Look at the image attached to this file for explanation.Say if 200 kilowatt of power is connected to wheel A in the picture above to move the wheel. Now by the teeth of wheel A wheel B rotates which will rotate the axle E which rotates wheel C. Then the teeth of wheel c will rotate wheel D.Now what happens here is that when wheel A makes one rotation wheel B will make 3 rotation and so will wheel C. When wheel C makes 3 Rotation wheel D makes 9 rotations making the electricity produced to be 1800Kilowats just from 200Kilowats.Even if a1/3 or 1/2 of the efforts is lost in friction you will have 1200 kilowatts or 900 kilowatts of electricity produced. Now you may want to use the 200 kilowatts of output electricity for running the same machine and rest of it for other purposes. So there is no need of external energy to run the machine For the wheels you may want to use light but strong metals and for collision damage of the teeth of the wheel you may want to engulf it in sponge. At G the device that may generate electricity like in winds mill may be connected. Do not take this lightly just because its simple.