Since early history, people have been harnessing the energy of the wind. Wind energy propels boats along rivers, simple windmills, and pumping water as early as 5000 B.C. New ways of using the energy of the wind eventually spread around the world. By the 11th century, people in the Middle East were using windmills extensively. Settlers took this new technology to the New World in the 19th century. They began using windmills to pump water for farms and ranches, and later, to generate electricity for homes and industries. In the 1940s large wind turbines began to operate small industries.
             Wind turbines fall into two basic categories, the horizontal-axis variety, and the vertical-axis design. Modern wind turbines take advantage of many of today's high-tech technology uses such as aerodynamics, engineering, and electronics. Wind turbines that are grouped together are called "wind farms", and generate a lot of bulk electrical power.
             Wind farms are in a variety of sizes and power ratings, depending on the location of where the farm is located. Some of the wind turbine propellers can span more than the length of a football field, and can stand up to twenty stories high, which creates enough electricity to power 1,400 homes. Some of the smaller turbines are 8-25 feet in diameter, and stand up to approximately thirty feet tall, which supplies the electrical needs of a small business or an all electric home.
             Constructing electric-generating wind turbines, regardless of the shape or size, consists of the rotor, the electrical generator, a speed control system, and a tower. Some wind turbines have the options of fail-safe shutdown systems. Fail-safe shutdown systems are designed to turn the blades out of the wind, or simply "put on the brakes" in the event of a mechanical failure.
             Wind energy is abundant throughout the United States. Characterized by wind-power density classes, ranging from the lowest c
             ...