Propane generator on board

[Dockhead]

Originally Posted by warrior 90

Certainly all those factors need to be balanced. I think here also the cruising range would have to be considered. Have seen set ups on sailing cats with 2 electrodrives, 2 equal generators and 1 battery bank. Made a good impression on me. Have a look at this system
New design possibilities
But I think as the size of the power requiered goes up things look different.

Indeed. And the system becomes much safer with all that redundancy.

The only problem is that is becomes much more complex at the same time. Which really begs the question of whether it is worthwhile or not.

I really like the conventional direct drive system on a catamaran, which is much simpler than that. You've got two engines you can use at the same time for maneuvering or when you need their combined power. You've got another engine if one ever fails. Long-distance motoring you do on one engine -- more efficient. You don't really need a separate generator -- put a jumbo alternator on one (or both) main engines. Plus unlike on a mono you've got plenty of space for a mongo solar installation.

This is much better than what I've got, which is also two diesel engines with the attendant cost and weight. Except that I can't use the second one (in my genset) for backup propulsion. I do have backup generation from my main, but less efficient than if it were driven by a smaller engine. And my main engine is twice the size that it would be, if I had two main engines, so that much less efficient when motoring under light load or motorsailing.

It's great that you guys are experimenting with avant-gard techniques like diesel-electric, but in my opinion it is more of intellectual, than practical value so far. A normal cat propulsion system, set up properly, is going to be just as efficient, and much simpler and cheaper.

[dlymn]

When I'm motorsailing on my36 footer, the diesel motor plods away for hour after hour pumping out probably 25kw after discounting inefficiencies. That's a fairly big genset configuration. You probably have to ignore the notion of energy storage for a long cruise. 25kw is 2000 amps at 12 volts. I would guess that after an hour or two you would be driving the electric motors straight off the genset. That seems pointless.
If you're motoring for 5-8 hours, there is no time to top up the batteries.
As others have pointed out, at the moment current electrical storage systems have nothing like the energy/mass storage of fuels like diesel and petrol. Marinas are not set up to provide high volumes of propane and the energy/mass argument holds somewhat.

[bmacneil]

I have a diesel DC charging system for sale if you are interested. Bmacneil





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[warrior 90]

I think the general idear of hybrid diesel electric is You cover the electro propulsion completly with the 2 generators and depending on power needed run the second generator while allways storing the power left over in the battery bank to where You also dump the energy from the solar panels wich in case of a cat would also be significant in case of using the effective space available.
As far as the generator control of engine is not as complicated as using engine for propulsion because of +/- allways the same RPM. Stabalizing energy comes from the battery bank.
Control and direction of the prop speed is a lot more simple.It´s just on or off, reverse polarity and a potentiometer or frequency pulses for RPM
Just guessing I beleave cost for instalation and maintanance should be far less. Fuel consumption is allways optimum and if handeled properly this installation should very little maintanance....very view moving parts for propulsion.
Compare a rewind and varnish bath of a small motor with a complete over houl of a diesel engine. Usually the vital contacts are all air and water tight Even the generators are in a much better enviroment.
I don´t think there is a lot that can go wrong compared to the tradicional diesel systems.
Of cause the generators also need attention but under those conditions they suffer a lot less. I also think in case of a generator wich is a lot smaller all service can be done in a shop wich is cheap while with a tradicional diesel it has to be done on board. Disconect a diesel engine from the boat...gear box etc. afterwards aligning the shaft or drive. With a gen it´s a couple of plugs and the fuel lines.Also the cooling in such a system like the Azimut is natural
No failure of pumps,belts, hull through fittings etc..the gen doesn´t need seawater for cooling.
Also there is a lot of safety back up in such a system and a very great feature...allways enough energy on board.
Another nice feature is... with a wifi joy stick the boat can be precision steered from any location on the boat. I find the tecnical posibilities amazing. You don´t controll the boat anymore... You just make decicions...the system does the rest
Have a look at this video

https://www.youtube.com/watch?v=iZXgDX8Wrw8

There is also one true fact that should not be under estimated. The most power requiered in a boat is while accelerating. And here an electro motor of the same KW rating clearly outperforms the combustion engine because full torque is available any time and all the time. Once the boat is in motion less power is requiered to maintain the motion. So as to have the same torque available it would need a higher rated combustion engine
I think there is a lot of future and I think it´s good to keep an open mind. Tradicional thinking set limits.
On the other side I beleave it´s only worth while in a new design where the full potential can be fully apreciated
Obviously with repowering a or even powering a new boat that´s no designed for diesel hybrid electro propulsion that would not be the case

[Terra Nova]

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[warrior 90]

Originally Posted by dlymn

Hi warrior 90

You seem to gloss over many key points about power generation.
A 10 kw genset typically weighs 100kg; you need a much bigger unit than this to power a cruising sailboat. I don't think that it is a simple matter of unplugging wires and carrying the unit to a workshop on shore. The load on a diesel motor driving a propellor is almost always constant and light, almost identical to the load on a genset motor. The wear and tear would be about the same. To run on electricity for 5 hours might require up to 50x 200amphour batteries assuming a 50%drawdown. This increased mass will certainly increase boat and engine performance. You also need to factor in the replacement cost of the batteries which might average out to be more than 2000 euros a year

I don't see it as a matter of not being open minded, but rather a matter of using your knowledge and experience to critically analyse an innovation.
At the moment, I cannot see a cost/performance benefit. When they get batteries to have 10 times the capacity for the same weight and price and which last for 10+ years and a 25kw genset to weigh less than 50kg, I will happily support you

Well You are right I might have used a rather over simplyfied way to express. Obviously there is a lot more to such a system.
First I understand such a system uses the batteries for stabalizing only. The electro motors are fueled by the generators and not by the batteries. Also lead acid batteries would absolutly not be suitable for reasons of DOD,weight and life cycle/price.
Taking that under consideration I think the batteries should more be like that
700Ah, 2-5C, 3V LiFePo4 Lithium Prismatic EV Battery
with considering a DOD at 50% and lifecycles between 3-4000 and a corresponding marine housing to spec.
Since the gens sets can be located at conveniance I asume servicing the gens would depend on design.
Also looks a lot less complicated on a cat than on a typical sail boat mono hull.
Fact is they use those system successfully in comercial marine applications on a much bigger scale.
The question is can those systems be used on a smaller scale. It looks to me that the relation of mass to boat size is critical.
I do agree a super critical analysis is of esence but here they are talking about up to 100 kw capacity and continous cruising and extended cruising at high speed So there are limits and specs for high speed applications
288V "C3 Cockpit" System
here are the motor specs
http://www.whisperprop.de/fileadmin/...otoren_eng.pdf
There also is a configurator on the web page but certainly a project would requierer a close colaboration on their behalf

This company is of the Fisher Panda Group and they usually deliver what they promise

Another question would be the price

[Kalinowski]

Thanks for all comments. Again, the use of my yacht will be coastal and interisland here in Hawai'i. Windless days here are a rarity as the trades are almost constant, so my engine use is in and out of harbor. I plan to store the dedicated propane tank in a newly constructed compartment in the lazarette that will be fitted with a drain. Going electric will free up an enormous amount of space presently occupied by both engine and fuel tank. The new motor, battery bank, and possible propane generator/tank will easily fit. From comments, it sounds like I should consider a generator space that is separate from the yacht's space down below, but with an opening hatch and drain to the outside. Thoughts?

[Dockhead]

Originally Posted by Kalinowski

Thanks for all comments. Again, the use of my yacht will be coastal and interisland here in Hawai'i. Windless days here are a rarity as the trades are almost constant, so my engine use is in and out of harbor. I plan to store the dedicated propane tank in a newly constructed compartment in the lazarette that will be fitted with a drain. Going electric will free up an enormous amount of space presently occupied by both engine and fuel tank. The new motor, battery bank, and possible propane generator/tank will easily fit. From comments, it sounds like I should consider a generator space that is separate from the yacht's space down below, but with an opening hatch and drain to the outside. Thoughts?

If you both propane tank and generator outside the main hull volume - sealed off from the rest of the hull - and the gas installation is to code and quality - then in my opinion the safety problem is reasonably under control.

Where will you buy bulk propane?

Have you worked out the size of a tank you would need for the range you expect?

And the $64 question - why?

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[nimblemotors]

While Propane is a cleaner burning fuel, and as you stated, you want something cleaner burning than diesel (did some of you GET THAT? ), it doesn't seem worth the additional trouble compared to petrol. As I would expect you hope to not actually run it very much, the cleaner burn of propane would not offset the trouble.

Having the generator isolated from the main cabin is they way to go.
In my current boat design, my generator and its fuel tank is completely isolated. And I mean completely. The generator and fuel tank can motor itself to shore to refuel while the main boat stays anchored out!

Just in case you need a visual of something similiar:

[Kalinowski]

Doc head: it's time to consider repowering as the boat's power plant is a 1981. The costs of diesel or electric power plants are similar. Going electric will forever eliminate fuel costs and tankage, continuous maintenance, noise, smell, and pollution. As long distance cruising is not part of our plans (Hawai'i is a long way from anywhere), these attributes make me lean towards electric.

[leftbrainstuff]

The energy density of diesel and the diesel engine is hard to beat except for some niche applications. Short range, extended stops or very large vessels.

You need to be an early adopter to go all electric. As a liveaboard cruiser electric just doesn't make sense.

A propane main engine makes even less sense. We use propane for cooking and love it.

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[phantomracer]

unsure if it would be up to the task, but love the efoy methanol fuel cell on our boat. then again, it is only charging a small bank of batteries..and (adding this year) refrigeration.

[rwidman]

Originally Posted by Kalinowski

................ Going electric will forever eliminate fuel costs ................... .

Yea, that's what the people who buy electric cars think as well.

It takes a certain amount of energy to move a boat from X to Y. Wind is free but it's unreliable and is difficult to store. A certain amount of solar energy is available but it is also unreliable and capturing it and storing it is difficult and has a large investment in equipment.

Unless you are getting your electricity from wind or the sun (or hydroelectric), there is fuel and fuel costs. You may not be able to figure out the costs directly, but they are there. As for fumes and pollution, you've only moved them to someone else's neighborhood.

[warrior 90]

I can see the benefits of electric propulsion in conbination with solar and wind etc. but never with out a total diesel generator back up.

Gas is no option for me
Very unreliable fuel source and very impractible handling