed to go to waste. This is incidentally one of the reasons I have pretty much given up on central power utilities and am looking to go off-grid: they operate against my interests.
     
    #17 SageBrush, Sep 19, 2014
    Last edited: Sep 19, 2014
  18. Zythryn

    Zythryn Senior Member

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    Do you have a link? I'd love to see how they handled the time of use data and how they adjusted for the increased efficiency to the entire output of coal plants that were heated up to increase efficiency?
     
  19. SageBrush

    SageBrush Senior Member

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    ^^ I'll look.
    I can almost remember the lead author name ... ends in 'ani.'
    Ruthani ? Rowlani ?

    Addendum: Here Elgowainy ;)
     
  20. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Remember I said,"living in Alabama." If I lived in California or Denver or even back in the DC area, air quality would be more important. Large urban areas that often suffer stagnant air are places where low emissions are important. But that is not where I live now.

    One of my biggest disappointments was the horrible implementation of the first EPA, car emissions standards. I was appalled by the 1970s engine compartments that were overloaded with all sorts of plumbing trying to meet the emissions requirements. Yet it was obvious improved fuel economy would accomplish the same objective with many economic improvements:
    • fuel-injection with active mixture feedback
    • efficient automatic transmissions
    • aerodynamic curves are back (like I prefer in women!)
    • light-weighting
    So I'm not into 'green' except as it applied to the dollars kept in my wallet. No, I'm not about to rip out the catalytic converters. But if one fails, I'll be using an after market replacement and as long as the mileage is OK, not give it a second thought . . . in Alabama.

    Bob Wilson