Electric Main Drive(s)

[ess105]

George - good post. Let's always remind ourselves that boat preference is driven by personal preference.

I agree there has been a lot of defensiveness around the 420. There are some bad reasons for this but there's been some good reasons too.

1) There's been a lot of categorical statements along the lines of "X is better than Y" rather than, like you have done, "for my needs, X is better than Y". In fact, there has been quite a bit of "Because of my backround, I can categorical state that X is better than Y" Owners are proud people - they'll defend this kind of statement. I personally wish people wouldn't make these kinds of statements because what they're really saying is "Attack me or believe me".

2) Lagoon changed the way weights are reported. No doubt this is a heavier boat but the numbers published in mags / internet are not normalized and look whacky. This fuels much debate.

3) The boat isn't really in service yet. Noone is in a position yet to state actual experience independent of vendor / magazine communications. I suspect most boats don't get this level of attention before production is figured out but this boat has - look at the numbers of subscribers on these threads. Unfortunely, this has led to much speculation which will only end once the public gives the manufacturer time to get this boat in the water.

Looking back on this email I realize it's defensive. However, from what I've learned of the Lagoon 420 owners that I have ben fortunate to meet in thie forum, we're all in it because we're excited by the concept, we believe it's the future, we love the boat, and we recognize we're part of a trailblaze and that may bring about a knock or two. We're keen to share our experiences - when we have them.

[TonyWest]

I just found a pretty interesting paper Glacier Bay wrote discussing fuel efficiency issues in diesel/electric boat setups. Thought you might like to see it - click here.

It really highlights why we need to do the prop testing work on my boat - I know we've got the wrong props on at the moment. This could make a big, big difference, not so much to max speed (which I expect to be about the same: 8-8.5 knots), but to burning much less fuel at max speed.

So the next steps in the Electric Leopard project are prop testing (in about a week in Fort Lauderdale, if we can set it up in time) to settle on a better prop setup, followed by careful fuel consumption measurements with those right props on.

Enjoy the paper,

Tony

[maribar]

Hello all,

As this is my first post I shall make a short introduction.
I have worked the last seven years for a hydraulics company in Holland.
Hydromar Marine Hydraulic Systems I no longer work there as I started my own business.
Unfortunately I don't own a catamaran, I do have an old (1914) barge which hopefully I get finnished to live a board.
I would love to be able to start sailing on a catamaran and live on it.

As a hobby I like to design so naturally I made up an ideal catamaran.
For this design I went diesel-electric and as such went over the net to find data. So, I read the electric leopard thread and this one.

As for independence I really like the regeneratives and was very happy to read in the E-Leopard thread that the OSSA system was able to implement it. I missed that on their site.
The L420 seems promissing and hope to read the reviews soon.

With all the alternatives thrown around concerning power generation/storage (BDK solar panels, fuel cells and Valence Lithium batteries) I missed one. Zebra batteries, starting at 24V up to 1000V and 2 to 50kWh. They are lighter and smaller than all others including lithium.
Beta Research & Development Ltd - Home of the Zebra Battery - Zebra Batteries. If you take a high voltage version than you don't need a DC-DC converter with the OSSA system. It would be nice to get some input from other people.

Anyway thanks for all the info, I like to make informed mistakes in CAD.

Maribar.

[henryv]

I hope the author of the web site electric green does not mind me taking his term " electro sailing " and posting it as the title to this note. It seems he has created a nice term for what may be the wave of the future. If you go to the logs section of the green power web site you will see his power draws when motor sailing. It seems that very modest power use adds a nice boost to sailing.

[Whimsical]

From the Zebra site
"Short commings
Suitable for large capacity batteries only (> 20KWh)
Limited range of available sizes and capacities. (Large multi-cell blocks)
Only one factory in the world produces these batteries.
High internal resistance
Molten sodium electrode
High operating temperature.
Preheating needed to get battery up to the 270°C operating temperature. (Up to 24 hours from cold)
Uses 14% of its own capacity per day to maintain temperature when not in use. "

High internal resistance?
Love the last two:- 14% of capacity per day to maintain temp of 270 C. A 20 Kw unit would be 2.8 Kw. in 12V terms this is 200 amphours, more than most boats would use for house loads. Would be good in cold climates though.

Mike

[maribar]

Whimsical,

That's why I included that site as well. Did you read through a couple of papers on the first site? I do think it has some merits.
I don't think that the batteries are idle in a cruiser, but I can't find what the minimum usage is to negate the 14%. The batteries only dissipate a 100W in heat during operation, the casing isn't 270°c.
Furthermore 20kWh from 184kg isn't that bad. . .

[Octopus]

Thanks for the link Maribar. The Zebra batteries certainly seem to have some merit, despite the bizarre short-comings. I'll certainly investigate these more fully when it comes time to replace the lead acids on my Lagoon 420. I imagine the purchase price is more than lead acids, but I couldn't find the price anywhere.

If their performance is as advertised, it opens up the prospect of ditching the lead acids and replacing them with equivalent weight Zebras with five times the capacity. This would then make it possible to strap a decent sized wind generator (>1KW) on a mizzen mast, solar on the bimini and get rid of the genset and diesel tanks completely.

Chris

[maribar]

Hi Chris,

On the first link you can get to "papers" the last dated 2003 has some information regarding cost. I don't know if they are actual, I suspect they are targets. http://www.betard.co.uk/ev20_zebra_battery.pdf bottom page 5, top 6. . . . $ 2,310.- for 21kWh.

Maribar

[ess105]

The Zebras Ah/kg rating is certainly impressive but on a boat I would be concerned about the minimum drain on them to keep them hot when idle. That energy is going to have to come from somewhere. It's too much to come from natural resources so you're back to being tied to shore power or genset to top them up. These molten lead things have been in the military for years - submarines I believe. Great situation - high power availability when off and on batteries. I don't see these working on a sailboat.

I'm looking forward to this sort of energy density in batteries that don't discharge. That way you can make hay when the sun is shining and eat your hay when you need to.

[maribar]

ess105

My thinking exactly, I can't seem to find the minimum usage of the batteries to keep them "warm" without using it's own power.

[henryv]

It seems Outremer have joined the move to electric drives with the launch of their 42 electric version.

[GordMay]

Torqeedo, a German manufacturer of high-tech electric outboards, has announced that it has opened a US subsidiary to better serve its customers.

Headquartered in Starnberg, Germany, Torqeedo specialises in the development and commercialisation of top-class electric boat drives. The company was established in February 2005.

Torqueedo: Torqeedo GmbH: English version
and
http://www.torqeedo.com/uploads/medi...english_01.pdf

[Jackstee]

Hi GordMay
I posted the info about Torqeedo a couple of weeks back. Two of the bigger, long shaft outboards for just under 1000 pounds .

Was going to use two but now probably going to use one as a bow thruster and get a bigger main engine.

Regards

[GordMay]

World-first sea trials of fuel cell
Voller

The sea trials of the world's first sailing yacht equipped with a 1kW fuel cell have begun in the UK.

Prior to the fuel cell system's official launch at METS in November 2007, Voller Energy is testing a prototype of its environmentally friendly fuel cell generator onboard the company's Solent-based Bénéteau Oceanis 411 Emerald.

Voller's 1kW fuel cell generator works by automatically monitoring battery voltage. When the battery voltage falls, it switches itself on and recharges the batteries. Once the batteries are fully charged the fuel cell switches itself off to conserve fuel.

The remote diagnostic capability of the Emerald fuel cell generator allows the team of designers and engineers to constantly monitor every aspect of the product's onboard performance from the Voller HQ in Basingstoke, Hampshire.

Voller Energy Portable Fuel Cells

[db8us]

Good discussion with a lot of pros and cons.
Other technologies (i avoid the term new) always raises concerns.
There are also those who want to be at the cutting (bleeding) edge of technology, then those who wait before they use it and those where everything in the good old days was better.

My cat still hast 2 30HP Yanmar Diesels. If i would have to go for a 40-44ft Cat NOW i do not know which route i would take.
If one wants to start a circumnavigation right away i i might not suggest electric drives due to lacking personal knowledge and experience.
But if you can use the boat for your normal sailing and you are willing to be on the forefront i think thats great.

So in a few years if the decision is coming i might be in a position to make a more educated choice

Good thread !

Greez from India

Michael