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  Topic Review (Newest First)
12-26-2012 02:07 PM
Re: Electric Sail Boat Motor

At this time I am not aware of a vendor with a off the shelf saildrive system. We have done several saildrive systems as custom installations. Contact me through my website and I will share information with you and give you some leads where you may follow up.
Regards, Mike
Electric Yachts of Southern California
12-25-2012 08:23 PM
Re: Electric Sail Boat Motor

Cool, I know this is from a older post, but I'm looking to pull the old OMC Saildrive from my S2 8.0B and want to go with electric power. What in your opinion is the best option and company to go with.
06-13-2012 07:09 PM
Re: Electric Sail Boat Motor

Sorry for bumping this old thread, but it seemed a shame to start a new one on the same topic!

I'm looking at installing an electric motor on a 32ft 9,500lb yacht which currently has a (horrible) 18hp diesel. I've read through all the pages on this thread, and there are clearly lots of electric powered yacht owners for whom it works really well. It's also been said several times that 'the maths might not add up, but electric motors work in the real world'. I'm currently in that situation. Let me explain!! (and sorry in advance for a big lump of numbers).

Most of my sailing is coastal cruising. This would involve perhaps 1/2 hour of motoring per day (15min in/out of harbour) at 3-4ish knots. Sails up ASAP, I hate motoring! I reckon the boat would need a 10kW motor, and it would probably use 5kW to reach these speeds. Electric Yacht produce a motor which would do the job. Clearly, there is no problem at all in getting this range (and a lot more) from a sensibly sized battery bank. The problem comes in recharging the batteries. I don't really like being a sardine in a marina (who would choose one over a secluded anchorage or a quaint harbour?), I'm on a swinging mooring, and enjoy being self sufficient. Shore power every night is therefore just not a guarantee when out cruising. Using the motor at 5kW for 1/2 hour every day means, then, that I will need to generate, on average, around 100 watts to recharge the batteries (5000 watts divided by 48 half hours in a day = 104). I prefer not to work in amps, it gets confusing! At 15kt, the average wind generator produces 50 watts. The problem is... most harbours or anchorages don't have 15kt of wind, or even close. The wind generator will only really work out on the water, 8 hours per day... in other words average 17 watts. 6 wind generators is clearly not an option! Solar panels... at best, 8 hours of sun per day, and from memory solar panels normally put out about half their rated capacity. To average 100 watts, then, I would need 600 watts worth of solar panels. Not an option either! The same goes for towed generators, 100 watts output but only for eight hours per day.

If I have a realistic 1 wind generator (50w for 8hr), 1 towed generator (100w for 8hr) and 200 watts of solar panels (100w for 8hr), I would average 83 watts output in a normal day. This doesn't even make up for the power use by the motor, let alone normal domestic consumption (and no, I don't have a TV or anything silly!). Basically, with a fairly impressive array of generating stuff, the battery charge would have dropped to risky levels after a few days, especially when relying on it for propulsion - and I would have to find shore power.

Will any electric yacht owners either back up or dispute my maths? It would be great if it could work, but suspect that electric motors are best either for marina-hopping, or for people that spend days at sea and therefore have plenty of time to recharge batteries - not the average sailor who goes coastal cruising and often finds themselves without shore power. But I would love to be proved wrong! Maybe regeneration with the motor when sailing fills the gap? Maybe I underestimate wind/solar? Overestimate the power needed to push the yacht? Look forward to your replies!!
01-31-2011 12:35 PM
P35juniper Mgunning, Be carefull keeping those Lifeline AMGs happy, What do you have for a dockside charger? any thoughts on a 48vdc genny? I take it you are planning to have the house bank as a back-up. Keep us updated on good, bad, and different, mustly the different.
01-31-2011 01:35 AM
centaursailor Read some of this thread and reckon its about were electric cars were 10 years ago.
The technology is there already but the cost/benifit is still prohibitive.
The traditional ICE supporters tend to be reluctant to come on board but nothing new there.
A few articles have appeared on electric sail boat motors and the results are positive, most of them have either a gen set or a fuel cell as back up. The fuel cell is more efficient but currently very expensive. Some fuel cells have been developed to use propane/butane, tho not ideal the fuel, is readily available.
In a sail boat with the ability to charge from wind, drag and solar and with the reliability of the electric motor its only a matter of time before the iron main will be purring like a ***** cat.
Opps,seems I have offended big brother with that annology
01-31-2011 12:21 AM
mgunning Well, I just installed my new electric system in my 79 Newport 30. It took towoof us to do it and it went quickly. Today, after our first test runs, we are now forecasting a bit better distance on a full charge. We went with a bit bigger battery package, 8 6v 300AH AGM's from lifeline, not cheap. Since I have two new 12v batteries for the house system, I am planning on getting two additional inexpensive 12v to produce a second 48v system with a stepdown to drive the 12v house systems (lots of blender power).
I am also looking at solar and a wind generator. Finally there will likely be a 2000w generator that will share the propane system that I will use of the BBQ and galley cooking.
I will let you know how it goes.
01-16-2011 12:39 PM
Jimske Interesting thread. Lots of good ideas. The installation must accomplish the need and if it does that then it is a success. I am thinking of putting a spin bicycle in the cockpit and using that to turn the prop. My wife spins so . . . Problem is I don't have a prop so I am going to start there.

What I want is to keep my 9.9 outboard which generates 12v for my single battery. My problem is the outboard, which is situated on a "sled" between the port ama and main hull on my SR 31 A Frame. Works fine much of the time but when I need a little more power for problem currents or headwinds when I don't feel like tacking all day to get home. It would be real nice to have 3 or 4 hours worth of "boost." And I guess that a prop deeper then my outboard prop would be better. Motor sail? Why not? Even though the SR31 will do half the wind even 8-10kn wind.

One of the many great things about this boat is storage and access to it.

What I want is to be able to use the outboard in conjunction for the most part and use a 12v electric motor attached to a shaft and prop which I need to figure the angle and size and placement. I might use the electric motor for a few hours on it's own.

I got a funny feeling from reading all these posts that 12volts ain't gonna make it! Too bad because I thought the outboard and a 12v wind generator could help charge the batteries.

Green? It'd be nice but I don't care! My truck gets 15 mpg, my house uses oil and is not that energy efficient. I would even consider running a small electric motor off of an easily removable gas generator push comes to shove.

Money? I don't have any but my wife says that doesn't matter and I should be able to get anything I want because I want it. ;-)

Any positive comments (read no bad vibes please) will be VERY welcome.

Thanks in advance.

Jim in CT now.
01-04-2011 09:19 PM
Originally Posted by COOL View Post
Your posts in this thread have all been far too reasonable.
Thank you Cool. Sometimes I think my opinions are unwanted on this forum. People get way too worked up about this stuff when really it doesn't matter that much.
12-18-2010 11:18 AM
Mark F Hi Mike,

Sounds like a good setup. It's interesting watching the industry become standardized. Electric Yacht is a good company with very good customer service. I bought a competitors product but have communicated with Scott and Bill at EY over the years and they have always been knowledgeable and helpful.
12-18-2010 09:58 AM
mgunning Been reading this blog and am puzzled. As a owner of several boats including an Ericson with a 23hp diesel, I have not been impressed by the ICE being the answer to get me where I want to go and back home. The systems are complex (starting, cooling, gear, fuel, and electrical) and need constant attention and that is with a newer motor.
I have just purchased a Newport 30 and will be repowering it with electric. I would like to check out Cool's Islander 30 as it would be a comparable boat. I am going with the Electric Yacht 180i, 48v, 8 Trojan 125s and a backup generator with solar and wind generators later. We have scoped the system for a 30 mile range at 4.5k. It is primarily a sailboat so I am not too concerned about the range. The issue I am trying become clear on is the best prop as the electric is so much more effecient at driving the prop, especially at low rpms, and its ability to regenerate.
I am in Dana Point. If you would like to show me your Islander, you can email me at
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