Wind energy is a renewable and efficient means for electricity production. For the small-scale user, wind power is inexpensive, easy to construct, and simple to maintain. The ease of wind systems comes from the straightforward design of such a system. It works just like the alternator in your car. Blades transform wind into mechanical energy, and this mechanical energy turns a generator that transforms the mechanical energy into electricity.

Wind systems come in many shapes, sizes, and configurations. There are Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT). Vertical machines are easy to build, but because most work on the concept of drag, instead of lift, their speeds and efficiency are limited. 

The most common type of wind turbine is the Horizontal Axis. You see these machines in the large wind warms in the western United States, as well as in water-pumping mills. The blades are perpendicular to the direction of the wind, and a tail keeps the blades lined up. The blades are designed as an airfoil to actually use lift, rather than drag, to make the blades move. This approach is very attractive, as your blades can travel faster than the wind speed. Blades of this type are usually tapered and slightly twisted to help with efficiency.

The blades are connected to the shaft of a permanent magnet generator or alternator. The shaft rotates either the magnets or the coils in the generator, which creates electricity. The electricity is then rectified, meaning transformed from Alternating Current into Direct Current for charging the system batteries.

The electricity coming from the wind turbine should be automatically controlled to prevent over-charging of the batteries. When the batteries are full, the controller should short out the wind generator. This method acts as an electrical brake, and slows the turbine. It is important to brake the wind turbine when not in use, to prevent overspeeding of the generator.

Wind systems can be easily built at home, using basic tools and skills. Some understanding of the concepts is required, but with a little practice and experimentation, you can be on your way to a wind expert in no time.