Electric motor for sail boat

[valhalla360]

Originally Posted by deluxe68

If our engine needs to be replaced in a few years I will seriously consider going electric. Battery technology is rapidly changing and sole phelps are getting more efficient. A few years ago I vaguely remember reading about an example of going electric, the weight saved on the electric motor was negated by the weight of the added batteries and generator. There is a federal tax credit (expiring this year) for adding energy efficient stuff to a first and second home. Hopefully the credit will get renewed and allow for the purchase of fuel cells and electric motors.

Might want to consider running that by the IRS before buying the system. In theory as a second home it may be eligible but also probably a huge audit red flag.

Then again, if you get your Uncle Sam to cover the first $8-10k and you are already replacing a pair of diesels, a hybrid system with say an 10kw and a 30kw generator and a modest battery bank might be financially viable option on a small catamaran.

[a64pilot]

I haven't pulled the Yanmar out of my boat and never will, except maybe to overhaul, or maybe repower.
I'm real conservative, and am still in the refit phase, I don't want any science experiments on my boat, heck I still have a lead acid bank.
But that doesn't mean that I don't think other technologies aren't viable, cause I think they are.
Maybe it will take fuel cells to make electric propulsion main stream? I don't know, but think there is a market for a silent, nearly maintenance free propulsion system.
One thing I thought odd when I first joined this forum was the excessive number of threads about the engines, I thought that unusual as most of us are Sailers? Then realized how seemingly a lot of maintenance activities on a sail boat seem to involve that engine.
What if you could remove 99% of those maintenance activities, and have silent propulsion? Think it might sell to day sailers?


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[valhalla360]

Originally Posted by a64pilot

I haven't pulled the Yanmar out of my boat and never will, except maybe to overhaul, or maybe repower.
I'm real conservative, and am still in the refit phase, I don't want any science experiments on my boat, heck I still have a lead acid bank.
But that doesn't mean that I don't think other technologies aren't viable, cause I think they are.
Maybe it will take fuel cells to make electric propulsion main stream? I don't know, but think there is a market for a silent, nearly maintenance free propulsion system.
One thing I thought odd when I first joined this forum was the excessive number of threads about the engines, I thought that unusual as most of us are Sailers? Then realized how seemingly a lot of maintenance activities on a sail boat seem to involve that engine.
What if you could remove 99% of those maintenance activities, and have silent propulsion? Think it might sell to day sailers?


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I think we need to clarify the definition of "viable". As an engineer, that includes financial viability to me. If cost is no object, lots of things are viable. I've seen superyachts running turbine engines. For your typical 35' sailboat a turbine engine isn't viable.

I don't know why you would think this forum would only consider sailing. It's a name is "cruisers forum" not "sailors forum". The vast majority of cruisers will crank up the engine when the speed drops below something on the order of 2-4kts except when on ocean crossings and even then sometimes.

As far as removing 99% of the maintenance, sure but only if it provides similar performance at a similar price. A system that provides the same performance isn't going to remove 99% of the maintenance with anything remotely close to current technology.

Once you get over 30' most boats are not purchased as "day sailors" even if that is how they end up being used so a maintenance free 5-10 mile range at 4kts won't sell.

It all comes back to use cases. Prius has a good use case for plug in hybrid...city driving where power demands vary wildly but average power demand is really pretty modest. Yet it can still provide decent range and efficiency highway driving. Since the majority of trips by small cars would be classified as city driving, there is enough benefit to justify the extra cost of the hybrid system.

Your typical cruising boat doesn't benefit as the use cases are different. If you are more of the purist sailor, you aren't burning much fuel to begin with so converting doesn't save you much. If you are the more typical cruiser, the use case representing the vast majority of engine run time is a more steady state (analogous to highway driving) running at around 90% of hull speed and they want the capability to maintain hull speed at least for a couple of hours if conditions call for it. That gets very difficult to provide without a significantly more expensive hybrid system and since the conventional system is already set up to run at near peak efficiency, at best the more expensive hybrid system will match the economy of the conventional system.

Unless someone comes out with a cheap small generator that is easily ganged together, so it can do double duty as an efficient house generator, I don't see any technology on the horizon that will significantly change the equation.

[a64pilot]

I had two Honda's, ganged together they would run my 30 amp boat Airconditioner and all, cost about 2K. That is already there, I believe the bigger Honda's can be connected together as well, it's not hard, and I don't understand why you would think multiple generators are needed?

Majority of boat owners are not cruisers, and from what I have seen, they aren't mechanics either. I wish I had a nickel for every time I've seen one wait days for the chance to spend hundreds of dollars on a mechanic for what I consider a simple job, like impeller changes, heat exchanger cleaning, raw water strainer cleaning, change the starter, etc.
Most I believe more than anything want to be able to come down to the boat, sometimes after having been gone for extended intervals, and have the thing start when they turn the key.

Very few Pirus are plug in hybrids,and again at a first look, the Prius would seem to be completely illogical, stupid heavy, expensive, slow and in the end, not much energy saved, just a whole lot of money spent, a gimmick only people who want to be green would buy. At least that is what I thought for years.

I think initially for the casual user an electric drive sailboat makes sense, and it may develop into a viable cruising boat, you may not, and hey that's fine.

At the airport in Winter haven Fl, right by the Jack Brown sea plane base, there is a hangar with a bunch of Solar panels on it, apparently inside the hangar is an electric sailplane, seems the panels charge it during the week and the owner flies it on weekends. For him it works, for me it wouldn't as I couldn't fly from Fl one day, land in OK that afternoon with it, but I guess he just wants to fly around Winter Haven?


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[valhalla360]

Originally Posted by a64pilot

I had two Honda's, ganged together they would run my 30 amp boat Airconditioner and all, cost about 2K. That is already there, I believe the bigger Honda's can be connected together as well, it's not hard, and I don't understand why you would think multiple generators are needed?

Majority of boat owners are not cruisers, and from what I have seen, they aren't mechanics either. I wish I had a nickel for every time I've seen one wait days for the chance to spend hundreds of dollars on a mechanic for what I consider a simple job, like impeller changes, heat exchanger cleaning, raw water strainer cleaning, change the starter, etc.
Most I believe more than anything want to be able to come down to the boat, sometimes after having been gone for extended intervals, and have the thing start when they turn the key.

Very few Pirus are plug in hybrids,and again at a first look, the Prius would seem to be completely illogical, stupid heavy, expensive, slow and in the end, not much energy saved, just a whole lot of money spent, a gimmick only people who want to be green would buy. At least that is what I thought for years.

I think initially for the casual user an electric drive sailboat makes sense, and it may develop into a viable cruising boat, you may not, and hey that's fine.

At the airport in Winter haven Fl, right by the Jack Brown sea plane base, there is a hangar with a bunch of Solar panels on it, apparently inside the hangar is an electric sailplane, seems the panels charge it during the week and the owner flies it on weekends. For him it works, for me it wouldn't as I couldn't fly from Fl one day, land in OK that afternoon with it, but I guess he just wants to fly around Winter Haven?


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The Honda 2000's only put out 1600watts continuous, so a pair can put out about 4hp.

I think the portable ones that have pairing ability peak at around 6.5kw, so still limited to the equivalent of around 15hp. Of course they aren't very portable and don't know where you would find the space for a pair of them on a 30' boat.

Most boat owners in the 30-50' range are cruisers, just not long term cruisers. The 30'+ boat bought new purely for day sailing is very rare. As cruisers, they expect to be able to motor at upwards of 90% of hull speed for several hours.

Plug in or not, the Prius has a viable use case that makes a lot of sense. That use case doesn't apply to a cruising boat.

[s/v Jedi]

I currently have a Yanmar that is 120hp continuous or so. When motorsailing I don't think I use more than 10-15hp but let's say 20hp. The one time I needed WOT was during the survey for buying the boat and since I only do it now and then because I'm told it is good for the engine. Still, I would want more power for when I need it during emergencies.

So let's just look at the numbers. I need a battery bank that can supply maximum power for emergencies and I need a genset with 144V or so charger that can supply me with the 20hp I need for extended motorsailing. I can also run the genset when things get hairy to extend the battery runtime at high power as much as possible.

I see 100-140hp motors, 144V hi power chargers etc. and there are plenty 20-22kW gensets available. I could use DC-DC converters for using a 144V bank as house bank.

I know it would cost more but it seems feasable. One battery bank for house plus propulsion and one genset to charge it is the better setup from an engineering standpoint. Better than an engine for propulsion plus another one for genset as well.

[Cadence]

Originally Posted by Stumble

Go take a look at the engine size on the average 40' boat. You would expect to see about 2kw/1,000lbs. The 80kw number was from our old 54' with a 120hp engine. It's probably a little large for this discussion admittedly.

But if we assume a 40' boat with a 40hp (30kw) motor, that's the size of generator you need to equal the same propulsive power. Assuming parasitic loads of the engine roughly equal the peak/vs continuious output of the generator. Since it is incredibly difficult to sync two or more AC generators the option really is one large or two small DC generators as well as a massive inverter to run house AC loads.

The problem of course is that you rarely need this much power, most of the time something like 1/2 power is all that's really needed. But those times when you need every bit of power you can get, you really need it. Clawing off a lee shore for instance, or motoring into hurricane force winds to reset a dragging anchor. Even motoring up a strong current, being able to maintain hull speed for a few hours can be critical.

So for our hypothetical 40' with 40hp, operating a 48v DC electric motor, a realistic generator profile would be what a 10kw and 20kw. By the time you price these out plus the electric motor you really haven't saved anything.


A64,
When did you pull the 44hp out of your IP?

I wonder if those advocating electric. Have considered the weight. An electric motor isn't light nor is a large battery bank then add a sizable gen-set. It is probably very feasible to make and leave a slip and the technology probably will make it long range feasible in the future. JMHO

[Stumble]

Originally Posted by a64pilot

I haven't pulled the Yanmar out of my boat and never will, except maybe to overhaul, or maybe repower.
I'm real conservative, and am still in the refit phase, I don't want any science experiments on my boat, heck I still have a lead acid bank.
But that doesn't mean that I don't think other technologies aren't viable, cause I think they are.
Maybe it will take fuel cells to make electric propulsion main stream? I don't know, but think there is a market for a silent, nearly maintenance free propulsion system.
One thing I thought odd when I first joined this forum was the excessive number of threads about the engines, I thought that unusual as most of us are Sailers? Then realized how seemingly a lot of maintenance activities on a sail boat seem to involve that engine.
What if you could remove 99% of those maintenance activities, and have silent propulsion? Think it might sell to day sailers?


Sent from my iPad Pro using Cruisers Sailing Forum

I was wondering when you pulled your motor because you said that it has a 25hp. But the boat originally came with a 44hp. It would be an odd repower that cut available power that much.

[Stumble]

Slaving two inverter generators together is relatively easy since all they have to do is sycronize the cycles. But to sycronize larger AC generators required getting the engine speeds identacle as well as the moment the magnets pass the coils. It is much more difficult.

Upsizing this isn't as simple as just switching to large inverter generators, the losses would be staggering, as well as the cost to buy 10 or 20kw inverters.

Originally Posted by a64pilot

I had two Honda's, ganged together they would run my 30 amp boat Airconditioner and all, cost about 2K. That is already there, I believe the bigger Honda's can be connected together as well, it's not hard, and I don't understand why you would think multiple generators are needed?

Majority of boat owners are not cruisers, and from what I have seen, they aren't mechanics either. I wish I had a nickel for every time I've seen one wait days for the chance to spend hundreds of dollars on a mechanic for what I consider a simple job, like impeller changes, heat exchanger cleaning, raw water strainer cleaning, change the starter, etc.
Most I believe more than anything want to be able to come down to the boat, sometimes after having been gone for extended intervals, and have the thing start when they turn the key.

Very few Pirus are plug in hybrids,and again at a first look, the Prius would seem to be completely illogical, stupid heavy, expensive, slow and in the end, not much energy saved, just a whole lot of money spent, a gimmick only people who want to be green would buy. At least that is what I thought for years.

I think initially for the casual user an electric drive sailboat makes sense, and it may develop into a viable cruising boat, you may not, and hey that's fine.

At the airport in Winter haven Fl, right by the Jack Brown sea plane base, there is a hangar with a bunch of Solar panels on it, apparently inside the hangar is an electric sailplane, seems the panels charge it during the week and the owner flies it on weekends. For him it works, for me it wouldn't as I couldn't fly from Fl one day, land in OK that afternoon with it, but I guess he just wants to fly around Winter Haven?


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[a64pilot]

Originally Posted by Stumble

I was wondering when you pulled your motor because you said that it has a 25hp. But the boat originally came with a 44hp. It would be an odd repower that cut available power that much.

I meant I use maybe 25 HP, probably less, or said another way, I believe I only have need of 25 HP
Right now I have a vibration issue that restricts me to 2200 RPM, I have $600 of motor mounts to install sitting in my den that I hope will fix that. Last year I had the shaft pulled, run out checked and new Cutlass bearing and paid for an engine alignment, but problem persists. I hope mounts, but next will check shaft run out myself if mounts doesn't fix it.

One difference in running a Diesel hard is the noise, I don't want to run above 2000 or so, due to noise, but an electric I don't think high power would be as objectionable.
But if your the type that is running your Diesel hard, then maybe electric isn't for you, even if it becomes available, at a decent price etc.

I don't think electric will replace direct Diesel drive, cause without fuel cells or some other breakthrough technology for a cruising boat I don't see any way around burning Diesel for more than causal motoring. But for some people that can afford it, and would place value in it, it may become available in the not too distant future. Most of my sailing could be done on electric drive alone as until we leave, I'm doing mostly day sailing, which means usually I'm back at the dock late afternoon, plugged into shore power.
I think my use is pretty common, actually it seems majority of boats never leave.
There is a beautiful IP 420 on my dock, I've never seen the owners, it disappeared last year for about two weeks, but before that and since then I've never seen it move, and that seems very common.


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[Rustic Charm]

Because im leading up to repowering, i followed this same topic last year, did some research and even contacted two electric suppliers for quotes.

When it came down to it, the 'cost' of replacing a diesel with an electric system, suitable for cruising, was simply well beyond sensible.

for those who dont cruise far, or only use an engine to get in and out of a marina, absolutely ill be following the video's Uma because they intend down the track to do extensive cruising. But at this point in time, its not the technology thats missing, but the cost.

A new diesel to replace mine (38hp) with fit out is about $15k aud. An electric unit to give me the same equivilent ability last year was anywhere from $22k up. That's just false economy even including the fuel.

[a64pilot]

I think it will be a long time before before it becomes logical from a cost perspective, but based solely on cost, I think I'd be in a trawler, except for my desire to see the South Pacific.
Has to be a reason you don't see any cargo carrying sailing vessels anymore
But then too from a cost perspective, I can't see how a new boat or car makes sense, yet a great many are sold every year.

It's going to take quite a few people buying these things for costs to come down and for the "bugs" to be worked out.
That's what I'm waiting for Life-PO, I hope that when my current bank dies, Life-PO will be mainstream with lower prices etc.


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