100% Solar Electric Catamaran

[Supervstech]

My first boat was an old 73 with "outboard just needs a new coil and spark plug"
I gave up when the leaves in it were enough to collapse the axles on the trailer...

Second one was a nice bayliner the owner "pulled the carb and intake to upgrade, so easy fix"

Last straw was the houseboat i put MONTHS into ressurecting, when city made it have to go...

I like my kayak...

 

[lborkey]

Now that there's no rigging to stiffen the boat do you see flexing between the hulls? I ask because when we stepped our mast on a fountaine pajot catamaran the salon windows on the bridge deck started squeaking.

We haven't seen anything yet, other than our solar rack being less stiff than we had hoped. We're adding some cables and turnbuckles to tie it to the original mast step.

 

[YoSteves]

Super nice, I miss boating. skiing & sailing.
Everyone knows the saying: The 2 best days in a boaters life are the day they buy and the day they sell. That was definitely not true for us, we used all our toys as often as possible. Money well spent as far as I'm concerned.

That saying if for people that can’t fix things themselves and get bent over by mechanics that drain their wallets.

 

[lborkey]

Sorry, I'll post more, I haven't been the best about documenting this.


Close-up of the motor mount, 8" aluminum angle 1/2" thick holds it to the boat. Small jack plate to get it low enough.


Shot of the ePropulsion control screen showing about 3400 watts at 5.5kn. The two silver pull switches are low voltage hooked up to an EV contactor. Allows us to turn the motors on and off without climbing down into a hatch, twice.


I was working with the motor manufacturer on a problem I was having with the motor shutting off at full throttle. They wanted to see my setup. This is duplicated in the other sugar scoop.


Early version of Raspberry Pi-based navionics system, OpenPlotter. RPI4 with SSD. AIS transceiver at the top right. Little tiny sub board coming off the RPI is accelerometer and magnetic compass. It's got a few other sensors as well.


Shot of the guts of the system in progress. We had to sacrifice the port cabin to install all this stuff. The EG4 6500 (black box) has since been replaced with another EG4 MPPT Charger (white box) and a separate inverter.

 

[yabert]

Really nice! Thanks to share.
Do you ever find a plug at shore power with enough juice to plus your 2 chargeverter?

 

[wpns]

Nice! How does the steering work?

 

[lborkey]

Really nice! Thanks to share.
Do you ever find a plug at shore power with enough juice to plus your 2 chargeverter?

They'll work off 30 or 50 amp plugs, pretty common at most marinas. I doubt I could run both at full throttle off one 50 amp plug but they're adjustable. I haven't had to use them yet.

 

[lborkey]

Nice! How does the steering work?

Steering is a sore subject. It originally had regular cable push-pull type steering with a double helm. I removed the rudders and got new cables that would reach the motors. It was 6 turns lock to lock so it was pretty difficult to control. Lots of turning. I switched to hydraulic and it went from 6 turns to 3/4 turns (despite my and the vendor's calculations) and was impossible to control. I swapped out the pump for a variable displacement model and now we're at about 2 turns. It's ok but not great. I'm thinking about some sort of servo steering but what I have is ok for now. It's a skill to keep it on course, however.

 

[Supervstech]

Steering is a sore subject. It originally had regular cable push-pull type steering with a double helm. I removed the rudders and got new cables that would reach the motors. It was 6 turns lock to lock so it was pretty difficult to control. Lots of turning. I switched to hydraulic and it went from 6 turns to 3/4 turns (despite my and the vendor's calculations) and was impossible to control. I swapped out the pump for a variable displacement model and now we're at about 2 turns. It's ok but not great. I'm thinking about some sort of servo steering but what I have is ok for now. It's a skill to keep it on course, however.

Wow, 3/4 turn to locks... i bet that was fun!
2 is bad enough.
Unless you are trying for rodeo style in the harbor!

 

[Bluedog225]

Great project. Is there a class t fuse in the system?

 

[IGBT]

Very nice! I love the amount of solar...you just built the ultimate Great Loop boat.

Question: Were your speed vs wattage numbers done with the low pitch thrust prop or the other one?

We have a single Navy 6.0 on order but it will be the new redesign version that only fits a single sort of in between prop.

I fear that the old motor with the low pitch prop is more efficient than the new motor but I am not even sure if you can still get the older version now.

 

[lborkey]

Great project. Is there a class t fuse in the system?

Not currently, I'm using DC circuit breakers.

 

[lborkey]

Very nice! I love the amount of solar...you just built the ultimate Great Loop boat.

Question: Were your speed vs wattage numbers done with the low pitch thrust prop or the other one?

We have a single Navy 6.0 on order but it will be the new redesign version that only fits a single sort of in between prop.

I fear that the old motor with the low pitch prop is more efficient than the new motor but I am not even sure if you can still get the older version now.

I'm using the low pitch props, which I believe are the ones for low speed, heavy craft. I did order the aluminum props as well as I've heard good things about them over the plastic ones but they're on backorder.

 

[lborkey]

The Wall O' Stuff. I swear it started off neater.

 

[mooresolar]

I've built a solar catamaran out of a 2000 Gemini 105M sailing cat. Some basic specs:

- 2x ePropulsion Navy 6.0 motors, 6000w each max.
- 16x BlueSun Bifacial 575w solar panels, max output 9200w.
- 2x EG4 100amp MPPT solar charge controllers
- 4x 48v 160ah LiFePO4 batteries
- 2x EG4 5000w shore chargers 120v/240v
- 5000w Inverter
- Starlink Internet
- Openplotter navigation with AIS

I've got two independent setups, motor, battery, chargers and panels. No fossil fuels of any kind on the boat.

Sweet spot is 5.3 knots @ 3200w, max speed is around 7.3 knots @12,000w. You pay dearly for that extra two knots. I've cruised all day and arrived back at my marina with full batteries.

Still in the testing phase, our longest cruise has been 30nm. We're hoping to do 60 to 70nm on the regular. This boat was built as an ICW cruiser between Norfolk, VA and the Keys.

Future plans include a water maker. I'm on the waiting list for an atmospheric RV water maker currently being developed.

Ask away!

View attachment 219582

Can you get the motors out of the water ?

 

[lborkey]

Can you get the motors out of the water ?

Yes, using the tilt mechanism of the motors and the jack plate mount. It's a pain, however, so I'm looking at some electric/hydraulic tilting mounts.

 

[yabert]

How all this is working after some time?
Do you have new data to share, new information, new challenges?

 

[multimyrtle]

I've built a solar catamaran out of a 2000 Gemini 105M sailing cat. Some basic specs:

- 2x ePropulsion Navy 6.0 motors, 6000w each max.
- 16x BlueSun Bifacial 575w solar panels, max output 9200w.
- 2x EG4 100amp MPPT solar charge controllers
- 4x 48v 160ah LiFePO4 batteries
- 2x EG4 5000w shore chargers 120v/240v
- 5000w Inverter
- Starlink Internet
- Openplotter navigation with AIS

I've got two independent setups, motor, battery, chargers and panels. No fossil fuels of any kind on the boat.

Sweet spot is 5.3 knots @ 3200w, max speed is around 7.3 knots @12,000w. You pay dearly for that extra two knots. I've cruised all day and arrived back at my marina with full batteries.

Still in the testing phase, our longest cruise has been 30nm. We're hoping to do 60 to 70nm on the regular. This boat was built as an ICW cruiser between Norfolk, VA and the Keys.

Future plans include a water maker. I'm on the waiting list for an atmospheric RV water maker currently being developed.

Ask away!

View attachment 219582

Have been looking at various gemini power conversions, especially those with outboards and/or electric propulsion. Am curious, have you removed the centerboards and sealed the board trunks.? I believe many/most small twin screw power boats don’t have rudders either. have you thought about removing or at least downsizing the rudders as well?

 

[multimyrtle]

Have been looking at various gemini power conversions, especially those with outboards and/or electric propulsion. Am curious, have you removed the centerboards and sealed the board trunks.? I believe many/most small twin screw power boats don’t have rudders either. have you thought about removing or at least downsizing the rudders as well?

Sorry, if i had read all of your extensive posts then i would already have known the answer to my last question.