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Old 07-02-2020, 21:58   #136
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Re: Replace Diesel with electric engine

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Originally Posted by Ken Fry View Post
There is no "simple difference".

Electric motors safely move ships of far more than 20 tons every day, and have been doing so for many decades. Electric power, in many different architectures, can be the most economical alternative, or the least. But one cannot make any blanket statement without sounding incredibly ill-informed if not a little belligerent.

Several of my boats were naturals for electric power, and several were not. Some new sailboats are routinely purchased with electric propulsion, others are not.

By writing about how electric propulsion has worked for me, I am not trying to suggest that you should power your boat the same way, but am offering the benefit of my experience, to anyone so inclined. And I am happy to do some math for anyone seriously interested.

Electric propulsion is seen in boats ranging from 28 lb kayaks to huge ships. Many people are making it work well. Some, like Greer, are cruising thousand of miles on solar power alone, using as much battery accumulation as they need for their style of cruising. I think that is a good thing, not a bad thing. His boat goes as fast as a similar-sized sailboat, but he doesn't need the costly, heavy, and complicated mast(s), boom(s), multiple sails, winches, tangles of rope, etc. He doesn't need to worry about when to reef or shake out a reef.
No where in your post did you mention that those huge ships propelled by electric motors are powered by huge generators. Most of which are diesel powered. A small number are nuclear powered. None of them run on batteries and solar power. Omissions count as deception.
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Old 08-02-2020, 01:23   #137
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Re: Replace Diesel with electric engine

OK solar power is a good choice:
I have around 6 m² panels (Voltage is 14-19V) with 500 Wp that give me lucky 20A = 240W = 160A on as sunny day. Minimum electric propulsion at sea is 20 Kw

20.000 / 240 = 83,33 x 9 m² = 750 m² x 3 (one need power 24 hrs and not only 8)
= 2250 m² of SOLAR PANELS ONLY !!!

So the solar catamarans are gimmicks and far off producing say 5% of the actual required energy.

To run 20 Kw you need 416Ah on 48V and that are 4 225Ah batteries with 200 kgs for one hours drive. Remember not to discharge the batteries more than 50%
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Old 08-02-2020, 05:47   #138
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Re: Replace Diesel with electric engine

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OK solar power is a good choice:
I have around 6 m² panels (Voltage is 14-19V) with 500 Wp that give me lucky 20A = 240W = 160A on as sunny day.
Where can you mount that many panels on a Vagabond 47 without the panels being shaded by the mast, sails or rigging?

On my 42 Pearson the only reasonable place for solar panels is at the stern on top of the davits but that isn't really practical but for maybe 2-3 square meters, at least on my davits.
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Old 08-02-2020, 07:18   #139
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Re: Replace Diesel with electric engine

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Where can you mount that many panels on a Vagabond 47 without the panels being shaded by the mast, sails or rigging?

On my 42 Pearson the only reasonable place for solar panels is at the stern on top of the davits but that isn't really practical but for maybe 2-3 square meters, at least on my davits.

OK only 2,8 m² (2x PN SPR S130 & 2x PN SPR S85) but it does not matter much for the calculation scheme and yes no one can avoid them to be shadowed and installation is tricky as separating bb and stb has to be parallel and does not give enough voltage to drive the bloody regualtors though the 130 had to be connected in serial and the 95 too which reduces the amp harvesting.

Quite problematic and a point the romancers out here won't even think of. Far to realistic.

And reasonable electric propulsion via genset is an investment of around 40.000 USD

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Old 08-02-2020, 11:28   #140
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Re: Replace Diesel with electric engine

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And reasonable electric propulsion via genset is an investment of around 40.000 USD

$40,000 is more or less what I've come up with doing the calculations. However the link from Jedi to the electric power company could change that a LOT. I looked at their systems and saw prices more in line with industrial motors I've priced.

Have never been able to understand nor get a straight answer from any of the "marine" electric power companies I've spoken with about why high power marine electric motors are $10-$15-$20,000 when I could by a heavy duty, continuous power rated, high quality industrial motor for $2-$4,000.

Even IF the industrial motors were lower quality (but they don't seem to be) you could buy 2-3 spares and still save a bundle.
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Old 08-02-2020, 19:47   #141
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Re: Replace Diesel with electric engine

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Omissions count as deception.
That is a lie.

If you want to make a meaningful contribution, then point out anything I have written that is untrue, or appears to you be untrue. I can provide links and data. But claiming that leaving something out of a discussion is deceptive is mean spirited. insulting, illogical and just plain wrong. We all leave (or should leave) many things things out, for the sake of a useful discussion.

My characterizations of your character, for example, are best left out of this discussion.

I have omitted many things from this discussion: millions of things, because they are not germane. An omission of a fact that virtually everyone already knows is not deceptive. It makes for more concise communication. That many boats are diesel electric hybrids is a fact known by many fifth graders, and so does not need to be stated here. Nevertheless, I have not omitted, but, in fact, clearly stated that I favor serial hybrids. The solution I proposed for someone with a boat like yours (with a 12 hp purpose-built dedicated generator and the capability to use the 50 hp electric propulsion motor for regen) is clear evidence that I have not omitted, but in fact, have advocated for diesel-electric hybrids. (nowhere in that description, did I say "You should do this," or anything of the sort. I was simply trying to help you understand that hybrid boats can function well, and that the OP is not a nitwit.

The OP, for whom this thread exists, clearly knows that diesel hybrids exist, and is in fact himself advocating for the same. In his boat, electrical energy will be produced by solar cells, by regen during sailing, and by a diesel generator. The ratio of sizes between generation facilities and consumption is his choice, and I am sure he will learn the optimum mix for himself, based not on the opinions of people who know nothing about his usage plans and nothing about powering boats electrically, but by himself. In fact, early in the thread he said this pretty explicitly: he is going to spend some time tuning before leaving on his next long voyage.

I have specifically stated that for many missions electric motors work well in the marine environment, and have provided my own first hand experience to support the contention that an electric motor can be a viable option, and sometimes the cheapest. That is simple fact, incontestable.

Was it not you who talked about motoring at one quart per hour? (Or was it the guy with the Pearson?) In any case, that's close enough for your boat.
That's 5hp (4kW) in diesel output terms. If you were traveling with my suggested powering of your boat, (12 kW purpose built diesel generator, 40 kW electric propulsion motor) that would be represent a 42% duty cycle, meaning that you could enjoy peace and quiet part of the time, instead of endless noise. Efficiency would be slightly higher (even ignoring the contribution of regen, solar power, etc.) because the diesel would run at higher, more efficient loading.

If someone else wants to challenge something I have stated, then he or she should ask me for clarification. I can provide the spreadsheets, the documentation, etc to support my case. As far as omissions, then let me state this "Lincoln was a US president." Are you asking for millions of other statements unrelated to this thread?.

If I fail to say some thing you want to read, that is not deceptive. In your competition to be abrasive, you have won. I will henceforth try to avoid interaction with you.
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Old 08-02-2020, 21:10   #142
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Re: Replace Diesel with electric engine

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Of course the ICW has been done under sail and electric. Also been traveled by kayak. People have crossed the Atlantic in 12' boats as well. But just because it has been done or can be done doesn't mean it's something I would want to do. Just doesn't sound like my idea of fun.

I guess by your definition what I do might make my boat a motorsailor butu in American vernacular a motorsailor is typically a fat boat with a small rig and big motor. In this context I would call my boat a sailboat with an auxiliary diesel engine. Certainly won't sail like a Sundeer but it not what us Muricans would call a motorsailor.
There’s many, incl. Steve Dashew himself, who classify the Sundeer as a motorsailer. I believe that performance and range under power is a factor.

This all just proves how different people are. I absolutely love it when the sails are up and the engine gets shut off... I can’t understand how someone would prefer to use the engine instead. Sailing down canals and rivers in silence is even cooler than out there offshore
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Old 08-02-2020, 21:42   #143
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Re: Replace Diesel with electric engine

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iting for a breeze. Don't know about you but I would rather ride out a moderate gale than to sit becalmed rolling around with the sails slatting and the boom slamming back and forth.
You let your boom slam back and forth why?

I have never been becalmed for more than a few days at a time, and that was in Indonesia!

In the whole indian ocean, only 20 minutes with not enough wind to sail!

Wind power is available. It takes effort to harness it efficiently. Burning diesel doesn't live up to the same standard.

A solar boat is also viable I met one who was doing the ICW. It was a voyage catamaran with no mast. 20kw solar and 16kwh lifepo4. He had twin oceanvolt motors and claimed 4-5 knots under full sun with no battery draw.
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Old 09-02-2020, 10:39   #144
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Re: Replace Diesel with electric engine

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Well yes sailing has always been my preference. However traveling the US ICW sailing just is not practical. Have some plans to cruise some of the canals and rivers in Europe and sailing isn't really an option there either.

.....
Using electricity to travel the ICW and canals of Europe is practical, but inconvenient. They are not the same things.

Motoring at 3-4kt is inconveniently slow but still a practical speed. Anchorages on the ICW are at most about 40nm apart. That means a 10-13hr day depending on the boat. Inconvenient yes, impractical for a recreational boater, no.
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Old 09-02-2020, 11:45   #145
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Re: Replace Diesel with electric engine

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Originally Posted by Ken Fry View Post
That is a lie.

If you want to make a meaningful contribution, then point out anything I have written that is untrue, or appears to you be untrue. I can provide links and data. But claiming that leaving something out of a discussion is deceptive is mean spirited. insulting, illogical and just plain wrong. We all leave (or should leave) many things things out, for the sake of a useful discussion.

My characterizations of your character, for example, are best left out of this discussion.

I have omitted many things from this discussion: millions of things, because they are not germane. An omission of a fact that virtually everyone already knows is not deceptive. It makes for more concise communication. That many boats are diesel electric hybrids is a fact known by many fifth graders, and so does not need to be stated here. Nevertheless, I have not omitted, but, in fact, clearly stated that I favor serial hybrids. The solution I proposed for someone with a boat like yours (with a 12 hp purpose-built dedicated generator and the capability to use the 50 hp electric propulsion motor for regen) is clear evidence that I have not omitted, but in fact, have advocated for diesel-electric hybrids. (nowhere in that description, did I say "You should do this," or anything of the sort. I was simply trying to help you understand that hybrid boats can function well, and that the OP is not a nitwit.
Wow, you sure are thin skinned. Your entire post about how ships are electric and General Dynamics started out building electric boats are not significant to this topic . You only post what you think will will support your instance that electric is the way to go. Go ahead and ignore the facts. You want to ignore my valid input to this topic - fine with me.
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Old 09-02-2020, 12:57   #146
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Re: Replace Diesel with electric engine

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Actually the only benefit is not quietness. Lets start at the beginning:
The first forms of motive power not using animals was electric, not diesel (next) or gasoline or another fossil fuel.
Not true. The first mechanical self-propelled vehicles used external combustion engines, aka Steam Engines, of various designs, decades earlier. And Karl Benz made what is considered to be the first production automobile, which used a gasoline engine, sometime in 1885, about three years before the first electric automobile.
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Old 09-02-2020, 13:16   #147
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Re: Replace Diesel with electric engine

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No. I think they stopped every night. Took 505 days
Named Solar Impulse 2, the longest single leg of the flight was from Japan to Hawaii, and it was just short of five days in length, over 117 hours. It remains the longest solo flight in history. Flew up to almost 40,000 feet altitude during the day to maximize partial gliding during night time.

Oh, and the project only cost 170 million dollars...
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Old 09-02-2020, 16:55   #148
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Re: Replace Diesel with electric engine

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I have been considering electric power for years but have not made the switch for several reasons.

1. Batteries. To get reasonable power and more than a few kilometers of range under power you need a lot of batteries. This can be very expensive and add a lot of weight.

2. Charging. Once you add a lot of batteries you have to add a way to put power back in after you use it. With your plan of 48kWh even if you were able to fit 1000 Watts of solar panels it would take you a week of good sun to completely charge the battery bank.

3. Power. 99% of the time when cruising most sailors use the engine for short periods and only use a fraction of the engine power. However there are times when one needs all the power possible like dragging anchor onto a reef in the middle of a storm or as happened to me once, entering a new marina to find a 3 kt current pushing me sideways into a megayacht. I read the specs for the motor you propose that said the 40kW motor would give up to 100 HP. Depending on the motor maybe for a very short burst but I think that rating may be highly exaggerated.

4. Range under power. At moderate speeds and calm conditions I'm estimating you could get 5-8 hours under power with the setup you propose but again it will take days to recharge the system after this. For most cruising 5-8 hours should be fine but would not work for cruising the canals of Europe or the US ICW.

5. Cost. Once you add batteries, charging systems, controls, etc electric can cost double or triple the cost of a new diesel engine.
Primarily my Beneteau 50 is a sailboat.
It is also blessed with a simple shaft drive 90HP Perkins.
It is further blessed to be able to carry 600Lt diesel.
Fuel use averaged over a few thousand hours is 2.7-3Lt/Hr@6-8Knots.
Motoring range experienced >1200NM
For serious cruising there are many many reasons why I would never replace the versatility, predictability, reliability, range and safety of this configuration with any sort of solar/electric motor/battery configuration.
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Old 09-02-2020, 17:44   #149
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Re: Replace Diesel with electric engine

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Originally Posted by s/v Jedi View Post
I absolutely love it when the sails are up and the engine gets shut off... I can’t understand how someone would prefer to use the engine instead. Sailing down canals and rivers in silence is even cooler than out there offshore
100% agree. The first time I was ever on a sailboat I was 25 and had no idea what to expect. When we reached the ocean, hoisted sails and turned off the motor it was magic. It changed my whole life. I still can't wait to switch off the engine any time there's the slightest breeze and dread having to crank it up again. When I first started cruising I spent a couple of years in the Bahamas and Caribbean and basically never cranked the engine unless I was coming into a dock.

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There’s many, incl. Steve Dashew himself, who classify the Sundeer as a motorsailer. I believe that performance and range under power is a factor.
Interesting. When I was a broker motorsailor had a different and very specific meaning although how one differentiated the exact dividing line between sailboat and motorsailor was exact. Roughly a sailboat with more than 2 hp/foot might be a motorsailor but also taking into consideration the sailing ability. Some even rated various motorsailors in ratios of sailing to motoring ability like 80/20 or 50/50. Otherwise it was referred to as an auxiliary powered sailboat.
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Old 09-02-2020, 17:57   #150
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Re: Replace Diesel with electric engine

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You let your boom slam back and forth why?

I have never been becalmed for more than a few days at a time, and that was in Indonesia!

In the whole indian ocean, only 20 minutes with not enough wind to sail!

Wind power is available. It takes effort to harness it efficiently. Burning diesel doesn't live up to the same standard.

A solar boat is also viable I met one who was doing the ICW. It was a voyage catamaran with no mast. 20kw solar and 16kwh lifepo4. He had twin oceanvolt motors and claimed 4-5 knots under full sun with no battery draw.
Not sure how long I would have sat but one trip there was not a breathe of wind from Great Inagua to well south of the Windward Passage. We motored through that in about a day and a half and finally caught some wind but pretty sure if we hadn't motored through it we would have sat another day or three.

Regarding the boom, maybe I should elaborate a little. While we still had a tiny bit of wind I tried to keep the sails up but the swells would roll the boat so much that the sails would alternately fill, empty and slam as the boat rolled. So droppe the sails and rolled around but I had no boom gallows so even with the main sheet very tight and a preventer rigged the boom still flopped back and forth as the boat rolled. Wasn't really slamming but after a day it felt like it.

Doing the ICW with electric and solar is much more practical with a cat, especially with no rig in the way. But I've got a monohull and a mast and that leaves me a with maybe 10% of the room for panels that boat had.
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