Timeline of Windmills
Vertical Axis Windmill
The first windmills invented were the Vertical Axis windmills. Built in the eastern Persia in the 9th century, these windmills were shaped like a big box with a motor inside, with vertical blades. They were made of six to twelve sails, and they were covered in reed or cloth material. Unlike the windmills you see today, these windmills were used to grind up corn or draw up water.
Recources: http://en.wikipedia.org/wiki/Windmill br />
After the Vertical Axis came an upgraded windmill, called the Fixed Windmill. This windmill was no longer in a box shaped room, and stood vertically on its own. The Fixed Windmill was an improvement over the Vertical Axis, because the blades can catch more wind then the enclosed Vertical Axis blades. These windmills were able to catch air from many different directions. The Windmill catching more wind led to more grains grinding.
Resources: http://en.wikipedia.org/wiki/Windmill br />
The Windmill Today
The windmills we see today no longer grinds grain or pumps water. Now they convert the wind energy into electricity. The windmills can save the environment, because we don’t have to burn fossil fuels for energy, but if there is no wind, the windmill won’t generate electricity.