Why not electric engine powered boats

[Jdege]

Originally Posted by Stumble

If you want an electric engine go for it, technically it isn't all that difficult. If you want more than 20-30 minutes of range at cruising speed then you have to install a massive generator because batteries suck.

I was watching a guy bring a powered fishing boat onto a trailer at the ramp, just yesterday, using his electric trolling motor. It worked amazingly well. No noise, no smell, no bother.

But he was only moving the boat a very short distance, in still water, with little wind, at a very slow speed.

Maybe when they get graphene supercapacitors figured out ...

[skipmac]

Originally Posted by SURV69

"real world application", dictate that we're talking about SAILboats and I know in this area the number one concern of sailors is how to protect the unused fuel at the end of the year.

?????????? I've been sailing for 40 years and that thought has never crossed my mind. I do hear the question come up rarely, most often with sailors that don't sail that much or sailors in the NE that haul the boat for six months every year but it is far, far from the number one concern.

Originally Posted by SURV69

For those who need "speed), relatively speaking, and the need to "push water", in a sailboat, the need for 1000lbs of battery and a 20kw engine might make sense ... or nonsense as it may.

Speed is secondary. The biggest problem with electric is range. For example, daysailors that use the motor only to leave the dock, sail around for a while and then use the motor to get back into the slip, electric is a viable solution. Sailors that never motor any distance, never travel the ICW, travel deep water port to deep water port could also use electric efficiently.

Any sailor that ever motors more that 20-30 miles, electric is not a practical, cost effective solution. It is impossible to get the range with batteries on any real world, practical cruising boat thus requiring a generator. So now instead of a diesel engine and transmission you have: an electric motor and controller, a diesel engine connected to a high output alternator to generate power to run the electric motor. I have priced these systems at least half a dozen times and the cost is always more than double, usually triple. So to go electric you have a more expensive, more complex, less efficient system.

I am not anti electric. I would love to go electric. On my boat an electric motor drive would be a better installation than the current setup. I am an electrical engineer and understand electric. When electric becomes affordable and practical I will convert. That time has not yet arrived.

[StuM]

Originally Posted by Btimmerman49

It takes 700 pounds of batteries to provide power equal to 1 gal of gasoline Big flaw

Nice necropost.

This thread had been dead for 10 years. Now we get to go through all the same tired old arguments from countless other threads, yet again.

[Lodesman]

Originally Posted by Btimmerman49

It takes 700 pounds of batteries to provide power equal to 1 gal of gasoline Big flaw

I'm bemused by this argument - with solar panels/wind genny I can recharge my batteries underway or at anchor. How do I generate gasoline?

[skipmac]

Originally Posted by Lodesman

I'm bemused by this argument - with solar panels/wind genny I can recharge my batteries underway or at anchor. How do I generate gasoline?

So with solar you recharge your batteries? OK, so you charge for a day (or two) to get enough charge to motor for an hour (or two). Will take you quite a while to get somewhere that way.

Or you can stop at the nearest marina and buy gas (or diesel) and motor for days.

[Cotemar]

Electric boats are up and coming, once you have stronger cheaper batteries.
Who would of guessed electric planes would be flying, but yes they are.

https://www.youtube.com/watch?v=PJKYekL7JsY

[SV THIRD DAY]

Originally Posted by StuM

Nice necropost.

This thread had been dead for 10 years. Now we get to go through all the same tired old arguments from countless other threads, yet again.

If people understood the power/energy then you would be correct, we wouldn't need to deal with this issue over and over. But Hey I have 300W of solar and I'm planning on pushing my 40ft cruising boat through water all day long or for more than 7 minutes. Education is a continuous thing, so it must be constantly reviewed and discussed.

[Lodesman]

Originally Posted by skipmac

So with solar you recharge your batteries? OK, so you charge for a day (or two) to get enough charge to motor for an hour (or two). Will take you quite a while to get somewhere that way.

Or you can stop at the nearest marina and buy gas (or diesel) and motor for days.

Got sails to get somewhere. Not all cruising grounds have marinas around every corner. Anyway you've quite missed the point. This whole "I've got umpteem thousand batteries worth of diesel in my tanks" argument supposes you need to drain that fuel tank in one go - most of us sailors take months to go through a tank of diesel. Since we sip in dribs and drabs, is it not reasonable that a few hours of battery capacity and/or a generator capable of providing enough juice for moderate (cruising) speed would meet the needs of many a sailor?

[SV THIRD DAY]

Originally Posted by Lodesman

is it not reasonable that a few hours of battery capacity and/or a generator capable of providing enough juice for moderate (cruising) speed would meet the needs of many a sailor?

Not to me it isn't...nor would it work for most of the cruisers I've cruised with. Day sailors...yes...weekenders....yes. Cruisers who spend 365 days/yr on their boats....no, not a realistic chance.

[Lodesman]

Originally Posted by SV THIRD DAY

Not to me it isn't...nor would it work for most of the cruisers I've cruised with. Day sailors...yes...weekenders....yes. Cruisers who spend 365 days/yr on their boats....no, not a realistic chance.

You spend 365 days/yr underway and motoring? Well that is a rather rare breed of cruiser.

[SV THIRD DAY]

Oh...so we want to play a little smarta## do we...I will play along.

Originally Posted by Lodesman

You spend 365 days/yr underway and motoring? Well that is a rather rare breed of cruiser.

Reading comprehension may not be your strong suit, so lets try again...read closely mi amigo...

Originally Posted by SV THIRD DAY

Not to me it isn't...nor would it work for most of the cruisers I've cruised with. Day sailors...yes...weekenders....yes. Cruisers who spend 365 days/yr on their boats....no, not a realistic chance.

Note the words "Cruisers who spend 365 days/yr on their boats". No reference was made to being underway, nor was one implied. Cruisers who do spend 365 days/yr on their boats also have a much better understanding of how their batteries work and would thus literally laugh out loud at the notion of adding the load of electric propulsion to their already taxed battery bank. 9 years of cruising and living aboard full time with a crew of 4 has taught me a thing or two about powering a cruising boat. Even with my 400AH LiFePO4 Battery bank I wouldn't dream of electric propulsion. Sorry...sell that myth to someone with a Catalina 30, but I'm not buying it.

Oh and since we now know a little about my background/experience, how long have you had electric propulsion on your boat? Now surely you are not recommending a technology to others that you don't have on your own boat are you....que lastima...

Cheers mate.

[skipmac]

Originally Posted by Lodesman

Got sails to get somewhere. Not all cruising grounds have marinas around every corner. Anyway you've quite missed the point. This whole "I've got umpteem thousand batteries worth of diesel in my tanks" argument supposes you need to drain that fuel tank in one go - most of us sailors take months to go through a tank of diesel. Since we sip in dribs and drabs, is it not reasonable that a few hours of battery capacity and/or a generator capable of providing enough juice for moderate (cruising) speed would meet the needs of many a sailor?

Of course it can. I said exactly that in a previous post on this thread. My point is solar is practical for certain, limited applications but not for most boaters and how they cruise. If your boating NEVER requires you to power more that a couple of miles (maybe 20-30 with enough batteries) then electric can work for you.

If you cruise the ICW then you would have to cover your boat completely with panels to have enough power to cruise all day at about half hull speed. If you only use your engine to leave the dock and get to open water then electric will work for you.

[seandepagnier]

What a fun thread!

Originally Posted by Stumble

Ya sail boats that may need to make way when there is no wind, or up a channel against the wind, or into a harbor where sailing is prohibited.

sail boats do not need to make way when there is no wind.

I can tack up just about any channel provided it's 30 meters wide. If it is less than this width I have several alternatives that allow me to also make my way.

I have never heard of a harbor where sailing is prohibited.

If you want an electric engine go for it, technically it isn't all that difficult. If you want more than 20-30 minutes of range at cruising speed then you have to install a massive generator because batteries suck.

I have motored 10 hours on a bank of 8 golf cart batteries, and drained them to 11.8 volts.

None of this is new territory. Most people want to be able to motor further than 5-6nm, if you don't then go electric. If you do then your stuck with liquid fuels.

Already you can easily motor much farther than this using flooded lead acid batteries and brushed motors without even needing any kind of electronics or controllers.

Originally Posted by valhalla360

We just came out of a period when petrol at the dock
To the OP: This has been beat to death if you do a search of this forum. If you are willing to accept drastically reduced performance, electric is viable today but it is no where close to meeting the capability of a good diesel engine at a similar price.

Using diesel is no where close to the capability of solar and regenerating electric and never will be.

This is because the solar can charge the battery anywhere from the sun, and regenerating makes it possible to quickly pass the wind holes from mountains in the lee of islands then recharge where there is plenty of wind at minimal boat speed loss.

How many of you have made your own diesel fuel in remote areas and compare this amount of labor? When I climb I take the coconuts for food I don't waste them.

Ultimately, it's the size of the fuel tank that kills the electric dream.

I don't have a tank.

Speed is secondary. The biggest problem with electric is range. For example, daysailors that use the motor only to leave the dock, sail around for a while and then use the motor to get back into the slip, electric is a viable solution. Sailors that never motor any distance, never travel the ICW, travel deep water port to deep water port could also use electric efficiently.

These statements are all incorrect.

Any sailor that ever motors more that 20-30 miles, electric is not a practical, cost effective solution. It is impossible to get the range with batteries on any real world, practical cruising boat thus requiring a generator.

It is not impossible, but it would be pointless anyway, because by the time you travel 30 miles (at the correct efficient speed), you will either have wind or sun.

So now instead of a diesel engine and transmission you have: an electric motor and controller, a diesel engine connected to a high output alternator to generate power to run the electric motor. I have priced these systems at least half a dozen times and the cost is always more than double, usually triple. So to go electric you have a more expensive, more complex, less efficient system.

While I'm completely against any form of generator, even if you had one, this is also not even close to less efficient considering you can still use solar and regen abilities.

Originally Posted by skipmac

So with solar you recharge your batteries? OK, so you charge for a day (or two) to get enough charge to motor for an hour (or two). Will take you quite a while to get somewhere that way.

This isn't what I have found at all.

I was able to motor 3 knots using 500 watts of solar with a few amps charge also going into the battery.

Or you can stop at the nearest marina and buy gas (or diesel) and motor for days.

Or you never stop at any marina, and motor for years using solar panels and regenerating under sail.

[dmeissner]

You guys are talking like this is something new. If it weren't for cheap gasoline, we'd be a lot farther along by now...
https://en.m.wikipedia.org/wiki/Electric_boat

https://youtu.be/ZKW2B45bsHw

[Paul Elliott]

Originally Posted by boat_alexandra

I have never heard of a harbor where sailing is prohibited.

Victoria harbor on Vancouver Island is one of those harbors near me that I visit. No sailing allowed.

As for my own use as a datapoint, where we sail we have passes with very strong currents. Over this weekend we motored and sailed about 120 miles round-trip, having to transit Cattle Pass and Deception Pass. Especially with Deception, if you can't hit it within a half-hour of slack, you probably ought to anchor and wait until the next slack. Even if you can motor against the ten knot current, the standing waves and eddies can be a big deal. Timing is important. Of course the wind was on the nose for half the trip. We motored a lot.

I also sail to Hawaii from time to time, and the return usually involves a day or two of motoring.

Sure, George Vancouver himself explored my cruising grounds with no propulsion but sails and oars. People have sailed to and from Hawaii for centuries with sails only. I race to Hawaii under sail-power alone.

But for my everyday use, electric just isn't going to cut it.