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EPA says Series Hybrid Better

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Anonymous, May 1, 2005.

  1. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    at current technology and production methods, it is a loss and the large non-centralized farms are the biggest reason.

    one proposal that has already been proven effective is small localized farms. they dont rely on heavy machinery to farm the land and the biggest thing is transportation and handling expenses. farm products travel an average of 1500 miles to get to your local supermarket... in Canada the average is 5000 miles. remove that energy cost and bio-fuel does become viable
     
  2. Anonymous

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    Biodiesel grown using soybeans or oilseed-rape (canola) is definitely energy positive, giving about 100 gallons of oil per acre per year and ~4 times the energy put in (coming mainly from tractor use and petrochemical fertilisers).

    But growing algae under plastic is MUCH more efficient - to the tune of up to 10,000 gallons of oil per acre per year. There are companies in the US starting pilot schemes in this area right now, the numbers from which suggest that they will be able to make renewable biodiesel at a cost less than that of fossil-fuel based diesel or gasoline.

    Oh, and back to topic, the reason Toyota didn't make Prius a series hybrid is because the battery and power electrics would have increased the build costs too much. PSD is the cheapest option as it allows you to use a small battery and small motor.
     
  3. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    there is a bio diesel farm just east of seattle that is small scale (just over 5 acres i believe) and has been experimenting with bio-diesel. there was a really cool website they had and i for the life of me cant find it...(actually dont remember saving it and am kicking myself now) they talked about how little needed to be done to convert any diesel engine to run this stuff.

    they talked at length about the feasibility of having several small local farms growing the stuff and maybe having one farm that processed all the bio-diesel for a small handful of people. they went through the number of like having 6-10 farms all under 10 acres providing the stuff and even recommended different things to grow that would harvest more often and stuff. the place was in issaquah i think...or maybe wenatchee... all HECK... i dont remember...
     
  4. KaniS

    KaniS New Member

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    From what I've heard from the research conducted by a hybrid-obsessed friend of mine, engineers originally worked on hybrids that ran an efficient engine at a more constant speed to store power in the batteries and use that power to drive the wheels. It was far more efficient than the Prius, but when they did consumer testing, consumers did not like it because the gas engine would run at "random" times to charge the battery, not when they stepped on the accelerator.

    People want what they're used to, not what works best. Car companies don't want to take the chance on an unusual product that might not catch on, especially when it requires so much development cost. There was some problem with the engine not being able to keep up enough battery charge to propel the car up an extended incline. If you run the battery down going up a mountain, the gas engine eventually can't provide enough power to keep the battery charged and keep the car moving. Anyway, the engineers gave up on solving the problem after the consumer testing results.
     
  5. usbseawolf2000

    usbseawolf2000 HSD PhD

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    <div class='quotetop'>QUOTE(richard schumacher\";p=\"86299)</div>
    I completely agree. I would like to add some more. For Series hybrid, bigger battery is necessary and the life would be shorter due to the motor usage all the time.

    Also, isn't the electric motor inefficient at high speed? For example, Rav4 EV needed more Kw per mile as speed increased.

    HSD is a continously variable mode hybrid. It made me laugh when GM-Chrysler announced their two mode hybrid(static) design. Now EPA is claiming that single mode hybrid is better.
     
  6. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    any one can say what they want about whats better... but until they start walking the path they are talking about, it dont matter.
     
  7. Anonymous

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    <div class='quotetop'>QUOTE(usbseawolf2000\";p=\"87703)</div>
    The bigger the battery, the longer the life. Assuming a conservative 1,000 cycles, a 20 mile pack would only last 20,000 miles. But a 200 mile pack would last 200,000 miles, and would be much less stressed throughout its life due to lower currents and temperatures.

    <div class='quotetop'>QUOTE(usbseawolf2000\";p=\"87703)</div>
    All vehicles use more power and are less efficient at higher speed. A series hybrid could still easily manage over 100mpg at normal highway speeds though.
     
  8. greencanuck

    greencanuck New Member

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    Biodiesel, I'm certain, has some great potential, but so too does ethanol. And also, thinking of improving efficency, I wonder why Toyota did not also add a CVT into the drivetrain. Cost?

    Perry
     
  9. usbseawolf2000

    usbseawolf2000 HSD PhD

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    <div class='quotetop'>QUOTE(clett\";p=\"87984)</div>
    Let's see. For a series hybrd, if electric motor is twice more powerful(100kW) than Prius(50kW), you'll need the battery twice as big. If the battery get used twice as often, the battery needs to be 4 times as big to achieve the same life expectancy. This is assuming the ICE is powerful enough to keep the battery SOC in the ideal range as HSD can. The inverter will need to handle more current as well.

    I don't think passing performance on the highway would not be as good as HSD because single electric motor torque curve drops significantly as RPM increases.
     
  10. Anonymous

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    For the same amount of power, an electric motor-driven vehicle is substantially better at accelerating than an internal combustion engine powered vehicle. E.g. passing will be much easier in a 100hp EV than in a 100hp ICE powered vehicle.

    Why? Because an ICE only gives full power at peak revs. If it gives 100 bhp at 6,000rpm, it will only have ~50 bhp at 3,000rpm (remember power = torque times revs). By contrast, the electric motor will always have full power available (ie it would have 100 bhp at 6,000rpm and also 100 bhp at 3,000rpm).

    Floor the throttle at 3,000rpm in the ICE car and you only have 50bhp accelerating you. Floor the throttle in the EV and you have 100bhp accelerating you. It's mainly for this reason that AC propulsion's T-zero can manage the 0-60 sprint in 3.6 seconds with only 200 hp.