What is the first thing you notice when you look at a wind turbine? The blades, right? Well, that’s exactly where we’re going to start and build wind turbine blades
There are a number of different orientations of wind turbines we have to consider. Let’s discuss them before we narrow it down to exactly what design would be best for what you need.
Horizontal or Vertical Blades
First, let’s talk about the axis. There are two types of designs for wind turbines. The horizontal axis wind turbine (HAWT) and the vertical axis wind turbine (VAWT). In a HAWT the main axis of the turbine is parallel to the ground. The blades rotate perpendicular to the ground, shown in the picture below. This 3-blade fan-like design that we all know and love dominates the wind turbine industry and can be seen dotted all over the world in wind farms.
A VAWT is an upright design with its blades perpendicular to the ground. This design can be a good option for a small-scale project. To learn more about the two types of wind turbine axis download the deluxe version of the 5 Steps to Building a Backyard Wind Turbine eBook. You’ll get an in-depth look at how you can design the perfect axis for your homemade wind turbine project.
What are Aerofoils?
Wind turbine blades are aerofoil type shapes which slightly resembles a teardrop. This same design helps give airplanes the lift they need to rise up into the sky. Here this design will help you wind turbine cut through the air when the wind blows.
Aerofoil blade designs can be created using a sheet of hardwood. Or from light steel if you have access to a workshop and the proper cutting tools.
However, for those of us who don’t a simple trick is to use some PVC pipe. This is the pipe you can see used commonly for underground water work and sewage piping. You can easily go to your local hardware store and pick up some meter-long off cuts of this type of pipe. If you ask the staff they might even give you some cut off for free!
Now all you have to do is cut the pipe in half and then into quarters using a hand saw. Now you have the perfect lightweight, strong and durable aerofoil blades. The image below shows the desired cutting process for the pipe where it is slightly narrower at one end, so the other end can be easily mounted to the hub.
For the design of your homemade wind turbine blades, a lot of design is trial and error. To get the best blade sweep diameter, lengths and number of blades and we suggest using the design measurements outlined in the figures below, but ultimately the final design will be up to you. Try playing around with our energy and savings calculator to see what blade length works for you.
The wind turbine we made with PVC pipe offcuts. Screwed onto a circular hardwood hub.
Have a look at this PDF drawing of the wind turbine blade we designed in the PDF below:
So that’s it now you have all the tools you need to go out and build your own wind turbine blades. The first step to getting your wind turbine blades built. Next up is the Hub, so look out for help with this in the next email.