Electric Sailboat Conversion

[Aether Brigade]

Hi all,
We have a sailboat that we would like to replace the diesel engine with an electric motor and need help. Does anyone know a good person or resource to advise us?
Considerations:
1. We have a solar panel and charger, but would need a much larger battery to maintain the kind of range the diesel had.
2. Removing the engine and diesel tank removes 500 to 700 lbs. but we need (roughly a ton of battery to power a motor). There is about a thousand of removable ballast, but we then still have to balance the boat to avoid listing. Help?
3. How do electric motors interface with our inboard propeller interface?
4. Tesla's new house batteries look great, but centering it for balance seems a challenge on a 30 ft., 8 ton sailboat. Help?

Thanks for any thoughts or resources,
The crew of the Peloton, SF Bay: Gwynn & Corey

[emartin00]

Well First off, how big is your boat?
If you plan to use the motor more than once in a blue moon, you're probably going to need to cover every available inch of the boat in solar panels. A couple small wind turbines would probably be a good addition.
The electric motor should be able to connect to the prop shaft at some point inside the boat via a gear or chain drive. That will probably be the least of your worries though.

[PNjunction]

While not trying to chase you away from the good engineering found here, a lot of the marine know-how for nearly all your questions can be found on this board's various forums:

http://www.cruisersforum.com/forums/f14/

Maine Sail is just one of the many I follow with interest.

[Naptown]

You will not get near the range from bstteries as your diesel.
However if you day sail and only need an hour or two motor time electric works very well.
The advantages ( at least here in Maryland where winterizing is necessary)
No winterizing. Wet store and go out whenever you want on a nice day without having to winterized the engine again back at the dock.
Some savings in weight but not all that much.
Disadvantages
Much shorter range under power ( you could not pit enough panels on the boat to appreciably extend range)
A bit lower speed under power vs the diesel ( although not much )

[Mike90250]

The simple way to do a quick calculation, is how many Hp is your diesel ? and how many hours per day do you run it ?

It takes about 1Kw of power for each HP