Solar Microtrawler conversion

Not having much luck finding a suitable 24ft donor hull with trailer for a custom build, my thoughts have shifted to more of a “bird in hand” model. I have a Sanibel 18 sailboat that I’ve started to think about converting into a solar electric micro trawler for sheltered inland waterways (see my 1/15 post for use specifics). A few months ago I stumbled upon a great deal on a gently used Torqeedo Travel 1003 with 2 battery packs. In water tests suggest about a 25 mile range at 4-5mph, and with flexible solar panels running as cheap as $2 a watt these days (see ECO-WORTHY) one should be able to add several hundred watts of solar supplementation on the cabin top without breaking the bank. Cutting away much of the cockpit would open up the interior for pilot house steerage and tight but doable accommodations for 2 (including sleeping, cooking and an enclosed head). I’ll likely add some sort of swim platform with motor mount and homebrew remote steerage assemblage (Torqeedo has a remote motor control accessory). I did some initial profile studies with digital images which prompted a full scale mockup using a stack of cheap furring strips, some mini clamps, ball bungies and Tyvek scraps. Attached is a photo of the mockup and another with a bit of electronic overlay. I like the sheer and the overall look, but I’m really torn on a uniform cabin top (as shown) or making the pilot house top taller than the rear cabin top. Would appreciate any observations or opinions.

Looks like a great project keep us upto date with your progress

Add some crown to the new cabin so it doesn't look like a single wide trailer.... not that there is any thing wrong with single wide trailers...unless you are trying to make your project look good.

Take a look at this review of the Torqueedo Travel 1003: Torqeedo Travel 1003 Electric Outboard Review | Cruising World. It implies that at full power it uses 1,000 watts and at medium power (maybe 300 watts) he could push his 24' sailboat to 2.5 kts. At that power and speed his 500 watt hour battery pack would last 3 hours.

So, translate those figures to your boat. You probably want to go faster than 2.5 kts but your hull is 18' not 24'. So maybe with the T running at 300 watts you can go 3-4 kts.

A couple of golf cart batteries (and I have no idea what voltage the T uses, so this is just for discussion) will produce 1,300 watt hours of power if you only discharge to 50%, so that will let you go about 7-8 hrs.

To keep these batteries charged up with solar so you can cruise indefinitely (but only in full sunlight of course) will take about 600 watts of solar panels. That isn't a huge number and should fit on your cabin top.

The foregoing is based a bit of theory, an extrapolation of the review numbers, and a bit of experience in solar panels.

Good luck with your project.

David

Thanks for the comments

Camber, curves, coves, overhangs and a nice eyebrow most certainly. My electronic art skills were too primitive to reflect these.

I'm confident of 4mph based upon experience with a 40lb thrust trolling motor on the same boat and initial use of the torqueedo, provided weight is kept to a minimum. Multi day trips will need to be worked out, and carting along my 1,000w Honda suitcase generator may be prudent as backup.

"a 40lb thrust trolling motor"

You might consider a 2-4 hp 4 stroke outboard as the get home , orb range extender..

It would be far more efficient than a noisemaker to charge a batt (20-30% loss) and then operating an electric motor.

4mph based upon experience with a 40lb thrust trolling motor


But I guarantee you that you will be going backwards once the tide changes

finally started deconstruction.

more early stage - good feel for interior space; lots of possibilities.

Great looking project that I look forward to following. Thank you for bringing the rest of us along for the ride John.

a few more pics in album of cabin sides in progress

http://www.trawlerforum.com/forums/members/10091-albums529.html

Great idea and I am eager for more.

port layout validation

http://www.trawlerforum.com/forums/members/10091-albums529-picture3198.html

Cutting up a boat for conversion with a sawzall must be satisfying.

Neat project.

port layout validation - exterior

Northern Spy said:

Cutting up a boat for conversion with a sawzall must be satisfying.

Click to expand...

Oh it certainly is!

This is a cool project!

Have you considered a simple cable type outboard steering setup? Maybe a mini mast just to fool with people?

Four 8D batteries under the deck plates would make some great ballast to offset the new house.

Did I mention how cool this project is?

Regards,
Bob

Just came across this thread.
Very interesting
In need...yes NEED ...of an update!

Nice to see I’m not the only crazy guy
http://www.trawlerforum.com/forums/...t-sailboat-mini-trawler-conversion-47099.html

Very cool project. Did you ever finish it?