Efficient harvesting of the wind energy

Problem: Current windmill-type designs are inefficient, dangerous for the birds and low-flying aircraft, etc.

Solution: replace the propeller blades with stacks of airfoils. Lift of the wind gusts raises and lowers the airfoils. Horizontal displacement is transferred into rotational motion required by the dynamo by a simple mechanical device not so different from the automatic winding devices of mechanical watches used in recent past.