Question!? need a large flat horizontal surface area for solar panels

Discussion in 'Boat Design' started by Val567, Aug 26, 2012.

  1. Val567
    Joined: Aug 2012
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    Val567 Junior Member

    True, true. I can definitely see your point there, but me offering advice about solar, and how to make a boat that I haven't even made myself yet when I am not a boat maker is not the purpose of my question. Me gloating about my currently fictional boat is also not the purpose of my question. Me explaining the details of the creation, storage, and consumption of every little watt on my boat is not the purpose of my question, nor are you going to get that, and quite frankly, even if I did give you that, why would you care? It hasn't proven itself yet.

    Why would I do that? That would be me teaching this forum about how awesome my creation is when I haven't even made it yet. I'm not the teacher. I am the student, and I am just asking a question, which is not about solar! This isn't a "let's talk about solar thread."

    I might come in and explain the details after I make the thing, and it has proven itself, but that is several years from now probably.

    The purpose of the question is just asking for some ocean going boats 50-100ft in length with mostly flat tops. Very few people have actually produced anything within the actual purpose of the thread.

    EuroCanal threw this suggestion out:

    Thank you EuroCanal. Keep them coming if you have anymore.
  2. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    But it is.

    You want big...Ok...I was on a Dufour Nautitech 98 catamaran once-about 35' beam.

    Had two Cummins 6BT powering it- 300 hp to cruise at 10 knots,maybe 200 hp to cruise at 7-8 knots.

    So great poly solar panels,tilted to the sun at noon and not too hot will give you 20+ watts a square foot. Laying flat,not at noon, you'd be lucky at 10.

    So build a huge platform over the entire thing-3500 sq ft x 10watts a foot= 35,000 watts= 35 kw= 46 hp.

    46 hp for not much of the day,sun angles are critical.
    46 hp will move this thing very slowly,and will have zero left over for night time.

    Oh we do....

    See ya then!!!!
  3. erik818
    Joined: Feb 2007
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    erik818 Senior Member

    I still believe that a catamaran is the correct type of boat to choose when you want a large flat top surface. A monohull with the same top surface will have much more drag. The cat from Solarwave is in my opinion a suitable start and they also provide some data on the boat.
    I assume you are doing a feasability study, and for that purpose you can just scale Solarwave to whatever size you need. Area will change with the square and displacement with the cube. It will be somewhat tricky to figure out the speed you can expect from a scaled version; I suggest that you learn to calculate drag using Michlet if speed is important. As a guess I would say that scaling up should give a minor increase in speed if solar panels with the same efficiency are used.

    I don't really see the benefit of going 100% solar except for testing technology or proving a point. Why not add a foldable mast plus a modest sail plan? I would also add a diesel engine to use when the batteries are empty but I have to go on; there already are "green" diesel substitutes if you're ready to pay the premium.

    I don't belive in combining houseboat with passage making. Choose one of the roles or you'll get a lousy houseboat that is a lousy passage maker.

  4. capt vimes
    Joined: Apr 2009
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    capt vimes Senior Member

    erik is right - solarwave is a start...

    i read some articles about this project since they are austrian and have promoted it quite big here...
    i also went through there news section on the website which unfortunately is only in german...
    they have huge batteriebanks and recently swapped their leadbatteries on one side to LiPos and ran some tests regarding their capacity...
    if they are leaving a marina for a daycruise, they only drive with 2 x 2 kW (48 V and 40 Amp)... but that gives them from say 10:00 hrs on excess energy from the panels to charge the batteries or to run other applications like watermaker, AC and such - but keep going at a snails pace...
    the other time they switched off the panels to see how long they could run on their 200 Ah, 48 V LiPo batteries... for 4 hours they only drove with 48 V, 25 Amp which translates in 2 x 600 W...
    can anybody here imagine how slow they must be going? ;)

    and i know from an article that when they traveled along the rivers and canals in europe, that they needed an outboard to cope with the currents in the rivers because their electric drive train would be too weak...

    all in all - i do not want to get in bad weather onboard that vessel and would definitely not do any long passages... a leeshore situation with considerable wind forces might be the ultimate end of this project...
  5. JonathanCole
    Joined: May 2005
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    JonathanCole imagineer

    I have done a lot of work in this area in plans to commercially produce a 55 foot by 24 foot live-aboard solar powered shoreline cruiser. I have been using solar energy to power my home for most of the past 30 years and am an international consultant in freestanding solar energy systems that can provide all the amenities. You can see a synopsis of the solar boat work which was started in 1991 and continues to this day at:

    There are many misconceptions about solar by people who have no experience with it and many unsuccessful initiatives are due to people with too much money and not enough sense going on a poorly thought out adventure with the seeds of its own failure built in to the concept. The SolarSailor in Sydney Australia is a good example. It is a totally impractical concept that ignores the realities of mechanics, physics, and materials science. What many of the less pompous of the responders here said is correct. A purely solar boat is much better if you don't try to make it do everything for everybody. Like blue water sailing. The Solar Planet boat had to spend 16 million $ to make it strong enough to ply the 7 seas. A pleasure craft meant for tamer conditions can be lighter and yet can supply not only a reasonable range (no tacking required) but also a level of comfort that no macho sailor would be interested in.
  6. WestVanHan
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    WestVanHan Not a Senior Member

    Perhaps you could enlighten us on how many watts per square meter(or foot) that one gets-on average- during high daylight hours on flat laying panels in lower lattitudes?

    What do you propose for energy storage on said lightweight catamaran? I looked on your site,couldn't find any info.

    • Utilizing the most efficient hull-forms to conserve energy allows 50-100 mile daily range at 10 miles per hour.
    • Completely powered by renewable energy utilizing photovoltaics, wind, regenerative braking and water current generators
    • Power system is comprised of a 15 kW Photovoltaic (solar-electric) array, 1500 watts of wind generation, with 30 KwHr of battery storage and two 9.2 kW electric drives.
  7. JonathanCole
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    JonathanCole imagineer

    Do you mean latitudes? This depends on the time of year, of course. A flat laying panel in summer yields a very high proportion of the rated capacity in latitudes from 30 to the equator. In the winter because of the tilt of the sun's axis across the sky there is somewhat less, but still a significant fraction of the panel's rated output can be expected on a clear day.

    What do you propose for energy storage on said lightweight catamaran? I looked on your site,couldn't find any info.
    If you look in the right hand column of the web log at there is a lot of technical information under the heading "Technical Help". I would use 24 Rolls/Surrette L-16 batteries (distributed 12 & 12 between the two hulls) to provide 30kwHr of usable storage congruent with a ten year battery life. These batteries would weigh 2880 lbs. or 1440 lbs per hull. I would use a Pro-fill battery watering system for easy maintenance. I would use my solar surplus to make distilled water for the batteries as I do in my home.

    Two 10 kw electric drives in circular wells fore and aft on the wing deck will drive the boat and with 180 degree rotational capability will act as thrusters for optimum maneuverability allowing for a single person to pilot and operate the vessel utilizing a hand-held remote control. Not intended to be a speed boat or a racing boat, this is a recreational vessel for those who love to live on the water as I do. Since it is a recreation vessel it means that one does not have to adhere to a particular schedule and so can simply wait for the batteries to be filled by the sun while the vessel is anchored or in a slip. Because of the limitations of solar, I believe this is the only type of solar boat to make much technical and economic sense right now. Still it should be a lot of fun and within reach of many people who can afford sailing vessels of the same overall length and width. Why bother to make such a vessel? What are the advantages? How about one man operation with incredible amount of living space with no guy wires and ropes to trip over. Plus a very low center of gravity means it is very difficult to flip unlike a sailing cat. Contrary to some of the claims made in this thread, the cost of sails and rigging and hardware is at least as much as a photovoltaic system of this size and probably more, since solar is solid state, with no moving parts, is highly weather and water resistant and is extremely durable. I would expect the photovoltaic panels to last 30-40 years and the batteries 10 years.
  8. SamSam
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    SamSam Senior Member

    Did you mean left hand column?

    It all seems to have very limited use, from latitude 30 (Jacksonville, Fl ) down to the equator during the summer.

    You say 'design, designed, plans'.
    Has the project progressed beyond the proof-of-concept stage and a single graphic image to any actual plans or prototypes, or is the fact that some one else has done it, the proof-of-concept? Anything 'concrete'?
  9. Val567
    Joined: Aug 2012
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    Val567 Junior Member


    You sir, are amazing. Superior data to work with.

    Can you tell me what your solution for corrosion is? One of the issues I was considering is that even with all-weather panels, the connections of wire to battery in salt water air if your boat is, say, along the east coast of the US, are points of loss. Multiply that by how many batteries you have and, well I was worried it might be a problem.

    Also, I see that your deep cycle solar batteries are liquid, not a gel type of battery. Are you concerned that the sloshing of the boat would cause the batteries to eventually begin leaking battery acid all over, or is that not really an issue? Perhaps you have devised some sort of special container?

    I know that batteries are supposedly sealed well, but we all know what is going to happen if you tip a car battery upside down and leave it for a day.

    Also, with such an impressive solar panel array, there is going to be lots of charging going on. Those batteries are going to be releasing gaseous hydrogen while doing that. Are they simply acceptably ventilated, or... If you have them sealed somehow to prevent corrosion / leaking, how would you prevent the build-up and eventual explosion of hydrogen?
  10. Red Dwarf
    Joined: Jun 2012
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    Red Dwarf Senior Member

    I have been playing with a Planet Solar style concept for a few months now.

    The first and most obvious conclusion I came to, as possible ways to improve Planet Solar, is to ditch the solar panels. They are a publicity stunt gimmick that makes a slow, heavy and ridiculously expensive boat.

    My next eye opener was why should I even put sails on it? A rig for a 70 foot boat is very expensive, I estimate $50-$75K.

    So the most viable, "green", efficient and lowest cost solution is to build a very light efficient smaller version of Planet Solar with 2-100 Hp diesel engines.

    I am still torn about not having sails but for the $50,000+ the sails cost I can buy 12,500+ gallons of diesel. If the boat is as light and efficient as I hope that should give me over 50,000 miles of range. I am looking at simple alternate sail rigs such as some motorsailers use with an aft mast and 2 headsails.
  11. Submarine Tom

    Submarine Tom Previous Member

    As an aside: Here, around the 49 parallel, we mount solar panels vertically for year round seismic data collection.
    Reason being, winter snow tends not to abscure them, better solar gain when it's needed most during winter, less over charging during high gain summer months.
    For what it's worth.
  12. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member much per square unit?

    I had done that,and if one clicks on info for batteries,one of them is a link to a newspaper :confused: and the other goes to the Rolls home page.

    What voltage running to the motors?
    With the batteries,are you using the 530 or the 600??

    I'd like nothing more than to jump on a solar boat and putt around the places I like to go.
    But having been heavily involved in the investment world- the investment world is a skeptic of any claims made by anybody about anything.
    Particularly in asking for $10 million....

    Even if you get it working,yachtworld has 400 cats for sale from 40-52' under $500k,that can cross oceans-most of them for half what you propose.
    And 200 from 36' to 40'
    And 160 power cats,that when cruised at 5-6 knots get very good fuel economy.Masalai's 41' power cat burns 3 litres an hour at 7 knots or that's about 10 nm per US gallon.

    And however noble it may be to cruise around on only solar power,at the end of the day a used cat purchased for $250k,that leftover $250k by not buying your $500k solar cat can be invested.
    Even at a measly 5%,that is $12.5 k a year,and if assuming the same use of small trips-the interest will cover any costs and pay your groceries and however much beer you want to drink.

    Not trying to pee on your dreams and no hostility-just a dose of reality
  13. erik818
    Joined: Feb 2007
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    erik818 Senior Member

    Has anyone compared hydrogen + fuel cell with batteries for electric energy storage capacity? I know hydrogen isn't practical in cars, but volume isn't as much of a problem in a catamaran.

  14. linxiao
    Joined: Mar 2010
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    linxiao Junior Member

    you also can get some samples from solarsailor in australia website,just use google and search it.

  15. Slimjim
    Joined: Sep 2012
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    Slimjim New Member

    What does the voltage matter? Just wondering about all this.


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