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halfsail marine current electric generator

Tithered sail marine-current power with no hard and heavy structures
  [vote for,

[Edit] after realizing that currents are faster therefor stronger close to the surface, at the end of this idea I propose a new simplification.

Typical sea current energy recovery is done with heavy and gigantic structures holding turbines. see link (to be posted).

Enter the halfSail system. The halfSail base, suspended directly beneath the boat/ship/platform, controls a folding sail, opening and closing it in turn.

When open the sail pulls a cable which transfers the power upwards via a pulley to the floating platform, pulling a transmission system for generating electricity. (See details below and illustration attached)

All electric generation is done at the surface above water, with existing electric generator technology and well known mechanical systems.

Thrown into the sea from any size ship, boat or floating platform, it can be easily configured to work with any sail size and thus can be configured to produce any required quantity of electricity available for recovery at the desired location.

There is no need for a permanent installation, and the system can be easily moved and redeployed at another location when the need arises. It is also extremely safe for marine life, with no fast moving parts in the water.

Here's how it works: (See illustration).

Two square half-sails overlap each other creating a rectangular sail.

When the sail reaches the end of its rope, two "connecting cables" are let to slide out from the sail connection, allowing the two halves to "fold out", and the sail to be easily pulled in.

Once reaching back to the base, the connecting cables are pulled tight again and locked in place so that now the sail is one large sail again, pulling on the current.

The ropes and the sail can be polycarbonates or plastics (Kevlar ropes and carbon fiber sailcloth) making the system cheap, foldable and lightweight.

That's all, folks! Stay tuned!

[Edit] simplification: The sail, floating with top on the water surface pulls directly at a cable powering the generator on the ship.

pashute, Feb 23 2017

typical marine current electricity generators http://www.marinetu...com/SeaGen-Products
[pashute, Feb 23 2017]

halfsail closed - https://drive.googl...kk/view?usp=sharing
pulled by sea current and generating electricity [pashute, Feb 23 2017]

halfsail open https://drive.googl...TQ/view?usp=sharing
easily pulled in to close and renew sail operation [pashute, Feb 23 2017]

look what i found!!! https://www.seabree...-by-air-kite?page=1
[pashute, Aug 27 2019]


       Is this idea that bad?
pashute, Mar 07 2017

       No, it's not a bad idea...just sometimes good ideas fall between the cracks..
not_morrison_rm, Mar 07 2017

       It happens to me a lot. It's often when other ideas are getting a lot of attention. Also, well all my ideas are obviously crap <sob>.
nineteenthly, Mar 07 2017

       I see a problem. If this thing is going to be moveable, then it will not be anchored solidly to the sea floor (which is quite difficult to do anyway).   

       If it is not firmly anchored, then you can only get a small amount of force from your sail, without dragging the whole thing off into the distance. And, if the force is small, you will only get lots of power by allowing the sails to travel quite fast over long distances. But now you have an underwater sail and lots of long cables, which will cause all kinds of problems.   

       So, why is this any better than a turbine-style generator? A turbine can recover a good fraction of the energy in the moving water, operates continuously, and is much better at generating power from a limited amount of force (remember, we're talking about something that be //redeployed//). A turbine blade is just a sail that goes in a circle.
MaxwellBuchanan, Mar 07 2017

       Hmm. Surely by running with the wind, then tacking against the wind it's possible to collect enough energy to make some electricity? Given a flat enough piece of ground, model sailing boats on wheels could do this on land.
not_morrison_rm, Mar 07 2017

       A paddle steamer works in exactly the same way as your design. Apart from the obvious direction of energy transfer, you're extracting energy by slowing down water, a paddle steamer expends energy to speed water up. The paddle takes energy from the engine to move water backwards before returning to its original position in a less restrictive form, by moving through the air not water. Your sails use moving water to turn an engine before returning to the original position in a less restrictive form, folded. It's the same. And for the same reasons a propeller is better than paddles, a rotational turbine has advantages over the sails. Mainly that they eliminate the folded/out of water component so that all the device is working all the time.
bs0u0155, Mar 08 2017

       And that they use lift instead of drag.
notexactly, Mar 21 2017

       An underwater sail or kite can push my ship at most at the speed of the currents which are usually at most 5.6 meter/sec or 9km/h.   

       But if I have a drag on my ship with traction to the sea floor, or even an anchor, or by catching an undercurrent going in the opposite or different direction, then I can pull a cable extracting the kinetic energy from the water which is quite a lot even at 5 meters per second. Say 10 square meter sail during 2 seconds stopping all the water that comes to it by converting it to energy (I'm being theoretical now): That would be kinetic energy from 1000 cubic meters of water weighing (1 ton x 5 meters/sec) =12.5 kJ or 3.5 KW*hours.   

       The advantages from a turbine are several 1. Only the sail is submerged. No special underwater electric generator. No underwater maintenance.   

       2. Easily movable to more favorable location, and allows location to revive if in any way altered.   

       3. Extremely low cost for a 100 meter wide 10 meter deep sail like this. Compare to cost of 100 meter blade turbine costs.
pashute, Aug 26 2019

       Those are some good advantages.
notexactly, Aug 26 2019


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