T-Pain Is On A Boat: Re: [Electric Boats] Re: Electric Catamaran

Tuesday, December 8, 2009

Re: [Electric Boats] Re: Electric Catamaran

You're designing a conventional boat and asking if you can use electric propulsion...wrong design approach.

If you want an electric boat, then don't sub-optimize with a conventional boat design -- design the electric boat.

For starters, why do you need a 60' mast with sails, when you could design a boat that uses wind turbines and solar panels to harvest the wind (which is really just a form of solar) and solar power?

I'd rather "point and shoot" with wind turbines and solar panels driving electric props than have to deal with cumbersome sails -- I can sail directly into a head wind with wind turbines and solar panels for power.

ScottO

From: john_casperson <john_casperson@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Tue, December 8, 2009 10:43:17 PM
Subject: [Electric Boats] Re: Electric Catamaran

Hi Bill--

I don't think you can obtain the speed you want for long periods.

I didn't see mention of weight in your initial post.

Using the speed calculator at

http://www.psychosn ail.com/BoatSpee dCalculator. aspx

and assuming a 34 foot waterline, one ton per hull, I come up with

5 mph requiring one HP per hull, or about 1.5 KW in aggregate.

For running off lead acid batteries, you'll need about 150 lb of batteries for each hour of 5 mph running time.

Unless you can figure out a way to make your collectors track or receive concentrated sunlight, you'll probably need about 2.5 KW of panels to meet the power requirement for a 5 mph cruise for several hours a day.

John Casperson

--- In electricboats@ yahoogroups. com, "Bill Gow" <billgow@... > wrote:
>
> Hello Group!
>
>
>
> I just joined today. The reason for my interest is finding help in planning
> out an electric alternative to conventional internal combustion engines on a
> catamaran I'm beginning to conceptualize.
>
>
>
> The dimensions will be ~ LOA 36', Beam 22', Mast Height 60'. It will be a
> light, fast, demountable sailboat that will fit on a trailer ~ 8' wide for
> towing anywhere. I may consider going into production if this works as I
> plan. The first one will be used to do a lot of fishing in the Pacific Ocean
> from Mexico to Panama. Weight is critical! Reliable power is critical. The
> boat will have all the necessary systems to sustain 4 adults for extended
> voyages, maybe even an ocean crossing some day. 3 or 4 knots in calm waters
> is of no use to me. I have to be able to control my boat in high winds and
> surging ocean currents and troll or motor at above 6 knots for extended
> periods. I have a couple things most sailboats do not, twin hulls = less
> weight for a much larger usable space and a huge hard bimini top for solar
> (~13'X14'). I'd like to cover this bimini with something like the Uni-Solar
> (http://www.uni-solar.com) PVL-68 laminates. I figure I can get 8 of the
> them up there and they'll weigh less than 100 Lbs.
>
>
>
> It looks like my bogey is battery weight. There is no way I'm adding a ton
> of lead to this boat! I can get great performance from a couple 20HP
> outboards that weigh less than 120 Lbs each. Is there any hope of electric
> propulsion or am I dreaming?
>