If you want to build your own windmill, there are several things you should consider.

You don´t just place a pole, attach a couple of wind blades to a rotating disc and plug the electricity cable into the back of your TV……….. unfortunately. No, building your own windmill is a little more complicated than that. But don’t worry, I will all explain it to you in this article.

 

What is wind?

First let me explain you what makes the wind blow.
Wind is blowing because of differences in temperature. When two fronts of cold (a low pressure) and warm temperature (a high pressure area) meet, the warm air is rising and the cold air is dropping. This movement of air is wind.

 

The parts of a windmill

If you decide to build your own windmill (which I do suggest anyone to do, check for the reason here), your DIY windmill should have the following parts:

  • A generator: a generator uses a magnetic field to transform mechanical energy into electrical energy. The generator itself does not produce energy but only changes the state of it.
  • Blades: the blades of a wind turbine are very important. Normally windmills have three blades to catch the wind and a hub to hold them together. Three blades have proven to be most efficient for a wind turbine.
  • A vane: you will need a vane to keep the turbine following the wind direction. When a windmill is not directed towards the wind it works much less efficient.


The blades of a windmill will rotate when the wind is blowing. Larger blades catch more wind and will produce more energy!  With the rotation of the blades mechanical energy is produced. The generator of the windmill will change this mechanical energy into electrical energy that you can use in your house, after it has been transformed from direct current (DC) to alternating current (AC).

When you build your own windmill, you would require a battery that is connected to your wind turbine. By this you store the energy that you don´t need at that moment in the battery and use it when more energy is needed than the wind is generating.

You would want to orientate your own home built windmill towards the wind. This is called yawing. There is passive yawing and active yawing.

  • Passive yawing is the most used for small wind turbines. You use a vane to change the direction of the blades from where the wind is coming. It is the cheapest solution and the solution you should choose when you decide o build your own windmill.
  • The active yawing system is most used by medium and large wind turbines. A meter and a vane “tell” a controller in which direction the turbine has to point and the yaw ´driver´ mechanically points the blades in the right direction. This system is more complex than passive yawing systems and hardly ever used for small DIY wind turbines.

 


The installation

When you build your own windmill, you have to consider the best spot for it. Let´s give you some tips:

  • Obviously the area should have a high average wind speed (check this map).
  • It is not wise to put a DIY wind turbine near large trees or other obstacles that can block the wind or damage the blades. Therefore the turbine should be placed as high as possible. You can put your DIY windmill on your rooftop but better yet is to build a tower or a large pole and mount the turbine on top.

To read more on wind and wind energy, check the american wind energy association or the U.S. department of Energy.

So when you are looking for free energy, live in an area with lots of wind and when you are looking for a fun DIY project, go for it and build your own windmill.


There are some great guides available that will make this an easy and fun DIY project.