electic kW / diesel kW

Discussion in 'Hybrid' started by horry_bv, May 18, 2009.

  1. apex1

    apex1 Guest

    How do you calculate 127hp equal to 20KW ??? The 20KW do NOT propel the vessel to top speed!

    What do you guess, how long is 13 tonnes of fuel driving a 127hp Diesel?

    No, sorry mate,

    you are biased and misinformed. You compare apples and oranges (as ALL your collegues), and then you call us closed minded.
    You are the closed minded, trying to cheat yourself with mad comparisons.
    Grow up and see the reality!

    What dou you think? We are doing our jobs in blissfull isolation?
    If NA´s and boatbuilders are not at least well informed about new technologies, they are out of business in short time.


    To make it short:

    Hybrid systems with equal properties to well designed diesel propulsion, do not exist in the marine market. period
     
  2. Alik
    Joined: Jul 2003
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    Alik Senior Member

    Given same power, both ICE and electrical motor will move same boat at same speed. Period. This is just physics, this is evident.

    Open Your mind not only to advertisement booklets, but to serious reading on propulsion and propeller design.
     
  3. Mr. Know-It-All
    Joined: Aug 2010
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    Location: Earth

    Mr. Know-It-All Junior Member

    That battery (1300 kWh) is equivalent to 26 gallons of diesel. Many boats have more fuel than that. Even if you can use only 33 % of the energy (and 100% energy from the battery), the 13-tonne monster is only equivalent to 75 gallons of fuel.



     
  4. CatBuilder

    CatBuilder Previous Member

    Apex1: Reading the Scientific American article, there are some interesting local points about the solar powered boat for you.

    "unveiled for the first time in a ceremony at a shipyard in Kiel, Germany" - a shipyard you know, perhaps?

    "PlanetSolar will be tested in the water for the first time later this month, and by early 2011 its captains hope to be on their way, with stops including Hamburg, " - you can go see this boat!
     
  5. apex1

    apex1 Guest

    Thank you Mate,

    yes I know the yard (Knierim), and have read some of the hype.

    It does not change the plain facts.
    There is no hybrid propulsion for ships and boats and yachts. period

    A vessel built with massive subsidies, operated in restricted use and areas, with a idiotic low payload and as idiotic shape, does not change any fact.
    It is just proof that you can promote every premature concept successfully.

    And just for the records:
    she failed already on her first voyage, and had to "refuel" in Leixoes after crossing the Bay of Biscay in cloudy weather!!!
    Mature concepts look different.

    Regards
    Richard
     
  6. kerosene
    Joined: Jul 2006
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    Location: finland

    kerosene Senior Member

    I am not so pessimistic as you richard. Concept and early prototypes are not proof of technology being mature for sensible us but they are important in developing interest and in taking the 1st steps in new tech.

    Of cours stuff like ocean crossing solar boat is impractical and provides really no real practical solution. Sails would becheaper and allow for mor seaworthy vessel.

    There are situations where electric powertrain already works fine. If you need regularily limited amount of capacity like shrtish commute a small e-vehicle already makes sense. A sailboat used one a week can get away with e-motor for getting in and out of harbor. For motor sailing or any application where there is/might be need for hours of operating it makes no sense.

    Key issues for e-power to make sense
    - regular use needed to cover investment to batteries
    - said use limited to <10 kWh per day and consistently about the same energy need per day
    - no quick charge needed

    - no need for exceptions like one day need to ride triple the distance. Carrying spare capacity like this is not feasible.
     
  7. apex1

    apex1 Guest

    I am not pessimistic, I am realistic.

    The entire Hybrid hype is just plain nonsense on yachts.

    I made my commercial tickets mainly on a Icebreaker in the Baltic. We had Diesel electric propulsion for a simple reason: always low operational speed, and always high torque demand. We could have operated three, much bigger freighters full speed with our fuel consumption.

    Everytime when the D/E topic came on the table in the past 35 years, some people immediately called that a clever solution for their boats!

    I guess half of these idiots still believe what they will belive. I gave up on them.

    Same is valid here.
    There was a simple statement by Alik, few posts ago. Do you assume that our believers here buy that? No, it does not fit in their well established preconception.

    Of course we need new ideas and concepts, no doubt. And we see that some of them work well to some extend. Hybrid cars for example. Far from being perfect and not very efficient by now, but a step towards the right end. That took 20 years from concept to market acceptance.

    But these systems cannot work on boats as we all know.

    So, when such concept hardly works in a car (the battery capacity is still extremely far from good even there), which is just about 15 to 20% as power demanding as a boat. Which has the big advantage of intermittend power demand. Which has the very big advantage of recovering brake energy.
    When we count all that, and then look at the upcoming battery developments (there are none really promising at present), we must come to the conclusion, it is not worth talking for the next several years. I guess we will not see any competitive hybrid propulsion in the next 20 - 25 years.

    The solar junk is a expensive and worthless gag, and failed at the first attempt. Not worth to waste any further comment on that.

    Thats it.
    Richard
     
  8. COOL Mobility
    Joined: Sep 2007
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    Location: Williamstown, Vic

    COOL Mobility Sailor using wheelchair

    If you read it properly, there is 127hp of solar collector cells, but the motors only generally output 20KW of power
    * PV installed power: 93.5 kW (127.0 HP)
    * Average engine consumption: 20 kW (26.8 HP)
     
  9. apex1

    apex1 Guest

    You are right I have missed the "PV" and only noticed the "installed power"

    Nevertheless the "average consumption" is a cheating point again. These 20kW do not provide the proudly advertised top speed.

    But that is valid for the entire article. PR drivel. We have seen how much the "indefinite range" was worth.

    And after all, she is useless and she failed.
     
  10. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    Anyone that studies solar panel discover many flaws very quickly.
    Heres is the top 5.
    1. They angle to sun greatly effects power generate, and I mean greatly. So no matter what you do you never get 100% and only have full power 4 hours a day.
    2. The panels get hot and power drops quickly.
    3. The panels with higher densities are higher voltage panels and require expensive charge converters
    4. By the time you ad solar panels, batteries, wiring and charges, inverters, electric engines their weight is much great than an equivalent diesel, fuel tank, transmission etc.
    5. Marine environment, specially pounding is especially hard on all thee electronics especially panels.
     
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  11. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    This from a guy that has 4 solar panels, two 180 watt and two 30 watt. I used for house power and emergency power.
     
  12. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    And from the guy that has 10 panels and sold several 1000's:

    Bird ****, a fallen leave or the shadow of a rope dramatically reduces performance. Cover one cell from a 36 cell panel and the output is almost nothing.

    I mainly agree with Mydauphin's evaluation except #5.
    Well constructed panels are quite at home in a marine environment. Many beacons at sea are equipped with solar panels, surviving extreme weather conditions when even large ships seek shelter.
     
  13. COOL Mobility
    Joined: Sep 2007
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    Location: Williamstown, Vic

    COOL Mobility Sailor using wheelchair

    PV panels are fine in Australia where we get so much sunshine, but even here wind gens with ~300W output are the general companion as wind (real or apparent) are what rives both the yacht and gen/alternator.

    Belt and braces and you don't need to rely on shore power.

    300W of Wind gen is cheaper than 300W of PV but not silent!
     
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  14. apex1

    apex1 Guest

    True, very true.

    But not very handsome. The wind gen is not the big winner while under sail. (physics)
    And he is the looser when not.

    Where do you drop anchor? In the windy corner of the bay? Ahh, you see?

    When you sit in port on a stormy day the wind gen might look as a winner, assumed there is no shore power, he is.
    But thats not sailors paradise.

    On the barefoot route I have seen a guy with a fire axe, getting rid of his landscape ventilator at 2.00 at night.

    Ask the circumnavigators about wind gen, and PV panels, you get enlightening replies!

    There are many things in our maritime world which seem to be a good idea. Few stand the test of time though.

    I agree with CDK, it is hard to kill a PV panel when proper installed, but unfortunately it is as hard to draw some juice from it.

    Regards
    Richard
     

  15. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    It is not the panel that fails but the mounting. The swinging and pounding of boat will either crack the fiberglass it is attached to, or bend the panel and crack it. Sure it can be mounted better but most people are trying to save weight or mount it out of the way. Just imagine the structure to hold 10 or 15 panels.

    Also lost several chargers to Marina power surges caused from crappy marina wiring. That is why I went 100% for charging batteries. Solar charges like outback Flexmate 80 solar charge controller are expensive but needed to maximize power output. CDK you know something cheaper? My panels make 48 volts, they are the BP180.
     
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