Diesel vs Electric Engine

[Joe Brown]

Originally Posted by skipmac

No engine, forget the ICW. Also a number of harbors that require sailing up a narrow, twisty channel will be out.

True enough, but I've done enough of the ICW so that I really am not interested in doing much more of it. That's just me.
And I guess I don't know the harbors that require navigating a narrow twisty channel, but what about using the dinghy to get it in?

I can speak only from my own experience, which may not be as much as others, but as I reflect on my cruising experience, there are not that many places I've gone that I could not get to using a motor (even electric) for a few miles.

[roverhi]

If all you are going to do is use power to get into and out of marinas/anchorages in calm conditions, electric power is a good alternative. The problem with electricity is longer term use especially at high power settings. Run a 30hp electric motor at max power and it will eat up 800amp battery bank in a very few minutes. Many of the electrical conversions seem to be using a small electric motor that will not use many amps but also won't push the boat in demanding conditions. If a boat needs a 30hp diesel for maximum thrust demands, it will also need a 30hp electric motor with its inordinately hungry amperage demands to do the same work.

I hate the diesel. Happiest moment in my life on the boat is when I turn off the noisy bugger and sail. Still, there are times when it's been a god send. When I sailed to Hawaii, had a bolt fall out of the self steering and it ripped itself out of the transom almost taking the backstay chain plate with it. Had to turn back as the rig was being held up by a thin strip of fractured fiberglass and the Self Steering Vane lashed to the stern would dig into the water with only a small amount of heel. Had to power 180 miles back to SF to fix the boat. Simple thing with the diesel, just started it up, set the auto pilot and droned on for a day and a half. With electric power, would have taken more than a week powering for a short while and then waiting for a long time for the solar panels to charge the batteries back up with the overcast. A series of short power episodes and long waits for the batteries to recharge. Solar panels work great for charging batteries IF the sun shines. Same goes for wind generators IF the wind blows. On the way to the Marquesas got into the Doldrums and temporarily disabled the engine. Seas were running 10' plus from a storm in the Southern Ocean, temps were near a 100 and water temp almost as high. In short, it made the Coleridges 'Rhyme of the Ancient Mariner' seem like an air-conditioned day at the movies. After rolling, banging, sweating and working my butt off to to sail a measly 15 miles for a day and a half, finally found a way to get the engine running again. Powered for 24 hours till we finally picked up some wind. The engine saved our marriage and the cruise.

There is a rumor floating around that the Pardey's were notorious for spending a lot of time begging boats for a tow to get into port. Yes you can sail around the world without an engine but don't try and get into a marina without one. Yes you can use the dinghy with its outboard to maneuver into a harbor or slip in flat conditions. The problem is how do you work the boat and the dinghy simultaneously while single handed. In adverse conditions with a foul tide and bucking winds, even a high powered dinghy might not be enough to save your butt. There again we are back to the problem with diesel electric, why have electric power when you have to rely on an internal combustion engine when you REALLY REALLY need a diesel inboard.

Until we have affordable batteries that are light years ahead of anything available today, electric power is for day sailors and true believers.

[jwcolby54]

Originally Posted by MoxieGirl

Would you ever consider an Electric Engine for your boat?

As I read people's sailing stories, blogs and books, I read about how they are always having to refill the tanks for their diesel engines. With battery motors becoming better and more reliable technology, would you ever (assuming money wasn't an issue) swap to electric?

Maybe you have an electric engine. What do you think of it?

MG

I am absolutely ready willing and able. I intend to live in a SAILboat. The objective is to SAIL.

That's just me. Lots o' folks like to motor places if there is no wind.

With current technology, range is definitely a factor. Big battery banks, though with lifePO batteries the battery is getting better.

http://www.cruisersforum.com/forums/...nks-65069.html

This obviously works for propulsion as well.

[jwcolby54]

Originally Posted by skipmac

Electric motors can fail just as easily as diesel engines

That at least is Soooooo not true.

Diesels have dozens if not hundreds of moving parts. And water pumps. and this and that and oil and belts and hoses...

THE BIANKA LOG BLOG: Going electric: Part 1: The why and how

Look at all the crap this guy hauled out and threw away when he converted. And how simple the resulting system was.

[jwcolby54]

Originally Posted by David M

Diesels still have a much better energy stored per pound of propulsion system ratio and a much better energy stored per unit of volume of propulsion system ratio than electric.

Until batteries can store much much more energy, electricity is not even close to Diesel.

Absolutely true. You have to be willing to sail your sailboat as the primary propulsion.

Folks live without any engine so to say it won't work is simply not true. To try to claim it will replace a diesel is also not true. But that is not what those using it are saying.

The range is currently between 30 and 50 miles. That is waaaaaaay more than "up a twisting channel" or "out of the bay".

Having electric propulsion has many advantages and some disadvantages, without a doubt.

OTOH those who love their diesel will never be swayed. But who cares?

[jwcolby54]

Originally Posted by SkiprJohn

Knowing how to sail has little to do with whether or not you have an engine aboard. I've had many boats without engines and some with. As Skipmac says there are many places or predicaments where having an engine will get you somewhere that just plain sailing will not. I wonder how many non-engine sailors accept tows from friendly powerboaters and auxiliary powered sailors. I know I had to on a couple of occasions going up a river or back to a mooring after the engine died.

I don't like the feeling of being dependent on the kindness and generosity of others.

Uhh and what does having an electric motor with a 30 mile range have to do with this?

[jwcolby54]

Originally Posted by MoxieGirl

With battery motors becoming better and more reliable technology, would you ever (assuming money wasn't an issue) swap to electric?

I think it is useful to acknowledge that a diesel is a power generator that happens to be hooked up to your propulsion system.

An electric motor is just a propulsion system, it does not generate appreciable power.

So it is just useless to even discuss "swapping a diesel for electric power". All of the various (non carbon based) power generators that you could stuff on your boat will never be able to replace the diesel for generating power.

Having said that, boats less than (picking a number out of thin air) 40 feet tend to have a power requirement small enough that often a diesel isn't really a requirement OTHER THAN propulsion.

On larger yachts, with dish washers, washer / driers, heat pumps, water generators and so forth, the diesel is simply part and parcel of the life style. The yacht just doesn't function without them.

And even for propulsion, for these big yachts, electric propulsion is just cost prohibitive relative to a diesel. For smaller boats that is no longer true.

[rwidman]

Originally Posted by MoxieGirl

Would you ever consider an Electric Engine for your boat?...............

Well that would be a "motor", not an "engine" and if you're talking about propulsion, my answer is "no way".

Yes I do have to fill my diesel tanks from time to time but it's very difficult to fill electric tanks. And it you're out of electricity you can't just have someone bring you a jug of it.

Tooling around the local harbor with a place to return and recharge the batteries every few hours might be OK. Cruising? Not practical. Maybe in a dozen years or so.

[fungod]

We are from SF and use our 34 year young Newport 30 for day sails and weeklong trips on the bay and delta. We replaced our diesel with electric about a year ago. We could not be happier with the results. Most of our sails are day sails and we only need the motor to get in and out of the harbor. Works like a charm.

With so many boats from the 70's and up needing to repower sometime soon, I hope they will consider electric. We installed it and the price came to $9k. We get about 3 hours of motor power at 5 knots. Our electric bill is about $11 per month. We call it Tesla Sailing!


Sent from my iPhone using Cruisers Sailing Forum

[nimblemotors]

Which electric motor did you use?

Originally Posted by fungod

We are from SF and use our 34 year young Newport 30 for day sails and weeklong trips on the bay and delta. We replaced our diesel with electric about a year ago. We could not be happier with the results. Most of our sails are day sails and we only need the motor to get in and out of the harbor. Works like a charm.

With so many boats from the 70's and up needing to repower sometime soon, I hope they will consider electric. We installed it and the price came to $9k. We get about 3 hours of motor power at 5 knots. Our electric bill is about $11 per month. We call it Tesla Sailing!


Sent from my iPhone using Cruisers Sailing Forum

[jwcolby54]

Originally Posted by hamburking

Agreed, better batteries would make electric drive better. I have always wondered tho, the problem with batteries is they are big, heavy, lead things. Sailboats already have a big heavy lead thing called a keel. If the keel itself could be used as a lead/acid battery to drive an electric motor, it could have a huge capacity. Just a thought.

And a great thought it is. The same though occurred to me long ago. I think the real issue is form factor. A keel shape doesn't allow just stacking batteries down in a "hold". If it did though... We could kill two birds with one stone. And have a monster battery as well. Of course a lead acid battery works by charging and discharging the plates, so while the storage would be huge, it would require the ability to charge the thing efficiently. And in the end, a LiFePO battery would still be preferred since exchanging the battery when it dies would be non-trivial as well.

Definitely a lost opportunity though. Imagine 4000 pounds of battery in your keel.

[fungod]

We used Electric Yacht. Let me see if I can find their web info.

http://electricyachtsocal.com

They were great to work with.

[valhalla360]

Originally Posted by jwcolby54

That at least is Soooooo not true.

Diesels have dozens if not hundreds of moving parts. And water pumps. and this and that and oil and belts and hoses...

THE BIANKA LOG BLOG: Going electric: Part 1: The why and how

Look at all the crap this guy hauled out and threw away when he converted. And how simple the resulting system was.

Classic logical mistake: It looks complicated so it must not be reliable.

There are proably more bits & bobs in the electric drivetrains than an old mechanical diesel has parts. The wrong transistor goes out, and don't count on the electric motor working and the average joe will have no clue what went wrong.

Diesel propulsion is well established and refined. As long as you don't abuse or neglect your drivetrain, it is incredibly reliable.

Especially with electric drivetrains being in the experimental stage of development, I'll give you 10-1 odds that electric will fail at least as often as diesel and probably more often.

If they ever get to the stage that they have 50-100yrs as primary propupulsion systems in cruising boats with all the refinement that comes with that, we may have a different situation.

[Captain Bill]

Originally Posted by hamburking

Electric motors have only 1 moving part, as opposed to the hundreds of moving parts on a diesel, so the electric is inherently more reliable.

I've got a very electric motor intensive boat, though not for propulsion. The boat is 13 years old and I've owned it for 10 years. I have a total of 10 12V dc motors on board. Only 3 have not been replaced due to failure since I have owned the boat. At least one was replaced by the PO because a dead one was left in a drawer when I got the boat Two of these motors have speed controllers. I'm on my third of one and second of the other. All of these motors are environmentally sealed "explosion proof" motors. Several of the other motors have been replaced more than once as well. I once had a battery bank short out which left me without house power which powers all of these motors. I also had a genset self destruct on me. The diesel engine powering it was fine, but the electrical side failed. Oddly I'm still on the two original propulsion engines. I had one quit one time when I got a slug of bad fuel, but a quick cleaning of a filter and pulling some crud out of the pickup tube had me back in business in short order. Replacing the battery bank and repair of the generator took a boat yard. The bottom line is the diesels have never left me stranded and I've never had to replace them. If I would have been depending on either my genset or my batteries I would have been stranded without power twice, just because of the power supply and based on an average of my success with electric motors odds are a propulsion motor or two would have failed as well. More reliable? Not in my experience.

[nimblemotors]

Don't you read the CF threads on problems with diesel engines???
Wood boats are also incredibly reliable..if you don't abuse and neglect them.

Originally Posted by valhalla360

Classic logical mistake: It looks complicated so it must not be reliable.

There are proably more bits & bobs in the electric drivetrains than an old mechanical diesel has parts. The wrong transistor goes out, and don't count on the electric motor working and the average joe will have no clue what went wrong.

Diesel propulsion is well established and refined. As long as you don't abuse or neglect your drivetrain, it is incredibly reliable.

Especially with electric drivetrains being in the experimental stage of development, I'll give you 10-1 odds that electric will fail at least as often as diesel and probably more often.

If they ever get to the stage that they have 50-100yrs as primary propupulsion systems in cruising boats with all the refinement that comes with that, we may have a different situation.