A twin sailing vehicles move back and forth wind generator
A new concept of low cost wind generator


Most sail or kite wind generators are able to generate electricity as wind blowing the sail or kite away. But they are often unable to bring the sail or kite back by wind force in same direction. So they cannot run continually.

A sail or kite wind generators only can run continually if:
1. The blowing away sail or kite can be brought back in same wind condition.
2. The energy generated by a blowed away sail or kite, must be more than energy needed to bring the sail or kite back.

Most sail or kite wind generators could not overcome these problems.


This design of wind generator tried solve these problems. This twin sailing vehicles move back and forth wind generator runs continually in any wind dirctions to generate electricy.



A twin sailing vehicles move back and forth wind generator

How does it works? Vehicle 1 with a fully raised sail 1. Vehicle 2 has a lowered sail 2. There are electric motors and controllers on both vehicles to raise and lower sails. Two vehicles are tied together by rope. The rope runs over wheel 1 and wheel 2. Wheels connect to generators in both base.

If wind dirction is from left to right, wind force will push sail 1 (and vehicle 1) to right side, at same time, it brings vehicle 2 (with a lowered sail 2) back to right side. This movement turns generators to proudce electricity.

As vehilce 1 reached stoper 1 at right side, (vehicle 2 also reached stoper 2), controlled moters on vehiles raise sail 2 and lower sail 1. Now, wind force on sail 2 is much stronger than wind force on vehicle 1 (because sail 1 is lowered). Vehicle 2 start to move to right side, and vehicle 1 is brought back to left. This movement also turns generators to produce electricity.

Electric moters and controllers on vehicles are powered by rechargeable batteries at both stopers. The batteries are always charged by main generators.

As described above, these twin vehilces will move back and forth continually to generate electricity as long as wind is blowing. Part of energy the generators produced is used to charge batteries for raising/lowering sails, rest of energy is power output.

This wind generate system only runs continually if:
1. Vehicle with fully raised sail can bring another vehicle (with lower sail) back to left side in same wind direction by wind force. As we can see, this shold be no problem if the raised sail is larger enough.
2. Vehicle (1 and 2) travel a single way must generate more energy than the energy needed to raise and lower sails at least once.

So, how do we do to make sure the vehicles travel single distance can produce more energy than energy required to raise and lower sails at least once? Answer is: Extending distance between wheel 1 and wheel 2. Why?

1. A sailing vehicle will get more energy from wind if it travels longer distance.
2. Energy needed to raise and lower sails is limited. Sails often are made from light materials, such as: fibra, foil... Most energy is used on raise sail. To lower a sail does not need too much energy because gravity force will help.

So, one side, sailing vehicle can produce unlimited energy if it travel a longer distance. Another side energy needed to raise and lower sails is limited. If we can extend the distance until moving vehicles generate more energy than energy needed to raise and lower sails at least once, this problem is solved.

To design this generator, first we make a decision on size of the sails. Then we calculate how much energy needed to raise and lower sails once in worst wind condition (called Energy A). Then we calculate how much energy the vehicles can produce if they move one meter in worst wind condition (called Energy B). Then we get a equation: Energy B X D > Energy A . "D" is minimum distance between wheels (1, 2) required to make sure this generator will continually run.

According this distance we can build this generator on land, maintains, sea and rivers as pictures below.


Building this generator on sea or river maybe much easier than build it on other places. Because boat can easily carry a large sail. And it is not neccessary to building this generator across sea/river, it can be built along sea/river bed.

This twin sailing vehicles move back and forth wind generator does not need a vane to steer all system into wind direction. If wind blowing in other direction other than from left to right, we can adjust angle of sails to catch wind power just like on normal sailing boats. There are automatic sailing systems for sailing boats can be used here. If wind direction changes more than 90 degree, this generator still can run continually, only change is the vehicle in wind is moved from right to left.

This wind generator can be combined with solar power. We can install solar panels on vehicles to power the moters to rais/lower sails.

This wind generator can be made as a circle, vehicles move in one direction in circle. In this case, 3 or more vehicles may needed working together. But buiding a circle system maybe much difficult and expensive.

(22 April 2011)



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