Solar catamaran

Discussion in 'Multihulls' started by guzzis3, May 20, 2021.

  1. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    I'm sorry if I overlooked your post. This thread has got a lot more replies than I can keep up with. Remember I'm half blind now and reading is a challenge. I'll try and find your post and reply.

    Are you referring to your post suggesting leaving out the batteries ?

    The batteries aren't a problem. You can get lithium batteries cheap enough from china on alibaba etc. The issue for me is how many panels would you need to run the boat at hull speed. The 3kW is the limit here in Queensland before you have to register, and 3.5kW before you need a licence. Bizarrely you could have a 15m long boat with 3kW motor and never pay registration, and operate it unlicensed.

    Given the panels are so cheap maybe removing the frame and cover glass would save the energy required.

    Regarding the Horstman. There are very few here. I was thinking more of just taking the idea and building something suited for this purpose. I don't see them come up for sale in the USA very often but I must be looking in the wrong places. Tris can have beams to lengths up to 1:1 so a boat close to 30' wide and 32' long would have to have room for a LOT of panels.
     
  2. SolGato
    Joined: May 2019
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    Location: Kauai

    SolGato Senior Member

    I think a 3KW inboard with the right controller and prop might get you the speed you are after. It really comes down to the RPM and prop and the motor co troller being able to handle the loading of the prop. With something like Thunderstruck’s inboard setup, you can use traditional props and not be as concerned about pushing the electronics beyond their limits.

    I see Horstmans for sale on the West Coast all the time. Here is an example of the kind of deals you can find on them. A lot of boat for the money!

    Sailboat Listings .com is a good resource, although most of them I see are on Craigslist, and typically they haven’t left the slip in many years and have become live aboard.

    1983 Ed Horstman TriStar 31


    1983 Ed Horstman TriStar 31 - boats - by owner - marine sale https://seattle.craigslist.org/sno/boa/d/bellingham-1983-ed-horstman-tristar-31/7323615374.html
     
  3. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    Thank you for the link. I don't search craigslist as you seem to have to search each area separately. Unfortunately the economics of shipping a boat to Australia are prohibitive, but I like to look for fun :D
     
  4. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

  5. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    Last I have seen in news, China has overtaken Germany in producing cheaper and more efficient solar panels.

    There was a member here, Jonathan Cole (I think he left) which has this project a long time ago. He discussed this heavily in the forum and he has done a lot of research. If you are interested, I will PM his last known email address.

    His design followed more or less the MS Tûranor PlanetSolar but scaled and same size as yours.
     
    guzzis3 likes this.
  6. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    Thank you for the comment.

    As I said above Australia is awash with panels, it's the batteries, controller and if you use one the inverter which cost.

    But weight is an issue.
     
  7. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    Its been a long time since we did the weight and balance analysis based on his SOR. Batteries and solar panels have improved so much.

    I just commented because your specs seems to be similar to Jon Cole.
     
    Last edited: Sep 15, 2021
  8. SolGato
    Joined: May 2019
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    Location: Kauai

    SolGato Senior Member

    110W panels are down to 4.3lbs and LiFePo4 100ah 12v batteries are now as light as 33lbs.

    The best way to save money is to buy direct and become a dealer if possible to get wholesale pricing.

    For example, buying the solar panels as a dealer can often cut the cost per watt in half.

    And a big advantage to buying LiFePo4 direct is that you can have the factory customize the product for you, like having the BMS’s and other internals configured for higher charge and discharge currents.
     

  9. dustman
    Joined: Jun 2019
    Posts: 162
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    Location: Tucson, AZ

    dustman Senior Member

    A monohull with that much weight and the extra windage up high may be pretty unstable. If you add enough ballast to make it stable you may lose all that you gained by going with a monohull.
     
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