Tug of War - Electric vs Diesel

[tp12]

I must be missing something here. I think the test demonstrates the advantages that EP has over DP but, of course, doesn't demonstrate the disadvantages. Having said that, I don't believe the disadvantages of going EP lie with the motors. More the storage and charging systems.

Wouldn't a DC generator for charging the bank be a smaller and more efficient used as a 'range extender'? I quite like the idea of two electric motors, a large modern storage bank with a suitable BMS with a roof full of solar. I like the idea that the electric motors can be used as generators while sailing, lessening the need for the DC genie.

I don't think the technology is as far away as people think, in terms of function. Price point is another story though. In my opinion the only thing holding EP back for a world cruising boat is the price and the availability of knowledgeable service people. Though I do acknowledge that system setup/teething problems aside, once these systems are working they are almost maintenance free.

If you're coastal cruising I think it makes more sense and the only disadvantage under that scenario is the initial price of the system.

[valhalla360]

Originally Posted by goat

One thing I would like about the idea of electrical propulsion is the ability to refill the 'tanks' when in the middle of an ocean.

goat

Sounds great in theory but run the calculations to maintain even a modest 4kts for a typical modern cruising boat and you will see that the claims to be able to refill your batteries on the go isn't going to work.

[Kalinowski]

Electric seems to makes sense for powering in and out of marinas. With motor regeneration, wind, and flexible solar panels installed on sails (UK sails presently doing this), recharging doesn't seem to be a problem. Of course long distances under power are not viable, but that's what sails are for. Fast motoring is for stink pots anyway. Check out the Systems section of December's Sail magazine, page 33.

[Terra Nova]

Dreamin'.

[charliehows]

hmmm, let me see, diesel; 150 hrs @4-5 knots on my boats modest fuel capacity, vs electric (sooo...which electric yacht engine maker has the best proven record of reliability? oh yeah, that's right, there aren't any) ? hrs @ 4-5 knots (dont really know) conversion cost? (dont really know but start with massive and work up)
2 boats in a tug of war - WTF is that trying to prove?

[Kalinowski]

Seems as though those that would prefer to power rather than sail have a valid argument. WWSS (what would Slocum say?).

[Seaslug Caravan]

Originally Posted by Kalinowski

(what would Slocum say?).

A double entendre regarding her pet cat Tiddles I guess.

If thats Mrs Slocum you are referring to.

[K_V_B]

Originally Posted by charliehows

hmmm, let me see, diesel; 150 hrs @4-5 knots on my boats modest fuel capacity...

It's obviouse that EP is not yet there for motor yachts. But for example, I absolutely hate turning the engine on. So I have no use for 150 hrs of engine range when I'm already annoyed by the 2 x 10 minutes I need to run the engine to get in and out of port or the anchorage...

I think it all boils down to what you use your engine for.

I think it's not a coincidence that the video in the first post shows cats. A large cruising cat will often have two diesel engines and a generator. Reducing that to two electric motor and a generator simplydies things a lot.
For weekenders and day sailors EP is already there. We see it here on the lakes: You can easily have a few hours of range (which is all you need) and you never ever have to arrange a visit to the fuel dock anymore.
For cruisers it depends on what type of cruiser you are.
If you have a boat that only needs a whisper of wind to get moving (the kind I like) then you're not going to motor a lot. Then EP becomes and option as well.
If you are the type of sailor that doesn't go upwind under sail, well that's anothe story.

[K_V_B]

Originally Posted by skipmac

How can a "marine" electric motor cost ten times more than an equivalent power industrial motor or twenty times an equivalent automotive like the one in my Prius? Yes I know economy of scale and such but still.

You have to of course make a correct comparison.

The ELCO price is for motor+controller. I wouldn't be surprised if the controller by itself costs several times the motor. The same for the Prius motor: I don't know what it would cost to replace the motor + the brains of a prius, but it will be a lot more than just the motor.

[a64pilot]

See, I'd love an electric boat, what I envision, is
a humongous Life-Po bank, that runs everything on the boat, maybe even cook with electricity, no more propane, I'd need as huge a Solar array as I could swing, and a rather large, say at least 7.5 KW Diesel genset.
I think it could work, if it were kept simple sort of along the lines of the WWII subs, but I think most fail from what I call creeping elegance, which is where all kinds of really neat things sort of creep into the design, usually from the marketing dept., you know, like retractable azipods, steered by a joystick or even regeneration.
Course it's going to cost way more than I could afford, and way more than I'll ever spend on Diesel, but I think it could work.

[Scout 30]

Originally Posted by charliehows

hmmm, let me see, diesel; 150 hrs @4-5 knots on my boats modest fuel capacity, vs electric (sooo...which electric yacht engine maker has the best proven record of reliability? oh yeah, that's right, there aren't any) ? hrs @ 4-5 knots (dont really know) conversion cost? (dont really know but start with massive and work up)
2 boats in a tug of war - WTF is that trying to prove?

Elco has been around for more than 100 years & the Elco motor needs it's first service at 50,000 hours. Not a misprint. The motor essentially never needs to be serviced. Over the life of a diesel engine that would be very significant savings & is something that hasn't made it into the discussion. Regarding conversion costs that's pretty easy to estimate. The Elco EP1200 list price is $8,000 which includes everything other than batteries & a charger. That motor runs on 48 volts so you'll need 4 batteries. Depending on which batteries you get that would be another $1,000 to $2,000. Elco estimates a run time of 7 hours between charges at 60% of hull speed for a 50% discharge.

The History of Elco, the Electric Launch Company

[a64pilot]

Scout,
I think electric makes perfect sense for the way the majority of sailboats are used.
It's a cruising boat that will be it's toughest challenge, people like to counter, well a real Sailor sails so you don't need no stinking motor, but some of us want to cruise the ICW or maybe the canals in Europe. Tough to sail either of those, and the issue is what do you do after that 7 hours, assuming you can live with 60% of hull speed and there is no adverse wind or current?
Drive system is not the issue, as you have stated electric propulsion is a very mature system, it's the generation and storage of power that is the problem, solvable for a Bay sailor with simple flooded cells, but not a cruising boat.

[Scout 30]

Originally Posted by a64pilot

Scout,
I think electric makes perfect sense for the way the majority of sailboats are used.
It's a cruising boat that will be it's toughest challenge, people like to counter, well a real Sailor sails so you don't need no stinking motor, but some of us want to cruise the ICW or maybe the canals in Europe. Tough to sail either of those, and the issue is what do you do after that 7 hours, assuming you can live with 60% of hull speed and there is no adverse wind or current?
Drive system is not the issue, as you have stated electric propulsion is a very mature system, it's the generation and storage of power that is the problem, solvable for a Bay sailor with simple flooded cells, but not a cruising boat.

I agree. For this system to be viable for a cruiser a generator is necessary. So it appears that electric is an economically viable option for day sailors & weekenders without a generator & cruisers that either already have or were planning on installing a generator anyway. Of course for this to be truly economically viable it would have to occur when a boat was new or when the diesel had reached the end of it's life. Replacing a functional diesel would throw the number out of whack although I'm not sure how much that matters with boats.

[a64pilot]

I believe I can get by easily with a 3.5 KW generator, but if I were to use it for propulsion, I'd need a much bigger generator. I would think I would want to size a generator so that it's output alone would push me to say 75% of hull speed, so I'm agreeing that electric propulsion would I believe make sense in the design or build stage. But, I think to make it work, you need to keep it simple, I wouldn't even want regen, believing that I would use it very little as I wouldn't want to give up boat speed for it.

Somebody like Hunter or another larger manufacturer will eventually adapt a simple electric drive meant for the day sailor who is tied up to shore power every night or nearly so, it will happen. I'm surprised it hasn't already.
But you have to realize Joe Citizen is completely ignorant of Solar power, vast majority of the public thought the solar panel on a Prius sun roof would run the Air Conditioner when all it can do is power a puny fan to help exhaust some hot air, they have no idea just how much electricity is required to move something or heat water etc.

[K_V_B]

Originally Posted by Scout 30

The Elco EP1200 list price is $8,000 which includes everything other than batteries & a charger. That motor runs on 48 volts so you'll need 4 batteries.

I find this rather expensive still. An equivalent system from Bellmarine (now Mastervolt) would come to about 4400 Euro. If you just get yourself the motor, plus the controller you'd probably look at around 1800 euro, but then you'd need to do all the systems integration yourself, and come up with a cooling solution.