Introduction: Savonius Wind Turbine

Renewable energy is getting more popular every day, but many products on the market are quite expensive. Solar panels can now be easily put onto roofs, but there are not many wind turbine designs that can be put on someone’s property without extreme upfront costs. We wanted to further a design on a savonius wind turbine that would be stable and resilient. We based our design off of rhackenb’s savonius wind turbine. In our design, almost all of our materials were recycled or reused. Our design is sturdier and can withstand more weather conditions, and we attached a motor to harness the energy made by the wind.

Step 1: Gather Materials

As our goal was to utilize recycled materials, we took our time gathering materials from around the physics shop at our school. The two components that were not recycled or reused were the bits of sheet metal used for the blades of the wind turbine, as well as two 3D printed custom pieces used to create a snug connection between the axis point and the PVC pipe.

List of Materials:

  • 4 rotor blades
  • Axis of rotation (pole)
  • PVC pipe
  • 3D printed caps/plugs
  • 32 screws
  • 2 bolts
  • 4 washers
  • 1 recycled auditorium chair
  • 1 generator
  • 2 ball bearings
  • Alignment piece

Step 2: Cut the Base, Stand, Support, Blades

  • Use a table saw to cut a piece of plywood (our was from an auditorium seat) down to a 20 x 20 inch square.
  • Cut stand that will support the generator and the axis in an upright manner. Our stand was 19.5 x 6 inches. In order to align the axis point with the generator, use the miter saw to cut two alignment blocks of wood. Our blocks were 3 x 6 x 0.5 inches, but the exact dimensions will depend on the size of the motor used.
  • For additional stability, cut a trapezoidal support beam that will connect the base and the stand. We first made a right triangle that was 13.1 x 13.1 inches. Then, we cut out a 6 x 6 inch right triangle for the opening at the bottom.
  • Cut the sheet metal into four identical pieces using metal scissors. Our blades were 21 inches tall and 12 inches wide. The height for future turbines will depend on the height of the axel rod.
  • We folded over the edges using a specialized machine for precise and safe edges on each of the blades.

Step 3: Curve the Blades

After folding the blades, run each of them through a sheet metal roller in order to create a curved form.

Step 4: Cut the PVC Pipe

Cut the PVC pipe using the miter saw so it matches the length of each of the identical blades.

Step 5: Drill

For all drilling, we used a drill press in order to maximize precision and drill holes in an efficient manner.

See the attached diagram for the locations of the holes.

  • Drill 10 holes into the base (6 to hold the stand and the support, and 4 for optional stakes that will can driven through the base and into the ground for additional stability).
  • Drill 7 holes into the stand (3 for the generator, 4 for the ball bearings that hold the axis in place).
    • Drill the same holes into the alignment blocks.
  • Drill 16 holes into the sheet metal blades, and down the sides of the PVC pipe.

Attachments

Step 6: 3D Print

In order to create a snug connection between the PVC pipe (connected to the blades) and the axel rod (our axis of rotation) we needed to custom print two plug-like pieces. The pieces fit like a plug or a cap on the top and bottom of the PVC pipe, and had holes that had the same circumference as the axel rod. Each piece took approximately an hour and a half to print after we had the design on Designer.

Step 7: Assemble

  • Attach the generator and the axel rod to the stand (via the ball bearings and the alignment blocks). Once the axis of rotation and the generator are connected, screw the stand to the square base.
  • Screw the trapezoidal support beam to both the stand and the base.

Step 8: Assemble the Rotor

The rotor is comprised of the PVC pipe, the 4 sheet metal blades, and the 3D printed caps.

  • Screw all 4 blades onto to PVC pipe, each measured and placed at equal intervals around the pipe.
  • Screw a bolt, a washer, and one of the 3D printed caps into place down the axis pole.
  • Fit the rotor on top of the 3D printed cap, then permanently set into place with the other cap, another washer, and a bolt on top.

Step 9: Attach LED

Attach the two wires from the generator to an LED bulb.

Step 10: Next Steps

In the future, this design could be improved by making the base more lightweight, increasing stability, and minimizing the number of moving parts.

We used a 3D printer to stabilize the blades, but we could potentially alter the design to eliminate the need for the 3D printer, as not everyone has access to this technology.

We would also like to be able to store the energy into a battery instead of using the power right away. This would increase the potential uses for this windmill, as well.