Anyone have experience with electric engine?

[Dan McGuire]

Electric Outboards-Comments

This is probably pretty boring stuff for most of you, but here goes anyway. A quick number crunch for the Ray Electric Outboard reveals the following: The efficiency of these motors is better than the motors in the original posting: 71 to 80% verses 69% in the original. It appears, however, that by putting the motor up on the top like on a conventional outboard, they hurt themselves. The Ray outboard requires about 19 watts to develop one pound of thrust. A conventional trolling motor of smaller size requires about 8 to 12 watts per pound of thrust. The drive train eats up a lot of power. I couldn't find any trolling motors as big as the original posting, however, generally they get better efficiency, the bigger they get.

 

[Gord May]

H.P.

Mechanical & Electrical H.P. are virtually the same. Boiler H.P. is a different animal (ie:1 B.H.P. = 13.155 Mech/Elect HP).1 Horsepower (M/E) is equal to:746 Watts Elect. (745.7 Mech.)33,018 Ft. Lbs / Min.= 550 Ft. Lbs. / Sec.42.41 BTU / Min = 2,545 BTUH

 

[Jeff M.]

Response to posting by Rick Webb

This is in response to the posting by Rick Webb 'What I'd like to see'; I too would really like to see an outboard manufacturer make an outboard in the 10 HP range that also had a 30-60 amp alternator built-in. Even if the alternator only put out full power when the drive unit was in neutral it would still be great. Because the docks where I keep my boat don't provide shorepower, I'm left with few (and expensive) options to keep my batteries charged. As to the original posting regarding electric motor options, boats wishing to use such a system will face all the same problems found with electric cars, ie batteries and a way to charge them. Here in the Peoples Republic of Kalifornia they have tried for years to push the idea (electric cars) but it always fails due to the lack of proper technology to power the system. A practical, reliable, safe and economically viable system simply doesn't exist at this time to replace the internal combustion engine in most of the applications where they are commonly used. Of course, the day will come when the technology will advance to the point that such systems will be viable, but you can bet that the first applications will be NASA/military in nature, as almost all real leaps in this sort of field are produced in that arena. Soo.. if you want an electric powered boat, get the biggest trolling motor you can find, drop a couple grand on AGM batteries and expect to spend a lot of time at the docks charging!

 

[Gord May]

O/B Alternators

Alternators and Lighting Generators (unregulated) are available for small outboards, but not in the 60A size Jeff M (& I) would like. A 60 A Alternator requires about 1.5 - 2 Horsepower to drive it, which would be inordinately high on a 10 HP engine (15-20%). I suppose it (Alt') could be made to work in neutral only, so that the HP consumption wouldn't matter, but I'd expect the cost of all this "stuff" to be prohibitive. Regards,Gord

 

[Rick Webb]

This was the Idea

An electric outboard powered by a gas generator. The Generator hopefully could power the air conditioner as well. Guess it would make sense to be able to drive the out board from the battery in case you could or did not want to start the engine. This makes more sense every time I think of it.

 

[Gord May]

Electric propulsion?

So, you want to add a Generator to a boat small enough to utilize an Outboard?The June/July issue (77) of “Professional Boatbuilder” Magazine had an interesting article, by Steve D’Antonio, describing the conversion of a 40' powerboat FROM ELECTRIC to diesel propulsion.Craig Walters designed the “Charger“ Electric Cruiser in 1995, to cruise at 6 knots in electric-only mode (Generator NOT running) for about 50nm, utilizing (24) Trojan ‘T-145' batteries configured in (2) banks. Charging one bank from the Northern Lights 6 kW Generator, while running on the other bank, increased the range to about 266 nm, utilizing 6 US Gallons of diesel fuel (44 nm/gal).In any case, Walters found no market for the purpose-built electric boat, and converted her to Diesel. Another seemingly “good idea” that didn’t catch on.Interesting article - it's not available on-line, but reprints are $12.www.proboat.comRegards,Gord

 

[Debra B]

Electric engines rated at continuous HP -

Deisel and gas rated at peak.... that is the differenceThere is also the value of low-RPM work with electric (AC) motors. Or as a particular manufacturer says..."Electric motors are rated entirely differently than their internal combustion counterparts. An electric motor is rated in continuous horse power while IC motors are rated at peak. The term continuous is very important because in a vector motor, the type that FEYS uses, continuous means across the RPM band. A 133 HP FEYS motor can apply 133 HP at 10 RPM, at 500 RPM and at 3600 RPM. Since torque is computed using horse power and RPM, a FEYS motors can deliver enormous amounts of torque at very low RPM. "http://www.feys.org/System/our_system.htmThis means you need a new transmission and a new prop. But if you were changing HP in a deisel to deisel upgrade you would get a new transmission and I hope a new prop - or you just wasted a lot of money.(Yes I know that cooling becomes a problem at low RPM, but the manufacturers know that too an design for cooling.)

 

[Debra B]

A really big boat with an electric drive system

Royal Carribean Radiance of the Seas runs on 2 GE LM2500+ gas turbine generators and steam turbine in a co-generation setup (use the exhaust of the gas turbines to boil water). Each of the gas turbines deliver 40,500 HP (times 2) plus the steam - all generating electricity for onboard and drive applications.http://www.royalcaribbean4me.com/rccl/radiance/royal_caribbean_radiance_of_the_seas.htmShip Facts • 401 Passengers, 3/4 occupancy cabins. • 2100 Double occupancy cabins. • 3360 Coast guard passengers limit. • 105 Ft. Ship beam. • 24 Knots Cruising speed. • 88,000 Tons. • 961 Ft. Ship Length. • Built at Meyerwerft Papenburg, Germany • Inaugurated on 10-March-2001People used to say that electric motors would never be used in cars because of battery problems. But deisel electric trains have been around since the 50's. And hybrid cars are here to stay - especially as the price of gas goes up.

 

[Garry @ S/V TASHTEGO]

Electric motors

Electric motors can run at constant horsepower but they can't do it at constant current. The motor generates a back voltage as it spins reducing the current required at running speed. When starting or running at slow speeds due to high loads the current required (sometimes called inrush current) is much greater, up to 5 times greater or even more. On the other hand they make maximum torque at stall, that's why diesel electric locomotives use them. The diesel runs at optimum rpms while the electric motors start the train moving. The electric motors function as an automatic transmission for the diesels.The real problem with electric drive is the number that Gord gave, 746 watts per horsepower. This means that a 10 horsepower motor requires 7460 watts or, at 12 volts, more than 620 amps. Lots of folks use 9.9 horse outboards on their Catalina 27s.The battery capacity and cable sizes required are pretty substantial. To run this motor for ONE HOUR will require a battery bank that can produce 620 amp hours. Since batteries shouldn't be discharged more than 40% of their capacity the batteries bank required will have a capacity of 1550 amp hours. Deep cycle flooded batteries with a capacity of around 100 amp hours cost around $100 so you are looking at $1550 of batteries for one hour of operation. One day cruising capacity is $37200. Of course a one horse trolling motor used to get in and out of your slip will run on one battery and cost a lot less but it won't be a substitute for the main propulsion in an auxiliary sailboat.P.S. The new Coast Guard Icebreaker HEALY has a 30,000 horsepower diesel power plant running AC/AC cycloconverters to synchronous electric drives. Breaking ice requires max power at stall!

 

[Debra B]

wrong Voltage - not 12 volts

Everyone seems to be trying to convince me that electic propulsion is not possible. Well if you check the Solomon technologies website you will find that they are OEM for several sailboat manufacturer. And they are the most expensive solution I have found so far. (They do seem to have the best support for the marine industry)In all these calculations you seem to be proving - at least to yourselves - the Hybrid cars and electric cars are impossible to produce. And yes there are plenty of 30 ft and larger sailboats with elecric drive. No fuel spills, not CO poisoning, no noise below decks, no deisel fumes making me sick, no 2.50 at the pump, no clogged filters, no clogged raw water intake, no damaged impeller, .....Anyway most electric motors whether DC or AC that are used in cars or boats are in the 72 to 144 volt range with some in the 200 to 300 volt range. Lots of volts, not a lot of amps - or amp hours - for a given kilowatt of energy. Even at 120 or 144 VDC, I can store the batteries I need in the space currently holding my fuel tank, and probably still find room for a small tank if I want a generator.Yes, controlling the current into an electric engine is a complicated process. Or in an AC engine controlling the sin-wave of the current to regulate RPM. That's why there are special purpose controllers - that cost more than engines do - which manage this. 2000 specs for a non-Solomon DC motor - 28 HP cont, 30 HP 1 hr thermal, 85 HP peak, running at 72-144 VDC, with all the controls, a 120 VDC charger - not a 12V charger like you have - and a DC to DC converter to supply 12 volts to the house speced out at less than $5000. Add few thousand for fabricating mounts and batteries.Remember it isn't HP that is so important as it is torque. And a 30 HP deisel (rated at 30HP by Yanmar, etc.) will almost never generate 30 HP at the shaft. How often do you run your engine at max RPM? I try to treat mine a little better than that.And it seems that no one actually has experience with any of these engines....

 

[Gord May]

Yes, Possible - but - Not Curently Practical

The subject of Electrical Propulsion could cover a very broad spectrum of technology, and raises some interesting & important philosophical questions. While the advocacyof this emerging technology is admirable, there are a few problems associated with it’s utilization in small boat (yacht) applications. Although Diesel-Electric propulsion systems have been long used in very large applications (Submarines, Naval & Cruise Ships & etc), the development of practical equipment for boats (& even automobiles) is in it’s infancy. This is not to suggest that electric propulsion will remain impractical, but only suggests that the current state-of-the-art is no-where near mature.A few specifics:Pollution: There is, as yet, no practical method to produce pollution-free electricity (nor any other form of usable kinetic energy). Hydrogen Fuel Cells seem to be a very promising technology, for continued development. I’m less optimistic regarding the development of Solar & Wind Power for yacht propulsion (despite their use as an auxiliary power source). Hmmm... a sailor discounting wind-power there's something wrong here.Higher Voltages (72-144V) reduce required Currents (Amps) - BUT do not reduce required Power (Watts, HP, Ft/.Lbs Torque, Ergs, or whatever). P = E x IIt doesn’t really matter how you connect a given battery bank (Parallel for low voltage, or Series for high voltage); you still get the SAME amount of power from the Battery Bank. Three 12V (nominal) batteries connected in series to provide a 42V Powernet will provide EXACTLY the same usable power as those same (3) batteries connected in parallel and operating at 12V.Obviously, higher voltages offer some important advantages (ie: smaller wire sizes) - as witnessed by the current trend towards the 42V automobile system. In fact, I predict that the automotive 42V Powernet will (as it matures) provide all sorts of spin-off blessings to we boaters; and I look forward to it’s continued development & implementation.Controlling the speed of a DC motor is, actually, a very simple & mature technology. AC Motors are more technically difficult to control, but (as Debra noted) there is a plentitude of industrial technologies currently doing this, though at considerable expense. I think that each technology must be analyzed within the context of it’s total life-cyclecosts (Economic, Environmental, etc...); which will include: the costs of Production, Operation, Maintenance, & eventual Decommissioning/Disposal. While the objectives embodied within the advocacy of Electric Propulsion are laudable (which I share), it is dangerous and counter-productive to overstate the current state-of-the-art. The naysayers can, and do, use our over-optimism to dismiss the truly amazing advances being made towards an clean & sustainable energy future.OMO & for what it’s worth...Regards,Gord

 

[Debra B]

Hybrid State-of-the-art is very practical

There are many hybrid driven boats and few boat builders are now providing hybrids as orignal equipment. Maturity of the technology: One of the suppliers I am looking at was formed specifically to supply the electric vehicle market - mostly in CA, and mostly cars, but not completely - was formed in 1984. DC motor technology for both cars and boats is pretty firmly established. The electic auto association was formed in 1967. Not 100+ like diesel, but as mature as the PC certainly.Granted small scale AC motors for transportation are newer, but this is a well developed marketplace with players like Siemens technology supplying integrated systems which are being rolled out of various car co. assembly lines. (everything being motor, triple-phase variable freq. sine-wave inverters and all the requisite controls.)Electric motor technology itself is quite maturePolution: There is nothing quite so poluting as an interal combustion or diesel engine operating well below its designed/target RPM. The best (greenest) mode for running one of these engines is to have it run at a constant RPM under a realtively constant load - like in a generator. Battery power density: This is the one draw back, as the power density of lead-acid batteries is low, and lithum and nicad batteries are expensive. Solomon addresses this by what they term regenerative motor sailing (see their web site for the details) and most builders are looking at hybrid not battery-only as a result. There is a battery-only electric car with a 200 mile range (62mph) on a 1hr charge, but the 84 lithium ion batteries make it disasterously expensive.This is why people are trying to come up with both better and cheaper batteries and alternatives like fuel cells and hydrogen storage. In the meantime, hybrid.Hybrid propulsion systems: These are not new. The only reason that we haven't seen them in more passenger cars is detroit's reluctance. That, and American Men's worship of the gasoline engine. People have been building conversions (do web search on the Volts-Rabbit Volkswagen Rabbit conversion) for a very long time. And detroit is reluctant to provide decent preformance, not because the technology can't provide it, but because they have so much invested in engine plants. Or they are in bed with the oil companies. (see http://www.nedra.com/ ) As to the cost of genset - well how many people have both a diesel engine and a diesel genset? And of those who don't have both, how many would really like to have the genset? New boats that come with aux propulsion and genset are considered nothing out the ordinary.The army is currently testing hybrid diesel-electric humvees. 0 to 50 in 8 seconds - not bad for a large truck - and 30 percent fuel savings over standard models ( http://www.uqm.com/press/news/03-22.htm ) . Engines are designed to be submerged up to 60 inches and still function. Try that with your diesel.The navy is also reviewing hybrid for small boats, but not so far along. Of course they have a lot of experience with electric driven boats.(BTW - my intent was never to start a debate - if you think hybrid is "too new" or "diesel is better" or this is only good for day-sailers, well then that's fine. diesel is yesterday's technology - the engines were designed in 1892 and aside from turbochargers haven't changed much. If I had to repower today, I am not quite sure what I would do, but since I have some time to plan, I am. And I am not going to adopt the "we've always done it that way" approach. I am still looking for someone with actual experience with these technologies for discussion. I suppose this was the wrong place to ask, but since Catalina is in partnership to provide an electric-drive boat I thought .....)

 

[John Visser]

to Debra

What does the National Electric Drag Racing Association have to do with Detroit supposed relucatance to provide electric car performance, or the a grand conspiracy between Detroit and big oil?Why does it matter how old diesel technology is? It works great.The reason the hybrid technolgies are not applied widely is economical - and where it is economically advantageous, it is applied - as in electric drive locomotives and tug boats. I prefer a hybrid drive system, which is why I'm following Vetus' developments.Regarding the developmetn project which Catalina has sponsored w/ a C42 - it sounds like teh proverbial perpetual motion machine to me:"HaveBlue systems use solar panels, wind generators, regenerative electric motors and shore power to “charge” or fill hydrogen tanks by splitting (electrolyzing) water (H2O) into hydrogen and oxygen. The oxygen is vented harmlessly to the atmosphere, the hydrogen is plumbed into hydrogen tanks. The very pure water required is produced onboard as well with customized reverse osmosis water makers and de-ionization systems. Each step in the process takes power and imposes an energy “loss” on the original source of energy. Of the original energy “in” a percentage remains in the tanks. There are further losses on use of the hydrogen, but at a much lower level (greater efficiency) than fossil fuel (diesel or gas) at the fuel cell and electric drive steps."Nothing will ever be simpler, more reliable, safe, or more economical in a yacht than a plain old diesel engine. See link

 

[MArk of OSMS]

Lost in the translation?

Instead of using wind to generate electricity... to run a motor...to push a boat,just use the wind to push the boat directly! (Novel idea??? Duh!) Every time you transfer energy from one form to another some of it is lost due to translation inefficiencies. The more directly you can use an energy source, the more useful energy you'll get. This is also why hydrogen fuel cells are destined to be the dot-coms of the next decade. You still have to put more energy into creating the hydrogen than you can get out by recombining it with oxygen in a fuel cell. This is not rocket science. This is high school level physics. Then there's the problem of free hydrogen destroying the ozone layer!Then again, maybe I would try a trolling motor for docking. Maybe even one on the bow and one on the stern!Did you know your zincs can generate about 1.2 Volts in sea water? See link below.Happy SAILS *_/),MArk

 

[Gord May]

And the beat goes on ...

DEBRA:You may not have intended, nor welcomed the ensuing, debate your query provoked; but I (for one) find a critical dialogue to be the quickest way to garner information. The dialectic method (thesis x antithesis = synthesis) quickly illuminates flaws in my thinking, and certainly cultivates a more thorough exchange of information. It's difficult for new, innovative, or unconventional ideas to germinate & grow in a sterile environment of mutual agreement.Electric Motors have long been considered a mature technology, but the imminent advent of (room temperature) super-conductors will certainly usher in a new era for renewed innovation. Future improvements in battery storage technology will, likewise, facilitate many new electrical applications. High Technology components (of all sorts) all require a long manufacturing chain, which (itself) utilizes energy. As someone pointed out, there is no freely available Hydrogen just lying around, waiting for combination /w Oxygen (fuel cell). Efficiency cannot be merely measured at final point of use, but must encompass the entire extent of it’s development from resource(s) to motion.Most of the links, posted here, seem woefully short of the kind of technical information I need to make critical judgements. They are, after all, primarilly sales brochures, not learned papers.I’m sorry that you’re disappointed in the point-counterpoint dialogue that your posting garnered. I suppose that if there were any “magic bullet” technology, we’d all be using it. Until then, I think that amicable debates, like these, support our efforts to understand the emerging technologies, and critically evaluate their potential applications. I don't "argue" to deafeat your thesis, but to make you prove it. I learn something from arguments that I (ultimately) reject, and even more from those that I find more convincing.I look forward to further thoughtful commentary and technical presentation, on this important subject.I should add that, you (prominent among others) have made me rethink some of my preconceived notions, and otherwise give original thought issues I might otrherwise have ignored. Thanks! OMOGord

 

[Garry @ S/V TASHTEGO]

Two more comments

Just two more comments then I'll butt out. The first is that hybrid autos are efficient because they use electric power for surge loads and replenish it when under low load such as cruising at steady speeds using a small constant speed, high efficiency internal combustion engine. There is no efficiency advantage to the electric system per se. In fact, it adds a lot of weight in the form of batteries and the motor/generator itself. It does have the advantage which is the same as that for diesel electric locomotives namely that electric motors produce maximum torque at stall and thus can eliminate the need for clutches, torque converters and/or transmissions. In a good design this will offset the extra weight of the motor/generator but not the batteries. But marine engines don't generally run under variable loads (no stop signs, no traffic lights, no hills to climb) and therefore a direct drive diesel is more efficient in power produced per gallon of fuel consumed than a hybrid diesel/electric system in the particular case of sailboat auxiliary propulsion.The second point is that there is no way I want 300 volts of DC in my boat!!! Not even 140. I have seen some pretty impressive sparks in 24 volt systems (most arc welders run at 24-32 volts DC) and anything higher is way too much for me. As noted elsewhere, the real measure of engine power is watts and the ratio of watts to horsepower (746:1) is independent of voltage. High voltages reduce resistive losses and use thinner wires (that's why high tension lines run at very high voltages) but in a sailboat these will be small in any case. The storage capacity required to run the motor is a function only of the watts required. To produce 10 hp for an hour from storage batteries is still going to require 7460 watts and 1550 amp hours of 12 volt battery capacity or about 16 batteries. If you hooked them all up in series and produced 192 volts they'd still be 40% discharged after an hour. Sorry, no free lunch from high voltage. 16 batteries will weigh around 800 lbs and I can store 50 gallons of diesel for that weight and have room for the weight of the engine, the transmission and the tank too. That's enough for over 50 hours of operation on my diesel motor. Generator/Alternator/Charging systems may be highly efficient but recharging the batteries is thermodynamically costly and a diesel generator will actually require more fuel to recharge the batteries than is required to drive the boat for the same length of time. No free lunch there either. Of course you can charge batteries from the AC line at the dock but this is only transferring the fuel consumption to the power plant with the addition of the transmission losses between the power plant and the dock and the concentration of the pollution source in one place leading to more serious acute effects. Charge for lunch here too.I promised only two comments but I'll make just one more about environmentally clean technology. The Altamont Pass wind farm in California has so far killed several thousand birds including MORE THAN 100 EAGLES. Environmentally sound? I wonder how many sea birds will get whacked in Nantucket Sound when that plant is built. Lunch continues to be available at a price.

 

[alan]

A few comments from a layman (in this area).

Very interesting discussion! I looked at this thread in the beginning then forgot about it. Most applications of electric drive in sailing vessels are probably due to enviornmental laws restricting usage of internal combustion engines on certain bodies of water. Here they are used for relatively short amounts of time but still require lots of batteries which are bulky, add alot of wieght, and cause "pollution" in other places during mining, production and in the waste stream. I suppose that using one diesal generator to drive an electric motor and provide power for house usage MAY produce the advantage of using a smaller motor at its most efficient output much of the time. In addition diesal and other marine engines fail from not being used, so that problem would be reduced. Having one internal combustion engine with fewer start-ups May produce less "pollution" as start-up is when most of this occurs. Electric motors generally require less maintenance. Calculations need to be done as to overall economy and "pollution". The generic term "pollution" needs to be qualified and quantified.Hybrid autos derive alot of their ecconomy from recovery of energy that would otherwise be lost in braking. Some savings is from having a smaller internal combustion engine made possible by an electric motor. One company saves wieght by using the starter as an electric motor when needed. They are also designed from the start as ecconomy vehicles AND are heavily subsidized. Add about 50% to get the true cost.Obviously in certain applications production of electrical energy to power drive systems is more practicable, HOWEVER don't assume that it's less polluting, more energy efficient or even cheaper. You can only assume that for that particular application it's been calculated to be better. As an example, dual-mode locomotives were brought up. The LongIsland Railroad does not use them because they are cheaper (NOT) or because they are more fuel efficient (NOT), only because diesal usage is prohibited in the East River Tunnels and those living East of where the tracks are electrified were getting tired of switching trains. alan

 

[John Visser]

To Gary

A brilliant note, I enjoyed it. Thanks.jv