so why doesnt it work?

Discussion in 'Hybrid' started by jbehr, Sep 23, 2010.

  1. jehardiman
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    jehardiman Senior Member

  2. daiquiri
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    daiquiri Engineering and Design

  3. jehardiman
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    jehardiman Senior Member

    That's why I'm still waiting to use them in my boat...:D

    Really, it is just a matter of time and market now. How long that takes depends on social things outside engineering decisions. What I expect is a slow development to liquid monofuel fuel cells. What I don't expect is a rapid move to cyrogenic gas fuel cells though this will fund development of monofuel. What is nice about this is that I can set up a nuclear or solar plant right next to the ocean and produce the H2-O2, but right now moving cyrogenic gasses has losses, though sponge metal hydride storage looks promising.
     
  4. apex1

    apex1 Guest

    Ohh,

    I was sure one will contradict. Did not expect it was you though.

    To make it short (we have already drivelled far too often about this nonsense),

    THERE IS NO ENERGY STORAGE AVAILABLE AT PRESENT AND FOR THE NEXT TWO DECADES TO MAKE ELECTRIC PROPULSION ON SEAGOING VESSELS POSSIBLE! PERIOD:::::::::

    You can quote me on this after 20 years I will be around!

    Of course that has to take into account the overall efficiency, including economic feasibility, of the installed systems, and does not apply on special purpose applications where cost is not a factor.

    And don´t come up with submarines or the day trip boats on lakes again, thats just hair splicing for the arguments sake, we talk yachts and motoryachts for coastal or ocean trips.

    Regards
    Richard
     
  5. jehardiman
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    jehardiman Senior Member

    I think, to bring this back around to the orginal post, you should change that to:

    "There is no electrical energy storage device available at present and most likely for the next two decades to make direct electrical propulsion on seagoing vessels economically practical"

    to be correct and agreeable.

    There are today, and have been for almost 100 years "energy storage" systems that make electrical propulsion economically practical for seagoing vessels. But most of these systems store energy to make electricty as it is needed as opposed to storing voltage potential directly. And there are many economically unpractical systems out there today that could be placed on ocean crossing "seagoing vessels".

    FWIW, I tend to avoid absolutes in hull and propulsion designs. I feel that there are no absolute "best" or "worst" solutions to many marine problems, rather there are solutions that better suit the needs and compromises. And we need to be sure that we all agree on what words to use to describe that. I lke to use:

    Possible= There is no theoritical reason given unlimited time and money that the task cannot be accomplished. Intersteller travel is possible.

    Feasible= All the technology is in place to complete a given task given sufficient time and money. Commerical space tourism is feasible.

    Practical= I can buy/make all the equipment needed to complete a task within a viable economic model. Commericial space launch is practical.
     
    Last edited: Sep 24, 2010
  6. apex1

    apex1 Guest

    Sounds better no doubt. But:

    No, sorry.

    D/E systems are not "economically practical", and they are the only systems around for 100 years.
    Neither are we discussing Icebreakers, Cruise ships, Tugs and Crane barges, nor do we gain any benefit from similar systems when installed on yachts.

    We need a reliable and affordable propulsion and the necessary fuel storage. Not electricity for hughe hotel loads, or extreme torque at very low speeds.
    Here we have absolutely NO alternative to diesel propulsion, on seagoing boats.
    That is so, and remains to be so for very, very long, because there is not even a good idea in sight to replace it, let alone a proven system.

    Of course, when we leave cost out of our equation, when we completely forget the chain from first step to generate energy, to consumption at the prop, one can call some systems "being on the market".

    But that is sure not what our new members here ask twice a week, when they talk about electric or worse, hybrid propulsionn. They live in a phantasy it could be bought off the shelve and be a good alternative. And that is nonsense.
    Any other month some snakeoil salesman pops up and spreads new (or old) lies and dumb drivel about his magic carpet system, like here:
    http://www.boatdesign.net/forums/reputation.php?p=399131

    It gets boring............

    Regards
    Richard
     
  7. Submarine Tom

    Submarine Tom Previous Member

    "What is nice about this is that I can set up a nuclear or solar plant right next to the ocean..."

    John, I'm just wondering which agency I should report you to for this kind of statement.

    -Tom
     
  8. jehardiman
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    jehardiman Senior Member

    Pick one, DOE (http://www.energy.gov/) and DOT (http://www.dot.gov/) is where I would start...but then again I wasn't violating the Wassenaar Arrangement (http://www.wassenaar.org/).
     
  9. Submarine Tom

    Submarine Tom Previous Member

    "...but then again I wasn't violating the Wassenaar Arrangement."

    That's funny, neither was I. Give your head a shake!

    -Tom
     
  10. jehardiman
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    jehardiman Senior Member

    Here we agree to differ. Lets talk cost per ton of cargo delivered over the life of the vessel by sea proven systems. Steam-solar and steam-diesel hybrids, from a pure energy cost consumption point, are still in the equation even if we exclude their secondary values. It is manning that kills it economically. Pure GT or CODAG is also more efficient than diesel when matched to requsite service needs. And Nuclear is way better than diesel from a purely technical powering costs, it is the political costs that make it unviable.

    What LSD's brings to the table is low manning and layday flexability which in todays glutted shipping market makes economic sense. And one MARPOL decision on stack gasses could really alter the field. As I said before, there is no one perfect power system just like there is no one perfect hull. Both must be matched to the requirements.
     
  11. apex1

    apex1 Guest

    We don´t,

    I am just not talking commercial appliances, that must be hard to get for many here.

    I can not only name hundreds of examples where combined propulsion is a sensible solution, I have operated them myself.

    But there is no place on yachts for such systems, and our enquiries here are exclusively addressed to yachts.

    There are no Icebreakers and nuclear submarines around in our marinas. (good luck)

    Regards
    Richard
     
  12. CDK
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    CDK retired engineer

    An interesting development indeed.

    If the purchasing price including an electric motor would be roughly the same as that of an outboard or boat diesel, there would remain only issues like weight, the very expensive fuel and the slow start-up procedure. But I fear it is a bit more expensive.

    The 60% thermal efficiency is quite an achievement, but is limited to the conversion of H2 and O2 only. If producing the fuel can be done with the same efficiency, the overall figure would be 36%.

    So what we have here is an energy storage system that returns 360 watts for every kW used to split H2O and compress/cool the gases to enable storage.
    I am not impressed.
     
  13. jehardiman
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    jehardiman Senior Member

    Which is why I'm still waiting for liquid monofuel fuel cells. But I believe that it is just a matter of time before some bright chemist figures that out.
     
  14. powerabout
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    powerabout Senior Member


  15. MatthewDS
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    MatthewDS Senior Member

    Basically, it doesn't work because of two problems, one with energy storage, and one with efficiency of energy conversion.

    Energy storage:
    First, energy density in current battery technology is not as high as the energy density in diesel fuel. Put simply, one pound of batteries powering an electric motor will not drive a boat as far as one pound of diesel burning in an engine.

    Energy Conversion:
    A system where a diesel engine turns a generator which powers an electric motor to turn the prop will NEVER be as efficient as a system where the engine turns the prop directly through the shaft. This is due to irreversible losses in both the generator and motor as motion is converted to electricity and back again.

    Until we have access to personal nuclear reactors, or battery technology improves dramatically, hybrid systems on personal yachts will remain a dream.

    That isn't to say it wouldn't work. Anybody could build a hybrid diesel-electric drive and put it in a 50' cruiser. It's just that you would burn more fuel per mile than a conventional yacht, so it's pointless both economically and environmentally.
     
    Last edited: Sep 26, 2010
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