Electricity From Wind
The kinetic energy of wind can be harvested to drive electromechanical electricity generators. The most common types electricity-generating wind systems employ a propeller or turbine of some sort to convert wind energy into the rotation of a shaft, which drives an electricity generator.
For centuries, the vast majority of wind energy systems have used variations on the same basic design, in which a propeller with a horizontal axis is made to face the wind through the rotation of a support about a vertical axis. Energy is extracted from the spinning of the propeller relative to the support, which mounts the propeller's axle. Recent years have seen deployments of an alternative design, particulary in small-scale installations, in which a paddle-type rotor mounted on a vertical axis spins in response to wind from any direction.
The designs described above use rigid structures mounted to the ground. Recently, systems that replace such structures with lofted objects, some lighter than air, have been developed.