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As the building moves into it's final furlong I'm looking at finishing ideas. I am considering omitting the twin 15hp petrol outboards altogether in favour twin 5kw electric longshafts. Dose anyone else here have an electric auxillary or have you ever considered one?

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Old topic, covered many, many times in many, many forums. Including here. Never hurts to bring it up again though as things may have changed.... But alas, they haven't.

Works fantastically well if you replace the outboards with a gen set rated at 8Kw or more to run the engines with and consider 4 times the complexity and cost to be a good compromise. At this stage I think the greenest thing is no engine at all, hey, don't scoff, there are still people out there doing it right now. Failing that, an inboard diesel with a long shaft. 


I keep going back to ask the same question as my build progresses/sits but so far it's not really practical. So outboards it is. Could run them on propane I guess?

Cheers Axel, I actually considered it but the freeboard is a little too high for paddles or oars, getting in and out of tight spots will be difficult.

Inboard diesel are too heavy. Personally I'd prefer a system with no fossil fuels at all.

Considering I'd be sailing most of the time I was told 2 x 5kw motors with 2 x 12v for each and as many solar panels and wind generators as possible to back them up would be sufficient, or was that just sales patter?

The current issue of Good Old Boat magazine has an article about electric conversion on an older monohull.  Things didn't look as grim as the budget Hans copied in above, IIRC.  But I believe the owner was looking for very modest range, not cruising with it.  Worth a read, in any case.


You might also consider adding hydro generation to your arsenal of green ways to keep the batteries topped off. 


16 lead acid batteries, phew, that's a lot of ballast.  The batteries alone make up almost the entire weight difference between the electric and fossil fuel packages Hans referenced above.  Think hard about how many batteries you really need; if it's that many, you might see about other battery technologies, such as lithium.  Perhaps salvaged lithium cells from wrecked Toyota Priuses would be available?  You'd want to work with somebody who knew what they were doing here, as lithium is supposedly finicky about charge management and I don't know how those batteries would handle the marine environment.

Finally, on the human power front, you might look into yulohs, as they don't stick out as far as western oars or paddles.  I'm pretty sure Glenn T. uses yulohs and no motor on his Child of the Sea.

COTS is 38', not 30', but it's a simple boat and much smaller than a Pahi 63!  I was thinking geminidawn was building a Tiki 46, which is somewhere in between.... A lot of my input is invalid, in light of this.  The 63 can handle more weight than the 46, and is heavy enough that human propulsion is probably not an option.  Thanks for setting me straight, Hans.

When I went to purchase the plans off of Hanneke I went to look at Pahi 63 "Big Cat" nearby which had all the mod-cons and inboard diesels. Hanneke said this was a bad example, inboards are too heavy and the Pahi 63 is designed as a light ship any extra weight I add will affect it's performance in light winds. If I can get equivalent propulsion out of electric motors for the same weight I'd prefer go down that route.
One of my pet hates is push button sailing, I'm a real believer in "working for your dinner". I'd rather take the three hours and sail from A to B than motor it in 30 minutes so what ever auxillary I have it'll not be used much. I was told by the sales people all I'll need is two 5kw engines and four 12v batteries which would give me about half an hours use before they require recharging. I'd have wind generators and solar panels topping them up all the time. If what the sales man said is true then I have no problem going for it. My only concern is a factor of safety. In high winds and heavy seas could I rely on that set up to get me out of trouble should the need arise?
Good point! What I've found so far is that there is no one easy answer and lots of different opinions. It looks like the whole auxillary aspect is going to require lots of homework, with the safety of the ship and it's crew a priority only then will I find if it is feasible or not. I better get writing some e-mails. My thanks to everyone who posted I'll keep this thread informed of any developments.

Gemini -

Google "Largyalo" if you haven't already. Pahi 63 with electric motors. Last I heard from them, they were happily cruising with their set up. Now, I'm not saying they didn't spend a lot of money to get it where they need it...that's something you can ask them. They are open and generous with their experiences.

Apparently, there's a lot of interest in electric propulsion right now.  Cruising World has an item about lightning protection in electric-auxiliary boats:


Cheers Hans, All I asked was to replace 2 x 15hp outboards and I was told 2 x 5kw motors on a 24 volt system but in order to get it accurately calculated I have to submit the LOA, LWL, Beam, Draught and Displacment. Thanks again for all the replys looks like I have got a lot of homework to do.

Remember when I said that there must be a lot of interest in this topic right now?  The current (June 2011) issue of Sailing (the magazine of the American Sailing Association) just showed up in the mail with an article on electric auxiliary conversions, too.  Their web site (sailingmagazine.net) does not show any info for the June issue yet, so I'll summarize the resources they list below:

  • QuieTorque ibl Systems (10-30HP equiv) and Weekender Hybrid series (8-12HP equiv), contact electricyacht.com
  • HybridMaster (no HP equivalent given), contact mastervolt.com
  • E-Pod Systems (7-15HP equiv), contact re-e-power.com,
  • and Torqeedo electric outboards (8HP equiv), contact torqeedo.com

Of these, it appears that the Weekender and HybridMaster are intended to adapt existing inboards to hybrid operation.  The first three are inboard designs; the E-Pod is a permanently mounted external pod; and the Torqeedo is an outboard, of course.  The E-Pod is the only one that mentions electric regeneration under sail. I could swear I saw something about somebody somewhere putting E-Pods on a Tiki, but I can't find it now.

For what it's worth:


See other discussions on this website reguarding electric power. The topic keeps coming up. We all want it, but at this point it's not worth it! I bought diesel outboards.


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