tiny wind generator

Othello

For demonstration purposes I m trying to assemble a generator consisting of a coil swinging thru a permanent magnetic field.
The coil should hang from a small windflap and should be able to temporarily light up an LED.

Currently I am concerning myself with the design of the windflap which can be thought of as a pendulum of certain length and a certain mass (eg. the material of the flap + the attached coil). This flap should be moved by the wind.

For the generator part I would need a short pendulum to achieve the quick flux change necessary to develop a useful voltage (Faraday's law).

For the wind to move the flap I think I would want a long flap to offer enough leverage to the wind to move the flap.

Since these two consideration, if right, are contradictory I would hope for some input to be able to build a test set-up without too much experimentation.

Thanks Uwe