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  Topic Review (Newest First)
08-02-2010 08:42 PM
P35juniper here is an idea, couple up a generator to the main engine, and if you are using an inverter for 120vac, couple to the shaft with a cluch aft of the motor/genorator and have a transmission that can handle spinning in neutal, you have the best of both.
06-25-2010 04:36 PM
SeaDreamer1Day There are many things to consider with the diesel-electric hybrid system you are contemplating. At around 12 HP, the 9K motor seems kind of small, but that's not my point.

For this system to make any sense at all, you:

1. Have a need to generate a lot of electricity.

2. Have a generator that is smaller than the capacity of the electric drive.

Regarding option 2. This is a sailboat. You can generate electricity while sailing via the drive. You can generate electricity via solar panels and / or wind generator. Your likely cruising speed will be some fraction of "full power" of the drive. That will allow you bursts of full power speed by pulling from the reserves of your battery.

If you actually charge your battery with the drive while sailing, solar panels, wind generator, etc. you could notice a significant drop in your fuel usage.

You should understand that if this is used as a system where you generate electricity with diesel to run your drive directly, you are only incurring more costs with little gain.

If I sound negative, I'm not. I just wanted to point some things out. I completely support the idea and I think you should research it more.

There is much discussion on the subject of electric generation and storage at fieldlines(dot)com. It is not a sailing site, but there is much to read on the subject of electricity generation and storage there.
06-03-2010 06:27 PM
hellosailor Lazlow, at this point ANY and EVERY electric drive for small craft counts as an "oddball propulsion system". It will be expensive, and it will be experimental, and if you change your mind and try to sell the boat, it may very well be a total loss because it is an ODDBALL system, no matter how well it works out.

If you're just plunging into boats, I'd really argue that you want to make CONVENTIONAL choices, so that if it doesn't work out it is easily put back on the market.

And once you're more familiar with boats, who knows, maybe electric driveswill have built up some kind of track record. Right now? Best suited for cruise liners and submarines, and some odder craft.
06-03-2010 03:08 PM
Originally Posted by Mark F View Post
I don't post much here as I have found some on this site to be too close minded to bother.
Love you too.

With that attitude, you likely won't win any new converts to the electric cause anyway. Are "some" "too close minded," or is your argument just not convincing enough?
06-03-2010 12:58 PM
Mark F Hi Lazlow,

Here is a link to a Yahoo group that might be of interest to you;
I've posted here a few times about the electric propulsion system on my Ericson 27, now two years old. You should be able to search "electric propulsion" to find some info. I don't post much here as I have found some on this site to be too close minded to bother. I do however keep an eye out for people like you that are looking for information.

Another link; Boat Bits
tells an interesting story about being dismasted with an electric drive.
06-01-2010 11:26 PM
Lazlow I ran across this link that answers many questions:

Thoosa electric inboard frequently asked questions Australia

Amongst other things the recharge mode only costs you about .02knots.

On a 27ft mono hull he can push it a 4knot for 6hrs on a 215Ah battery pack. It also mentions using a 2kw generator. It never occurred to me that you do not have to run a 9Kw motor at the full 9Kw, reducing the Kw just means you go slower.
06-01-2010 10:46 PM
Lazlow One thing I forgot to mention about the THOOSA is that when you are under sail you can set it to recharge the battery (60ah max, with voltage limit). How much this will slow you down is an open question.

Reducing the size(Kw) of the generator gets pretty tricky. You can go more batteries and just run the generator longer(say a 5kw) but how much more weight (batteries) can one afford?

Having a couple of solar panels (100w?) I had just assumed was the standard now.
06-01-2010 10:25 PM
Dfok The equations we now use inevitably will be useless in our future, why do we persist in screwing around with them? They're hindering development while we wait for the inevitable as if it is a definitive line we'll cross somewhere down the road.
On the northern Chesapeake this Memorial Day weekend there were far fewer boats than I expected - probably a sign of the economy - there are also many, many boats for sale.
The monster cigarette boat roaring up and down the river near North East MD seemed particularly obscene in light of the BP disaster and the assumed decline of the "lords of the universe" with money and fuel to burn. Utterly destroying the ambiance of a pleasant place at such a time ( Memorial Day and an era where conscience should rule out ostentatious display of fuel/money gluttony) was lost on these guys, yet indeed it was a display of fuel versus hp efficiencies.
They may spend their 10 bucks a year on "Save the Bay" crabfests but they're killing a bit more of the bay with every high speed run, only possible by the "efficiency" of on board diesel or gas.
I have a thumping universal 3-20 which frankly is healthier than I want it to be, because I envision an electric drive, battery bank and solar charging system in its place. Yeah, I know there are heavy metals in the batteries, inefficiencies in the motor winding and far more in the solar collection but I want a sustainable/recyclable system even if it is less efficient, even if it is a drop in our proverbial bucket.
Going slower or not going as far ( by car, boat or whatever) may be the selling point of our future propulsion.
Oil and gas let us travel fast and far but except for a wealthy few we all ended up in the same placed - screwed.
We gotta look at this problem differently.
So I say go to it Lazlow - you have an excellent dream there - there will be twists and bumps (remember the last big oil/gas crisis?) but you're going to learn, do something meaningful and pave the way for the next person.
Some solar, wind and maybe water/wave generation might shrink that diesel down too.
06-01-2010 10:17 PM
Lazlow Well I took a look around;

Yanmar 3ym30 (30HP)($2.3k without saildrive)
3600 rpm
346lbs (dry)
1.5gal/hr full out

Yanmar 9ny(9Kw)($8k)

So size is essentially a wash. Generator is 100lbs heavier but also uses quite a bit less fuel(~.6gal/hr). Price tag hurts at over three times the price, but you are also comparing a 1800 vs 3600 rpm motor(lives twice as long).

The THOOSA 9000(9kw drive) is also $8k,requires 48V, and weighs 50lbs.
06-01-2010 08:36 PM
Ulladh I would really like diesel-electric hybrid systems to work for sailboats, but simple diesel inboard motors currently will be more efficient and reliable for propulsion.

If your desired use involves on board equipment that has a large electric demand, then production of electric for that demand has priority and propulsion is secondary. An electric propulsion system may then be the smart choice.

Search for Nigel Calder articles in Sail magazine for research on hybrid systems.
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