Obama Announces High Speed

Hytec Apr 16, 2009

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  1. jagged ben

    jagged ben TrainBoard Member

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    You're overstating your case. What I said will be true for the vast majority of road vehicles, enough to say that it "comes close" to being true for all cars. (Can't find a source, but I'd wager more than 95% of those on the road.) Your vehicle is in a small group of exceptions that proves the rule. I could have picked higher numbers (say, 65 and 90) and it would definitely be true for all cars. Once a vehicle is cruising in top gear, laws of physics pretty much dictate that fuel economy will drop with increased speed. (And since trains don't have transmissions, it's even more true of them.)
     
  2. Mark Watson

    Mark Watson TrainBoard Member

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    Looking at that report I was at first surprised by the results, then I read the conclusion "If electricity is generated from fossil fuels". Remembering back in High School Physics we were taught 90% of energy is lost to friction. Taking fuel to produce electricity, then that electricity to power trains, that would mean we're only utilizing 1% of the fuel's energy. That then makes it obvious that a car and even a plane using 10% of the fuel's energy (assuming similar passenger/seat ratios) has more efficiency than the fuel generated electric train.
     
  3. jagged ben

    jagged ben TrainBoard Member

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    The way you're using the term "efficiency" doesn't fit the dictionary definition. Whether a source of energy is renewable or not has nothing to do with efficiency as the term is normally used. The efficiency of a high speed train, expressed in kilowatt-hours per passenger mile, does not change if the electricity comes from wind instead of coal. It does change, however, depending on how fast the train goes.
     
  4. Mark Watson

    Mark Watson TrainBoard Member

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    I'm using the term efficiency in a broader sense than you assume. Wind electricity is more efficient than fossil fuel generated electricity because there is no loss of resources in producing the electricity from wind, where as using fuel we not only loose about 60% of the energy to heat but we lose the fuel itself. Therefore a train running on electricity generated by fuel is not as efficient; productive with out waste, as a train running on wind electricity.
     
  5. Hytec

    Hytec TrainBoard Member

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    I'd like to add a side-bar regarding wind generated electricity. I do not want to start any arguments, merely provide some information.

    Operators of large-scale wind farms, mainly in Europe, are discovering that the row of turbines directly facing the wind are significantly disturbing the airflow available to the rows of turbines behind the first. For instance, where the flow of air approaching a wind farm from the ocean has a streamlined flow, after intreracting with the first row of turbines, the flow of air changes to a turbulent flow. Then the second row of turbines disturbs the air flow even more, until the flow becomes almost unuseable when it reaches the fourth or fifth rows. The result is that the second and subsequent rows of turbines generate far less energy than the first row of turbines for the same wind speed. (Consider how an airplane bounces when it passes through the wake of one that has passed up to 3 miles in front.)

    This information has not been discussed in the public press because it still is considered anecdotal. However, reports based on local company studies of this phenemonon are beginning to be presented at periodic industry meetings that focus on wind turbine power generation.

    I doubt if these negative observations will become widely publicized until the press and general public are willing to accept that no power generation technology is the "perfect" solution, that every technology has a cost or downside to its benefits. What is needed is for the public and governments to stop jumping on every "new and exciting" techology that comes along, but to develop and accept the best solution(s) or technology(ies) for a their region and useage.
     
  6. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    No. I am not. I knew full well you'd try to respond by saying my vehicle was an exception or aberration. Theories are all too often just that, theory. I speak from actual expertise. Not wishful thinking.

    Boxcab E50
     
  7. Hytec

    Hytec TrainBoard Member

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    Electrical power generated at a central location, i.e. a large power plant, is a far more efficient process than power generated locally on a small scale as with a diesel-electric locomotive. The reason that electric rail is not more widely used in the US is the initial cost of installing catenary, which has been borne by the rail company. Where the government pays for installation, the benefits are significant. This is why most of Europe, and an increasing amount of Asia are electrified.

    When the US government accepts that part of reducing our dependency on oil involves rail electrification, then we will see federal assistance with that process.
     
  8. jagged ben

    jagged ben TrainBoard Member

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    Provide some statistics to support your claim that your vehicle is not unusual. Tell us what vehicle you have and provide a graph of its speed vs. mpg. Otherwise your own experience is just one experience and asserting that it applies to the general case is itself wishful thinking.
     
  9. jagged ben

    jagged ben TrainBoard Member

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    Not necessarily. Diesel motors in locomotives and cars are more thermally efficient (>40%) than coal power plants (30-40%) and less efficient than the latest natural gas plants (up to %60).

    I would say it has more to do with the fact that Europe had no significant conventional oil resources, and thus got in the habit of using coal and eventually nuclear instead, to avoid the import bills. Essentially, it made more economic sense for them to install catenary regardless of who paid for it. (And since 1970, when US production peaked, it would have made more sense for us to do it too, instead of spending the money...to secure new oil supplies.)

    You could say the headline that started this thread might be the beginning of that. Hopefully.
     
  10. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    Nope. You first. You made the original unsupportable claim. Lead on, and make it real, not theory.

    A graph? I gave you more than enough in those two mileage/speed numbers. All that is needed, when comparing 55 versus 70mph speed limits. In between is meaningless as to this discussion.

    I have years of actual experience in the automotive performance field. That was just one of many, many examples I can cite. Hmm- Maybe I should just make things up like so many "experts" in theories do these days.

    Boxcab E50
     
  11. jagged ben

    jagged ben TrainBoard Member

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    There is a loss, because it takes energy to produce the windmill and to produce the wires to transport the electricity. If the wind mill does not produce more energy in its lifetime than it took to make it, then it is not more "efficient" than fossil fuel, by any meaning of the term.

    Also, transmitting electricity over wires loses energy. Over the course of long distances this can be a significant percentage. (5-10%) All these factors have to be quantified to make true comparisons. Thankfully, wind energy has become roughly as cost-effective as fossil fuel energy in recent years.

    I certainly agree that wind energy is more desirable than fossil fuel energy. But that is still not what engineers mean by efficiency. Nor is it what I meant when I brought it up.
     
  12. jagged ben

    jagged ben TrainBoard Member

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    Green Car Congress: Fuel Consumption at Higher Speeds

    http://ntl.bts.gov/lib/5000/5800/5844/21st_edition/Edition21Chapter07.pdf
    (see page 26)
    http://commons.wikimedia.org/wiki/File:Fuel_economy_vs_speed_1997.png
    (same data graphed)

    http://fueleconomy.gov/feg/driveHabits.shtml
    We Test the Tips

    mpg vs. speed - Metro graph - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
    mpg vs mph: prius graph - GasSavers.org - Helping You Save at the Pump
    http://www.delphifaq.com/faq/auto/f994.shtml

    Now I've spent more time than I should on this and still haven't found any data for a vehicle that get's better mph at 70 than at 55. Your turn.
     
  13. Benny

    Benny TrainBoard Member

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    Here's what get's me most riled up...

    [ame="http://www.youtube.com/watch?v=k2kLTj3aHFA"]YouTube - 1960 - Wonderful New World of Ford[/ame]

    Par particular attention to 1:52 - for the quote at 2:03.

    So today we're raving about how we're getting 20-25-32 MPG on our new cars. AND YET that was accomplished by in 1960 on a 6 cylinder 144 CID Ford Falcon. Hmmmm, it really makes me wonder...

    Yes, you will argue that now we have all these controls on that reduces emissions. I ask you this; when we take into account all the energy that went into making the emission control systems [factory output], all the energy lost in assembling the systems, and now all the energy lost in maintaining those systems, just how much Energy are we saving Net Total? NONE! If there is one thing for sure, it now takes MORE non-renewable fuel to go the same distance as it took Then!

    I understand this is car is not the field; it is an anomoly. And yet...weight wise, the falcon is quite close to being between a compact and a midsize...

    I also seem to recall that it takes between 5 and 15 years to recover the energy it requires to make one wind generator. What's worse is that the wind generator only lasts up to 15 and 20 years and it could fail even sooner.

    I do kow that once static friction is overcome, sliding friction is very low...then you incorporate mag-Lev and the world's the limit...
     
  14. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    Congratulations! You did exactly as I expected- You dove straight into the theoretical world. With it's strictly controlled scenarios. To even note hypermiling, which has silly extremes such as rolling down hills and drafting behind trucks... Which BTW- Are also illegal techniques.

    The only test result which could have any merit would need to come from a sampling of millions of vehicles and drivers, in the daily use world. Where at very least weather, vehicle maintenance, and individual driving skills come into play and vary wildly. A sampling which would at it's best be difficult beyond belief to monitor for any accuracy.

    Boxcab E50
     
  15. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    Yup. The '82 Honda we still own got better mileage than most today. 45-46 city, 55mpg at 70mph highway. The technology exists. But the bandaids hinder.

    Speaking of the many vehicles I have owned. only one fell in mileage when driven above 55mph- A 1957 Chevrolet Delray 210. (2 door post, 235cid, PowerGlide w/3.08 gears.) Which would fall from just barely hitting 14, down to mear 11.5 at 70. But back then $2 also bought me ten gallons of gas.

    Boxcab E50
     
  16. jagged ben

    jagged ben TrainBoard Member

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    It's as if you didn't even look at what I posted. Everyone one of the links I posted contained data showing that cars in general, or various individual models that were tested, got worse mileage at 70 than at 55. Data (not theory) on 16 different vehicles (including a light truck and an SUV) in the first two links alone.

    I even looked for counterexamples on the web, to help you out, and could not find any.

    Forget anything else that was in those links and address the data.
     
  17. Mark Watson

    Mark Watson TrainBoard Member

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    *sigh* We could go back and fourth on this forever. For instance, it takes just as much energy to produce the gas turbine and wires to transport the electricity from it.

    Either way, going back to the original topic, something we can ALL agree on, it's great to see the government finally exploring high speed rail travel. Now lets shut up and go have a beer on Friday night! :p
     
  18. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    Oh but I did. I have been seeing things like these for years.

    Take for example the first link. Their tests were held under highly controlled conditions. Not in every day driving. The real world is not that way, which makes their results useless outside of that tiny environment. Not to mention that there is a bias in play as well.

    Show me something not theoretical. So far, no go.

    Boxcab E50
     
  19. Hytec

    Hytec TrainBoard Member

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    D'Accord! :tb-rolleyes:
     
  20. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

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    A nice Lager sounds good to me. Make mine a Grolsch....

    Boxcab E50
     
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