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The mooring lines are cast off and your replica Spanish Galleon pulls away from the wharf using an inboard electric motor. You only have enough charge stored in your batteries for a short jaunt but luckily the wind has picked up substantially in the last few hours and you will be able to hoist sail
as soon as you clear the quay.
The sails, as they raise, look more like spider webs than cloth or canvas because each spring anchored strand seen is actually a fine conductive filament stretched taut between, but not touching, hundreds of cross-braced magnetic brackets.
Wind catches wire and the sails begin to hum with the low pitched cacophonous drone of a thousand guitars all simultaneously strumming the same chord off key.
As the air flow vibrates the wires they begin to oscillate back and forth in their, permanent magnet-dotted, cradles. Each pass of the wires through the magnetic fields producing one amp of electricity to trickle charge the batteries for your electric inboard.
Your Galleon heads toward open water, directly into the wind.
Getting more miles per galleon.
http://movieweb.com...asureplanet/co1.jpg Solar wind sails. [Amos Kito, Oct 05 2004, last modified Oct 17 2004]
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Folks racing these ships would have special spinnakers to catch St Elmo's Fire. |
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So, when sailing downwind, you might have to tack to keep the sails charging? |
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This is an intriguing idea. If it works, then why not use such an approach instead of wind turbines? This sounds like a great DOE study using small business award funding. |
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Yep, great idea. Love the imagery, too. Maintaining the sails would be a bitch (salt air attacks EVERYTHING), and they'd be quite heavy. A catamaran would probably be a better platform for this. Due to their poor windward performance, catamarans are considered motor sailers by most owners. Under other than ideal wind conditions, you just can't get there on a cruise without doing a lot of tacking. Since the sails are effectively a nice add-on, why not use them to generate juice? |
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Alternatively, since the galleon idea is so pretty, the Hunter HC-50 has ballast tanks in each side of its hull. When filled, a tank is the equivalent of having 20 or so crew standing on the railing. In conjunction with a heavy wing keel, something like this might counteract the boat's top-heaviness. |
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The amount of current induced in a wire depends mainly on two things. Frequency that the conductor cuts the magnetic lines of flux and the length of the conductor cutting the lines of flux. I imagine that since the conductors in this example are making noise the frequency would be high. And maybe the conductors are coiled (as most intended to induce voltage are) like an electric guitar string. The problem is twofold as I see it. |
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1. The size of the guitar string would have to be quite big in order to be able to carry the 1 amp of current you suggest. This would be magnified by the fact that your high frequency would create severe "skin effect". Skin effect is where the outer part of your conductor becomes non-useable because of eddy currents. So only a percentage of the cross sectional diameter of your conductor is useable. Skin effect goes up as frequency goes up so the higher the frequency the more induction but the larger wire you need to carry the current. |
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2. The wind that is blowing creates vibration in the wires. The wires convert wind into electricity. The electricity makes your boat go faster. This makes your wires vibrate faster which makes your boat go faster which makes your wires blow harder etc.... this would be a perpetual motion machine that everyone knows is not possible. I imagine a sail of coiled wires would only slow you down or act as a really inefficient sail. |
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More efficient would be a big windmill mounted on deck, which would be a decent sail and also generate electricity. But this is not about efficiency. |
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With tuned up sails and a crew of musicians you could traverse the doldrums while taking in the eerie harmony that propels you. |
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This may stray dangerously close to WIBNI, but manufacturers claim that they're close to making LCD panels that can be rolled up. Assuming that these panels are still based on silicon in some way, then perhaps the same idea can be applied to solar cells. The result would be a "solar sail." It would be much bulkier than a conventional sail, but it would be a functional sail that produces electricity. |
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This sail would introduce an additional variable into sailing. Optimal efficiency would require both seamanship and "sunmanship" since the sail would have to be oriented to gather the most juice possible while still making the best possible use of the wind. But then, the sail would have a convex and a concave side and there's lots of reflected light from the water, so maybe its ability to make juice would stay pretty constant regardless of orientation. Ideally, both sides of the sail would be able to gather electricity. |
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Now, since I got (rightly) nuked for my last co-generation idea, I'd like to add that this would be just one of several power generation systems: gas-electric hybrid motors, wind generator, towed array, etc. NOT perpetual motion, no, no. |
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This is fabulous, so I'm croissanting it from a concept standpoint. |
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Getting into some nitty-gritty engineering details: |
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A serious problem would be waveform regulation of the current. You don't want the sails to flap in the breeze, for two reasons. Firstly, loose sails make for slow boats. Any rippling is simply energy lost. |
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And secondly, Each wire would have to be vibrating in-sync with the rest, otherwise you cancel the A/C waveform out. The output would be extremely 'noisy' current, if it had any regularity at all. |
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I suppose some sort of additive AC to DC converter on every circuit might be employed, but as I'm not a EE, I don't know quite how that works. |
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The weight of the metal wire sails would be nightmarish, requiring a huge mast, rigging, and boat, though that's getting nitpicky. |
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Thats what I said. (I must cease being so cryptic... Nah). |
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The illogic of the idea is appealing -- especially the bit about heading directly into the wind. By the same logic, you dont even need wind, since your forward motion provides it. |
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Wouldn't it be more efficient to mount a large windmill on the mast, and use that to turn a prop or generator? |
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[pluty-d] You'd still need wind. If you didn't, you'd have perpetual motion, as someone mentioned above. |
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The simple maths of this is that firstly, a conventional solid sail would capture more of the available wind energy, and secondly, that conversion losses in going from kinetic energy to electric and back to kinetic would be huge. All up, your galleon would move a lot faster with plain vanilla sails. |
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But I like it for lateral thinking. It would certainly generate something. |
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This reminds me of Wile-e-coyote's fan electric driven sail powered skateboard thingie. |
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