When building windmills, people think about how to improve their efficiency. To do that, they analyze the mechanism. The most critical components of a windmill are, naturally, windmill blades.

The very first thing to take into consideration when talking about windmill blades is their number. The more blades a windmill has, the harder will be for it to rotate. The old ones used to have four very heavy blades. Most of them were use in grain grinding. Now, the most recent windmills have 2 or 3 blades.

The length is important too. If a blade is longer, it covers a bigger surface when it rotates, so they can catch more wind with every rotation. This may lead to extra torque. To protect the windmill blades we must not forget about their surface. If we provide them with efficient maintenance, they will last longer and will also be more efficient.

Besides, the shape of windmill blades influences their rotation. There're many different shapes of windmill blades: the flat, rectangular types, the wing shaped types and the ones with both edges tapered to a thin line or both edges rounded like the ones of an airplane wing. In case of the horizontal axis windmills, the wing shape has proven to be by far the most effective one. The vertical axis windmills works extremely well with all the shapes of the windmill's blades, but optimum performance is given by the flat types and the ones with both edges rounded.

About the material with which the windmill blades are constructed from, if we think about the old ones, they were usually made from wood. Although those windmill blades are made of wood, their structure modified over time. They're much lighter now so they can spin quicker. A common material which brings a high performance because of its sharp edges and its light weight is carbon fiber. One more material that's light, but also low-priced is PVC. It's a synthetic material often used for windmill blades. New substances are always being tested, in the hopes of finding a less expensive, more effective solution.

Windmill blades are constantly developing, although they appeared a very long time ago. At their beginnings they were somehow inefficient, but people learned to improve them and to make the windmills a desired source of energy. Many more shapes and materials have and will be for windmill blades and people begin using more and more this alternative source of energy which will not only save our money, but also our environment.