Wind Energy
Societies have taken advantage of wind power for thousands of years. The first known use was in 5000 BC when people used sails to navigate the Nile River . Persians had already been using windmills for 400 years by 900 AD in order to pump water and grind grain. Windmills may have even been developed in China before 1 AD, but the earliest written documentation comes from 1219. Cretans were using "literally hundreds of sail-rotor windmills [to] pump water for crops and livestock."
The Windmill
The Dutch were responsible for many refinements of the windmill, primarily for pumping excess water off land that was flooded. As early as 1390, they had connected the mill to "a multi-story tower, with separate floors devoted to grinding grain, removing chaff, storing grain, and (on the bottom) living quarters for the windsmith and his family." Its popularity spread to the point that there were 10,000 windmills in England. But perfecting the windmill's efficiency to the point that it "had all the major features recognized by modern designers as being crucial to the performance of modern wind turbine blades" took almost 500 years. By then, applications ranged from saw-milling timber to processing spices, tobacco, cocoa, paints, and dyes.
The windmill was further refined in the late 19th century in the US; some designs from that period are still in use today. Heavy, inefficient wooden blades were replaced by lighter, faster steel blades around 1870. Over the next century, more than six million small windmills were erected in the US in order to aid in watering livestock and supplying homes with water during the development of the West. The first large windmill to produce electricity was the "American multi-blade design," built in 1888. Its 12-kilowatt capabilities were later superceded by modern 70-100 kilowatt wind turbines.
Wind Energy Sources
Today, people are realizing that wind power "is one of the most promising new energy sources" that can serve as an alternative to fossil fuel-generated electricity.