Higher power parallel hybrid applications?

Discussion in 'Hybrid' started by Bosun, Nov 25, 2009.

  1. Bosun
    Joined: Nov 2009
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    Bosun Navigare Necesse Est

    Can anybody return my feet on ground from having dreams of powerful parallel hybrid application.

    So far I haven't found any commercial supplier that could provide more powerful application than 7 kW Steyr and 10 kW Hybrid-Marine Ltd + Epic Boat´s Wakeboard monster (fake or reality? They do not present too much of technology in their U'tube show)

    What are the actual limitations to adapt let's say at least 20 kW (or higher) Electric motor with combustion diesel engine? Is it price or battery technology (too heavy battery bank or too dangerous to have higher voltage systems onboard than 48V). Or is it the gear causing problems with higher revs and moments?

    There are already numerous on-highway applications running with much higher electric drives so the technology really exists. Battery technology is developping with huge steps and size and price of Lion-batteries will split in about half within next few years. Of course a vessel do not have the possibility to benefit energy coming from deceleration as trucks and smaller vehicles can do.

    My interest would be in setting up a hybrid into app. 30-35 semi-planing vessel w/ app. 4000-5000 kgft displacement, providing boosting option, electric drive for harbour maneuvers. When running with combustion engine it would charge the battery bank.

    Just wondering why it is not on market yet.

    Thanks for your replys in advance.
     
  2. masalai
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    masalai masalai

    Boson, I am no expert, but may I suggest you sit and think for a while?

    You are postulating that you use a diesel engine to generate electricity to drive an electric motor to drive a propeller???? why add the electric generator and electric motor and consequent losses of around .8 each? No advantage unless you have other critical uses for the electricity generated? - - Additional power required to get up in top of the water and plane that load? 4 to 5 tonnes, man who sold you a story on a 7kw engine to do that??? At a guess 120kw just to get a boat on to the plane... that is about the weight of my build when finished 12M x 6.4M sailing cat!

    There is only two BIG advantages with electric drive...
    1) - - near 100% torque from zero rpm to peak rpm delivered to the propeller...
    2) - - "silent" running whilst battery capacity remains (except for the motor/gearbox/something wine that seems to be emitted from most efficient PMC motors...

    disadvantages include comparative cost and complexity in specialised motors and control systems... Ancilliary weight penalty - - - batteries and charging systems (genset & PV panels etc),
     
  3. Bosun
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    Thanks masalai,

    My intention would have the electric motor boosting up the diesel when accelerating, not taking all of it. The gearbox should have centrifugal clutch in order to combine these power sources.

    The benefit of electric drives is in torque and instantaneous peak power being more than 7 or 10 kW. But till 7 kW and 10 kW wouldn't give the wanted boosting in order to decrease the load of diesel. Pls review the Hybrid-Marine's presentation on parallel hybrids (http://www.hybrid-marine.co.uk/10.html) which describes the benefits in nut shell.

    Todays electric drives on- and off-highway can provide very efficient solutions and torque/power curves can be as high as ~170 Nm with 35 kW continuously, providing that you have sufficient high electric power (meaning minimum extra 200 kg load of battery bank). One supplier could be

    http://www.heinzmann.de/index.php?option=com_content&task=view&id=257&Itemid=306&lang=en

    So far I haven't found other disadvantages but very high cost (including controlling of it and SW-work) and additional weight of ~200 kg's<.

    What are the other limitations - that's what I'm after. Would really appreciate if someone could enlighten me. Thanks ;)
     
  4. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Could it be that boat builders in general prefer mechanical solutions over electrical ones? There is of course the reality that electricity and water is a difficult combination demanding many precautions.

    But probably more significant is that to understand, design and service electrical systems, knowledge and imagination are required. The average mechanic understands how a drive train works by looking at it, but very few people can actually see electrical currents flowing.

    As a result, the boating world can be considered a hostile market which attracts very few manufacturers. It is like trying to sell knife and fork to the Chinese.
     
  5. apex1

    apex1 Guest

    Ah come on Cornelis.......

    It is much easier. The Hybrid does´nt make sense, thats it.
    The average boater never gets a net profit installing such a system. The additional cost (and maintenance, and replacement), will not pay back. But boatyards produce for the average Joe with less than 100 hrs of useage a year.

    Regards
    Richard
     
  6. CDK
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    CDK retired engineer

    A valid point Richard. Joe represents the majority in this market, so the industry offers him outboards, direct cooled gasoline engines and stern drives.

    But the picture isn't complete. Retirement allows for much more than the annual 100 hours, there are numerous small fishers, excursion boats etc. When I visited Venice in spring, the town didn't smell like pizza or pasta but a mix of gasoline and diesel. Bobbing in the harbor are hundreds of small craft where the gondoliers are replaced with an Iveco diesel.
    For that part of the market, hybrids or electric propulsion could present a solution if boat builders could be persuaded to change their attitude.
     
  7. Joakim
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    Joakim Senior Member

    There is a huge difference between marine and road applications. The high low rpm torque is an important feature for a car which needs a high torque to accelerate. The torque required to spin a propeller drops very fast with decreasing rpm and thus high torque is not needed during acceleration (except for some planing boats having difficulties to get into plane).

    Another big difference is that a car doing 80 km/h needs only ~10 kW, but has easily more than 100 kW. Thus most of the time the engine is working under extremely low load (less than 10% of power). In marine application this is typically not the case. Typically 30-80 of the full power is in use and thus the engine is operating close to it's optimum efficiency.

    For a 5000 kg semi-planing boat, you need in the order of 100 kW for just the cruising speed. 10 kW is not useful above displacement speeds and even maintaining 10 kW for a longer period would require some very heavy and expensive batteries.

    So the only use I could see is at slow displacement speeds. Is the extra cost and complexity worth it?
     
  8. Bosun
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    Bosun Navigare Necesse Est

    Yes Richard, I also agree.

    A research from 2004 points out that an average Finn goes boating app. 50 hrs per season... And this country has relatively high quantity of pleasure crafts per capita (country with thousands of lakes and thousands of islands, counting archiplelago and inlakes).

    But think of when EPA or Tier requirements penetrate to pleasure boat markets and when price of fuel exceeds the treshold of pain in your wallet. At that time the market should have some medicin to offer.

    I'm not starting a boat production but trying to see a possibilities to launch interesting research project.

    We all know that environmentally friendliest (and most enjoyable) option of boating is sailing. But having so little time and 4 small kids do not match with 5 kn/hr or even less :)
     
  9. fcfc
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    fcfc Senior Member

    Heard of this :

    http://www.greenlinehybrid.com/

    Important points : (taken from specifications/main dimensions.)

    top speed with electric : 6 kts.
    top speed with 75 hp : 10 kts
    top speed with 165hp : 15 kts.


    Range at 7 kts with std engine : 700 nm.

    The electric engine is around 10 hp (7Kw) and tops at 6 kts. For 7 kts, you are likely to use something like 15-20hp, no more).

    range at 4 kts with electric = 20 nm. Youre likely to use something around 2Kw power.
     
  10. Joakim
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    Joakim Senior Member

    Funny how they claim the same annual fuel consumption and CO2 emission as for a sailboat. A similar size modern sailboat would get that 7 kn at less than 15 hp and with better range than 700 nm for 430 l tank (= 0.6 l/mpk). No sailing in the comparison? No driving at 10-15 kn in the comparison? Already at 10 kn the range is less than 300 nm and at 15 kn it is ~200 nm. And a sailboat at 6 kn would be ~0.3 l/mpk thus double the range.

    A 33' sailboat would need only about 500 W of effective thrust at 4 kn, thus 1 kW electric power should easily be enough unless there is waves/wind. That motorboat probably needs far more at 4 kn.
     
  11. Bosun
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    Joakim, thanks for base info.

    I know on/off road vehicles can't be compared with marine applications in terms of resistances and needed power out-put of engine when cruising speed or acceleration - rolling energy on wheels vs. friction and water masses etc.

    My knowledge so far is based on common info from suppliers mentioned in comments above. I'm also reading the default power out-put from existing power curves of one off-road application when using higher voltages.

    I'm no specialist in engineering or power calculations nor physics - only Aku Ankka-matematiikka YO-kirjoituksissa :), some 25 yrs ago.

    I might be wrong when stating that power curves of combustion and electric drives are linear and can be summed up, providing that one have a proper power line and sophisticated control system - even for motor yacht with higher resistances and masses.
     
  12. apex1

    apex1 Guest

    Cornelis you know, it is´nt the question if we builders like equipment and installations or not.
    The buyer rules te market, not the manufacturer.

    There have been hundreds of attempts to build hybrid boats, ALL failed. It is quite simple: at present we do´nt have adequate technology off the shelve. period
    And it is neither "green" nor cheap to add anything to a proper diesel propulsion.
    Even sailing is not so overly "green", because sailing needs a lot of equipment (and a Diesel too), and it costs money!
    A lot of money! In many cases sailing costs several times more, than motoring at the same speed / displacement / accommodation level would cost!
    We all know that, but the customer does´nt like the plain truth. He prefers to believe sailing and el. propulsion is cheap and green.
    So, who is going to throw his money in a advertisement campaign for selling nonsense?
    The paper linked above, is the typical marketing drivel.

    THERE IS NO HYBRID PROPULSION FOR BOATS AT PRESENT!

    Retired boaters btw. give up sailing! Since more than 12 years we see a steady growing trend from sail- to motoryachts, after retirement.
    But impressively the operating hours p.a. do not increase very much.

    Regards
    Richard
     
  13. CDK
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    CDK retired engineer

    Richard, you won't here me say that sailing is green or cheap.
    In the big pond in front of my house I observe many sailing boats throughout the season, easily recognized by their long, empty masts. After investing in many winches, ropes and sails the skippers press the starter button of their small diesels. Except this friend of mine, an Austrian academy professor who is a die-hard sailor: if there is a white triangle at the horizon I know he is coming my way.

    But you know what my passions are.
    With a small diesel, a battery and a starter motor, all the basic ingredients for a hybrid drive are already there. Just make the starter motor larger, add a clutch to disengage the diesel, some batteries, solar panels and a small black box. Much less expensive than all these winches, sails and the mast.

    Btw, I feel very unhappy on my friend's 43' sailing boat. On any sailing boat in fact, unless it is tied and padlocked to the shore. But that is not the point here.

    Regards,
    Cornelis
     
  14. apex1

    apex1 Guest

    Of course Cornelis, I know.
    And I´m sure YOU would be able to make a working installation of some sort in a fully displacement vessel!
    But here we have a request for a semi displacement boat, and "higher power" was part of the game.
    We both know that does not exist!

    Almost everything is doable though.
    But I´m sure we agree not to talk solutions, way out of any sense and budget.

    Regards
    Richard
     

  15. Bosun
    Joined: Nov 2009
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    Bosun Navigare Necesse Est

    Richard,

    My point is that why hasn't it been taken to more seriously into consideration production wise? Yes, my interest would be in semi-planing but bigger benefit would be achieved in heavy "full-planing" boats.

    The technology exists with higher power out-put but unfortunately not in marine applications. Yet.

    But like you state, is there any sense in general and budget wise? Battery technology is developping in huge steps and price will be splitted half within few years. So now it should be the time to develop if possible.

    In any case, I have gotten very good feed back and found very interesting forum to share thoughts and get more knowledge. Have to say that I've gotten addicted to this site. Thanks for you all gents.

    Rgds, Puosu ("Bosun" in Finnish)
     
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