Electric drive conversion

[TropicalPengy]

Ahoy All!
Im new to this site, and have recently aquired a coranado 35 CC, this is by no means my first boat, and am quite capable in the customizing/retofitting and modification game. Ive been a live aboard cruising sailor for about 12 years and have often debated with freinds the potential benifits and drawbacks of an electric boat, preferably one that could recharge by free spinning the prop under sail in combination with solar,wind,and perhaps a small portable 110 generator thu the house recharging system. I am aware that the loss of the motor will loose weight and that this would be good for a race boat, however id actually like to increase the weight in the existing eng.room, and fuel storage areas by going overkill with batteries, extending bank life and amp hour cushion, and increasing stability and righting moment (the coranado35 is a little light and top heavy in my opinion). the actual mechanics and retrofit part im comfortable with, and the energy use/management I am very familiar with, its the actual models of motors and battery combinations I am most curious about. I have been researching several different options and beleive that something in the 30-40hp equivilent would suit my needs with a comfortable cushion for heavy load in rougher weather (though i do not plan on bashing waves for fun it does happen) She is equipped with a gasoline tractor type motor at present, and I am not a big fan of gas motors being they suffer the same crutch as any electrical based ignition/propulision in marine environment and also have the risk of volitile fuels, vapors,ect. so its either go diesel or pure electric... so the basic question is anyone with any experience orgreater knowledge or practical application of this approach have any useful thoughts or recomendations for the specific type of motor/batteries and or how they have liked it?

 

[tommays]

What gas motor do you have now A4 ?

There is a lot of electric conversion work going on in small ways but nothing has really caught on and i have not seen anything in the 30 to 40 = at all as the amp draw would be huge

The Lagoon Cats have hybrid diesel/electric system

 

[sailingdog]

Not a big fan of going electric on small sailboats. This is especially true if the engine might be needed in heavy seas, as there is no real way to "refuel" an electric engine's battery bank quickly. Where adding fuel to a gasoline or diesel engine is relatively simple, recharging the battery bank of an electric engine takes time, a commodity that is often in short supply in an emergency.

Yes, you could have a genset that was large enough to power the motor, but then you'd have a severe weight penalty, as you'd have the batteries and the diesel genset, rather than an equivalent size engine and a much smaller battery bank. Also, the additional complexity of such a system is generally a bad idea on a small sailboat, where things get wet pretty easily and reliance on complex electrical/electronic systems is just asking for trouble.

 

[TropicalPengy]

While I do agree that there is no way to easily refuel ie recharge battery banks, the benifit of regenerative power while under sail,including in heavy sea flying fractional rig, would keep banks topped off, Im not a big fan of motor sailing, but have grown to like the idea of passive solar sailing on an electric drive, using only any wasted energy to get maybey that first knot on sunny calm days. Days you would usually have to either run the motor or just sit. Also I have never been in any emergency where if you were out of fuel it was easy to get more fuel, or if battling waves was easy to transfer fuel, even from deck storage cans. and then if its a question of needing power right away, a small dedicated 3kw 110 generator with fuel tank included in package would get plenty of juice flowing for lets say motoring into a harbor if lost solar panels and wind gen and rig from demasting? Many of the electric drives available are actually water cooled and quite at home being wet, so there isnt even a worry of getting water in the air intake system of internal combustion. the more i look at it it just makes sense to do away with the fuel except maybey 5 or 10 gallons for that little emergency gen stored in a lazarret. the botomline is when your out of fuel your out, if a motor dies its pretty much dead in any emergency, though repairs to a diesel would prolly be easier than rewinding a cooked electric motor...repairs happen after you survive an emergency though, and as a sailor i will always swear the most important power is from wind.

 

[TropicalPengy]

oh yea, no its not an A-4 its a palmer I beleive, older than dirtbut runs,want to replace it before it becomes an issue. and again, the coranado 35 isnt necessarily a "small" boat no irwin 65, but no 25-30ft boat either. she is cavernous interior, no real bilge area to speak of, eng.room is under cc. so adding a bunch of heavy batteries an such down low in the fuel areas, and eng.room would make her ride a little smoother, im not trying to win races, just get there free,comfortable,and with reasonable safety...there is nothing inherently safe about traveling beyond sight of land...one last note, if its that nasty out your probably much better off in deep water than trying to motor for shore...once in the frying pan best to avoid the fire

 

[tommays]

Hows it going to be free as what your talking about will cost more than a new diesel ?

 

[Shooter II]

By coincidence, I was talking about electric boat possibilities and feasibilities just last week. Please keep us abreast of your progress.

 

[kenn]

Nigel Calder is currently exploring hybrid propulsion. Details in his blog and elsewhere.

I can agree with sailingdog that a pure electrical system isn't ideal.I've found that alot of people have the misconception that hybrid power means lots and lots of batteries. The ideal boat hybrid setup is closer to that of a hybrid car,where the battery bank is sufficient to support the boat electrical systems and short running, but for extended running it's expected that the generator is running continuously. So extended or emergency running is still powered by a gas or diesel motor. In a well designed hybrid setup, the battery bank could completely fail but you'd still be able to drive the electric motor(s) directly from the genny.

I've also read that in a well-designed hybrid system a well-matched generator/electric motor set can be more efficient than just a comparably powerful engine.

Of course, any energy you can pick up from solar or wind generation, or from prop regeneration is a bonus, and it's quite possible that the average cruising sailor could get most of the electric power required for instruments and harbour manoevring from these sources, reducing the need to run the genny.

There's alot of other benefits to hybrid power, including better weight distribution.

 

[TropicalPengy]

its not really about weather or not it is free financially,or if even it would be free in terms of its carbon footprint, oviously it takes industry to make the batteries and thats messy, the lead itself even poses a polution risk, yet occurs natrually anyway, its more a question of theoretical range. If you have to think in terms of how long wil my finite liuid fuel(which also pollutes and also cost carbon to produce)will last in my tank in terms of motor running time, vs sailing range which is already theoretically infinite less degredation of sail material and lines, also costing fuel to produce, it really comes down to efficiency and operational time between fueling or maintenence while still retaining useful power at sea, the real question is can you carry enough food? but still there are some definite benifits to daylight solar sailing, a large battery bank for balast,freespinning for house power under sail while also recharging ect ect...true it would be cheaper to just put in a deisel but not neccesarily less complex, or provide the better range under cruising conditions

 

[kloudie1]

There has been a lot of discussion on the site in the past.. Lots of good points concerning electric propulsion.. Nigel calder is doing some investigation and data collection on his new boat that will be very informative. http://www.maloyachts.se/Blog/tabid/195/EntryID/16/Default.aspx
It is all about energy balance and how you use your boat and engine. for instance, Lynn and Larry Pardee don't have an engine and would argue that one is not necessary..

 

[TropicalPengy]

the one thing I have used in my life at sea, which i think is a serious point is in the event of electrical failure ie lighting doing its random thing and killing the system even if properly grounded, is with a small diesel, you can still crank it by hand, disconnect the raw water intake, and close the ball valve and it will become a bilge pump...that was very useful once..though it wasnt lightning but a failed alternator...

 

[sailingdog]

In the OP, there is only mention of having a genset for occasional charging, and thus my guess in that he would need a very large battery bank.

Given the displacement of his boat and the current power requirements, the battery bank would have to be of significant size if he were to get any real use out of it.

In a cruising sailboat, there may come a situation where the engine is needed for extended periods of time, for instance, to keep the boat pointed into the wind or to try and fight a current to make it into a safe harbor—and any system that can not be refueled easily and run for extended periods of time without issue is one that is asking for trouble.

Unless there is a sudden exponential increase in the efficiency of solar or wind generation, it can only supply a tiny fraction of the electricity needed to re-power an all-electric sailboat. Look at all the space the Sun21 required for enough solar panels to properly power it...

Nigel Calder is currently exploring hybrid propulsion. Details in his blog and elsewhere.

I can agree with sailingdog that a pure electrical system isn't ideal.I've found that alot of people have the misconception that hybrid power means lots and lots of batteries. The ideal boat hybrid setup is closer to that of a hybrid car,where the battery bank is sufficient to support the boat electrical systems and short running, but for extended running it's expected that the generator is running continuously. So extended or emergency running is still powered by a gas or diesel motor. In a well designed hybrid setup, the battery bank could completely fail but you'd still be able to drive the electric motor(s) directly from the genny.

I've also read that in a well-designed hybrid system a well-matched generator/electric motor set can be more efficient than just a comparably powerful engine.

Of course, any energy you can pick up from solar or wind generation, or from prop regeneration is a bonus, and it's quite possible that the average cruising sailor could get most of the electric power required for instruments and harbour manoevring from these sources, reducing the need to run the genny.

There's alot of other benefits to hybrid power, including better weight distribution.

 

[Shell]

If I remember, 10 years ago, Hava Blue converted a Catalina 36 to a Solomon electric motor for offshore use. They used solar panels and hydrogen osmosis generator. I think regeneration by the prop will give very little juice.
I bought an electric motor and considered converting my boat. The motor is rated at 25hp at 64 volt from near 1 rpm. A straight electric is really quite simple. It really is a matter of math. Amps used at a certain voltage against the time those amps are being used and how much are stored by the batteries. The problem is hybrids. That's where it gets complex. You now have 2 mechanical systems to get to work together on a small boat. Keep in mind most large ships are electric propulsion charged by a diesel generator.

Search the net. There is a wealth of info. Someday, I hope, we all will be driving pure electric cars, bikes and boats. Remember, electric is only green if the source of electric is green. Diesels and batteries are not.

Good luck,
SH

 

[TropicalPengy]

the purpose is to have a sufficient battery bank for cruising power needs mainly under sail,recharged by the action of sailing.the solar,wind, and emergency portablegenny would just suppliment this, I sailed my cal 28 using an inverter to run tv vcr and laptop, with 3 house deep cycles(rv/boat wal mart brand) a single 40watt solar panel, and was able to meet my 12 volt needs plus 110 on inverter for as long as 5 days without running the motor at all, im talking about having free spinning sail power 2 80watt solar, maybey a small wind turbine, i can take downif not needed i hate the noise, a 3kw portable gas genny for emergency power, and a bank comparable to 6 to 8 D8's for house, and equal voltage on lithium to balance draw, because deep cycle gel sealed batteries last forever, the lithium will cover the surge the regulator would be at the selector switch with a voltage gate, the genny is hand cranked, and my power needs will only increase by 3 or 4 small 12v house lights tops...maybey led bulbs...

The example i most recently found was a modification for a catalina 30 which had the a-4 removed saved 350lbs of weight from the motor fuel and lines after difference from batteries and elect motor were computed, the vessel range was about 30NM on electric alone at 5Kts, more than enough to enter a harbor, I hardly ever use any motor as it is, so this would actually make me faster and more efficient with no fuel burn, basically ever, because the 1kt apparent wind gained by neutral thrust would stave me through the dull nights, and solar would top it off by day.or free spinning or both. i only need the motor really as a tafrail generator, its just nice it can replace the harbor power and free me of the existing gas motor, im not trying to save weight,im trying to gain weight, in the right places, and not have to stop for gas. lol even though when cruising the cal I think i burned 10 gallons of gas a month, not diesel but gas...i wouldnt mind a sippy diesel, but why have fuel spill risk below decks if not needed?....will miss the emergency bilge pump trick though...sigh whale gusher...

 

[COOL]

TP,
I have removed the 500lb diesel engine from my Lancer 36.
and I am moving forward with an electric propulsion project.
I see an electric system as perfect for me, and perfect for the
way 75% of auxiliary sailboats are used.
The system I plan on installing in my boat will be will have
many favorable attributes over a diesel replacement.
I will be going with a very straight forward 48V DC system,
that involves only a 15HP DC motor, a controller, an AC charger,
and four Group 31 12V batteries. This system will be far less expensive
than a new diesel instillation, will weigh less, take up less space,
it will require very little maintenance, and I can understand it.
I expect to have a very limited powering range, but I have a
sailboat with an auxiliary motor, not a motorboat with auxiliary
sails. I will be reliant on shore power for recharging the battery
bank, initially, but will eventually add solar capability.
On a Coronado 35 it should be possible to easily exceed the
performance of the old Palmer,with an electric system,as far
as maneuvering in an out of the marina is concerned.
It will be difficult to achieve much range in powering
that much windage in a seaway. But it can be done
with two battery banks and a small gas generator.
As you point out, an engine is only needed when
near shore, at sea it is only a convenience to get
somewhere on a schedule.
If you have not joined the Yahoo Electric Boats Group,
you should do so. There is a lot of information and
expertise available there, but you have to sift your
way through quite a bit of material, and varying
opinion, to glean what is helpful to you.

 

[TropicalPengy]

Cool, cool lol
Thanks for the info will try there also, and yes am very aware of limited range but lighter is not my goal, so hoping to compensate by going way overkill on batteries, extending the range on battery alone cushion, im not really after a hybrid boat, im after an electric boat that self charges.

 

[TropicalPengy]

Re: Saildog
I also notice in that photo that the sun cat pictured has radar anda gimbaled gps receiver, if they are running those they would probably burn half the power from the panels

 

[TropicalPengy]

plus... note lack of sails...therefore no freespin charging under wind power, also no wind turbine, thats an all solar boat with high power demands...

 

[Moody Buccaneer]

"Ive been a live aboard cruising sailor for about 12 years ..."
"I sailed my cal 28 using an inverter to run tv vcr and laptop, with 3 house deep cycles(rv/boat wal mart brand) a single 40watt solar panel, and was able to meet my 12 volt needs plus 110 on inverter for as long as 5 days without running the motor at all, ..."
"I also notice in that photo that the sun cat pictured has radar anda gimbaled gps receiver, if they are running those they would probably burn half the power from the panels."

40W rated panel ... at 100% for 10 hours a day .. 40W = 3.3A @ 12V right? so your 12V budget is 33 ah per day?
2 grp 27's is about 300 ah ... so you have 50% of that available or 150 ah for 5 days. 30 ah per day.

30ah per day out of the house bank net loss after a daily input of 33 ah tells me that your 12VDC budget was about 60 ah per day ... on a 28 foot boat ... that sounds reasonable.

How simple are you going to keep the boat? How much cruising vs living on the boat are you planning on? SAILING back from Cabo, compared to Motorsailing is a big deal for most people. Are you ready for that?

No offense intended, but if you had 12 years of long distance Cruising experience I don't think you would be asking the questions you are.

Almost EVERY Cruiser that has come down here is looking for ways to increase fuel capacity. They have found that they motor or motorsail much more than they ever thought they would. Is your experience different from mine?

A Centre Cockpit Coronado 35 is not a passage maker for most people, if your Cruising plans are weekends and the occasional week away around Long Beach rather than setting off for 1500 miles or more, your needs and wants will be very different.

Can I take it you will run your laptop rather than have a GPS and Radar?

Have you looked at prop/motor efficiency when towing to generate power? Somehow I doubt that efficient drive system will be able to produce much power. If you optimize the system for power recovery, it won't drive the boat very well.

I wish you the very best of luck, but I don't think your goals are realistic if you are going Cruising for real.

Randy

 

[kloudie1]

consider this.. The panels on that catamaran are 10 kilowatts! At Harbor Freight, that would cost $62500 ! just the panels.. to drive two 8 kw motors (10.7 hp Max).. normal running was in the 2 KW range (2.7 HP) . not many 46 foot boats are going to go very well with 2.7 hp.. Battery is 1040 amp hours at 48 volts.
Just some interesting numbers..