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Converting a yacht to electric propulsion - maximise hydro generation

tcmtech

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Because that's how he chose to post it. :rolleyes:

Linguistic OCD issues? :confused:
 

large_ghostman

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Normally at this point I just stop posting, but you av got luky (not have got lucky), What i have in mind would make a really good post for one of my blogs. So I am building a small scale version to see if it would scale up at reasonable cost. If it does then you have a solution that is relatively cheap and apart from the buying of a few materials, the actual generation of the electric is free of charge. As long as we except free means you will have to replace a couple of very very simple parts now and then.

So One last time are you solely looking for complicate hydro means or are you interested in a simple system with fewer parts? Until i build the micro system (i am about 30% through it), I cant give you figures as to how much electric it will produce. But if it is viable it will produce electric around the clock for you, so this makes it suitable to charge up battery banks. It works alot better with tides or motion but will even work moored up for a reasonable periods.

Two questions I dont know the answers to yet, can it produce enough to be worth doing. Can it last long enough before you need to replace a couple of things, to make it worth it. A simple small scale model in the lab will answer both questions, if it works with a slightly different material to the one I have in mind, then potentially its a very cheap way to make energy at sea. It wont make enough to power your engine on its own, but it will make enough to recharge the battery bank in a reasonable period.

Drag wise, depending how you fit it or set it up, you could add hardly any drag. I got the idea from something else I am looking into and from something thats been tried on a much larger scale already.
If you want to focus on Grammar and spelling then honestly I am not the person your looking for. If you want outside the box thinking then maybe i am.
 

tcmtech

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If you want to focus on Grammar and spelling then honestly I am not the person your looking for.
He's from the UK which we all know is not a place well known for having superior proficiency in and of the global English language by any means. :p

Also being both our spoken and written languages are adaptive living languages regional and even local sub dialects, grammar and whatnot adds sub layer variants to things that can make two or more ways of saying something correct even if they are in formal contexts contradictory to one another when viewed from the opposing local standards.

I know my northern midwest ways of saying some things is different than how someone from the deep south US says the same implied points. Both are correct in local contexts even if neither reads exactly right and proper by classic formal standards. ;)

Rather why grammar naziing anyone almost always fail and immediately collapses in on itself over some simple oversight. :facepalm:
 

large_ghostman

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Generally i spot my mistakes but dont correct them, i figure your smart enough to know what i mean or your not going to be smart enough to do it. As i am not getting paid i tend not to consider it my obligation to correct errors i deeem offf no use.
 

tcmtech

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I do a once over with spell check and then a quick proof read then post. If its a bigger or more important write up I will do a re read of my post a hour or two later when whatever I posted is not fresh in my mind so I have a better chance of catching the words that spell check wrongly substituted or the sentences that just dont read right.
 

camerart

Active Member
He's from the UK which we all know is not a place well known for having superior proficiency in and of the global English language by any means. :p

Also being both our spoken and written languages are adaptive living languages regional and even local sub dialects, grammar and whatnot adds sub layer variants to things that can make two or more ways of saying something correct even if they are in formal contexts contradictory to one another when viewed from the opposing local standards.

I know my northern midwest ways of saying some things is different than how someone from the deep south US says the same implied points. Both are correct in local contexts even if neither reads exactly right and proper by classic formal standards. ;)

Rather why grammar naziing anyone almost always fail and immediately collapses in on itself over some simple oversight. :facepalm:
Hi T,
Thanks for the enlightenment, I assume you are referring to me, I have slight dyslexia so reading is sometimes quite an effort, if I don't know the meaning of something.
C.
 

large_ghostman

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Hi T,
Thanks for the enlightenment, I assume you are referring to me, I have slight dyslexia so reading is sometimes quite an effort, if I don't know the meaning of something.
C.
Ok i think we have crossed wires.
I think maybe you asked a question and I didnt see it as a question, i saw it as a dig.

All i really wanted to know was, are you set on some kind of hydro system that maybe turns shafts etc etc. OR are you open to completely different techniques to generate electric? no fidget spinners no coils no more energy out than you put in. BUT Your post jogged a memory of a trialed Magnesium battery that was really simple in design, they used a decommissioned oil rig a few years back.

Seawater acts as the electrolyte, magnesium shows promise especially as a alloy, the main issue is Magnesium Hydroxide builds up on the electrode, this is negated in a sea vessel by movement and currents as it washes it off. I have been looking into alternative non led based batteries from renewable energy storage like wind turbines. magnesium was one tech we looked at, no good in our situation because it was stationary.

No good for you on its own but it produces alot of energy constantly so would suite as a battery recharge system. Out of interest i am rebuilding one on the bottom of a model boat, just to see if its got any merits.
Also in your situation your looking at linear technology chips and harvesting energy from every nook and cranny you can find.
 

cowboybob

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Given the OP's title: ("Converting a yacht to electric propulsion - maximise hydro generation" ...), my initial reaction was, assuming the yacht was a sailboat, Why would you even consider it?

Electric propulsion has been a mainstay of submarines since their inception (well, excluding the CSS Hunley, a local effort a few years back). For surface ships, the only examples I'm aware of were the Sub-tenders I served on (Howard W. Gilmore AS-16 and the Orion AS-18. Both were diesel/electric). And we spent precious little time (as in practically none) at sea.

I only point this out because the conversion of fossil fuels or atomic fission (high energy density sources) for electric propulsion is hugely inefficient, and only the military can afford to ignore the conversion losses.

And for certain, all sailed vessels using passive energy scavengers, such as have been suggested thus far, are at best "trickle chargers" and only suitable for keeping a battery bank sufficiently charged to power the radio you'll need when you're broke down and/or in the doldrums and in desperate need of a tow... :nailbiting:
 

large_ghostman

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I think he is looking short term like into and out of Harbour, not sure if its every where but here you cant sail out under sail from a harbor over a certain size. And honestly around here i would power out anyway! So using the sea as a battery to charge a battery bank kind of makes sense, free electric from the point of view its a chemical reaction, use Mag wheel alloy for one electrode and its cheap, in reality you need alot of tiny ones.
Once you under sail they continue to charge your battery bank up, I cant find the paper on the oil rig test, but they ran a huge amount of equipment off of Magnesium rods dipped into the sea. The main issue was hydroxide build up, the tides helped but under sail in a boat this isnt an issue. The shape can be anything you want it to be, its light weight. Energy output is good but is it good enough?

This is what I dont know because I abandoned testing in favor of something better for my application. Wind turbine storage is something many people are looking into, Magnesium showed promise especially for sea based wind turbines, but again twice a day tides dont clear the Anodes enough. Hence now looking at Nickel batteries but Nickel is a bad idea in a sea type environment. Nickel Chloride Toxic waste in the sea dosnt go down well.

Anyway its a soap day!! Got cutting and packing to do not playing with chemicals :D.
 

cowboybob

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... Energy output is good but is it good enough? ...
Yours was the only one with merit, LG.

But, even still, the OP's quest is fraught with issues that will always point to non-electric motive solutions for when sails can't be used.
 

large_ghostman

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I have seen those under hull hydro things, they are hopeless. Mostly i have seen them on boats out the water having the seaweed taken out the tubes etc. Small wind turbines like those on canal boats give small amounts of electric, but depends what the use is. If this is electric engine to get out the shipping lanes and then sail, then yes recharging the battery bank 'free' is possible. But its a limited range and power thing, your going to quickly reach the point where the number of Batteries needed, takes alot of room and weight.

Actually in all honesty a small outboard is the answer unless we are talking short (<1mile) distance. after that you might as well use an outboard as the only real option is a petrol/diesel generator to recharge. Cost wise and the fact they get stolen, means your back to option A (out board).

I intend to try a magnesium battery on my little boat, but its function is to charge the batteries a little while the engine is off and radio etc is on. Once the engine is on it charges the batteries up pretty fast anyway.
Which reminds me i need to weld my trailer up!!
 

Frozenguy

Member
Using a turbine to harvest energy while using your motor to push through water? Do this instead:

Power your alternator directly from your motor. you'll have less loss than sending the power to the water for motion then extracting it again. Just extract at the shaft.
 

tcmtech

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Power your alternator directly from your motor. you'll have less loss than sending the power to the water for motion then extracting it again. Just extract at the shaft.
Show us the numbers behind that setup including efficiency losses relating to both the motor, 20KW, and the alternator, 2 KW, assuming a 95% efficiency for both.
 

large_ghostman

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Most Helpful Member
Using a turbine to harvest energy while using your motor to push through water? Do this instead:

Power your alternator directly from your motor. you'll have less loss than sending the power to the water for motion then extracting it again. Just extract at the shaft.
Whats wrong with the current place the alternator on a boat is?

I think the OP is on about charging while under sail, in that case it dosnt matter where on the engine you put your alternator! Your not getting anything out of it :D. If you got a aluminum boat and can get some speed up with it, i have a way you can make alot of free electric!! But you have to not mind holes appearing in the hull after a while :D
 

Frozenguy

Member
Whats wrong with the current place the alternator on a boat is?

I think the OP is on about charging while under sail, in that case it dosnt matter where on the engine you put your alternator! Your not getting anything out of it :D. If you got a aluminum boat and can get some speed up with it, i have a way you can make alot of free electric!! But you have to not mind holes appearing in the hull after a while :D
This is what convinced me he wants to recharge batteries by putting a turbine in the water, extracting energy from motion. motion created by a motor taking energy from those same batteries.
My calculations worked out that 15hp will be sufficient. If current units can produce 1hp with barely noticeable drag, surely I can get to 8-10hp?

To be clear, I want to produce the power while using the motor. If I can sail (conditions favorable) I don't need more than my existing power reserve and I intend to sail as much as possible, that's what I love and look forward too. Most offshore sailors recommend that you should be able to steam/motor for 1,000nm, best case scenario.
 

Frozenguy

Member
Show us the numbers behind that setup including efficiency losses relating to both the motor, 20KW, and the alternator, 2 KW, assuming a 95% efficiency for both.
Doesn't need to be a quantitative example. Same motor, same alternator; his example has additional features for loss: prop to water, water to turbine.
 

large_ghostman

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This is what convinced me he wants to recharge batteries by putting a turbine in the water, extracting energy from motion. motion created by a motor taking energy from those same batteries.
Now i am confused.....
So let me try and work this out..... Your saying he has a electric motor, your suggesting he connects an alternator to the shaft or whatever of the motor to recharge the batteries?

Do you think there could be a slight problem with this solution?
 

large_ghostman

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I can understand something like a small windturbine say on deck, maybe one of those vertical types. I have looked after QR% and QR6 vertical wind turbines all three were roughly 6KW output (max). Now lets forget a really bad design issue with them and pretend that dosnt exist. They are not that bad regarding drag, look at the blades on them and you see they are like airplane propeller blades.
image_2__79026.1453904758.500.750.PNG
So drag wise they are not too big a problem, forget the size as well and we pretend they are small and not around 3M from tip to bottom. So unconnected to a generator and the boat going along, those blades will spin at very high speed, they have an issue where they actually tend to spin past destruction of the bearings!

Sounds good for energy? Well yes and no. I have 3 of these at home that I decommissioned from a school, they have a narrow window of operation. The stated figures from the company are total wishful thinking, the actual figures are a min wind speed of 12mS and with a speed controller (this is the thing we are trying to forget they have) it kicks in at 14mS and allows the blades to run upto 24mS. The only point those turbines are not having energy fed in to keep the speed up or down is between 12mS and 14-16 mS, so roughly a window of 4mS wind speed before you need some of the energy produced to be used as a motor or a brake.

Now as i said drag wise they are not a problem until you stick a generator on, in the wind they will produce some electric, although nothing like predicted and indeed there is a report from surrey university, it describes how this model costs more to run than the electric it produces!! As soon as you put a generator on you will get drag, not a problem in the wind because your not paying for it, but on a boat the energy to overcome that drag will have to come from the motor.

In a perfect world the amount of energy used to balance the drag will equal the amount of drag, in the real world think of it as tax! There are losses or tax if you like. And like Tax, losses are everywhere in a system. But sat bobbing about on the water in a decent breeze and without the small issue with the control system, then yes it would make sense. 22 hours bobbing about should give you 20 mins power (roughly and adding in the control system error).

Your idea of a alternator works like this......

There is a shaft turning, and if you turn an alternator it produces power. These assumptions are both correct, but it isnt as simple as that. The universe says you cant get more out of a system than you put in. So in reality what happens is the alternator becomes harder to turn and this draws more current from the battery, in a perfect world it would be equal, you wouldnt loose or gain anything. In the real world you pay energy tax and it costs you more energy to run than it produces.

The one way you can overcome this to some degree is chemically. In all mechanical systems they act as above, but with a chemical solution you dont break the laws of physics. Energy comes from a chemical reaction, so the losses are from electrons and material that makes up the battery, so theoretically you can use magnesium and a few other metals and effectively make a saltwater battery.

The main issues with this are, the energy produced isnt great for a decent sized set of electrodes. To produce large amounts of energy would require electrodes that are large enough that they would have a mechanical effect on the boat, you could go small scale and trickle charge, this is akin to charging your lead acid battery with a dozen AA cells, you can put a bit of energy back into the battery but you got to ask yourself is it worth it.

Then you have cost, you would need to replace the metals now and then so it isnt free energy, there is a real cost in terms of material used. I really understand how and why people put 2 and 2 together and get 5, it seems reasonable that a shaft turning a generator will give energy, and indeed it does. But you have to take it as a whole system, the world has one nasty truth you cant run from.

There is NO SUCH THING AS A FREE LUNCH!

To add insult to injury i would amend that to.... There is no such thing as a free lunch, plus you got to pay TAX on your free lunch.
 

tcmtech

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Doesn't need to be a quantitative example. Same motor, same alternator; his example has additional features for loss: prop to water, water to turbine.
Actually, to prove something works it does have to be quantitatively defined. :rolleyes:

Your imagined reality is not fact unless you can define it with solid laws of physics.
 

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