Electrical Propulsion vs Diesel Propulsion

[mbianka]

Originally Posted by smj

I read your blog and really like your system but for me in a catamaran with twin motors it doesn't make sense. Installing twice the weight you installed would overload my boat and the fact the prop is in the water full time would lead to to much drag thus destroying the sailing performance and having me motor more.
What is your average speed with the EP?
The Torqueedo motor would be more in line for the type boat I sail but still I think there would be a weight penalty with all the batteries and the need for a large generator.
Hopefully sometime soon.

If it does not work for you today it may well in the future as the technology evolves. Especially batteries. I did see one cat that had motors in pods that lifted up out of the way when sailing. Pretty neat don't have a link unfortunately.
As far as speed goes I like to keep things around 4 knots when cruising along. The 3 to 4 knot range seems to be most efficent for my boats hull. It varies for each boat. But, again it is a sailboat and I'm more often under sail exceeding that and not using any EP at all or just enough to eliminate any prop drag which just uses a few amps. I often sail in and out of the harbor now too. The channel has a narrow dog leg which can have some strong currents. So when I see I'm losing headway I turn on the EP and power through. Shut it down once I'm again sailing. Since there is no "warm up" issues like with a diesel I often just use it for minute or two and then turn it off. Use to run the diesel from before I dropped off the mooring until I cleared the harbor entrance. Don't need to do that with EP. But, even when you use it it's still quiet. No need to yell at the crew. Unless you really want too.

[Sailmonkey]

these guys were posting a lot here, and actually sailed the cat from south africa to europe if I remember correctly. It's not pure electric, but rather a hybrid that allows you to "motor sail" for thousands of miles without running the generator.


Green-Motion retractable propulsion/generating system patented - African Cats

[James S]

Originally Posted by Alberto

Yes. How many sailors that went electric would go back to an ICE? I have to find one yet... How many naysayers have ever been on an electric boat? I have to find one yet... How many people who have sailed with us wished they could have electric propulsion in their boats? 100%

http://www.cruisersforum.com/forums/...0-a-49334.html

and excerp from this thread http://www.cruisersforum.com/forums/...ion-24131.html
Last update I heard from Nigel Calder on electric drives (January 09) is that a number of those D/E Lagoons were converted BACK into straight diesel propulsion at the request of the owners.

According to Calder, nearly ALL of the D/E propulsion systems on the market now (Lagoon or otherwise) are LESS efficient than straight diesels. There is still some work to be done on the generator side of things.

Chances are that Lagoon you are looking at is less "green" than a traditional diesel setup.

His articles explaining all of this should be appearing in Professional Boatbuilder in the next few months.


Part of an old thread from here http://www.cruisersforum.com/forums/...rid-14640.html

My wife and I met a couple that have spent 10yrs of their life sailing the world. We had lots of questions and had a wonderful evening with them telling their tales. However, the very first thing the Guy said to me was, "have you got a good engine?" A little stunned of the question, I replied, "yes, it's a ....." Good he said. What about the gearbox. A little perplexed now I again said a tentative yes it's a ...... Good was once again his reply. Quickly followed by "Because you'll need them. There ain't no wind out there". Huh?!? No I was really puzzled. What do you mean? I asked. "There ain't no wind out there" he replied again. I had a puzzled look on my face which meant I didn't have to ask again. "NZ and these latitudes have wind" he said. "But much of the world doesn't. You will clock up thousands of hrs on the engine. It needs to be a real good one and a really good gearbox or you will constantly be fixing them and some places parts are hard to find." I was surprised and I have never forgotten that information. So relying on wind may not always be the best bet. In regards to Electric drives, I think the only advantage is the ability to place the engine anywhere that the design suits. Apart from that, I see huge limitations. the power these drives take to run means that you have to find away to put the power back in. Even via sailing using the prop to generate, that results in a huge reduction of speed. The power the motor produced to push the boat through the water is the same plus some for losses in reverse. That results in a great deal of drag. Don't get me wrong, I am not wanting to knock the system, but I just don't see practical solutions to recharging the system yet, nor the ability to get long term power for the system unless you run a genset. And if you run a genset, you may as well have just had the main engine/s to begin with.

I accept that some of this may be dated but some is very relivent.

[deckofficer]

And since it is quiet, other sailors in the same light wind, adverse current channel can't help but think "how is he sailing through here!" Has to leave an impression don't you think?

Since two posts got between mine and Capt Mike's, my post is a reply to Capt Mike.

[jostalli]

Originally Posted by Alberto

Yes. How many sailors that went electric would go back to an ICE? I have to find one yet... How many naysayers have ever been on an electric boat? I have to find one yet... How many people who have sailed with us wished they could have electric propulsion in their boats? 100%

Wait, did you not read my last post? Almost all of the hybrid Lagoon 420's have been converted to conventional diesel by the owners. I am asking for someone to find me a hybrid Lagoon 420 owner who is happy with the hybrid.

[mbianka]

Originally Posted by deckofficer

And since it is quiet, other sailors in the same light wind, adverse current channel can't help but think "how is he sailing through here!" Has to leave an impression don't you think?

Since two posts got between mine and Capt Mike's, my post is a reply to Capt Mike.

Well, I do get funny looks sometimes when I'm coming into a dock (don't do it often) A guy will look up from his boat surprised to see my boat since I'll be using motor and moving silently along. He knows there is something different about the boat but, can't quite figure out what it is. Plus I can come in at any speed I want since the range of the speed control is from 0 to full power. I'm not limited by the 700 rpm of the diesel.

[deckofficer]

Aw, come on Capt Mike, you never motor sail in winds so light they hardly keep your sails filled, passing folks that have shut off their noisy engines because they see you have enough wind to sail, not knowing you have some silent mechanical help?

[Alberto]

Originally Posted by jostalli

Wait, did you not read my last post? Almost all of the hybrid Lagoon 420's have been converted to conventional diesel by the owners. I am asking for someone to find me a hybrid Lagoon 420 owner who is happy with the hybrid.

Yes, I did. I have commented on the Lagoon case in another thread in this forum: a great idea launched to the market before it was fully developed, tarnishing a promising technology.

I do not preach EP, and I don't have a hybrid system. I just share comments based on my personal experience, because there are many people genuinely interested in EP and (as I mentioned before) there are many naysayers that quite often provide opinions on what I consider a very narrow perspective, and sometimes plain misinformation.

For our sailing (no blue-water, no long-distance) our EP system, which is based on proven and available technologies, serves us pretty well, and we love all of its advantages: quietness, instant power, being practically maintenance free, providing flat torque response, etc.

Regarding its shortcomings, which I've never denied, my only concern is range. As MBIANKA has perfectly stated many times in this and other forums, EP is modular, and by the time our batteries finally give up, we are sure we will have fantastic viable options that will make our system even better. Some of them, like LIFEPO4 are already available, but currently out of our budget.

Alberto

[Notpopeye]

Originally Posted by jostalli

Wait, did you not read my last post? Almost all of the hybrid Lagoon 420's have been converted to conventional diesel by the owners. I am asking for someone to find me a hybrid Lagoon 420 owner who is happy with the hybrid.

Isn't this is purely a monohull discussion? At least all us monohull owners thought so.

[Sailmonkey]

Originally Posted by Notpopeye

Isn't this is purely a monohull discussion? At least all us monohull owners thought so.

I thought this was a propulsion discussion

[Notpopeye]

Originally Posted by Sailmonkey

I thought this was a propulsion discussion

well yeah, propelling monohulls

[mbianka]

Originally Posted by deckofficer

Aw, come on Capt Mike, you never motor sail in winds so light they hardly keep your sails filled, passing folks that have shut off their noisy engines because they see you have enough wind to sail, not knowing you have some silent mechanical help?

Yeah, I guess it can cause some confusion when they don't see any exhaust and I'm leaning back in cockpit eating an apple moving nicely along. There was one time a few years ago when a bunch of us where out sailing on Narragansett Bay. It was a mix of cruisers and racers. So I'm kicking back in the cockpit sailing along when a fellow comes by who is an avid racer. He sails by me with his new $5k sail. Nice guy but, bit of a blowhard. I thought of cranking up the EP catching up and passing him with my 20 year old sail and see his reaction but, I didn't have the heart. More often I'm looking at guys like this and just scratching my head wondering what they are thinking on such a beautiful sailing day.

[tsmwebb]

Originally Posted by Notpopeye

Isn't this is purely a monohull discussion? At least all us monohull owners thought so.

Originally Posted by Sailmonkey

I thought this was a propulsion discussion

It is appearing in the "Multihull Sailboats" forum for me...

[Notpopeye]

Originally Posted by tsmwebb

It is appearing in the "Multihull Sailboats" forum for me...

perhaps I am mistaken. Sure, why should those people with more than one hull remain ignorant of the tremendous values in knowing the advantages and disadvantages of varied propulsion systems? I mean, how could anyone deprive our fellow sailors, regardless of their choice of vessel?

I would say welcome to the discussion, but it is likely you were here first so to that end, I respectfully and humbly add, glad to be here to gain so many perspectives and insights.

[niel12]

Originally Posted by Notpopeye

perhaps I am mistaken. Sure, why should those people with more than one hull remain ignorant of the tremendous values in knowing the advantages and disadvantages of varied propulsion systems? I mean, how could anyone deprive our fellow sailors, regardless of their choice of vessel?

I would say welcome to the discussion, but it is likely you were here first so to that end, I respectfully and humbly add, glad to be here to gain so many perspectives and insights.

I could'nt agree more, it's all about propulsion multi or mono, i greatly apprechiate all the responses and contributions, i find the learning curve extremely satisfying! Thanks all!