Hybrid Electric Motor for Sailboats

[delstanton]

I signed up with sailboatowners because I read some comments about electric auxiliary power on, I believe the Beneteau forum.

I had just stumbled upon Solomon Technologies, they make electric motors and the necessary controls for their motors. They are well adapted to be auxiliaries for sailboats.

The motors designed for 144 VDC and run off twelve 12 volt batteries connected in series. They use unusually large propellers, 16 to 18 inches in diameter.

In normal cruising the motor is idled, drawing very little current, so than the prop does not create either thrust or drag. If there are considerable swells, so the your boat surfs down the swell at a higher than average speed, the prop will run in reverse, powered by the increased speed of your boat through the water, generate electricity and charge the battery bank. You can also adjust the throttle to that the prop is driving the motor/generator (it works as both a motor and generator, from now on "MG" for short) all the time. This might slow the boat when being driven by sail by a knot or two. A small price for generating power without running the diesel generator, if you even have that installed. (Some installation just have the battery bank and shore power charger, depending on the sea to keep the batteries charged on long cruises.) Then you can be continually charging your battery bank while on a long passage, and perhaps even use this to slow the boat under gale conditions.

It seems having such flexible power might make times when running with heavy seas much safer, you could speed up the boat while surfing and perhaps great reduce the number of waves breaking over your transom. Certainly having such flexible, easily and quickly reversed power, will certainly make manuevering in close quarters much easier.

The have a 120 VAC Inverter that runs off the 144 VDC battery bank to provide boat power. There is also the option of installing a small diesel generator, rated at 144 VDC to charge the battery bank if needed. And of course there is also a 144 VDC charger to run off shore power and charge the batteries while tied up.

The basic motor, as I recall sells for about $9000. A complete installation, w/o the batteries or diesel generator, runs less than $20,000. These are all "remembered" numbers.

Check the following web page: http://www.solomontechnologies.com/m_recreational.htm

I look forward to the discussion I hope this post causes. Let me know what you think!!

 

[Rick D]

Premature

I think it is premature technology. I have followed electric propulsion for years, but not in depth. This needs a breakthrough in storage batteries and / or fuel cells to be an attractive option in my opinion. I know of several ventures into this market that were dead-ended. It just isn't as efficient as converting diesel to thrust. And, I am not about to give up a knot of boat speed to a large prop. Geesh, the things we do for sail trim and drag reduction would be a waste!

 

[Don S/V ILLusion]

Not to mention the weight (which wasn't mentioned) of this number of batteries and also at what current rating? It must be something truly massive to crease even a reasonable amp-hr supply as connecting 12 batteries in series doesn't create more current. No doubt this technology will someday replace all others but this sounds like an advertisement rather than a practical contemporary option.

 

[Bill Roosa]

Some comments

Delstanton
you are willing to sacrifice a knot or two for power???
Not sure how new you are to sailing but a knot or two would be 25-30% of my boats flat out speed.
You say it only costs $20000
That could buy a LOT of diesel if I stick with my OEM engine. Where is the incentive?
Where do you put the batteries?
144 volts DC is deadly. There is a reason that they use 12/24 volts on vehicles.
If I take your $20000 I could buy a dandy combo wind/hydro genset, a radar, replace all my instruments and still have $$$ to buy some diesel.

Perhaps it is a GREAT idea but it in not a realistic solution from a cost standpoint.

 

[Ross]

The submarine navies of the world powered their boats underwater with electrics. Battery coupled motors. They had to surface or at least come to periscope(snorkle) depth to run their diesel and recharge their battery. For short run service electric is good. Golf carts have demonstrated this for years.

 

[Don12364]

Just a Few Negatives to Consider

* Engines and gearboxes weigh, cost and occupy valuable space.
* A conventional engine and gearbox will still be required for when the batteries run down - though perhaps somewhat smaller if you don't ever go offshore and will never need to charge the batteries in a hurry.
* A motor/generator represents additional weight, cost, space and complexity.
* Twelve 100Ah deep cycle batteries at 80 lb each, weigh (1000lb), cost a bomb and take up even more valuable space.
* If you are lucky a 12V 100Ah battery can put out 1.4 Hp for one hour before becoming 100% discharged.
* Lithium is better but very costly.
* 12 of these will give 1 hours running at 16.8Hp.
* My diesel tank will give 50 hours at this power yet still supply 40Hp when I need it.
* Batteries have a finite and limited life, even deep discharge ones, and you certainly would not want to carry 24 of them thus only needing to discharge each by 50%.
* Picture coming alongside the fueling dock for between 4 and 14 hours to get charged up again. The other guys would never tolerate it and neither would you.
* Dreadfully slow sailing due to the enormous weight and increased prop drag.

All for a quiet smooth motorized ride on the occasions when there is no wind or you are not sailing.
Technology is not there yet. It needs fuel cells, superconducting motor magnets which do not need large negative temperatures, and batteries which can accept charge at similar rates to that which energy comes from a hose at a filling station.
I think the only winner is the bank manager who makes your loan.

 

[Rob Hessenius]

I came across this video on youtube about electric replacement motors for sailboats. Looks interesting!

http://www.youtube.com/watch?v=yjqC9wZUVL8

 

[Hermit Scott]

I found this unemployed electrical enigneer on a forum for electronics. I paid him to build me a board for my latest invention. He was going on and on about Lithium-Iron-phosphate. I said don't you mean li ion phosphate, and he said no. He claimed they are everything that one could wish for in batteries except weightless.
This guy was so smart his words hurt my head, but i have never heard of this before. Has any one heard of lithium-iron-phosphate?

 

[delstanton]

Dear respondents,

I am delighted by the interest shown, even if only to debunk the idea. But I feel many responses were knee jerk reactions, that the concept really deserve more thoughtful attention than it was given. Here are some points to ponder:

1. Most of you probably tie up with shore power available. Thus you will sally from port with a fully charged battery bank.
2. Thus for short excursions there will be no need to charge underway, with the resulting speed penalty.
3. The idea that you would tie up to a fuel dock to recharge doesn't deserve comment.
4. The 1 knot penalty only occurs when charging with the prop, not all the time you are sailing. You get to choose between speed and charging. So on a long passage you might be quite willing to lose speed for a few hours, or even days, to recharge you batteries.
5. The are many times you may be willing to lose a knot or two of speed: desiring to delay a landfall until dawn; sailing in company with a slower boat; not wanting to arrive BEFORE happy hour.
6. If you installed a small diesel generator that would always be available to recharge the battery bank. The small diesel will be much quieter and use a lot less fuel (and make a lot less exhaust) than a diesel auxiliary engine.

Admittedly lead acid batteries are a very heavy and inefficient way to store energy. To assure long life one should never use more than 20 to 50% of their capacity. Super capacitors might come to the fore withing the next ten years, though the voltage, dropping linearly with the remaining stored energy, will require complex and expensive electronics to hold a steady output voltage as they discharge. But the cycle life should be awesome.

Thanks for your responses.

Del Stanton

 

[RobertLangdirect]

. . . The 1 knot penalty only occurs when charging with the prop, not all the time you are sailing. . .

The only way the oversized prop doesn't ALWAYS drag is if I am using the batteries to idle it, or, I fold it away -- like I do with my current martec folding prop.

Don't think, please, that this is a knee jerk reaction to your observation, but really, TWELVE BATTERIES and an OVERSIZED PROP, and NO PENALTY? I think not.

 

[sailaway78]

Maybe for day sailors

Maybe this would be a viable idea for day sailors, who run out into the lake or bay for an afternoon, possibly an overnighter. But for anyone cruising any distance, is not even worth considering. The little film clip of the Ericson, says 4 knots for 35 miles. So, what do you do if you are going to make a 50 mile run on the ICW. That is a typical days run. How bout when on a recent offshore run between Appalachicola and Tampa the wind totally died after sundown, and it was necessary to motor all night. The film clip shows an Ericson 27, which is at the lower end of the size scale for a cruising boat. What is the expected range and weight for a bigger boat. Also, last but not least. As with most advertising, their numbers represent the absolute max. possible performance. How bout it you have to come home up a long narrow channel, with te wind, or tide or both against you. If you have a small boat, and just need to get into and out of the slip, get yourself a large electric troll motor from Wally World, and a couple of golf cart batteries. Save some bucks. For most of us, I think this is just pure snake oil.

 

[delstanton]

Perhaps this is the end of this thread. My sincere thanks to all that joined in - in any way!

Best wishes, Del

 

[Franklin]

want to charge your batteries, get a wind generator...no drag there