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Paul Scheuer
10-24-2002, 09:09 PM
Dale's thread about small generators got me thinking... Anybody ever ponder using a small, suitcase generator in a hybred auxilliary system ?

Seems like you could do a lot for a 20-25 footer with a 2 Kw charging system and a battery bank with maybe 5 Kw max output. The battery bank could serve as ballast. You would have "instant" power, and the gen set could operate a small ac or other "household" appliances. Upgrades would be relatively painless, and might be done incrementally. Portable power could have many other uses, as well, on and off the boat.

WWheeler
10-25-2002, 09:50 AM
And push the whole darn boat with an electric trolling motor. It's lightweight and can be pulled off the transom when not in use. ORRR, even better, an electric prop that mounts right on your rudder, out of sight and out of mind, until you need it.

Normally there's 2-5 hours of battery life in a good battery setup. (I'll leave to the experts for exact numbers.) But, the auxiliary gen. gives you a much better safety factor. For example, what if you're running against the tide, or you need to motor straight for home, etc.

And, you can probably dispense with the cost of multiple batteries. It seems to make an electric setup much more realistic.

ishmael
10-25-2002, 10:06 AM
I've had similar musings, but without the generator. Though a truly quiet one would be okay. But I was thinking of using solar, wind, and possibly the motor itself as sources of power.

Someone who knows electricity better than I could comment on the feasability, but it seems to me a motor and a generator are first cousins. Have the propellor freewheel whilst sailing, feeding the batteries?

Anyway, I think it'd be cool! The addition of a generator would simplify the entire project, if make it a bit less "green".

TomRobb
10-25-2002, 10:12 AM
There was quit a lengthy discussion of this general notion a while back. A NA who designs big ships was thinking of something similar but rather more sophisticated. On vessels with large electrical loads, cruise - Vegas-on-a-barge - ships for instance, it makes sense.
The search thingy may shed some light on it.

[ 10-25-2002, 10:12 AM: Message edited by: TomRobb ]

Bill Dodson
10-25-2002, 12:09 PM
These folks make electric auxilliary propulsion systems for sailboats- Solomon Technologies (http://www.solomontechnologies.com/home.htm) . They design systems with internal combustion generators to extend the motoring range, if desired. They also advocate using the prop under sail to charge the batteries.

It's pretty interesting stuff, but I'm not ready to give up my Perkins.

Bill

The Schooner Etain
10-25-2002, 12:22 PM
Definately check out Solomon Technologies. I'm planning on putting one of their engines in my boat. That won't be for a bit yet though.

My personal philosphy, is that, unless your really not a good sailor, or your in a hurry all the time, you don't really need an engine. If your motoring against a tide, it's only because your in too much of a hurry to wait to go with the tide...etc. To me, the electric engine is just a way to get in and out of the slip, which is also possible under sail if you want to.

Chris

TomRobb
10-25-2002, 02:17 PM
Ish, re green.
If the genset isn't there earning its keep with your manifold electrical loads, the heater, the sauna, the air conditioning, the christmas tree, the electric toilet, the TV & stereo, etc., the gas/electric is just wasting more hydrocarbons converting potential chemical energy into motion - useless electrical losses. :(

Meerkat
10-26-2002, 12:22 AM
Solar, wind and water turbine combined probably would not meet demand, especially if you have refrigeration or propulsion loads. In addition, you're getting all kinds of drag from the wind and water systems, a lot of noise from the wind turbine, and solar needs far too much deck space (bigger boat, more deck space, but more load too). Really good solar cells are well under 20% (13% amorphous - 17% crystaline under ideal conditions) efficiency, unless you are in the spacecraft price range - and those only work as well as they do in space. The wind and solar systems do make decent supplements though and _could_ support loads for an unrefrigerated/sail only situation.

Paul Scheuer
10-26-2002, 09:25 AM
Thanks for the references.

I wasn't really thinking on the Green track. I don't think I'd make a very good poster boy with my SUV, air conditioned shop, etc.

I'm thinking that at some point I'm going to have to replace my 9 Hp, 2-cycle outboard (already illegal in some waters). The thought of putting a 4-cycle out there on the motor bracket got me to looking into a "real" inboard for a replacement. I've never liked the idea of climbing out over the transom to drop the bracket, etc. Expecting my inexperienced crew to do it in a emergency is a concern. The installation in my boat, while possible, would not be a walk in the park.

I would be willing to suffer the additional noise of running a gen set for maybe twice the time I normally run the motor, if I could get a relatvely easy installation, comparable price, and instant auxilliary power.

As for running an air conditioner in a slip from a generator, I'd do what my neighbors do, close the hatches.