Electric Drive: Who uses it?

[Steadman Uhlich]

Originally Posted by StuM

You "curate" a thread? How, pray, do you do that?


Are you permitted to delete, edit, approve other people's posts in that thread?

No. Nothing like that.

That is the role of a forum moderator.
________

Here is what I mean when I used the term "curate" in this forum, regarding a few threads:

I see "curator" as most importantly meaning "care for" (a thread or topic) in this forum.

A word origin of "curator" (from Latin: cura, meaning "to take care").

I simply started the topic, continue to add interesting content to it over time as I see good content, and maintain an interest in it, and respond to questions and good posts within it.

Rather than simply posting a question and then dropping out, I take an active, ongoing role in seeing that more good content is added, including encouraging others to participate and to contribute to it.

I don't "own" it, nor do I prevent others from posting in it or try to discourage others from participating. Anyone can add to it (which I hope they will) but I have an interest in seeing the discussion continue on topic, and like seeing more good content shared within it.

Here is another example:
http://www.cruisersforum.com/forums/...ts-179638.html

[valhalla360]

So many misunderstandings in this post.

Originally Posted by storx

I understand that it doesn't make sense to take out good diesel engines out for electric, but you have to understand that electric motors are far superior to fueled propulsion in the long run.

There are far less moving parts involved in an electric motor to fail and most electric motors are designed for milions of hours of use before needing to be rewound with new wiring and rebalanced. Million hour motors? I think not. Please share the specification. That's 109years of continuous operation. Electric motors are good but so are modern ICE engines. Plus you ignore all the other components of an EV (or worse hybrid) that can fail.

I was only asking about it because this was a first for me to hear about it in a boat, he claims it works flawless in his boat and gets around using very little diesel. If you have very low expectations, it is possible. Of course, if you only run 100hrs per year at 2-3kts, you will use very little diesel to start with.

He said he has solar panels mounted on the roof and deck of his boat that charges the battery bank everyday the sun is out, so he can cruise a little on basically solar, then anchor off enjoying the new spot while the solar charges the battery back up. He said he only uses the generator when he is driving further than about 40-50 miles, because then the battery bank is depleted. Again, how long is he anchoring in place? If it's a week in one place, he might get a measurable distance but outside of extreme solar installations, getting measurable distance at typical cruising speeds (5-8kt) in normal conditions (not only glass calm conditions) in a day at anchor just isn't happening.

I know an electric drive, diesel engine range extender setup can function well because i currently drive a chevy volt, this car is ALWAYS electric driven, the car runs off the batteries tell it runs low, then the gas engine comes on turning another generator head that feeds power directly to the motor controller circuit, so when im cruising down the highway doing 75mph, the gas engine is running only at 855rpms to maintain speeds, so a system has to be properly setup for it to function correctly and a lot of companies out there are still learning this now as the use of this tech is still new...
When was the last time, you had to bash thru 6' waves in your volt? I also doubt the 855rpm. Assuming it takes around 60hp to maintain 75mph, that would imply the motor is generating 370ft-lb of torque at idle if you run the calculations. Most modern V8 motors couldn't match that.

Reasons i say electric is superior....

My uncle works for union pacific railroad, the trains use 4-8 electric motors to drive the heavy heavy train that has a single diesel engine just barely idling to supply enough power to drive the train.
This is incorrect and makes no sense. Diesel power output correlates very closely to the fuel consumed. Idle is the worst efficiency since more of the power is overcoming internal engine friction. I suspect you misunderstood that the low RPM that these big slow turning diesels run at implied that it was running at idle.

He told me years ago when i bought my electric car that when they converted the trains over, they dropped fuel consumption down to a factor of 1/10th of the diesel they used with just diesel engines driving the trains.
Again, I'm betting you misunderstood or he had no idea what he was talking about. If you could get 10 times the MPG, why haven't all cars been converted long ago (trains have been diesel electric for a few decades now).

The reasons for this is because the diesel engine can be reduced down to near idle speeds and use a turbo sized so it produces near perfect peak torque this low in the rpms, this allows for far less fuel being used. Now he tells me they have dropped the train engines in half, and raised the compression and tolerances to the point that at room temperatures the engine is to tight to turn over, so they have a heating element encasing the bottom of the engine that heats the block up enough to allow the engine to turn over and start, then uses half as much fuel providing the same amount of output in power.The reason for diesel electric in trains is because as HP increased, the mechanical transmission to take the train from 0mph to 60mph would massive and complex. These big slow turning diesel engines have a very narrow RPM range where they put out peak power, so there would have been dozens of gears. Add in the complexity of shifting 5 engines simultaneously, and the hybrid makes a huge amount of sense as you could spin the diesel up to ideal speed and let the electric motors draw what they need. Coordination electronically is very simple.

Electric motors are used in heavy equipment all the time now, many of industrial equipment has moved over to this, fork lifts, mining equipment, bulldozers... they are getting far more running hours out of the diesel engine, because its running at a constant speed and load.... and the electric motors are lasting very long and far cheaper to rebuild vs a conventional diesel engineElectric fork lifts are usually for light usage. Heavy usage is typically propane or diesel. Usually it is used because they are indoors and exhaust is an issue. Please share a link to an electric bulldozer. Never heard of one. Electric motors are common for fixed installations where you can plug them in.

Electric motors are extremely torquey, so like a 20kw motor may only output 55hp, but around 100lbs of torque.. Torque is not what you need for a displacement cruising boat. HP (or equivilent KW) is what counts. Plus more importantly a 20kw electric motor is 27hp not 55hp. If you really want a lot of torque at the prop, put it thru reduction gear on and for the same HP, the torque will be pretty much identical. This is simple physics.

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[Lost Horizons]

Originally Posted by valhalla360

Give us the assumptions as your numbers don't add up.

10kw of power (even under good conditions would presume a small boat that wouldn't have room for 1000w of solar. Also, unless you have a massive battery bank, you run into issues, where that 100hr of run time per year isn't 1 hr every 3.65 days. so if you are away from the boat for 3 months, much of that solar is lost because the batteries are already full.

So before we look in detail, give us assumptions regarding the boat, use case, location, etc...

Assupmtions are: a sailing vessel between 35 and 40 feet overall, displacing 6 to 8 tonnes. Used 12 month a year for long range voyaging without reliance on fuel dock visits. Awerage 10 kW power usage is perfectly adaquate for an auxiliary motor. Even excessive most of the time.

Such vessel may have a cockpit canopy with an area of 7-8 square meters. If a tender is suspended off the stern, the area above it adds another 4-5 square meters. This is sufficient to house over 2 kW of solar panels. Massive storage battery will replace some of the dead weight in the ballast, so no need to sacrifice a payload.

[Steadman Uhlich]

Two weeks ago I motor-sailed through some tidal currents that were far stronger than I think any "2 knots electric power" boat would safely navigate at those times.

Ponce Inlet Florida. (which flowed fast like a river)

Chesapeake Bay Entrance. (which flowed fast like a river)

"The Race" in Long Island Sound. (which flowed fast like a river)

Montauk Point (entrance to Long Island Sound). (which flowed fast like a river)

Case Cod Canal (which flowed fast like a river)

Penobscot Bay in Maine (which flowed fast like a river)
____________

Even when transiting these areas at favorable times and in good weather, the currents can be fast and strong. Buoys were leaning on the currents.

If one had an underpowered sail or power boat and low or no wind or unfavorable wind, it could be very challenging.

[valhalla360]

Originally Posted by Lost Horizons

Assupmtions are: a sailing vessel between 35 and 40 feet overall, displacing 6 to 8 tonnes. Used 12 month a year for long range voyaging without reliance on fuel dock visits. Awerage 10 kW power usage is perfectly adaquate for an auxiliary motor. Even excessive most of the time.

Such vessel may have a cockpit canopy with an area of 7-8 square meters. If a tender is suspended off the stern, the area above it adds another 4-5 square meters. This is sufficient to house over 2 kW of solar panels. Massive storage battery will replace some of the dead weight in the ballast, so no need to sacrifice a payload.

In calm conditions only used to get in and out of harbor, 10kw is probably adequate. In any kind of adverse conditions, it would be woefully inadequate.

If it's a sailboat, the cockpit area is typically shaded partially or fully by the sails, mast, boom. If you are familiar with solar systems, even a small amount of shading can cut power output by half or more. Typical monohull in that size range peaks out with around 400-500w of solar, which is typically all used up by the house electrical system.

Even if we assume the 2kw is viable, solar only generates for around 4hr per day, so that's around 8kwh per day or around 48min of run time per day if your house loads are ZERO (which they won't be). So if you have a 5hr run on the ICW, that means you need to anchor out for a week using no electricity before heading on.

For a monohull, cargo capacity isn't much of an issue but fitting batteries into the keel would be expensive and complicated, so it doesn't really replace the keel. If it's an existing boat converted, you already have the ballast in the keel, so yes, it's eating into cargo capacity and more importantly taking up limited space.

[a64pilot]

Maybe not bulldozers, but the huge mining machines like shovels and draglines are almost all electric I believe. I suspect bulldozers may not be because they are too mobile, dragging around a huge extension cord ,might not be a good idea.
http://parkerbaymining.com/mining-eq...ic-shovels.htm

As far as running the numbers to prove that a Solar powered Boat would work, how about talking to people with panels? On mine with 1000W Solar, we don’t quite make it, it takes generator or motoring runs every week or so to get by. Now I’m sure we could tighten our belt so to speak and make it, but we chose not to.
You could make an electric powered sailboat work, people sail with no motor, but it’s not practical as a sole source of propulsion, no matter how much you want it to be.
If it were there would be electric boats, just as there are electric automobiles.

[Pizzazz]

Could it be more helpful if we discuss what technologies do we need to make electric propulsion viable on recreational boats?

For example, on a sailboat, it would be perfect to have the lead keel replaced by an integrated keel+lead acid battery. This should be an option at the factory, it should have an automatic meintenance system and a 2-3 service interval (between haulouts).

Let's come up with more ideas.

Regarding solar on a boat being sufficient for propulsion, this is similar to solar on a car and it just does not work. One way to convince yourself not using any calculations is to think about the sun warming up huge areas of the ocean, creating wind that you convert into motive force with a highly efficient sail. Now try to replicate this with solar/electric and it should be obvious that the numbers do not add up.

[valhalla360]

Originally Posted by a64pilot

Maybe not bulldozers, but the huge mining machines like shovels and draglines are almost all electric I believe. I suspect bulldozers may not be because they are too mobile, dragging around a huge extension cord ,might not be a good idea.
PBCo | Electric Shovel Population | Mining Equipment Database & Mining Market Research

As far as running the numbers to prove that a Solar powered Boat would work, how about talking to people with panels? On mine with 1000W Solar, we don’t quite make it, it takes generator or motoring runs every week or so to get by. Now I’m sure we could tighten our belt so to speak and make it, but we chose not to.
You could make an electric powered sailboat work, people sail with no motor, but it’s not practical as a sole source of propulsion, no matter how much you want it to be.
If it were there would be electric boats, just as there are electric automobiles.

For fixed installations where large industrial systems can connect to the grid or install a massive stationary generator (similar to trains, the transmissions are a problem with very large equipment), sure but that's a far cry from electric propulsion on a small cruising boat.

Agreed, if you are willing to substantially reduce your motoring capabilities, you can get by but modern diesels are very reliable and efficient so what gains would there really be? It's not like displacement cruising boats are fast to begin with, so cutting cruising speeds by 50-75% means snail pace travel for negligible benefits.

The only use cases I've found viable:
- Weekender sailboat or purist sailor who refuses to motor more than absolutely necessary and is willing to risk trying to sail out of any bad situation.
- Canal boat where the entire topside is covered in solar panels.

[valhalla360]

Originally Posted by Pizzazz

Could it be more helpful if we discuss what technologies do we need to make electric propulsion viable on recreational boats?

For example, on a sailboat, it would be perfect to have the lead keel replaced by an integrated keel+lead acid battery. This should be an option at the factory, it should have an automatic meintenance system and a 2-3 service interval (between haulouts).

Let's come up with more ideas.

Regarding solar on a boat being sufficient for propulsion, this is similar to solar on a car and it just does not work. One way to convince yourself not using any calculations is to think about the sun warming up huge areas of the ocean, creating wind that you convert into motive force with a highly efficient sail. Now try to replicate this with solar/electric and it should be obvious that the numbers do not add up.

It is theoretically possible to convert the keel into a built in batterie but...
- What is the upfront cost including design and tooling? Cruising boats aren't like cars where you expect to sell 10's of thousands of each car model. A 1000 boats in a year would be a lot for most models and each model would require a different keel design.
- What happens in a hard grounding? Wiring could be jarred loose. If there is a crack at the hull line, it could introduce corrosive saltwater into the battery destroying it very quickly.
- What happens at the end of the battery life? How do you swap out a built in battery?
- Who's designing this custom system? Your average boat builder isn't qualified and even the electric conversion folks seemed to be mostly marketers with little understanding of the physics.

[Woodland Hills]

Why not just buy a 130lb thrust trolling motor and pair it with couple KWH's of 52v ebike lithiums with BMS and a dc to dc step down converter. Charge at home and use to get out of the harbor and back in after a daysail.

[a64pilot]

Originally Posted by Woodland Hills

Why not just buy a 130lb thrust trolling motor and pair it with couple KWH's of 52v ebike lithiums with BMS and a dc to dc step down converter. Charge at home and use to get out of the harbor and back in after a daysail.

I want to think at least one manufacturer has to some extent done about this, it appears that they mounted an electric trolling motor in the rudder. I don’t know the specifics, but is can’t be rocket science.
I’m sure it’s meant to be a day sailor, returning to the dock every night. But isn’t that what most boats do?

[valhalla360]

I know it's a bit different but just got back from Amsterdam.

We rented a 15' aluminum electric powered boat to cruise the canals. Talking to the rental guy it was just under 2hp. Inboard engine with transom hung rudder. 8 - 12v lead acid batteries.

Flat out it did 3.5mph (checked with GPS speed app on the phone). At one point we got out on the Amstel River against a good headwind with about 6" waves. Speed dropped by about 1 mph.

Yes, you could go from full forward to full reverse but it easily took 10seconds to come to a stop and another 5-10seconds before you started making way in reverse. A little scary when the big tour boats popped around a corner. I quickly took to just throwing the helm over rather than trying to reverse.

We were out motoring for about 3hr and the website claims a 10hr run time. Not sure if they derated the controls so we didn't get the full HP but it was pretty anemic. Only consolation is the speed limit is only 4 or 5mph.

Still was fun and for the use case, OK but in many harbors I wouldn't be comfortable with the limits.

[Lost Horizons]

Originally Posted by Woodland Hills

Why not just buy a 130lb thrust trolling motor and pair it with couple KWH's of 52v ebike lithiums with BMS and a dc to dc step down converter. Charge at home and use to get out of the harbor and back in after a daysail.

This is almost exactly how my second boat was set up. It is described in the thread that Steady curates.

[Lost Horizons]

Originally Posted by a64pilot

As far as running the numbers to prove that a Solar powered Boat would work, how about talking to people with panels? On mine with 1000W Solar, we don’t quite make it, it takes generator or motoring runs every week or so to get by.

I remember you mentioned it before. There is either something wrong with your panels, or charging system, or you have an inefficient appliance.

[Lost Horizons]

Originally Posted by a64pilot

You could make an electric powered sailboat work, people sail with no motor, but it’s not practical as a sole source of propulsion, no matter how much you want it to be.
If it were there would be electric boats, just as there are electric automobiles.

My first trailerable sailboat, which I sailed extensively on Lake Ontario, Fingerlakes, New England coast, and Florida including two trips to Dry Tortugas, had a 2-stroke Nissan outboard with a 3.5 gallon tank that I fueled once per season. So I probably motored about 30 miles or so out of, say, 1000 miles sailed annually. A 7-8 tonn mid-thirties cruiser with a Tesla-like capacity battery can go twice as far at near hull speed on a single charge. Without any solar supplement. And it will be practical for some.