Electric Drive: Who uses it?

[seandepagnier]

How well does sailing off the dock work when you have a 10-12 kt wind or a 2-3 kt current pushing up against the dock?

I can scull off a dock against 15 knots of wind. The electric motor could make progress against 20 knots (barely) using about 400 watts. With more wind, I have to dingy an anchor out to pull off, so if it's wind, it's not really an issue.

As for current pushing against a dock, usually current flows along docks not directly into them. Typically you can wait for tidal change.

You can always come up with an impossible scenario. Try motoring off a dock where you ran out of fuel and you though you could but cannot find fuel to buy in that place.

Originally Posted by StuM

2-3 knots tidal current in one direction all night in winter in the South Island (14 - 15 hours?)? Where would that be?


Lucky you didn't need to go the other way

The tidal current was 7 hours in one direction because it changed at different times along the route. Going the other way would be possible, but not work as well.

I just made it into a bay a few miles deep to escape the counter tide to motor the last 3 hours without much current at a much slower ground speed.

Even with 850 watts (chinese rating) of solar it was difficult to charge batteries in winter in the queen charlotte sounds.

I had 450 mounted, and another 400 (8x 50w) below that I put in the cockpit and foredeck at anchor or in fair weather to get extra charge. Despite the rating, I only measured at best 40 amps into 12 volts. I did not have mppt. I could never get all of the panels facing the sun perfectly at one time, and they didn't output their rating anyway.

It was May, so I don't think the winter night was quite 14 hours yet, but close... I anchored around 5 am a few hours before sunrise.



The rest of the time there I had plenty of wind to sail on.

[skipmac]

Originally Posted by boat_alexandra

I can scull off a dock against 15 knots of wind. The electric motor could make progress against 20 knots (barely) using about 400 watts. With more wind, I have to dingy an anchor out to pull off, so if it's wind, it's not really an issue.

OK, sculling off I can see but won't work for my 12 ton boat.

Originally Posted by boat_alexandra

As for current pushing against a dock, usually current flows along docks not directly into them. Typically you can wait for tidal change.

Not that uncommon where I boat on the US east coast. Lots of marinas have piers sticking out into a river, channel or off the side of the ICW and depending on your slip could be parallel or perpendicular to the current. Even the slips parallel with the current can be tricky since that usually involves going down a fairway with the current pushing you sideways before making a 90 degree turn into a slip.

Originally Posted by boat_alexandra

You can always come up with an impossible scenario. Try motoring off a dock where you ran out of fuel and you though you could but cannot find fuel to buy in that place.

Of course you can. I can think up lots of improbable, unlikely scenarios that would make for difficult boating.

However here I was trying to address issues that are not uncommon for typical boaters.

[Wayfarer1008]

I know there is a bit of environmental one-upmanship trying to be played out here but it is the case now that electrical powered systems have not crossed that threshold into being a viable form of power for anything beyond a harbor cruise boat and or a short run ferry. Diesel electrics are a bit more common and I need to point out that the bug reason for them on heavy equipment and tugs is that they remove the need for a transmission and do help power be transferred more efficiently but it does not mean they are using less fuel.

[Corvidae]

Originally Posted by skipmac

That definitely sounds like way, way more engine than that boat would ever need. In fact, as your experience indicated, one of those would be plenty of power. Was this some kind of custom installation? How come so much power?

The engines are original, which is why they're dead at this point. 40 years of occasional use and what doesn't leak is seized. I can only assume they intended it to fight heavy currents and wind channels in areas of the Med. It takes almost nothing to reach a good cruising speed, and all that extra power just punches into hull speed. Great way to waste fuel, but not much else.

Originally Posted by skipmac

I have to say though that 20 kW (about 26 HP) does seem to be underpowered for your boat and may occasionally leave you wanting. However I recall some of the electric motors I researched spec'd a much higher power output in bursts and somewhat higher for short term use. That may answer for maneuvering.

The replacement motor:
ME1115

It'll peak out at 30kw, although only ~20kw in my installation at 48v. After the install is done, I'll have enough room to double my battery bank. Giving the option of more range or more power, depending on how she handles.

[Go Wildcats]

We have built a couple Class 7/8 trucks that run 10 hours for deliveries, takes 6 hours to charge to 100% and with a GVWR of 33Tons. However, they also weigh 1 ton more than their sister diesels. The batteries required to get the range and carrying capacity simply amount to a lot of weight and mass. On top of that, the cost is an additional $75K over the ICE chassis'. With that said, for commercial, tethered fleets, electric chassis' are ready for the streets.

Battery technology isn't at the point where electric drive can replace combustion engines uses in most cases though. But the leaps in battery science is accelerating and closing the efficiency gaps a bit every day. I suspect in another 6 years, electric drive will be viable for many uses.

I'm so interested in having a fully electric boat and am excited by the pioneers making their attempts. Keep at it. Push the envelop and help develop the technology. Don't listen to the nay sayers.

[Woodland Hills]

Originally Posted by a64pilot

There was a hybrid Cat, my understanding it didn’t do so well.
My bet was the purchasers had unrealistic expectations, then couple that with not many, if any people out there knew how to maintain it, or repair it, and you have a mess.

Porsche for example years ago built what I thought was a very good airplane engine, even went through the hassles to certify it, and shelved the thing. Largely due I believe to not many knowing how or wanting to work on it, they only wanted to work on the same old engines they always had.

The failure of the Porsche aero engine program had nothing to do with the engineering and everything to do with the market. Most GA aircraft are American made and American pilots do not like geared engines, they want the prop to be bolted to the crankshaft and to turn the same rpm as the motor. One of the two big engine makers, Lycoming or Continental, introduced a geared motor about twenty years before Porsche and it flopped too. Pilots were just not comfortable cruising at 3600 rpm on the tach.......

[CarlF]

I have a Torquedo electric outboard on a 15ft sailboat. It is far better than the old 3HP gasoline out board - but it only pushes the 600lb boat at about 4mph for about an hour - after which it needs an overnight charge.

There's very little space on the boat for solar panels but I thought about it. It draws about 1000 watts so I would need a full day from 300 watts of solar panels to charge the batteries for an hour running. There's no room for this much panel. If I only needed the outboard 1 day out of three for an hour, solar panels would be a good option.

I think it's fairly easy to scale these numbers. A sailboat that needs 21hp diesel engine would need 2100 watts of solar panel just for an hour running at 50% hull speed per sunny day.

And running a generator on a boat is always less fuel efficient than a diesel directly turning a propeller shaft at cruising speeds. If there were stop signs and hills in the ocean, this would be different.

[john61ct]

Thanks for the reality check.

And Torqueedo makes great practical products, very energy efficient.

[StuM]

Originally Posted by Corvidae

One motor was able to keep the boat at 6.5 knots at about 900 rpm against steady headwinds with no problem. Both engines were governor limited to 1700 rpm which put the boat at 8.5 knots (hull speed) in just about any conditions. There was a lot more engine there than the boat was using. Especially with the 22 inch props it's running.

Something way wrong there. To limit that engine with a design spec of 3000-4500RPM to 1700 RPM means that there was something very strange about the transmission gearing or prop selection.

[StuM]

Originally Posted by Corvidae

With the electrics I expect the batteries to last about 20-40 minutes at full throttle, at near hull speed,

...
and I'm going with AGM rather than LiON batteries.

That's going to kill those AGM in not many cycles at all!

[a64pilot]

Originally Posted by Woodland Hills

The failure of the Porsche aero engine program had nothing to do with the engineering and everything to do with the market. Most GA aircraft are American made and American pilots do not like geared engines, they want the prop to be bolted to the crankshaft and to turn the same rpm as the motor. One of the two big engine makers, Lycoming or Continental, introduced a geared motor about twenty years before Porsche and it flopped too. Pilots were just not comfortable cruising at 3600 rpm on the tach.......

Geared motors go way back to the 30’s and likely even further back, there is a geared P&W R 1340 for example.
If they didn’t like the tach numbers, then show prop RPM, that is what you see on a turbine for example.
There were a couple of Lycoming geared motors, I believe they had issue unrelated to them being geared.
A significant difference is I believe it takes an IA to overhaul a geared motor, where an A&P can overhaul a non geared motor.
The orphaned geared motor is to a large extent what kept me from getting a Helio Courier.

However from my understanding nobody wanted to work on the Porsche and Porsche I think ended up paying for the PFM Mooney’s to be converted with IO550 Continentals, I think. Before my time, so I’m not sure, it’s all second hand knowledge.

The point is though that even a Porsche product has to have service and support, without it, and trained mechanics, it may flop, cause people don’t want to, and don’t know how to maintain or repair it.
I don’t think there was anything “wrong” with the Porsche motor was there?

So I think it’s going to take someone like Yanmar or Volvo etc to launch a successful Hybrid.
A company with no dealer network and service and support is going to have problems.

[barnakiel]

Many day charter trip boats in Le Marin are electric. They use Torqueedo and one other make which I did not collect the name.

They are small boats though - maybe up to 1 ton, I think.

I have also seen a superb and elegant maxi yacht launch this year. This one could be anything between 1 and 2 tones. I bet on the lower figure as it could be a carbon hull too.

b.

[Corvidae]

Originally Posted by StuM

Something way wrong there. To limit that engine with a design spec of 3000-4500RPM to 1700 RPM means that there was something very strange about the transmission gearing or prop selection.

4500 is the red line for the engine when it was used in cars, really terrible cars. Anyone in them at the time they reached that rpm, were probably screaming in terror...while traveling well under the speed limit. They're honestly great sailboat engines though. Lots of torque at low rpm for big props, very similar to electric motors.

[storx]

Wow,

I didnt expect people to take this posting personal, calling me an idiot is a little childish....

In regards to my Car that i brought up previously, 2012 Chevy Volt.

The chevy volt is NOT a hybrid, it is an electric car with gas range extension. The electric motor powering the wheels is used both when pulling power from the batteries or when receiving electrical power from the gas engine. The gas engine is not connected to the wheels in any way except via electrically. The electric motor powering the car is 150hp/275tq rating at 0rpms. The gas engine onboard is 78hp/61tq rating at 6300rpms. The gas engine turns a 2nd electric motor rated at 55kw, to generate power for the drive electric motor to continue driving. When i am cruising here in Florida on I75, my gas engine rpms typically run just under 900rpms according to the display for me maintain a cruise control speed of 75MPH. Basically i have 275lbs of tq on tap to be used instead of the 61lbs of tq the gas engine puts out at 6300rpms.

In regards to folks calling me an idiot for wanting to ruin a boat by converting it to electric and adding a bunch of weight. I did not state i was the owner of an electric boat, i did not tell or say i was going to convert one to electric. I purely asked if anyone else was using them, i had never heard of a boat being powered by electric motors before and was curious how many others out there are trying it out.

In regards to the electric vehicles i brought up, i have friends in the mining industry up in canada, he has told me about all these vehicles they have recently replaced with electric versions... plus i travel to south korea often and they were using a bull dozer there for demolition that said electric drive on it....

I think a lot of folks are hung up on the batteries, the person i brought up who converted his boat to electric did not intend to run the electric motors off batteries alone. He bought a damaged boat for a fraction of the price with already damaged engines in the engine room from an unknown water leak situation. Both of the diesel engines were heavily damaged according to him and would need to be rebuilt due to sea water entering the internals of the engines. When he had a mechanic price him on rebuilding and bringing both of the drive motors back up to shape it was in the ballpark of 30-40k he told me. So he sat on the idea of buying the boat from the owner and haggled him down on the price heavily to make it worth his time, plus in his mind he said if he would have rebuilt the diesel drive motors that he would have had a fresh engine boat for less than some of the boats he looked at with already running engines in similar shape elsewhere outside of the engine room.

In regards to the batteries, he told me the old batteries that were in the engine room were unusable. So from the start he needed new batteries and 2 diesel engines to be rebuilt and if he was to keep them, the generator on the boat was already repaired previously by a mechanic with intentions to rebuild the main engines, so it was in good running order with fresh rebuild.

So after a lot of research he bought electric motors roughly equal in output to the diesel motors that where on the boat, he mentioned they were curtis motors with rated output of 190hp @144v each with controllers in a kit for 15k and he payed another 1k for the converter that converted the output voltage from the diesel generator he had so he could input the correct power from the generator directly to the electric motor circuit. So he disassembled the diesel engines in the engine room so they would be easier to remove and painfully had them removed from the boat, after removing those engines he had a local boat shop purchase them from him for 10k he mentioned.

After the diesel engines were removed, he repaired the engine room and had brackets made up to install the electric motor kits he purchased while he sourced batteries. He wanted to go lithium for more storage and range on the electric motors, plus double the use of them as house batteries to run the boat electrical system, so he won an auction on a totaled tesla model s for just under 8k and removed the battery modules from the tesla he purchased along with added a few extra modules over time he picked up from ebay for good prices. He said he rewired the boat so everything ran off the tesla battery bank.

The intentions he said of the build was to run the boat off the voltage from the generator with the battery bank as a buffer, but he underestimated the amount of load he uses while cruising with the boat, so he is in the research phase of figuring out what to do with that side of the system. He has since added solar to the boat to trickle charge the batteries.

His ideas he brought up in our conversations was the possibilities of adding a 2nd generator to the boat with custom generator output of 144v, or upgrade his old generator to something larger and more efficient. He said if he adds a 2nd generator then he still has the ability to run the smaller generator for day to day use and use the new one mainly for driving the boat loads. He said there is so much more space in the engine room with those big diesel engines removed, that he could add a 2nd generator and even 2x or 3x his battery bank if he wanted to.

He told me he has less than 20k into his entire conversion from diesel drive to electric with the giant increase in battery storage with the tesla modules after taking out the money he got back from selling the old diesel engines. He also mentioned he has sold a handful of items off the tesla car to people for a few k along the way. His only reason for not increasing his battery bank is he said the prices of tesla's at the auctions has nearly doubled in price on totaled cars, with everyone wanting the batteries now the value of them has increased out of the range he is willing to pay for, but he keeps bidding on them with the hopes of scoring another for more modules.

Also a correction, i thought he said it was 41ft, he said his boat is a 44ft defever, not 41.. that he purchased it for 27k

[handmer]

Originally Posted by storx

The chevy volt is NOT a hybrid, it is an electric car with gas range extension. The electric motor powering the wheels is used both when pulling power from the batteries or when receiving electrical power from the gas engine. The gas engine is not connected to the wheels in any way except via electrically.

I think electric boats can and do work well in the right circumstances, so no argument from me there.

But a correction about the 2012 Volt, because technically correct is the best kind of correct.

First of all, no connection from the ICE engine to the wheels is called a serial hybrid. A hybrid car is literally just one that uses two or more types of energy storage.

Secondly, the Volt is a series parallel hybrid, as the ICE engine can send power to the wheels via a mechanical linkage.

It caused minor controversy at the time, because Chevy marketed it as an electric car with ICE range extension. But that was only because they created their own definition of what counts as a 'direct' connection to the wheels, or not.

The drive system is complex, but basically it has a large motor that directly drives the wheels through a planetary gearbox. It also has the IC engine connected to a generator, and the generator can also act as a small motor, connected in via a different part of the gearbox. The ICE can drive the generator only, acting as a range extender.

At higher speeds the main electric motor is spinning fast and is not as efficient, so the generator can engage as an electric motor with a higher gear ratio - acting as a 'second' gear of sorts, improving efficiency.

But the IC engine can also be engaged to the generator while it engages to the gearbox, creating a direct mechanical link between between the IC engine and the gearbox.

The catch is that because of how the ICE then drives the planetary gearbox, the main electric motor must also provide some torque at the same time for the system to actually drive the wheels. So the ICE cannot be used to drive the car without some input from the main electric motor.

Chevy got creative here and decided that since there was 'no fixed gear ratio' between the ICE and the wheels (since it was dependent on the torque from the electric motor) that it did not count as a 'direct' link.

Semantics aside though, there is an actual mechanical link through from the wheels to the IC engine if engaged. That is a good thing though, since it only engages it when doing so improves the efficiency.

I found more info here - Chevrolet Volt Electric Drive Propulsion System Unveiled - GM-VOLT : Chevy Volt Electric Car Site GM-VOLT : Chevy Volt Electric Car Site