Have read mention of using the ability of forward momentum (sailing)to turn the propellor shaft which is hooked up by pulley to a second altenator thus generating auxillary power. Does anyone have any experience with this?
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R
Ray Bowles
Gene, this is a marginally qualified response,
but I think that friction losses, through seals, struts, bearings and even the gearbox drag (in neutral)probably rob most of the power available. There is also the loss of performance due to the prop being reversely presented to the water stream. A standard automotive alternator of 40 to 70 amps can require 10 to 15 engine horsepower to recharge a drained 12 volt battery. These alternators also require fairly high RPM and therefore a high gearing ratio. Marine towed, water powered charging systems are a totally different ball game. This might be more of what you had in mind. Another option is a system such as used in many racecars. There is an alternator that is driven off the cars driveshaft that runs between the transmission and the rear axle assembly. This area has the power available to drive such a system. I do hope this helps. Any way to make electricity without burning fuel DOES help. Ray S/V Speedy
but I think that friction losses, through seals, struts, bearings and even the gearbox drag (in neutral)probably rob most of the power available. There is also the loss of performance due to the prop being reversely presented to the water stream. A standard automotive alternator of 40 to 70 amps can require 10 to 15 engine horsepower to recharge a drained 12 volt battery. These alternators also require fairly high RPM and therefore a high gearing ratio. Marine towed, water powered charging systems are a totally different ball game. This might be more of what you had in mind. Another option is a system such as used in many racecars. There is an alternator that is driven off the cars driveshaft that runs between the transmission and the rear axle assembly. This area has the power available to drive such a system. I do hope this helps. Any way to make electricity without burning fuel DOES help. Ray S/V Speedy
N
NH
Yes, BUT..
I know that it actually works, and some boats do charge their batteries from their free-wheeling shaft.... I studied this option carefully, and decided instead to tow a small propeller to drive a generator. The generator is mounted on the taffrail. If you want to instead attach an alternator/generator to your freewheeling prop shaft, you must be concerned with the following: 1) Does your transmission like to be constantly spinning in neutral. Check your owner manual, some transmissions will wear excessively or experience other problems. 2) Noise. There will be some noise generated from this. The quiet is one for the pleasures of sailing. I’ve heard of people becoming very irritated by the constant drone of the generator on the prop shaft. 3) Shaft RPM. You will need a specialized low-rpm alternator, or (more likely) a fixed-magnet motor designed for low-rpm application. You prop shaft spins relatively slowly while sailing. 4) Alignment wear. You may have to install a support bearing to counter the side-load created when you run a pulley off of your shaft. Failure to do this can cause problems with water seals, bearing wear, transmission wear etc. If you have a 1” shaft, it will most likely not be designed for a side-way load. 5) Mounting the pulley and belts. You will need to remove the shaft to do this. You’ll have to do that any time you replace a belt, so you might as well mount several spare belts the first time. 6) Gear ratio. You may need some way to step up the RPM to match the generator. 7) Clutch. You need some way of detaching the generator from the shaft when you are using your deisel/gas motor to move the boat. The RPM’s will be too high and there is no need to waste fuel. 8) Boat speed. Some people believe that a spinning prop create more drag than a stationery prop. There are studies which prove them right and studies which prove them wrong. Who cares if wind power is plentiful and you are not in a race? 9) Sailing/Motoring ratio. I’m sure you’re thinking about this carefully.. Consider how much sailing you realistically do without motoring. If you motor part of the time any-way (as we do in the Pacific Northwest), then you will charge from your motor, so no need to drag your prop through the water. 10) Resale value. I was very interested in this approach to reducing my consumption of fossil-fuels. Then I came to realize how my home-baked clugey hatchet-job would look on my pristine boat.. Better to do something that causes less scar tissue. If you have an old wooded boat it’s easier to make something that doesn’t look like a miss-fit, I suppose. 11) Space. You need space to mount this contraption.. Space around the shaft for a pulley to generate some RPM’s. 12) Economics. Hahah! Economics on a boat? If it costs you $500 to do this, you will need to make up the savings by NOT docking at a marina with power for 100 nights (at $5 per night for power supply). Or, at $1.50 per gallon, you will need to save 333 gallons of diesel. That could be 500 hours of diesel motoring that you would have to save to compensate. Of course if you’re planning an ocean-crossing, there are other arguments for spending money in the interest of fuel conservation.
I know that it actually works, and some boats do charge their batteries from their free-wheeling shaft.... I studied this option carefully, and decided instead to tow a small propeller to drive a generator. The generator is mounted on the taffrail. If you want to instead attach an alternator/generator to your freewheeling prop shaft, you must be concerned with the following: 1) Does your transmission like to be constantly spinning in neutral. Check your owner manual, some transmissions will wear excessively or experience other problems. 2) Noise. There will be some noise generated from this. The quiet is one for the pleasures of sailing. I’ve heard of people becoming very irritated by the constant drone of the generator on the prop shaft. 3) Shaft RPM. You will need a specialized low-rpm alternator, or (more likely) a fixed-magnet motor designed for low-rpm application. You prop shaft spins relatively slowly while sailing. 4) Alignment wear. You may have to install a support bearing to counter the side-load created when you run a pulley off of your shaft. Failure to do this can cause problems with water seals, bearing wear, transmission wear etc. If you have a 1” shaft, it will most likely not be designed for a side-way load. 5) Mounting the pulley and belts. You will need to remove the shaft to do this. You’ll have to do that any time you replace a belt, so you might as well mount several spare belts the first time. 6) Gear ratio. You may need some way to step up the RPM to match the generator. 7) Clutch. You need some way of detaching the generator from the shaft when you are using your deisel/gas motor to move the boat. The RPM’s will be too high and there is no need to waste fuel. 8) Boat speed. Some people believe that a spinning prop create more drag than a stationery prop. There are studies which prove them right and studies which prove them wrong. Who cares if wind power is plentiful and you are not in a race? 9) Sailing/Motoring ratio. I’m sure you’re thinking about this carefully.. Consider how much sailing you realistically do without motoring. If you motor part of the time any-way (as we do in the Pacific Northwest), then you will charge from your motor, so no need to drag your prop through the water. 10) Resale value. I was very interested in this approach to reducing my consumption of fossil-fuels. Then I came to realize how my home-baked clugey hatchet-job would look on my pristine boat.. Better to do something that causes less scar tissue. If you have an old wooded boat it’s easier to make something that doesn’t look like a miss-fit, I suppose. 11) Space. You need space to mount this contraption.. Space around the shaft for a pulley to generate some RPM’s. 12) Economics. Hahah! Economics on a boat? If it costs you $500 to do this, you will need to make up the savings by NOT docking at a marina with power for 100 nights (at $5 per night for power supply). Or, at $1.50 per gallon, you will need to save 333 gallons of diesel. That could be 500 hours of diesel motoring that you would have to save to compensate. Of course if you’re planning an ocean-crossing, there are other arguments for spending money in the interest of fuel conservation.
G
Gene
B
Beau Fin
Electric power..looks good on paper.
Hi Gene! Was this the Solomon Technologies device usually used to repower? It really looks good, at least on paper. Does anyone have any experience with it? What did you think of it on the cat?
Hi Gene! Was this the Solomon Technologies device usually used to repower? It really looks good, at least on paper. Does anyone have any experience with it? What did you think of it on the cat?
N
NH
This is what one person relayed to me.
You want to drive an alternator from the center of the SS drive shaft in your sailboat. Right? Be careful... knew a guy who did this...2 weekend trips later he went dead in the water on a lee shore in a fair breeze... .. it got rather exciting. His 2nd error was in not being prepared to hoist sail at the drop of a hat (or loss of propeller power) Neither end of the typical sailboat drive shaft is designed for side load. The flex coupling between gear box and shaft is the weakest link. Also consider what a side load would do to the stuffing box over time (water leak). After considering many such "make shift" solutions, I replaced my 50amp alternator with a low speed 150amp unit which required a whole new mounting bracket. Costs a little more but well worth it. I retained the ability to easily go back to the 35amp and stowed it as a backup with all its own bolts, bracket, regulator, etc. my $0.02 -Steve,
You want to drive an alternator from the center of the SS drive shaft in your sailboat. Right? Be careful... knew a guy who did this...2 weekend trips later he went dead in the water on a lee shore in a fair breeze... .. it got rather exciting. His 2nd error was in not being prepared to hoist sail at the drop of a hat (or loss of propeller power) Neither end of the typical sailboat drive shaft is designed for side load. The flex coupling between gear box and shaft is the weakest link. Also consider what a side load would do to the stuffing box over time (water leak). After considering many such "make shift" solutions, I replaced my 50amp alternator with a low speed 150amp unit which required a whole new mounting bracket. Costs a little more but well worth it. I retained the ability to easily go back to the 35amp and stowed it as a backup with all its own bolts, bracket, regulator, etc. my $0.02 -Steve,
N
NH
Some alternatives
There are commercially available water-generator, you can search the web.. Below are some links I have found.. See these options: http://www.zetatalk.com/energy/tengy12k.htm http://www.marlec.co.uk/products/prods/amozon.htm http://www.lvm-ltd.com/water_generators.htm I think there is a brand called "aqua4gen" too, search for that. I made my own towed generator, with great help via email from someone who had done it before.. I'll post details in another message to this conversation.
There are commercially available water-generator, you can search the web.. Below are some links I have found.. See these options: http://www.zetatalk.com/energy/tengy12k.htm http://www.marlec.co.uk/products/prods/amozon.htm http://www.lvm-ltd.com/water_generators.htm I think there is a brand called "aqua4gen" too, search for that. I made my own towed generator, with great help via email from someone who had done it before.. I'll post details in another message to this conversation.
N
NH
My home-made one.
I decided on the towed log generator option, rather than driving the generator from the spinning/freewheeling prop shaft... I received a lot of help via email from another sailor, so can't take much credit.. I have two motors for this generator, one is a spare. The first motor was a salvage (dumpster-diving adventure with my son) from a discarded treadmill (exercise machine). The other motor is from an old mini-computer tape drive, and I had to get new brushes for it. Both of these motors will generate sufficient voltage at low RPM's. The motor is attached to the taffrail by some nylon line. The shaft of this motor has a shackle onto which a 50 foot nylon line is attached. At the end of that line, dragging in the water is an old outboard motor propeller, which has been mounted on a stainless steel shaft. The steel shaft is to weigh the prop down, keeping it below the water surface. The spinning prop turns the shaft of the motor, making power! I bought a regulator (so not to over-charge the batteries), diodes (so the battery doesn't try to run the motor), and cables to get the power to the battery.. Total cost with two motors $168.00 Not quite, but almost free power, as long as I don't mind the speed-loss caused by dragging the prop and line in water.. And now, I have to be concerned with where my dinghy is when I tow this prop. As well, any other boats etc coming too close aft of me. Rocks, kelp, crab traps, logs etc. With the setup and break-down, it's not worth deploying unless I'll be sailing for some time.. By now, most readers will see the benefits of just boosting their alternator on their diesel engine... Much simpler eh? Since this was a project enjoyed with my 10-year-old son, there were bonding-benefits.. Hehehe...
I decided on the towed log generator option, rather than driving the generator from the spinning/freewheeling prop shaft... I received a lot of help via email from another sailor, so can't take much credit.. I have two motors for this generator, one is a spare. The first motor was a salvage (dumpster-diving adventure with my son) from a discarded treadmill (exercise machine). The other motor is from an old mini-computer tape drive, and I had to get new brushes for it. Both of these motors will generate sufficient voltage at low RPM's. The motor is attached to the taffrail by some nylon line. The shaft of this motor has a shackle onto which a 50 foot nylon line is attached. At the end of that line, dragging in the water is an old outboard motor propeller, which has been mounted on a stainless steel shaft. The steel shaft is to weigh the prop down, keeping it below the water surface. The spinning prop turns the shaft of the motor, making power! I bought a regulator (so not to over-charge the batteries), diodes (so the battery doesn't try to run the motor), and cables to get the power to the battery.. Total cost with two motors $168.00 Not quite, but almost free power, as long as I don't mind the speed-loss caused by dragging the prop and line in water.. And now, I have to be concerned with where my dinghy is when I tow this prop. As well, any other boats etc coming too close aft of me. Rocks, kelp, crab traps, logs etc. With the setup and break-down, it's not worth deploying unless I'll be sailing for some time.. By now, most readers will see the benefits of just boosting their alternator on their diesel engine... Much simpler eh? Since this was a project enjoyed with my 10-year-old son, there were bonding-benefits.. Hehehe...
T
Tom
Very Cool NH......Have you measured the output
of your water driven generator?....How many amps does it produce at what boat speeds?.....
of your water driven generator?....How many amps does it produce at what boat speeds?.....
C
Chris Hyland
Interesting
I heard that Catalina was giong to introduce a new aux power/drive system. The idea was to install a diesel genset and an electric drive motor. This way when the boat is on the hook or mooring you have the getset for 110 power and charging. The genset would generate enough power to run the electric drive motor for full hull speed propultion. The possible upside is that the genset would be quieter. Also for people in a slip you may never have to fire up the diesel if your just going for a day sail. Regards, Chris
I heard that Catalina was giong to introduce a new aux power/drive system. The idea was to install a diesel genset and an electric drive motor. This way when the boat is on the hook or mooring you have the getset for 110 power and charging. The genset would generate enough power to run the electric drive motor for full hull speed propultion. The possible upside is that the genset would be quieter. Also for people in a slip you may never have to fire up the diesel if your just going for a day sail. Regards, Chris
J
Jerry Villines
is it worth it?
Wind generators are designed to be towed for improved power generation when the wind isn't doing all we would want. Wind generators are designed to generate power from the wind that comes by. Moving parts like those from wind and make noise. Solar panels provide power quietly and with minimal maintenance. Sure solar power is less efficient than wind/water driven systems but solar is easy. A good, quiet wind system is about a thousand bucks and so is a solar system. Everything seems to be in "boat increments", ie $1000. Low maintenance and reliability is my goal and solar seems to fit that better than anything else. If you find less maintenance and reliability than solar please write. jcvillines@aol.com
Wind generators are designed to be towed for improved power generation when the wind isn't doing all we would want. Wind generators are designed to generate power from the wind that comes by. Moving parts like those from wind and make noise. Solar panels provide power quietly and with minimal maintenance. Sure solar power is less efficient than wind/water driven systems but solar is easy. A good, quiet wind system is about a thousand bucks and so is a solar system. Everything seems to be in "boat increments", ie $1000. Low maintenance and reliability is my goal and solar seems to fit that better than anything else. If you find less maintenance and reliability than solar please write. jcvillines@aol.com
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