Electric Propulsion on Catamarans

[44'cruisingcat]

Originally Posted by nimblemotors

To answer the question, there has not been anything new in 2013 that I'm aware of in boat electric propulsion.

An electric motor is one of the most simple and reliable and low maintainence
devices ever made. The generators at Hoover damn have been essentially in continuous operation for over 50 years.
Solid state transistor electronics have also become highly reliable.
Their lifetime is generally limited by electrolytic capacitors.

Solar panels are also highly reliable and essentially maintainence free.

Battery technology is the limiting factor. A hybrid then seems needed, and somewhat fouls the simple and reliable solution.
However, my Prius has about 200,000 miles and I have done nothing but change the oil and filters. I replaced the battery at 130,000.

I disagree that batteries are the limiting factor. Solar panels, while reliable, simply don't produce enough power for propulsion purposes.

A 1000 Watt array is pretty big on a boat. 3000 Watts is very big. Yet 3000 Watts is only about 4 1/2 horsepower. So with a BIG solar array operating at 100% (which doesn't happen often) you'd only be able to run a 4.5 hp motor from them.

Batteries will allow you to store power when you're not motoring, but realistically, whenever you do motor, you'll be drawing power much faster than you can replace it.

[deckofficer]

I've shared this on other threads...

10 kw of solar on a cat ferry hull crosses Atlantic at 5.5 kt.
transatlantic21: The world's first crossing of the Atlantic on a solar boat

8 kw of solar, 8000 nm cruising The Med.
Boat - SolarWave

6 kw of solar in Florida, Bahamas, Caribbean.
Island Pilot DSe Home Page

[crew moonwave]

Here just a short note from SY Moonwave - as mentioned in the previous post we are having one of the "latest" and most advanced integrated hybrid systems with electric propulsion on board and it works great.
If you have any questions about our system, please don't hesitate to contact us and have a look at our websites Sailing Catamaran for Charter - Gunboat 60 - MOONWAVE & Electric propulsion system for catamarans and sailboats

With best regards,
Sophie - SY Moonwave

[bryguy67]

Moonwave: I read about your boat and you talk about the possibility of an electric dinghy; but no specs or pics. Do you have one? Details please

[crew moonwave]

Originally Posted by bryguy67

Moonwave: I read about your boat and you talk about the possibility of an electric dinghy; but no specs or pics. Do you have one? Details please

Hi bryguy67,

Have a look at www.torqeedo.com - they are have nice electric outboard engines in different ranges.

Best regards,
Sophie - SY Moonwave

[bryguy67]

I'm very familiar with Torqeedo but what I was meaning to ask is whether you were using an electric outboard on the dinghy on your Gunboat. If so, what style & size dinghy? What size/brand of electric motor? And how is it working out for you? Range? Top speed? Its important to get feedback from those actually using them as that market is still in its infancy. Thanks so much!

[44'cruisingcat]

Originally Posted by Mr B

There is a very large ferry Cat in Sydney Harbour That runs full Solar power,

Pretty sure that was unsuccessful, and has been retired to Lake Macquarie.

[wraaski]

try take a look on this

Electric Drive Systems for Boats from Fischer Panda UK

Peter

[deckofficer]

Bryguy,

You didn't mention if your new build with electric galley will be using induction cook tops? Also curious of your 48 volt battery bank. Will this bank also power the inverter and what size and chemistry? I'm using Winston LiFePO4 cells with very good results. In your new build I would think (16) of the 700 a-hr cells would fill the bill for propulsion and inverter loads. 36.4 kw-hr and 750 lbs, all for about $9000. Could run a 15000 btu A/C at 50% duty cycle for 2 days without charging.

[Cotemar]

Originally Posted by bryguy67

Moonwave: I read about your boat and you talk about the possibility of an electric dinghy; but no specs or pics. Do you have one? Details please

I have a good catamaran dinghy as a candidate, but need a torqeedo electric to test with.
Someone in my marina has a torqeedo, so I will see if they will let me barrow it for a bit of testing.

[bryguy67]

Originally Posted by deckofficer

Bryguy,

You didn't mention if your new build with electric galley will be using induction cook tops? Also curious of your 48 volt battery bank. Will this bank also power the inverter and what size and chemistry? I'm using Winston LiFePO4 cells with very good results. In your new build I would think (16) of the 700 a-hr cells would fill the bill for propulsion and inverter loads. 36.4 kw-hr and 750 lbs, all for about $9000. Could run a 15000 btu A/C at 50% duty cycle for 2 days without charging.

Yes, she'll have an electric induction cook top and an oven that is a microwave/convection oven. No propane/cooking alcohol or gasoline on the boat or dinghy. Safer that way and the two battery banks will supply power for propulsion and/or house needs including limited Air Conditioning without running the diesel. The batteries you mention are something I need to research. The engineer of our hybrid system is recommending the Odyssey pc1800 batteries PC1800 Odyssey Battery
Four of these in series will give the desired 48 volt system. One system on each side of the cat and I can switch between them for house use. Lithium batteries sound terrific until I read about fires on Boeing aircrafts due to them. Overall weight of added battery capacity and small electric motors on the hybrid system are off set by the elimination of a diesel generator (plus one less diesel to maintain).

[kitehawaii]

Hi, Please check out our Solar Catamaran project.

We are group of experienced boat builders and designers with years of experience.

CleanEnergyCatamaran.com - VerdeCat Clean Energy & Sustainably Built Yachts

I look forward to your input.

[bryguy67]

Originally Posted by Cotemar

I have a good catamaran dinghy as a candidate, but need a torqeedo electric to test with.
Someone in my marina has a torqeedo, so I will see if they will let me barrow it for a bit of testing.

That looks like a fun little cat-dinghy. I like the inflatable cat-dinghy's too. But I'll need a V-hull dinghy for our set up so I'm considering the Walker Bay RID310. It's basically a hard dinghy with inflatable support. Adding a Torqeedo 1003 with a small flexible solar panel (not Torqeedo's huge one) should make it as just as self sufficient as the last solar powered dinghy I built. The solar energy is stored in the battery and used to power it day or night. I never had to plug that one in to land power or take from the boats power with the last one. We should get about 5 knots out of the new one in mild conditions. I may buy the extra battery if range becomes a concern.
Please report back on what model Torqeedo you test yours with and what kind of speed you get out of it. I'm very interested in how it works out for you!

[deckofficer]

Originally Posted by bryguy67

Yes, she'll have an electric induction cook top and an oven that is a microwave/convection oven. No propane/cooking alcohol or gasoline on the boat or dinghy. Safer that way and the two battery banks will supply power for propulsion and/or house needs including limited Air Conditioning without running the diesel. The batteries you mention are something I need to research. The engineer of our hybrid system is recommending the Odyssey pc1800 batteries PC1800 Odyssey Battery
Four of these in series will give the desired 48 volt system. One system on each side of the cat and I can switch between them for house use. Lithium batteries sound terrific until I read about fires on Boeing aircrafts due to them. Overall weight of added battery capacity and small electric motors on the hybrid system are off set by the elimination of a diesel generator (plus one less diesel to maintain).

Those fires were with a different chemistry than LiFePO4. Reuben Trane started with the Odyssey PC 1800's (2 strings of 48 volts) on his boat "Sunshine" and is now running a single series string of Winston 1000 a-hr LiFePO4 cells and reports a vast improvement. I also when racing EVs used the Odyssey batteries, but have switched to LiFePO4 and there is no comparison, a 400 a-hr lithium bank gives more usable a-hr than a 800 a-hr AGM bank. Other benefits are minimal voltage sag under heavy loads and almost nil Peukert effect. I strongly recommend LiFePO4 cells over any other chemistry.

[SunnySky]

For someone seeking to usually be actively sailing their <40' catamaran another possible combination would be two 4kW Torqueedos with modest solar but two Watt & Sea hydroelectric generators and adequate battery for anticipated Torqueedo run time (make 1 kW when sailing 8 knots with no big prop drag since even a feathering prop contributes a decent amount of drag that isn't getting you anything.) and drains batteries 4 kW when motoring, so figure 6-8 hours sailing for 1 hour motoring (conservative off the top of my head ballpark increase in sailing time to account for electrical conversion inefficiencies..). Wouldn't be a good system for a cat that didn't sail well (or regularly..) though. Also not economically reasonable compared to two Yamaha 9.9 high thrust outboards and a little gas generator unless you are willing and able to pay the premium for increased autonomy and longer term sustainability to not be dependent on government subsidized fossil fuels..