How to Build Your Own Small Scale Wind Turbine Using Scrap Materials

Building your own small scale wind turbine from scrap materials can be a fun and rewarding project. With some basic mechanical skills and creativity, you can generate renewable electricity even with limited resources. Here is a step-by-step guide on how to build a small wind turbine using recycled and repurposed materials.

Gather the Necessary Materials

The basic components you'll need are blades, a generator, a tower, and a tail. Here are some ideas for sourcing scrap materials:

• Blades: The blades can be made from plywood, aluminum sheets, plastic barrels/buckets, or even cardboard. 3-5 blades is optimal.

• Generator: Use a permanent magnet DC motor or an old computer fan. The higher the rated power, the better.

• Tower: A metal pole, PVC pipe, wooden beam, or ladder can work. The higher it is, the more wind exposure.

• Tail: A tail helps orient the turbine into the wind. Use an old horizontal plank or piece of sheet metal.

You'll also need fasteners like screws, bolts, zip ties, and glue to assemble the components.

Design and Build the Rotor Blades

The rotor blades capture the kinetic energy from the wind and transfer it to rotational motion. Blade design has a big impact on turbine efficiency. Follow these tips:

• Make 3-5 blades for good rotation at low wind speeds. More blades increases torque.

• Optimal blade length is about 1.5-2x the rotor diameter. Longer blades capture more wind.

• Twist the blades slightly so the inner part angles back and the outer part angles forward into the wind.

• Round the leading edge and taper the trailing edge. This aerodynamic profile reduces drag.

Test different materials and profiles to get the most power at low wind speeds in your area.

Attach the Blades to a Rotor

The rotor connects the blades to the generator shaft.

• Use a solid circular plate, saucepan lid, pizza pan etc to make the rotor.

• Mount the blades evenly spaced around the rotor using screws, zip ties or glue.

• Make sure the rotor spins freely without wobbling. Balance it by adding some weight.

Connect the Rotor to the Generator

The generator converts the rotational energy into electrical energy.

• Remove the fan blades from a DC generator.

• Attach the rotor directly to the generator shaft using a bolt, screw or glue.

• Make sure the shaft connection is straight and tight.

Build the Wind Turbine Housing

The housing protects the rotor and generator:

• Use thick plastic barrels, drums or buckets.

• Cut an opening on one side for the rotor. Make it only slightly larger than the rotor diameter.

• Seal the housing well so no water or dust gets inside.

• Add a layer of primer and paint for weather protection.

Attach the Tail Vane

The tail orients the turbine into the wind.

• Use a plank of wood, piece of sheet metal or a recycled wall vent.

• Mount it on one side of the housing, perpendicular to the rotor shaft.

• The side area of the tail should be at least 2x that of the turbine front opening area.

Construct the Tower

The tower elevates the turbine to catch more wind.

• Use a metal pipe, wooden beam or ladder for the tower.

• Sink the lower end at least 1 ft in the ground or attach guy wires for support.

• Make sure it can safely handle the turbine weight and wind forces.

• The general rule is a 20 ft tower for every 1 ft of rotor diameter.

Wire up the System

Connect the generator to your load or batteries:

• Use a bridge rectifier to convert AC to DC if the generator is AC.

• Add a dump load like a water heater or space heater to burn off excess power.

• Use a charge controller to charge batteries to avoid overcharging.

• Size the wire gauge to minimize losses over longer cable runs.

With some clever use of recycled materials and conversion of waste rotational power, you can build a small wind turbine for very little investment. This can be a fun and educational renewable energy project that also reduces waste.