Electric Propulsion

[Nausikaa]

Many of the regulars will recall that we discussed electric propullsion a while back. Well, this evening I found a company which offers electrical propullsion for yahts at a reasonable price. I am certainly going to asj for more information because when NAUSIKAA eventually needs a new enging (a long time from now I hope) then electric propullsion may be just the thing.

Check the site out. If nothing else, it is interesting technology which should only get better as fuel becomes more expensive and we become more environmentally concious.

http://www.ozmarine.se/Produkter/Eng/ProdukterEng.html

Aye // Stephen

[santeana]

Stephen, Here's another manufacturer, http://www.lemcoltd.com/

I chartered a Lynch powered Pegasus 800 way back in 1994 on the UK Norfolk Broads (ref the history section on the website). I understand this was the first yacht application. It coped well with 2-3 knot currents but reverse was "a wing and a prayer". The early engine has now been developed into much more powerful models about which I've no experience. I've got to say the electric Pegasus was a delight to sail especially in such an area of natural beauty. Also great fun to 'cheat' other yachts into your pointing and light wind sailing ability!

Cheers, Ron

[Arni]

I have been interested in electric propulsion for many years, and when I bought my new Manta catamaran 2 1/2 years ago, I considered an electric version. They had already supplied one using Solomon Technologies electric wheel system. It had not been a success!

The problem is, to maintain, say, 5knots for a substantial distance, you need to run the generator. That generator will consume substantially more fuel to achieve this than a conventional diesel propulsion engine. Don't believe me? Ask the propulsion manufacturers. Its hard to get figures, but it can be done.

The cost of the installation is substantially higher than an equivalent diesel installation.

The drag of the regenerative propeller charging is substantial. No problem if wind is strong, but it is otherwise.

The whole question of charging is important. Typically suppliers use high voltage DC motors as they are more efficient. However, this limits charging to the props or the special generator. Solar panels and wind generators are no use. Frankly it seems to me that it would be beneficial to sacrifice some of the benefits of 144VDC motors and use 24 volt, which can be charged from multiple sources.

I don't know why these systems are most commonly seen on catamarans (Lagoon 429 for example) where the weight of the battery bank is an issue. A monohull's ballast could be modified to compensate for the heavy batteries.

These boats also depend on one engine for everything. If that generator engine fails you are in trouble.

Where they undoubtedly work well is on a boat that lives in a marina with a shore charger, and only uses engine power to manoever in and out of the dock before and after a day sail. Perfect, you don't even need the generator. Very restrictive though.

There is not nearly enough information out there. Somebody should compare a Lagoon 410 and a Lagoon 420 on a side-by-side voyage in the same weather. Then we'd get an idea of costs and efficiency. I suspect Lagoon know, as they sail them across the Atlantic, but they don't publish any figures, only 'sales' talk.

Arni

catamaran Jade

Originally Posted by Nausikaa

Many of the regulars will recall that we discussed electric propullsion a while back. Well, this evening I found a company which offers electrical propullsion for yahts at a reasonable price. I am certainly going to asj for more information because when NAUSIKAA eventually needs a new enging (a long time from now I hope) then electric propullsion may be just the thing.

Check the site out. If nothing else, it is interesting technology which should only get better as fuel becomes more expensive and we become more environmentally concious.

http://www.ozmarine.se/Produkter/Eng/ProdukterEng.html

Aye // Stephen

[Nausikaa]

Originally Posted by Arni

There is not nearly enough information out there.

Hi Arni & Ron,

Thanks for your responses. I agree that there is just not enough information available. I chated on the 'phone this morning to a very helpful guy at Ozeco Drive. He was totally committed (as he should be) to electric propulsion but admitted that there is no way I could get anything approaching the 50 or so hours motoring time I now get with my Perkins M20 and a 50 liter tank. At economical speed we would be loking at approximately 7 hours running time with a 660 Ah battery bank. As propeller charging gives between 3 - 15 Amps at speeds from 4 - 6 knots then we are not going to recharge the batteries very quickly either.

On the other hand, as pointed out, for the marina based yacht it could be a good deal. The entire installation bateries not included costs about 50, 000 Swedish Kronor. Divide that by ten and we have the approximate cost in Euros. The motor only weighs 14 kg and is very diminutive in size. I can immagine that it would be ideal for yachts based on smalller lakes such as Windermere in the U.K. I doubt I would feel happy with it before batteries get very much better as even though I sail mostly in a tideless area we do have quite strong currents at times. Battling a 2 - 3 knot current and a bit of a chop under wind against current situations would sonn drain both the battery and the skipper!

Ozeco Drive have however invited me to take a trip wih them on their demo boat in Gothenburg. Nice of them! So, I suppose I will have to arrange a "buisiness trip" there soon. I will let you now how it goes.

Aye

Stephen