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Electric Propulsion - solidnav.com

52K views 186 replies 38 participants last post by  510datsun 
#1 ·
I have a friend who is involved in a company called Solidnav. They are selling electric sailboat re-power gear. I thought that it would be neat to hear from anyone who had actually done an electric conversion and see how their conversion went? Who did you go with, and how did it work out?

I've looked a bit and I see a lot of DIY type stuff and then the really expensive saildrives, but little in-between. Would any of you who have done an electric conversion try a product like the Solidnav Explorer in a re-power?

The first one off engine that they made worked well, and it seams that they have solved a lot of issues in the first run that remain on other systems production units. The motors are not brushed motors, the controller is sealed, it is belt driven with a reduction gear, etc.

I guess I am sold on the product, but then I am close to it as well. The Engineers seem to have done a lot right. What do you think?

solidnav.com
 
#2 ·
Not for me.

Not enough sun here boys, and none at night.

"Remove your portion from our oil burden while silently cruising into distant harbors".... what????

Beware you don't get swept along with the great global warming cabal.

In blazing heat, through the doldrums, with solar cells everywhere, an 8 kW electric motor will move your ship ok, but from where would you get the energy needed... 8 kW+ ?

And how fast would solar cells really move a 10 ton ship? It's not the power of the motor that bothers me. they could list 100 hP in there. The vital questions is the energy source, not the power of the motor.

Be sceptical.
 
#3 ·
That is a very NEW company. For the last three years I have pretty much been to every "e-power" website - this was not one of them. Re-e-power has been in the business the longest and even they have problems with keeping up, and the changes they have to make.

The one crucial thing to consider in any endeavor of this type is that they require huge battery capacity. No way any amount of solar unless your hull and deck is made of solar panels - do you get "free energy". The regen capabilities are only a small fraction of the total battery capacity to begin with.

Hence why Soloman, Volvo, and other hybrid sail drive manufactures bundle in generators otherwise you would be limited to 4-6 hours of engine time before needing to spend 12 or more hours recharging. Lets face it - rarely if you are cruising is it always under sail. Here in the PNW I spend more time motoring to get somewhere - unless its a daysail and I don't mind drifting around a bit.

If all you do is casual day sailing - maybe its all worth it as you are not doing anything extended in lines of point to point traveling. Otherwise - you have to look at the actual nature of what you can accomplish with one of these units. But I would say beware - there are no reviews and the company in question maybe just a fledgling company trying to make a start - but in the end you might want to know that for warranty issues etc they will be around awhile...
 
#5 · (Edited)
It looks like they have a good product, nothing new, which is good.
They are using 48volts which is also good. Almost every boat has room for 4- 12volt batteries.

I will consider this system closely as I would like an elect drive for various reasons.

As already mentioned to get any range at all you will need a generator. There are applications where you wouldn't need a diesel gen. These include: Day sailing where motoring out of the harbour only takes a few minutes, offshore sailing where harbours are days away, and for sailors who can adapt to not always having an engine or having to conserve the use of motoring.

The reason electric drives have not taken off is not technical. They always have been a very viable alternative, even superior in many cases but they have a major problem.

All the patents needed for electric propulsion have run out. Electric drive systems are so much cheaper that no major company is going to make billions. Even if they "caught on" and started to sell some company in India or China could undercut the market, heck people can just build them in their garage.

And many do. thousands of people have used electric drive systems. General Motors says they cannot make an electric drive car for less than hundreds of thousands of dollars each but thousands of people have converted cars for less than $20G.

Most of the negative views and opinions about electric drives are a result of the established industries advertising against a competitor. Objectively electric drive systems are better in most applications and this is true for sailboats which already have a need for large battery installations.

It is even better for motorsailors because the generator, battery, motor system gives much better fuel economy and the ability to use power other than that derived from diesel.

The only down side is the high up front cost. People wont insulate their homes to save money later so it is with removing a perfectly good diesel engine and replacing it with a more expensive motor-gen-battery system.

EDIT: They do have these systems available on about 3 weeks notice, which isn't long to wait considering it is a complete engineered package (sans batteries of course).
 
#6 · (Edited)
There is no way on this earth, with earthly laws of physics, that a fuel-driven electric generator, feeding mechanical energy to a generator, then electrical energy to a motor, and from there mechanical energy to a prop will EVER out-perform the direct drive-to-prop diesel in the first place. There is just no way that can happen.

What am I missing here?

If you want something quiet to get you in and out of harbour, then perhaps, but this stuff must not be advertised as being capable of prolonged motoring into a tide, or headwind, or chop, or all three.

It won't cut it, unless you have a very big battery bank indeed, and a lot of time to charge it.

For example, 25 hp (shaft power at the prop shaft) for 6 hours is about 112 kWh delivered, and probably about 1/4 more than that is needing storing to deliver on it. They will not try to deliver that at 12V, but, if they did I calculate the energy storage to be (corect me if I am wrong)...

112 kWh * 1.25 = 140 kWh = 140,000 Wh = 140,000*3600 = 504 MJ

.... call it E.

If you are to find E from your battery bank, then...

E = current*voltage*time

E = I*V*t

Make the product of I*t the subject...

I*t = E/V

Say, for argument, your power is delivered at 12 volt...

I*t = 504,000,000/12 = 42,000,000 amp.second

= 11,666 Ah

My current house battery is 275 Ah.... that is about 1/42 of what would be needed for 6 hours motoring.

That was 6 hours motoring, and I'd need 11,666 Ah to do it, discharging the batteries to nil to do it.

My current tank capacity will keep the motor running for about 30 hour.

Pls correct me on this one there guys. Did I get it wrong?
 
#9 ·
There is no way on this earth, with earthly laws of physics, that a fuel-driven electric generator, feeding mechanical energy to a generator, then electrical energy to a motor, and from there mechanical energy to a prop will EVER out-perform the direct drive-to-prop diesel in the first place. There is just no way that can happen.

What am I missing here?

If you want something quiet to get you in and out of harbour, then perhaps, but this stuff must not be advertised as being capable of prolonged motoring into a tide, or headwind, or chop, or all three.

It won't cut it, unless you have a very big battery bank indeed, and a lot of time to charge it.

For example, 25 hp (shaft power at the prop shaft) for 6 hours is about 112 kWh delivered, and probably about 1/4 more than that is needing storing to deliver on it. They will not try to deliver that at 12V, but, if they did I calculate the energy storage to be (corect me if I am wrong)...

112 kWh * 1.25 = 140 kWh = 140,000 Wh = 140,000*3600 = 504 MJ

.... call it E.

If you are to find E from your battery bank, then...

E = current*voltage*time

E = I*V*t

Make the product of I*t the subject...

I*t = E/V

Say, for argument, your power is delivered at 12 volt...

I*t = 504,000,000/12 = 42,000,000 amp.second

= 11,666 Ah

My current house battery is 275 Ah.... that is about 1/42 of what would be needed for 6 hours motoring.

That was 6 hours motoring, and I'd need 11,666 Ah to do it, discharging the batteries to nil to do it.

My current tank capacity will keep the motor running for about 30 hour.

Pls correct me on this one there guys. Did I get it wrong?
If this is true than why are almost all cargo ships and ALL locomotives diesel/electric and have been for 50 years?

MedSailor
 
This post has been deleted
#8 ·
What am I missing here??
A: The efficiency increase in the diesel engine being used to drive the generator.

Many drive systems do not have the diesel engine directly connected to the drive wheels or propeller and most do not use the battery bank. A sailboat would because it has many other uses for a battery bank, including silent drive mode.

And your are missing the fact that it is not a straight conversion of HP to KW when looking at replacing a diesel with an electric drive. The drive in question is using a 4KW system (7.2KW peak, 48v@150a) to replace a 24HP system. Again efficiencies of the electric system and the inefficiencies of the diesel system are not being taking into account.
 
#10 ·
trolling motors

Another short term option for using electric propulsion is a removable trolling motor. It will not push your boat very fast, but is possible to dock, anchor, tour close to shore and motor sail effectively with no noise and not having to warm up the diesel. It is not possible as the only propulsion source, but can be a great add-on. The new Torqeedo 2.0 looks sufficient for our 33' boats for that purpose.

We used a pair of EM54 Minn Kota trolling motors one season on our Pearson 33 day sail charter boat. These trolling motors on brackets wore out because they are not meant to be towed or left in the water. We did use it for 1-4 hours per day for about 70 days. With both of them on, we could go about 2.5-3 kts. It was a 24v system and would run at about 30 amps, if I remember right. On two 3 hours sails with almost no wind, we used about 200 amp hours on the heaviest days. There were weeks doing twice-per day trips that the diesel was not used at all. Our docking situation is simple, so that helped. The best part was that you can just flip a switch for instant power. We were able to sail into situations that most people would use the motor and have the instant boost of power if the wind failed us. A little boost on light wind days to get to another puff of wind, or just to get some air moving over the sails really cut down on diesel motoring.

Experimenting with electric drives is fun and will drive technology. What we need is an electric motor that works on the current drivetrain when needed. Briggs & Stratton made a brushless motor (Etec?) that was about 8 hp, worked in both directions, charging and driving, and was for golf carts.
 
#11 ·
trolling motors

Another short term option for using electric propulsion is a removable trolling motor. It will not push your boat very fast, but is possible to dock, anchor, tour close to shore and motor sail effectively with no noise and not having to warm up the diesel. It is not possible as the only propulsion source, but can be a great add-on. The new Torqeedo 2.0 looks sufficient for our 33' boats for that purpose.

We used a pair of EM54 Minn Kota trolling motors one season on our Pearson 33 day sail charter boat. These trolling motors on brackets wore out because they are not meant to be towed or left in the water. We did use it for 1-4 hours per day for about 70 days. With both of them on, we could go about 2.5-3 kts. It was a 24v system and would run at about 30 amps, if I remember right. On two 3 hours sails with almost no wind, we used about 200 amp hours on the heaviest days. There were weeks doing twice-per day trips that the diesel was not used at all. Our docking situation is simple, so that helped. The best part was that you can just flip a switch for instant power. We were able to sail into situations that most people would use the motor and have the instant boost of power if the wind failed us. A little boost on light wind days to get to another puff of wind, or just to get some air moving over the sails really cut down on diesel motoring.

Experimenting with electric drives is fun and will drive technology. What we need is an electric motor that works on the current drivetrain when needed. Briggs & Stratton made a brushless motor (Etec?) that was about 8 hp, worked in both directions, charging and driving, and was for golf carts.
 
#12 ·
Medsailor...

You have got this wrong.

By "diesel electric" you are referring to a power system that has a generator, an electrical power line, and a remote motor. The reason why they do this is to avoid the mechanical engineering involved in coupling a big motor to a big prop. Also, the generator serves a power for the ship also, BUT IT IS RUNNING ALL THE TIME!!!! Diesel electric trains do it too, and for reasons of coupling also, particularly with multiple drive wheels on the loco.

What they are referring to is... and I quote...

"Picture yourself in pristine lagoons and allow the power of the sun, tides and wind to replenish your cruising. Motor away from distant fuel docks of unknown diesel quality without bating an eye. Remove your portion from our oil burden while silently cruising into distant harbors. Live the Solidnav shift, change your world. "

This is charging a battery, then running constant loss on the battery, and no-doubt having to compete with the sort of energy delivery I calculated.
Is that what you mean by "diesel electric"? ...because that is not what ships have and not what trains have.

Where does the energy I describe come from?... does anyone plan to store even a fraction of that in a battery bank???. How far would you get before you have to start the diesel to drive the prop. When you do, you would be much better to save energy a-plenty by joining the prop to the motor by a shaft and dump the generator, cabling, and motor.

There is just not enough energy stored in the battery bank, this side of sanity.

For a submarine submerged it can work for a while... another type of "diesel-electric"... but have you ever seen the battery bank on one of those beasts?
 
#13 · (Edited)
What they are referring to is... and I quote...

"Picture yourself in pristine lagoons and allow the power of the sun, tides and wind to replenish your cruising. Motor away from distant fuel docks of unknown diesel quality without bating an eye. Remove your portion from our oil burden while silently cruising into distant harbors. Live the Solidnav shift, change your world. "

This is charging a battery, then running constant loss on the battery, and no-doubt having to compete with the sort of energy delivery I calculated.

Where does the energy I describe come from?...

There is just not enough energy stored in the battery bank, this side of sanity.
You do not yet understand how these systems work. They do not need the batteries to see the reduced fuel costs and the use of batteries can remove the need for diesel.

The Solidnav system recommends using windmill generator, solar, tow drogue generator, and regenerative power under sail, to achieve the "Solidnav Shift" with no diesel. If you are sailing away from the diesel pumps you can be charging the batteries. That would be the same battery bank you could use to run other, or all, electrical items on the boat.

This "Regenerative power" is produced whenever the system is on, and the boat is under sail, moving fast enough to cause the propeller to rotate. This rotation causes the electric motor to act as a generator. You can adjust how much charging occurs once you are above the minimum speed required to generate.

This means that if winds are light you might discharge the bank to add to the sailboats speed and then recharge later when the wind picks up. It would be a different way of sailing which I expect would take some getting used to.

And the assumptions you used for your calculations are incorrect which is why your calculations and understanding appear insane. A little more research should have you seeing why these drive systems are so much more efficient. Maybe start here: solidnav.com/faqs.htm
 
#14 ·
I'm with Rock on this one BUT...things are getting interesting with the new battery technology and I can imagine a day in the not too distant filter where a diesel gen and electric motor, with an advanced battery bank may be the preferred way to build a boat and go to sea.
 
#16 ·
I think you "Einsteins" need to read more...
Good link but we don't all figure things out the first time. I seem to recall it took Einstein a while to get his head around the need for ether. :D
 
#21 ·
I think your link to the benefit of Diesel/Electric drives has been a major contribution to anyone wanting to learn more. Thank you.

I just find some posts confusing. :confused:
 
#18 ·
Arch... what you are saying is TOTALLY impractical on a cruising sailboat. This is so ridiculous I can't even begin to refute it. Tell ya what...as soon as someone crosses the Atlantic or Pacific with their cruising electric motor sailboat and NO diesel...let me know. The FAQ's you reference are a complete joke and lack any substantive information. This is presently smoke and mirrors.
 
#20 ·
This is really very old news, there isn't anything new being posted or suggested.

Electric motor sailboats have been around since, well, since before diesel engine sailboats. This technology using Pulse Width Modulation is more efficient but has still been around a long time.

And yes people have crossed oceans with this type of drive system. Solomon technologies has been around for years: The longest-distance STI customer we know of - a retired Los Angeles physician - has been at sea for years with a battery-bank-only system and no backup generator. He has successfully sailed the Pacific to Tahiti.

This technology has been used in electric cars for years. They do not get the same regen effect because they cannot get motive power from the wind. If they were to only drive down hill I guess it would be similar.

As for the idea that it is better to have a diesel motor run a generator which then runs an electric motor for power, that is well over 50yrs old and is in common use every day.

I'm not sure why people are not aware of this. It hasn't been a secret. The only problem has been the extra cost of the installation. Like insulating your house it can be hard for some people to understand why it is a good idea but once you look you will notice that lots of people insulate and lots of people (not as many) use electric drives.
 
#19 ·
power density of combustible fuels is orders of magnitude higher than that of electric batteries we have today. until fuel cells arrive - all this electric stuff is a total bs. look, on one hand everyone runs around wondering how to reduce electric use so that running a tiny pathetic refrigerator for a day does not kill batteries. and yet someone can seriously propose pushing the entire boat with this? This is just ridiculous, no other words for it.
 
#22 · (Edited)
Arch...

You have got your head stuck up the wrong end of your digestive tract.

I will quote you here...

"As for the idea that it is better to have a diesel motor run a generator which then runs an electric motor for power, that is well over 50yrs old and is in common use every day".

Are you seriously pedalling the idea on this website that it is better to run a diesel engine, couple it to a generator (take the losses in generating power there), then cable the power aft (taking losses again), then covert the electrical power to shaft power via an electrical motor (taking losses again)... than to couple the diesel directly to the prop via a shaft? All those losses compound.

Is that what you believe?

Are you serious?

You don't need to be Einstein to kick that idea up the sexual organ.

No-one is denying the existence of diesel-electric systems, but they exist primarily because of the ease of transmitting power along a tortuous (or mis-aligned) paths, or to multiple motors (on mulit-wheel power vehicles, for example). They are NOT used for their efficiency, just like hydraulic systems are not either.

On a sailboat, and it's practical, it is far better to couple the motor directly to the prop via a shaft. I promise you that a diesel electric system will NOT be as efficient, because the combination of generator, cabling, and electric motor will not be as efficient as the shaft. The generator, and the motor will heat up and throw the energy into the engine room.

I have not seen a prop shaft heat yet, in 20 years.

This diesel electric idea, running off a big battery bank, simply cannot store enough energy. Certainly, the batteries can turn the prop for a while, but not for long.

If my calculations are correct above.... pls correct them if not so... then just one hour 25 hp net, will need a battery bank of close to 2000 Ahr (12V base line calculation), and run to exhaustion. What will that weigh? Where would I store it? What will it cost?

I'd sooner have my diesel, and its 30 gal tank. I reckon that's worth about 58,000 Ah, and about another 8,000 Ah in each of the ship's two Jerry cans. My ship simply cannot carry a battery that big to compete.

In the dead of night, into a headwind, and chop, with the wind rising, and a young crew looking at me for what to do next, I'll settle for that, and it's just a key fob away, it charges my ship's batteries when I start it, AND IT'S MORE EFFICIENT AT TURNING THE PROP THAN A DIESEL ELECTRIC WITH THE SAME PRIME MOVER BECAUSE I DON'T NEED A GENERATOR, CABLING, AND AN ELECTRIC MOTOR.
 
#23 ·
Arch...

You have got your head stuck up the wrong end of your digestive tract.

I will quote you here...

"As for the idea that it is better to have a diesel motor run a generator which then runs an electric motor for power, that is well over 50yrs old and is in common use every day".

Are you seriously pedalling the idea on this website that it is better to run a diesel engine, couple it to a generator (take the losses in generating power there), then cable the power aft (taking losses again), then covert the electrical power to shaft power via an electrical motor (taking losses again)... than to couple the diesel directly to the prop via a shaft? All those losses compound.
You Einsteins seriously need to read more.

I'll just respond to that quoted part because like smarter people before me in this thread I've had enough.

Of course there are losses in such systems but it is when they add up to less that makes the diesel/Gens more fuel efficient.

A quote from the already supplied link:
To get started it should be acknowledged that placing a motor and generator between the propeller and diesel engine does indeed introduce new losses into the drive train. These losses can range from relatively minor to very significant and are directly proportionate to the efficiency of the motor, motor controller and generator. Different motor technologies and construction methods result in products of widely varying performance. Using a greater number of thin laminations will result in a more efficient, though more expensive, motor or generator than if they are built using fewer and thicker laminations. Similarly, saving energy in the controller means spending more on the electronic chips that control the flow of power.

It's not only a matter of spending money, but also one of developing and applying the most appropriate technologies. Some motor designs are quite efficient at one speed/load condition but drop off quickly as soon as the speed or load changes. Others have a much flatter efficiency curve. The collective impact of these differences can be huge with real operational efficiencies varying from better than 98% to as low as 72% for motors and typically between 97% and 84% for generators. This means that for every 100 HP out of the engine you could obtain as much as 95 hp at the propeller shaft or as little as 61 HP. At the high end this compares favorably with the 3% to 5% loss typical of a mechanical transmission (although not all electric motors can be directly connected to the propeller shaft).

Considering these electrical losses, is it really possible to improve energy efficiency? The answer is clearly yes, so long as the basic efficiency of your motor, generator and controller is high. What you are relying on is that you can improve the efficiency of other parts of the system by more than the new losses you have introduced. Fortunately, if the electrical system losses are relatively low, this isn't too hard to do. It turns out that there are many limitations inherent in conventional direct diesel drive that waste fuel. By making more efficient use of the engine and propeller it is possible to more than offset the electrical conversion losses.

The foundation for this saving comes from the fact that, in a well-designed diesel-electric drive system, the power required by the propeller is "decoupled" from the diesel engine speed. In other words, in a diesel-electric system, the engine/generator could theoretically be running at full speed (100% output) while the propeller is only tuning at 50% of peak speed so long as the motor is sized to handle the power. Similarly, if the propeller were lightly loaded, the engine/generator might only need to turn at low speed to provide enough energy to drive the propeller at full speed. This means that diesel-electric systems can be much better at "self-optimizing" to accommodate varying loads than are conventional systems. At sea, load conditions change by the trip (number of passengers), by the hour (wind and tide) and by the minute (going up a wave or surfing down it). These variations provide a significant opportunity for fuel savings.


As for batteries being used, there has already been one post saying it can be done. Since many sailboats have no engine (gee I guess that too is impossible) it would seem that a trolling motor would be an an obvious improvement, but I guess not to some.

My professional associations would also suggest I charge for this.

Or are you guys just kidding? You must be joking, people cannot be that opinionated and ignorant at the same time.

HaHa you got me but thats the last time in this thread, try another.
 
#24 ·
What about that Swiss (non-sailing) catamaran that crossed the Atlantic using (I believe) only solar power to drive electric engines? I believe that they covered the whole boat with solar panels and are now touring the states. The trans Atlantic trip was done to prove the concept although I know none of the technical details.
Are there commercial ships using the diesel-electric marine power set up that Giu/Alexa mentioned? If the big boys are using it already then it can't be too long before it comes into wider use.
 
#25 ·
There is a difference in terminology here that probably creates some miscommunication.

When diesel generator drives electric propulsion, what we have is in essence another type of transmission - mechanical, hydraulic and sometimes electric. It has its advantages and disadvantages, I am sure.

This is not the same as true electric propulsion - which really isn't so much about the motor but about the fact that energy is stored not in a form of liquid combustible fuel, but in a form of electricity stored in a battery.

The former is a viable transmission option. The latter is not viable at the current level of battery technology.
 
#26 ·
There are only two kinds of electric propulsion.

1. Totally powered by renewable resources using the batteries as the storage.

2. Hybrid where mechanical means are used to generate electricity and charge the batteries - sometime in combination with solar, wind, turbine power.

There are no others.

The company in question - has very much the same mantra as Re-E-Power. And for further clarification - electric propulsion is usually defined as that powered by the batteries where a sail drive propulsion is categorized as being that which has mechanical assist from aux gen sets.
 
#27 ·
Let's look at this from another direction - weight vs range.
So, my boat currently has an approx. 50hp (50kW) engine and a 50-60 gallon fuel tank (it's inside the keel, and I don't know for sure as I try not to go on empty, the fuel on the bottom is pretty nasty). 50-60 gallons of diesel (at 7 lbs a gallon) weight something like 350-420 pounds.

Now, the engine from E-POD system (they had a spec) provides an equivalent of 7-9 hp outboard (yikes) and has a max. continuous amperage of 170 amp (and recommended cruise amperage of 50 amp, which clearly would provde about 30% of max power, or 2-3 hp). It is also 24-48v, which of course makes a lot of difference, but let's assume 24v somehow (24v * 50amp = 1200 watt, or 1.2 kw or about 1hp, at 48v it's 2 hp - but hey, 1 hp is aplenty for a boat, right?).

Ok, so 50 gallons of fuel last me from 50 to 75 hours. Let's go with 50, just to give electric a headstart. We'll need 50*50 = 2500 watt-hours of 24v electricity to run this thing. Now, modern battery amp hour ratings are given at 20 amp draw (and go down with higher draw) but we'll assume the best. So, our favorite 6v golfcart dekas are 215 amp hours each. We would need 4 times each for 24v and then 12 times groups of 4 for 2500 watt hours. Total of 48 batteries. At 65lbs each, thats about 3000 lbs. I suppose if you replace the ballast with batteries that might just work :) 3000lbs may be a bit difficult to stow though, what with carrying each of the 48 batteries. Of course since you can't discharge the batteries all the way (unlike the fuel tank), you need twice as much - 100 batteries, 6000 lbs :)

Of course that just gave us a system that is 50 times less powerful (1hp vs 50). For more power, don't forget to multiply the battery count and weight times 50 :) :)

With current lead-acid battery technology, electric propulsion is just not there. Anyone trying to sell it is either a crook or a nutcase.
 
#28 ·
I used to have an electric Ford Ranger available for my use (because everyone else hated it) that I drove whenever possible. Only had three drawbacks, the batteries, the batteries and the batteries. They were really heavy, discharged too fast even with regenerative set at max, and took 10 times as long to charge as they would run. Only repair for any breakdown (there were several) was a tow to Ford Motor Co., you'd get in and it was just dead. No way to troubleshoot or duct-tape a repair. Until we get giant Li-Ion laptop type batteries or dependable fuel cell I'll stick to diesel. If worse comes to worst you can always homebrew a little something that'll make it run long enough to get to sea.
 
#30 ·
This was actually a very informative thread. Not so much about technology but how it is perceived. Thanks.
 
#33 ·
Interesting comment.

I agree.

Intelligent people can see a sales pitch of an, shall I say, 'undeveloped product', when it hits them in the face.
If it doesn't actually work more efficiently than current technology, it doesn't have a hope.

Keep working on it, and get back to me in a few years.
Good luck. :)
 
#32 ·
We never got there. People haven't got past the point of understanding that these systems are already proven, used for over 100yrs, used in most of industry (including the shipping industry) and used every single day in everything from trains to the car down their street.

It is a very long way from that to talking about the numbers. Those numbers are not can it be done but is it cost effective to use on such a small scale as a 5 ton sailboat. It seems so given the success of the 420 Cat but is it for a conversion? Maybe.

Still talking about how impossible such systems are preclude any discussions about numbers. At least numbers of value. Look at the numbers used so far, they mean nothing. When people refuse to even read the link explaining the reality of such systems it is safe to say that posting numbers is best saved for another thread.

Maybe start another thread? It is going to be hard to get this one to be taken serious.
 
#34 ·
Ok, more wishy-washy stuff, no numbers still. I am not aware of any significant number of large ships that use battery-stored electricity as their source of energy, but perhaps you can point me in the right direction.

I would also be interested to see a simple and specific example or proposal on powering a small craft (such as an average sailboat) using electric propulsion with battery stored energy, for a realistic use profile.
 
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