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Mirai production begins @ 3/day

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by fotomoto, Feb 25, 2015.

  1. austingreen

    austingreen Senior Member

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    Steel not carbon fiber tanks. Smaller tanks, less volume. That's why they don't truck hydrogen at 10,000 psi its cheaper to do it in liquid. You need some major cost breakthroughs on 10,000 psi to make it work on larger vehicles. I know I know, hydrogen is magic and the price will magically come down. Until then liquid is cheaper even if it does take more energy.
     
  2. usbseawolf2000

    usbseawolf2000 HSD PhD

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    It doesn't show coal either. Otherwise, it would heavily favor H2.

    It was comparing the cleanest fossil fuel that happens to be abundant in the US.

    Energy independence first then renewable next. That's how I see the progression.

    There is no need to truck it. Low pressure ambient temp central pipeline brunch to stations along the H2 highway. You chill and pump up to 10,000 psi from the station to the car. It is only about 4% loss that way. Much better than electricity 6% transmission/distribution loss and then 10-15% loss charging the battery.
     
    #262 usbseawolf2000, May 14, 2015
    Last edited: May 14, 2015
  3. GrumpyCabbie

    GrumpyCabbie Senior Member

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    What are the cost and maintenance implications of a hydrogen fuelling station compared to a traditional petrol station?

    I know the buried tanks have to be checked and maintained for leaks and safe venting of vapours with existing petrol stations, so how will this work with hydrogen cost wise? And will they need to be above ground?
     
  4. austingreen

    austingreen Senior Member

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    Key assumptions are hybrids and fuel cells will be more efficient than they are. If we take toyota's assumptions for efficiency well to pump or plug we have

    FCHV 44% (74 mpge epa)
    EV 33% (105 mpge epa)
    HV 34% (50 mpg)
    ICE 19% (28 mpg)

    Compare Side-by-Side
    So problem #1, if we use epa for all instead of a japanese test versus EPA, even given toyota's numbers for energy the fuel cell isn't adding up. Its going to fall far short of the 74 mpge. The clarity is 19% low, who knows about the mirai. If we are keying off the camry, we can pretend we should use the prius instead of camry hybrid for hv, but then the EV leaf can be used 11% more efficient than toyota's prediction. Or maybe we should use that tesla 70d, which is 4% worse ;-) but then its much faster than the camry and prius, then if that is the standard than the tesla must be at least compared to the camry hybrid, and the EV's win again.

    Can fcv improve that much? Probably but plug-ins aren't standing still, nor are hybrids.

    So we get to the next really bad assumption of the graph, that plug-ins and fcv will use only use natural gas, and the grid won't even be as efficient as today. Say 20 years from now, shouldn't we have more fast ccgt power plants. Those built today exceed 50% efficiency natural gas and grid losses to the plug. The chart used 39%. What about renewables. California says that 33% of hydrogen needs to be on renewables, that means at least 17 kwh of (renewable) electricity per kg of hydrogen unless someone figures out how to make it more efficiently. That 17kwh would power the tesla S 70d for 51 miles, the kg of hydrogen that mainly comes from natural gas would only get a clarity 9 miles more. That's a lot of natural gas for 9 miles.
     
    #264 austingreen, May 14, 2015
    Last edited: May 14, 2015
  5. austingreen

    austingreen Senior Member

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    Bob was talking about long haul trucks and hydrogen. Say you are going LA to Houston. It would cost a fortune to build that pipeline, and the trucks would still need bigger more expensive tanks. If you are only doing LA, maybe you can build H2 pipelines, but you need a lot of vehicles to make it worthwhile versus what they are doing now which is putting it on trucks for most stations. You aren't going to build a pipeline to bfe nevada or arizona. If you are doing long haul trucking hydrogen whether 10,000 psi, or liquid doesn't make sense but liquid makes more sense. Short haul cng is much cheaper for the truck or bus for fuel. Its a problem with the lobbies segmenting. I think the tanks and fuel are too expensive except for light vehicles. Now if you get down to light vehicles We have to see how big and expensive those tanks are for a pick up truck or SUV. My guess is Toyota and Honda and Hyundai and Mercedes looked at the highlander and equinox and decided cute utes and midsized cars are better for the pre commercial test. If they can lower the price of tanks a great deal then maybe we will see it on the midsized suv and pick up trucks. That might be 15 years but isn't today, and I think long haul trucks are never.
     
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  6. El Dobro

    El Dobro A Member

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    You are getting sleepy, FCVs are good, you want an FCV.

    [​IMG]
     
  7. Trollbait

    Trollbait It's a D&D thing

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    Define low pressure. NG transmission lines can be up to 1200psi.
    But the real issue is building the hydrogen pipeline in the first place. Which will cost more than the gasoline and NG lines cost to install and maintain. Hydrogen is a more reactive chemical than either of them. It can act like a halogen,i.e. chlorine, at times. Along with the embrittlement issue.
    There will be more maintenance. That's just simply because of the requirements of handling and containing a gas under pressure vs a liquid. I can't say how much more, but it will be more for a hydrogen station.

    The Mirai has been in production for over 2 months now, any official JC08 numbers yet?
     
  8. SlowTurd

    SlowTurd I LIKE PRIUS'S

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    it's still FUGLY
     
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  9. orenji

    orenji Senior Member

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    Not really, in the flesh it looks much better, it is a very attractive design.
     
  10. Jeff N

    Jeff N The answer is 0042

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    Let's not get carried away now...

    It's true that beauty is in the eye of the beholder but so is fugly. In my opinion it's an awkward child. Photo attached from the LA Auto Show where I saw it in person.

    image.jpg
     
  11. orenji

    orenji Senior Member

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    Photo's attached from my test drive today! image.jpg image.jpg image.jpg image.jpg
     
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  12. usbseawolf2000

    usbseawolf2000 HSD PhD

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    You live to tell. How was it?
     
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  13. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I'm glad you got a chance to test drive. Ordinarily, I don't care about 'style' but in this case:
    • the hood looks like it has popped open
    • the front looks like a bunch of parachutes
    An ordinary engine powered car has to dump ~1/3 of the wasted heat out of the radiator. So a larger radiator inlet suggests a more powerful, ordinary engine. In this case, it suggests wasted heat, not efficiency.

    Ordinarily, GM styling turns me off but this is one exception:
    [​IMG]
    Minimizing aerodynamic drag elements on the front is the way my cars should (and have) gone:
    [​IMG]
    [​IMG]

    Air scoops are the signature of inefficiency: (1) an engine dumping heat, and (2) high drag.

    Bob Wilson
     
  14. fotomoto

    fotomoto Senior Member

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  15. Trollbait

    Trollbait It's a D&D thing

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    In the Mirai's case, the air funnels are supposedly to provide air and oxygen to the fuel cell.
    The Honda Clarity managed just fine with a more typical front grill (I can't find an image that isn't obnoxiously large).
    Either way, the side intakes still look like awkward add ons to me.
     
  16. austingreen

    austingreen Senior Member

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    I believe the mirai's look is supposed to convey air changing to water. It is supposed to stand out at say look at me. IMHO the designers failed, but fugly is in the eye or the beholder.

    I'm sure if it works, and people like the looks (doubtful), good for them. If not I don't think there is a technical reason that it needs to look like that, so can easily be redesigned in the next generation, though it does need a design with a strong airflow for the fuel cell stack to work right. That airflow increases drag, but really lots of places to make the mirai more aerodynamic so I wouldn't blame it on the stuff that looks like gills.