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Old 29-06-2020, 21:30   #181
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Re: Replace Diesel with electric engine

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Do yourself a huge favour. Get a new fuel efficient diesel engine. Install more than less diesel storage. Be grateful for whatever solar charging you get.
Enjoy hassle free sailing safely.
Listen to lordgeoff. If you are going to cruise half way around the world you need diesel propulsion. If you plan to go through the Panama Canal you need diesel propulsion. There will be times when you can't wait for your batteries to charge. This is both a safety and convenience issue.
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Old 29-06-2020, 21:35   #182
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Re: Replace Diesel with electric engine

You can deal with the Panama Canal without a diesel inboard.

It requires mounting an outboard on the mothership and using both the outboard and electric drive at the same time. You may find you need a small generator too but a little experimentation ahead of time will give you fair warning.

5kt just doesn’t take that much power to maintain, even for a very large boat like the Super Maramu.
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Old 29-06-2020, 21:43   #183
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Re: Replace Diesel with electric engine

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5kt just doesn’t take that much power to maintain, even for a very large boat like the Super Maramu.
And then, as you do your hybrid motoring across Gatun, barely making the required 5 knots, an adverse wind pops up... w hat then?

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Old 29-06-2020, 22:06   #184
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Re: Replace Diesel with electric engine

For a little reality, my 33' Greenline Hybrid low profile motor cruiser has a 48V 12kWh lithium pack, and a 10/7 kW motor/generator coupled to a 165HP VW turbo diesel. With a WL of 32.5', hull speed is 7.7kts. Your plan has 4X the power and battery capacity, and a hull speed 1kt faster, with a much larger wetted surface area and a huge amount more windage with ketch rig and mid cockpit.

On the often very inhospitable wide-open Monterey Bay and the usual summer 15-20 kn prevailing NW winds, 5-7' swell and 2-3' wind waves, I can make little effective way to windward with the full 10kW electric w/ 17" 5-bladed prop and 2:1 reduction gear. It will pull the full 150A only for several minutes before settling to about 130A @ max throttle. The boat specs give a range of 10nm @ 6kn max power, ideal conditions, and 20nm @ 4kts. We use the electric mode for leaving the marina, for whale watching on calmer days after dieseling out to find them, and often for the last downwind 5 mi back home. It is reassuring to have it for diesel backup, but it's simply not up to any severe demands. Maybe scaled up with your very large boat it would be different, but I really doubt it.
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Old 29-06-2020, 22:30   #185
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Re: Replace Diesel with electric engine

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And then, as you do your hybrid motoring across Gatun, barely making the required 5 knots, an adverse wind pops up... w hat then?

Jim
All depends on how big the generator is. I went back and looked at post #1 which seems to indicate a significant generator. Let’s say it’s a 20kW generator, that means there’s power for 5.5-6.0kt in flat water without even touching the battery. At 5kt you are probably anchoring half way which gives plenty of time to recharge overnight.
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Old 29-06-2020, 22:33   #186
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Re: Replace Diesel with electric engine

Lenz: the schemes are nice for wiring but they do not tell me anything about Watts.
How many Gensets do you have? Data? Which motor do you have? Data?

You mention that you plan to install 48 KWh for 48V
OK so far.
Displacement: 16 tons
Engine: 80Hp which is enough but not overwhelming (with 60 knots of wind and waves you may have problems drifting leeward!)

Due to better power managagement 60 HP (45Kw) equivalent on electric propulsion may be enough.

Watt ist the unit of power and it does not matter if this power is served through a cable or a prop.

If you have to do full speed for ONE HOUR your banks are DONE.
Solution: you provide a Genset that gets you, say, 53 KWh.
45 for propulsion and 8KWh for charging.

Warning! only 33 KVA Caterpillar C3.3
The generator itself has 1000 Kgs!!!

YES electric propulsion makes sense as engines efficency is max 40% and motors are said with 93% But it is NOT true that you can replace a 60 Kw engine with an 25 Kw motor as you are better off to have a 45 Kw motor and run it on 25Kw.

That is far more efficient than to power up a 25KW motor to always 25Kw
It may end up that you get a better ratio motor/prop and just serve 20Kw for the same 25Kw result of the smaller motor at the prop.

And only the combined power of the proper genset and the batteries give you the safety you need.
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Old 29-06-2020, 22:42   #187
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Re: Replace Diesel with electric engine

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Originally Posted by Adelie View Post
All depends on how big the generator is. I went back and looked at post #1 which seems to indicate a significant generator. Let’s say it’s a 20kW generator, that means there’s power for 5.5-6.0kt in flat water without even touching the battery. At 5kt you are probably anchoring half way which gives plenty of time to recharge overnight.
Adelie, I was referring to your post suggesting a small outboard plus a honda genset for the electric driver. I've kinda lost track of what boats with which electric motor we're talking about in this thread, but for some of the marginal ones, the canal passage could be a problem if conditions ain't just right. The canal folks operate on fairly strict schedules, and schedules are bad for cruisers in general.

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Old 30-06-2020, 05:41   #188
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Re: Replace Diesel with electric engine

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Listen to lordgeoff. If you are going to cruise half way around the world you need diesel propulsion. If you plan to go through the Panama Canal you need diesel propulsion. There will be times when you can't wait for your batteries to charge. This is both a safety and convenience issue.
You need to read this again! and again! Decades of real experience here.
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Old 30-06-2020, 07:31   #189
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Re: Replace Diesel with electric engine

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You need to read this again! and again! Decades of real experience here.
I think what's missing here is how much solar the OP is planning on installing. While the Amel 53' (Super Maramu) does not have a hard bimini (probably due to the Ketch arrangement), it does have hard safety rails where one could mount 6, 425 watt hard solar panels with the Mantus rail mount system. Also missing here is how much regen is possible with this system. I'm thinking a folding prop may not be the best choice here. The advanced SD system I'm looking at will produce 500 watts of regen power at 6 knots sailing. If they are doing the Panama Canal route this is mostly a downwind sail (just unfortunately not in the canal itself) and a Super Maramu is easily capable of averaging 6 knots. If they choose the Rhumb line route (as the crow flies) this becomes more iffy crossing the Indian Ocean in the wrong direction. I guess the main hurdle is getting through the Panama Canal and is the battery bank and recharging capacity large enough to push a fairly large boat through the canal for hours on end? Of course there's always the horn or northwest passage - I think I'd opt for the canal
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Old 30-06-2020, 08:13   #190
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Re: Replace Diesel with electric engine

Yes Yes Solar Panels will make it (Uaargh I think I throw it up - at all)
unless you install 1000++ m² you won't make it.
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Old 30-06-2020, 08:30   #191
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Re: Replace Diesel with electric engine

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Yes Yes Solar Panels will make it (Uaargh I think I throw it up - at all)
unless you install 1000++ m² you won't make it.
Could you expound on that ?- maybe I'm slow, but I didn't quite get your meaning
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Old 30-06-2020, 08:30   #192
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Re: Replace Diesel with electric engine

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Originally Posted by joelhemington View Post
If they are doing the Panama Canal route this is mostly a downwind sail (just unfortunately not in the canal itself) and a Super Maramu is easily capable of averaging 6 knots. If they choose the Rhumb line route (as the crow flies) this becomes more iffy crossing the Indian Ocean in the wrong direction.
The shortest distance as the crow flies would be over the north pole - any other route is basically 12000 nm+, through either canal, or the third option - south around Africa.
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Old 30-06-2020, 08:44   #193
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Re: Replace Diesel with electric engine

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The shortest distance as the crow flies would be over the north pole - any other route is basically 12000 nm+, through either canal, or the third option - south around Africa.
I've never heard of crows flying over the North Pole
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Old 30-06-2020, 09:03   #194
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Re: Replace Diesel with electric engine

joelhemington just check for yourself! for say 50 KWh you need how much m² of Panels if your 1 m² Panel gives you 130 Watts PEAK? This is 60 Watts real for say 8 hrs a day.

60 W / 48 V = 1,25 Ampere OK skip it let us stay on Watts 60 W x 8 hrs = 480W /Day
48.000W / 480W = 100 m² of solar panels to go for one hour.

OK sayin this is only a 16% panel (We are on 24% Now)
No matter - double it up to 32% makes 50 m² of panels IF you got enough sunlight at all
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Old 30-06-2020, 09:23   #195
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Re: Replace Diesel with electric engine

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I've never heard of crows flying over the North Pole
"As the crow flies" is an idiom meaning the shortest, most direct route, which would not be a rhumb line as you put it, but rather a great circle. It really has nothing to do with the way crows fly.
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