[kd3pc]

you might google - Nigel Calder, as he has been tasked with designing and implementing a true electrical propulsion system and documenting the advantage or disadvantage. A year back, electric was not there yet, in any commercially viable way and I think that is still the case. This was with the best and most advanced technology money could buy. As the Elco drive is "old technology"...

He is a genious, IMHO, and has the skills and credentials to do this.

I think that given the weight, cost and installation issues that you will encounter in bringing this to your Mariner....it will be a no-brainer to NOT do it. It is not a trivial task, and few yards or techs are on the Bay that know anything at all about to help you.

That being said, if I had the money to test this, I would be all over it, just to see for my self how it plays or doesn't. I would contact Stevens Institute (or other engineering college) and hire two or three interns with an interest to help.

Keep us posted as to what you learn.

 

[kd3pc]

Are you "sailing" or "motoring"?

If sailing with an electric motor which is rarely used, a generator is not needed. The batteries can be topped off with solar or wind.

If motoring everywhere, why bother with sails?

It really depends on how you choose to travel. The original poster sounds like he wants to sail mostly, but have a backup or auxiliary. Electric will do that.

John

Even on the Chesapeake, with decent wind almost all the time blowing some direction, motoring is a needed thing. Sometimes in an emergency or to avoid.

So as much as I love to sail, in the real world motoring is happening quite a bit.

Electric MAY do that, or may not...depends on budget, size of boat (not a DIY on my 42') even if I had the money, currents, how far up the creek you berth or moor, etc, etc.

 

[kd3pc]

My important issues
1) amount of energy/power needed in an emergency for short while
2) amount of energy/power needed to maintain a leisurely speed(2-3 knots)
3) how long can my batteries move me at my leisurely speed
4) can I renew my used/spent energy on a daily basis
5) can I spend most of my time on the water actually sailing . . . with the sails

I think the electric option fits the need of the first 4 and the 5th is not dependent on the source of engine power.

I like WD's conditions, and will note that I agree totally, maybe even adding a top category for over 16,000 lbs..

For the smaller boats:
1. this is a major consideration. A function of torque/prop/motor and ability to sustain high loads for the duration of the event.
2. More of a battery consideration and clean hull than anything else. Hull design would play into it, as well
3. Exactly, you can only rack so many batteries in a 7,000 lb boat, safely
4. This point is a gotcha, no matter what the load is. I have 220 watts of solar, and a windmill. Solar will keep things topped up, but will not replenish my losses without some engine running. On the bay, wind gen is a non issue, almost can not count on it to be anything but icing on the cake. The wind just isn't there for it to perform.
5. If you do not work, did not bring the kids, do not slip up a creek this MAY be possible, for the rest of us, or those of us who actually do go somewhere and expect to return, it is a show stopper.

No comment on the money, as I am one who believes that with enough time and money anything is possible, although in reading Calder and his +40' I am no longer sure that $$ will work. Just too many variables.

That being said, those who have the drive leg hole (as the previous poster documented) on a small boat, the delta between electric and gas is likely not much and electric may work for you. I would not have a gas inboard, but that is just me.

Those of us with 50-60 hp who need quite a bit of that to move the 18K lbs, are likely out of luck with current technology, money or not.

be careful with DC, as those who are double and quad banking 12volt sources need to be cautious of DC burns and correctly protecting all connections....that voltage and the currents will hurt you, in a much different way than AC

thanks for the thought provoking.