How to Build a Windmill Using a Car Alternator

Making power with a windmill alternator can be used to power home appliances and even supplement moderate electrical usage for a group of homes. Building the windmill power plant can be done with inexpensive and commonly available items, and can be finished by the average backyard builder in about a day.

Things You'll Need

• Sheet metal
• Metal snips
• Bicycle wheel (rear with gears)
• Stand or pole
• Drill
• Welder
• Screwdrivers
• Socket set
• Drive belt
• Automotive pulley wheel
• Axle bolt
• Long mount bolts (grade 8)

Instructions

1. Cut the sheet metal into eight blades about four feet long and eight inches wide, depending on the size of the bike wheel. The blades should mount at the center and extend past the wheel by a foot or so. Attach the sheet metal to the bike wheel's hub by welding or using washers and bolts through the spokes. Bend the extended portion of the blade to a thirty degree angle so that the blade has a curve to it. Face the curves of all the blades in the same direction.

2. Weld the automotive pulley wheel to the gears of the bike wheel. Remove the smaller gears by turning the hub nut counterclockwise, then sliding each gear off one by one. Leave the last, largest gear for attaching the pulley wheel.

3. Mount the bike tire onto the pole or stand by drilling a hole through the mounting surface and driving a bicycle axle bolt through the wheel and mount. Turn the axle nut clockwise to secure it. The internal wheel bearings will allow the wheel and steel to spin, and it likely will begin to turn in the wind as it is being mounted.

4. Mount the alternator below the wheel mount by slightly less than the distance of the drive belt. Using automotive alternator mount arms, or long bolts driven through the stand or mount, will hold the alternator firmly enough to withstand the torque.

5. Wrap the drive belt around the alternator pulley wheel, then the bike wheel's welded pulley wheel. There should be a half inch of belt play. Raising or lowering the alternator can tighten or loosen the belt.

6. Wire the alternator mount bolt to a suitable ground, or the negative terminal of the battery storage bank. The positive terminal on the alternator can be wired to the positive terminal on the batteries. An inverter can be rigged in the same fashion to use the power directly, but a battery will stabilize the power output.

7. Place the assembly into a high-wind environment and give the blades a starter spin. The wind will turn the alternator and generate power. More power can be generated by turning the alternator faster, which can be done by adding more windmills and additional pulley wheels.

Tips & Warnings

• Choose an alternator with an internal voltage regulator, typically found in domestic cars.

• Use extreme caution when working with electricity.

References

• Wind Turbine Concepts Defined and Explained
• Wind Generator
• Wind Power Projects

Resources

• Dragonfly Wind Generator