Electric Drive Propulsion for Catamaran

[downunder]

Attached is a link to an electric catamaran - the solarwave project

Boat - SolarWave

[JayCall]

I spent about 3 years looking at diesel/electric for a 65' trawler. I even went up to the point of having Bill Crealock design the boat abot 2 years before he passed away. I spent many hours with Siemens folks on the disign of the system. the technology is not new, Siemens powered a diesel electric boat in like 1905. I have looked at porbably 12-15 installations both in pleasure raft up to 100' and in very large commercial ships. Based on everything I could find, I came to several conclusions. First, the technology is not hard to find and to make work. It is out there and has been for a long time. The major advances lately have been in controllers. Second, there is no real fuel savings on propulsion engines, maybe 5% at best. If you need a total of 350 hp with direct drive, you will need a very similar sized power plant to run the DE system. While the generator does run at a constant speed, the fuel and maintenance savings are negligible.
In these respects, direct or DE was really about a wash.

I did find two advanntages, at least regarding trawler design. First, a 65' ttrawler would normally have 4 diesel plants, 2 propulsion, 1 large generator and 1 smaller generator. In a DE system, you can design a good system that would only have two diesels, 1 large, 1 medium. Second, is the size of the mechanical space and the placement of the engines. In the 65' design we did, we could make the engine room about 25% smaller, thus increasing usable space on the boat. This is because the engines do not need to be in line with the shafts. You can place the engines anywhere and you can totally enclose them in sound shields as you would a generator. The DE can be a very quiet system.

We did figure out that we could carry enough batteries to run the ship's power, with all them amenities of a 65' yacht, for about 48-60 hour without running the generator. That is a decent benefit for a powerboat.

But, in the end, we just did not feel that the potential benefit,chiefly space, outweighed the up-front cost. To us. all other factors were about equal. I wouldn't think that the space issue would apply in a sailing cat and engine and battery palcment is pretty much set whichever system you go with.

[ArmyChief]

deckofficer,

Have you put together your vessel yet? I have just started determining what I'm going to do. however, I'm not planning to do this for about 8 + years...with Moore's law..I'm sure battery, controllers and solar panel efficiencies will al limprove...along with size and weight being reduced.

[deckofficer]

Originally Posted by ArmyChief

deckofficer,

Have you put together your vessel yet? I have just started determining what I'm going to do. however, I'm not planning to do this for about 8 + years...with Moore's law..I'm sure battery, controllers and solar panel efficiencies will al limprove...along with size and weight being reduced.

No, as I'm a care giver to my 93 year old dad. I have done an electric kayak with Winston lithium cells and 3 different EVs. These cells are the future, 2000 cycles, nil Puckert effect, no voltage sag under load, and can take a charge rate higher than what can normally be produced by engine driven alternator or dedicated DC diesel charger. All components needed are out there for my project.

[ArmyChief]

Yes, I've built a few camping, portable backpack battery packs with foldable solar panels utilizing LifePO batteries with MPPT controllers. no boat projects yet. I've searched much, see very little catamaran EV units. There is one powercat utilizing twin torqueedos, but that IMHO, is not the best matchup.

Thanks,

[deckofficer]

Are you familiar with the A-frame masted SMG 50?

[ArmyChief]

No sir

[deckofficer]

Originally Posted by ArmyChief

No sir

Do you like? I sure do.
SMG 50plus - innovative catamaran with A-frame-rig

[ArmyChief]

It's innovative to say the least. I can see the benefit of A-frame. However, I'm not sure I like the forward helm station. I don't see any protection from sun..let alone elements. I also do not see any station inside. Not typical for a 50' is it? Don't see a price either

[deckofficer]

With modern systems you don't need the big throttle/shift quadrant or wheel, it is drive by wire from the nav desk in the background of this picture. They have made 3 or 4, and the first one built is for sale at around $350K and 5 years old.

[mrty]

This is how we are doing this in the States we are pairing a 25kw axial flux generator with a Bedini motor please look at these three web sites-

Zero Force Motor - John Bedini - YouTube

Also-

Axial Flux Permanent Magnet Motors || Ashwoods Automotive Ltd

The motors run on just two 12 volt batteries (no Diesel)
that's it they never stop until the bearings fail and they don't over heat, I am going to put two in my boat they are small strong and light weight it should push it to a max speed of 25 knots and that's fast enough.
I am going to put it in a sail boat and use both the sails and the generator set just in case one fails but I have ran the one here for a month and a half with out stopping and it has not failed.
Do yourself a favor and check it out and stop wasting your money on Diesel when you don't have to.

[colemj]

You plan on doing 25kts in a sailboat under motor? Do tell…

Mark

[goat]

Perpetual motion machine. It's about time.