A wind turbine is a power generating device that is driven by the kinetic energy of the wind. Wind turbines general fall into one of two categories: Horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs). HAWTs, the more common type, consist of propeller-like rotors fixed around a central hub and facing into the wind, like a windmill. In a VAWT, blades surround the drive shaft of the turbine. The device resembles a giant push mower laid on its side and extending into the sky. Both types use bladed rotors of various designs driving a shaft to a generator that uses electromagnetic induction to produce a voltage. Today, small-scale wind turbines for individual use generally have a maximum output of 400-1600 watts. In contrast, the largest industrial turbines might generate as much as 7.5 megawatts of wind power. A grouping of turbines in a given area is known as a wind farm or a wind park