Looking for Feedback on Electric Propulsion

donrr1 · #1 (**permalink**) 02-14-2007

Hello all, I am hoping to find someone who is using electric propulsion for their boat who could give me some feedback on its performanceI am seriously considering a diesel electric system for my 41' Morgan. Anyone?

Thanks, Don

f123olly · #2 (**permalink**) 02-20-2007

Electric propulsion has many benefits but may not suit all situations or be for all types of boating. You might check out the yahoo group 'electricboats' which has over 6000 posts going back several years. This group covers just about all of the ins and outs of electric boating.

There are many ways to convert a larger vessel and for a 41' I suspect that a hybrid would be in order unless you are just day sailing and need power to get to and from sailing waters. Without an on board generator you are looking at about 8-10 hours at 2-3 knots or maybe 2 hours at 5-6 knots. The limiting factor is the Amp hour capacity of the battery system used and not the Hp that can be generated. Amps go quickly when you want to get to hull speed!! If you are thinking that with a solar panel or two or a small Honda generator you will be able to sail the world then you should stay with a standard IC diesel system.

There are several companies out there that sell electric systems that are reliable and work well. The cost will be anywhere from $1500 to $15,000 depending on what you deem necessary.

I have converted a Ranger 29 and a HA-18 catboat to electric and have had no regrets. I use both boats for day sailing or short cruises. I wouldn't have
them any other way. Do your research and you will probably end up with a super electric system that will suit your needs very well.

Good Luck, KF

f123olly · #3 (**permalink**) 02-20-2007

Electric propulsion has many benefits but may not suit all situations or be for all types of boating. You might check out the yahoo group 'electricboats' which has over 6000 posts going back several years. This group covers just about all of the ins and outs of electric boating.

There are many ways to convert a larger vessel and for a 41' I suspect that a hybrid would be in order unless you are just day sailing and need power to get to and from sailing waters. Without an on board generator you are looking at about 8-10 hours at 2-3 knots or maybe 2 hours at 5-6 knots. The limiting factor is the Amp hour capacity of the battery system used and not the Hp that can be generated. Amps go quickly when you want to get to hull speed!! If you are thinking that with a solar panel or two or a small Honda generator you will be able to sail the world then you should stay with a standard IC diesel system.

There are several companies out there that sell electric systems that are reliable and work well. The cost will be anywhere from $1500 to $15,000 depending on what you deem necessary.

I have converted a Ranger 29 and a HA-18 catboat to electric and have had no regrets. I use both boats for day sailing or short cruises. I wouldn't have
them any other way. Do your research and you will probably end up with a super electric system that will suit your needs very well.

Good Luck, KF

Goodnewsboy · #4 (**permalink**) 02-20-2007

You seem to want to make your boat an electric hybrid. Here are a few facts:

1. The area near the shaft log in a boat is not a real friendly atmosphere for continuously running electric motors, especially those that have commutators.

2. A hybrid system is usually less efficient. Think of it as the sum of INefficiencies. You have the inefficiency of the engine, the inefficiency of the generator, the inefficiency of the batteries, the inefficiency of the motor controls (analogous to the throttle), and finally, the inefficiency of the motor. If it were a car, you would make a significant gain in fuel efficiency whenever driving in the city because you would consume no energy when stopped. (That is the big advantage of hybrid autos over those gas burning engines at idle.)

Your conventional marine engine has inefficiencies too, but fewer; engine, transmission. (I am assuming that parasitic loads such as the alternator and pumps are figured into the engine performance.)

3. Electric advantages:
Silence

donrr1 · #5 (**permalink**) 02-22-2007

Thanks for the feedback guys, here is what I've found out in my research on electric propulsion. The system I am most interested in is produced by re-e-power (re-e-power.com). They use external propulsion pods, I would require 2 engines for my 41' Morgan. They provide the controllers for the units. They are currently working on a complete system which would include a DC generator and all of the components necessary for any method of recharging the battery bank(s) including the house bank. The estimated cost for the system now, using an independent DC generator source, would be about '14K' not including the battery bank if used as a hybrid system.

Their system 3000 draws 80 amps per motor at full load, they recommend a 200 amp DC generator to supply the power (allows for true working load of the genset). I have no doubt that fuel consumption would be less than the standard 'iron genny' for similar performance. Will it eventually pay for the additional expense?

While I don't intend the boat for racing, I am concerned about the additional drag of two external pods. Some in-depth testing on two identical boats, one with a pod, the other without would be helpful.

Don

Goodnewsboy · #6 (**permalink**) 02-22-2007

I've never heard of a twin screw installation that was as efficient as a single.

Let us know how they do it.

donrr1 · #7 (**permalink**) 02-22-2007

My Morgan is a full keel boat, the system uses 2 engines mounted on either side of the keel with the control wires coming thru the hull. Hull fairing is necessary to provide alignment of the engines. There would be no downward thrust as in most conventional engine installations thus maximizing available thrust. Maneuvering would become enhanced because of the twin screw setup. The engines would provide charging to the battery banks as the props spin while sailing. Feathering props could be installed on one or both engines to reduce drag, of course this would provide no charging capability if both props were feathering.

The Morgan 41 was a CCA racer/cruiser in it's day. The hull is easily moved to hull speed on a reach in 15 knots with a jib and jigger alone. I'm considering the extra drag of the pods would not make my boat a dog. If the boat is a dog to begin with this application probably wouldn't be practical.

SailorMitch · #8 (**permalink**) 02-22-2007

Nigel Calder is a big proponent of electric propulsion. Last I knew, he had ordered a big Malo that was going to have electric motors for power. I think he has written an article or two about that propulsion method in some of the big glossies.

Sailormann · #9 (**permalink**) 02-24-2007

http://www.asmomarine.com/2005/asmo_uk/00.shtml

http://www.solomontechnologies.com/m_recreational.htm

These two sytems recharge while you sail. The propellor becomes a dynamo...

Goodnewsboy · #10 (**permalink**) 02-24-2007

I looked at the Solomon ad:
http://www.solomontechnologies.com/fueleffic.htm

Before you put your money down, get a real comparison of fuel cost based on equal power to the propeller/s. Comparing the fuel flow for twin 29 HP (Why 29 HP?) diesels with the fuel flow required to run a genset supplying 6 HP electric motors doesn't sound like an apples vs. apples comparison. As they say in Sweden, something is rotten in Denmark.

If you really want electric propulsion, go for it, but do so with your eyes open.