Electric Auxiallary

[Nausikaa]

Hi,

From Yemen (where many of you know I am at the moment) nothing new. But I did bump into a former Royal Navy commander the other day and we had a long chat. Unfortunately not over a couple of glasses; that kind of stuff being outlawed here. Anyway, we discussed amongst other thing the possibility of using an electric motor, say 36 or 48v, as an auxiliary engine in a yacht. I did not take it seriously at first but the guy sailed in subs so I suppose he knows a thing or two about electric boats.

Anyway, I started thinking about it. On the plus side an electric motor weighs far less than a diesel, it does not need a large tank, it is almost maintenance free, very quiet, reliable (less moving parts), can drive the shaft directly if low speed, etc.

The cons of course are: battery weight, batteries require charging, lack of power, time between charge cycles.

On thinking it over though it could make a lot of sense. Using a dc motor, when sailing the spinning prop will run the motor backwards so it should function as a dynamo and charge the batteries. They can also be charged by solar cells, wind generator or, at the dock, by a hook up to the grid.

I am, I freely admit, electrically challenged. Maybe I am way out here but I would like to know more. Any of you guys got some ideas on the subject?

Cheers,

Stephen

Yacht NAUSIKAA

[Peter Owen]

In my innocence, I started to get interested in this idea and found all sorts of "projects" on the web. More importantly, I think that Lagoon catamarans already offering cats with electric drive and generation supported by a diesel generator for topping up batteries as and when; trailing electric generators under sail to supplement wind vanes and solar are apparently readily available but small.

A search for "electric boat" on Google will throw up any number of sites one of which points out that Queen Mary 2 uses the principal of diesel generator and (four) huge electric final drives so it's not just subs and pond toys!

My instincts tell me that it's a real possibility that makes real sense though developments in battery/fuel cell technologies will be key. It might, of course, also open the door to electric cooking (and heating) with energy sourced from wind, sun and, inevitably, diesel; great news if you dream of an alternative to LPG, kerosene etc.

Like you, I'd be very interested to know more about the energy accounting balance - more weight (but better distributed in batteries but less in terms of engine and even fuel.

See ya!

[JeanneP]

Peter's military service was served on an icebreaker in the US Coast Guard (in the Arctic). The icebreakers are driven by electric motors. Diesel generators provide the power for the electric motors, but they were very effective.

We've been enamored of the idea of electric motors, but haven't had the opportunity yet to try them on our boat. Anybody else out there who has tried the new Lagoon with electric motors?

[Nausikaa]

Thanks for your replies guys!

I too served on icebreakers with diesel electric propulsion. It has been arround for years. The old passanegr ship Canberra had it. It is great and a very reliable system.But I am looking for diesel electric propulsion without the diesel! after all, the idea is that we spend most of out time sailing when at sea and just use the engine when coming alsongside etc.

I am convinced that this is the way to go, especially as the cost of fuel sky rockets. Maybe it can be done today or maybe we will have to wait until battery technology improves. Fuel cells are also have great potential.

Like you Peter, I have a gut feeling that this is the way things will develop.

I googled 'electric boat'before I started this topic and was amazed at the number of sites it turned up, but the vast majority of sites related to smaller craft seemed to concentrate on small electric trolling motors and electrically driven launches for inland waterways. I woiuld like to know what is available for traditional yachts.

Incidentally, Vetus offer a diesel-eletric package which, even though it will not fit in my boat, is an interesting development.

All the best,

Stephen

yacht NAUSIKAA

[Oscar]

Greetings, relatively new around here, but not new to forums. In fact you're invited over to "my place".... http://www.midnightwatch.org (NOT a commercial site...just a bunch of sailors, and family friendly.)

Re. electric propulsion, it's not in the future, it's here:

Fisher Panda is doing quite a bit of work in the electric propulsion arena:

http://www.solarnavigator.net/fischer_pand...el_electric.htm

Lagoon is either offering, or installing electric propulsion in one or more of it's models....

http://www.theautochannel.com/news/2...28/051892.html

http://www.catamarans.com/news/2006/...elelectric.asp

http://www.multihull-maven.com/Electric_Lagoons

A Catalina 42 was fitted with the Solomons fuel cell (hydrogen....)

http://www.solomontechnologies.com/h..._fuel_cell.htm

http://www.thelog.com/news/newsview.asp?c=15400

http://www.haveblue.com/news/archivedpr/092402.htm

[Nausikaa]

Hi folks,

Thanks for the feedback Oscar. I followed the links and was impressed by Solomon Technologies. I have written and asked them for further details.

I will let you all know how things turn out.

Cheers,

Stephen

Yacht NAUSIKAA

[Sailboatman]

I have done some research on the idea and have found the following.

Briggs and Stratton makes a 48V Etek motor and a controller that will put out about 8 HP under normal loads and i believe 24 HP for upto 30 min. I was going to mount two of them together to drive a 22,000 lbs 41 foot sailboat. It take 746 watts for 1 HP. By my calculations I should have been able to motor for about 9 hours at 5 knots in light seas with 600 amps at 48 volts.

the controller will enable you to charge the battery bank and is about 80% efficient. so if you motor for an hour it will take about 90 min to recharge taking into account battery effiency.

The problem is controlling the charge to the batteries. you can monitor them and physically stop the propeller and thus the regen or dump the load to another system. the only way i have found to automate this was to use the Xantrex 48V Inverter Charger. It will monitor your batteries to a user controlled setting and then you can have it turn on your 110v water heater. you would be dumping the load through the inverter to the water heater, electric heater or air conditioner. you could also have a light at the helm or nav station to let you know this is going on and then stop the regen.

The next issue is heavy weather and motoring time. The inverter charger i think will charge at 50amps so i planned to use a small portable gas genset that would put out 2000 watts. i believe this would give me about 40 amps to the batteries and the motors or about 2.5 HP. This along with 48V wind and solor panels i thought i could make it work.

I did not find any weight advantage in switching because of the number of batteries required.

I really like the idea of no desiel fuel, fileters, and all the maintenance that goes with it but my new used boat has a brand new Yanmar so it will be awhile before i get to try this out.

Hope this helps.

[Texasman54]

Look at lagoon boat site they have a new boat that has electric motors

[Moby Dick]

Originally Posted by name='Converted Post'

Originally posted by Texasman54

Look at lagoon boat site they have a new boat that has electric motors

Or strictly 'will do' as hull no.1 has only just hit the water for tests.

Note, they claim only 2 hours motoring before the generator starts to top the batteries up

[Duckhead]

For emergencies, the idea of going without a fossil fuel generator of some kind would be dangerous as solar power or water generation is collected by the watt and the output needed would be by the ampere, quickly depleting your batteries.

Secondly one would initially think the conversion of mechanical energy (diesel) to electrical energy (batts) and then back to mechanical(motor) is still too inefficient but they are getting better at it.

Then you would have to have the room for huge heavy batteries.

Maybe the ballast in a monohull boat could be replaced by a huge battery (read expensive). A catamaran would have even more problems with this as they are designed to be light.

The reason they have diesel/electric in the first place is not because it's efficient or cheap but to solve a problem. Trains use it, can you imagine the clutch they would need if they didn't? Subs use it to go undetected. Ice breakers ... hmmm don't know bout that one?

Even tho you can't tip a few, I'd still rather be in Yemen than working! have fun out there, Duckhead.

[Nausikaa]

Thanks for your comments folks!

I was actually considering dumping (when the time comes) the iron genoa completely and trying to run a system built entirely on batteries charged by solar / wind power with top ups from shore-side mains when available.

I am still thinking along those lines. I am not so woried about having a 'fossil fuel' engine for emergencies as Duckhead pointed out - after all many an engineless yacht has sailed arround the world and many a yacht has started out with a working engine only to find it stops and is no more than ballast. I like to think I take care of my engine and it won't just seize on me but I am still vary much attached to the idea of free, pollution free energy.

By the way Duckhead, you might rather be in Yemen than working but I am doing both [xx(] .

I'll be sending you guys a 'status reort' soon letting you know what progress has been made here regarding the piracy issue.

All the best

Stephen

Yacht NAUSIKAA