4 Easy Steps to Build a Wind Turbine

Four Methods: Planning Your Wind Turbine, Assembling the Wind Turbine Head, Building the Wind Turbine Tower, Erecting the Wind Turbine

Like old-fashioned windmills, wind turbines generate energy. Instead of using that energy to grind grain, though, modern turbines harness wind to generate and store electricity, helping to meet the growing demand for green energy. While industrial turbines may be too large for individual households, you can learn to build a smaller household version to supplement your own power needs. See Step 1 for more information.

Method 1 of 4: Planning Your Wind Turbine

1

Determine the average wind speed in the area you plan to build. To be cost-effective, an efficient wind turbine needs to be exposed to winds of at least 7 to 10 miles per hour (11.2 to 16 kilometers per hour) to generate electricity and performs best at speeds from 12 to 20 mph (19.2 to 32 kph). To find the annual average wind speed for your area, follow the instructions at http://www.mywindpowersystem.com/2009/05/wind-finder-wind-speed-anemometer/.
2
Know the building codes related to erecting windmills and wind turbines. The building codes may stipulate the minimum required distance between turbines, as well as how far away the turbine has to be from the property line.
- It’s also a good idea to discuss building a wind turbine with your neighbors to address their concerns about the turbine and deal with any misconceptions they may have about the amount of noise it makes or whether it will interfere with radio and TV reception.
3

Evaluate how much horizontal and vertical clearance you have for the wind turbine. Although the turbine itself doesn’t require much space, to avoid potential conflicts with neighbors, you should have at least half an acre (0.2 hectare) of space for a turbine that generates up to 3 kilowatts of power and a full acre (0.4 hectare) for a turbine that generates up to 10 kilowatts. You should also have enough vertical space to build the turbine high enough so that buildings and trees don’t block the wind.
4
Decide whether to build or buy the wind turbine blades. Although the older farm windmills were basically small sails attached to a rotating shaft, wind turbines resemble giant propellers with their large teardrop-shaped blades. These blades have to be sized and pitched correctly for the turbine to work properly. They should be anywhere from 20 to 60 percent of the height of the windmill itself.
- If you choose to build the blades, you can make them out of wood or cross-sections of PVC pipe. Instructions for making blades from pipe can be found at http://www.yourgreendream.com/diy_pvc_blades.php.
- Whether you build or buy the blades, you’ll probably want to follow the design of most commercial wind turbines and have 3 blades on your wind turbine. Using an even number of blades, such as 2 or 4, makes a wind turbine more likely to vibrate as it spins, while adding more blades increases torque but actually makes the turbine rotate more slowly
5
Choose a generator. Your wind turbine needs to be connected to a generator to produce electricity. Most generators are direct current (DC), which means that to use them to provide household current, you’ll need to connect the generator to a power inverter to produce the alternating current (AC) that household appliances use. You can, however, use an AC motor as a generator, although there may not be sufficient residual magnetism to produce a strong enough electric field.
- If you decide to buy a DC generator, look for one rated for high voltage and current and low rotation speed (several hundred instead of several thousand revolutions per minute). You need to generate at least 12 volts over a consistent period of time. Your generator should be connected to a deep-cycle battery bank and charge controller in between the generator and inverter to protect the inverter and battery from power spikes and to provide continuing power to the inverter during low-wind periods.
- Automotive alternators are not recommended as generators because they need to spin at much faster speeds to generate power than wind turbines usually turn at.

Method 2 of 4: Assembling the Wind Turbine Head

1
Bolt the blades to a hub. The hub will connect the blades to the motor/generator shaft. The blades should be attached so that they are angled in the same direction and spaced evenly. For a 3-bladed wind turbine, the blades should be 120 degrees apart; for a 4-bladed turbine, they should be 90 degrees apart.
- If you don’t have a pre-made hub, you may need to bolt 2 metal pieces together, 1 suited for attaching the blades and the other suitable for slipping over the generator shaft.
- Once assembled, you may want to add a conical or hemispherical cover for the hub to give the blade assembly a more professional look.
2

Drill a hole in the head shaft. A simple head shaft can be made from a length of 2 x 4 long enough to keep the blades clear of the turbine tower and allowing enough space for a decent-sized wind vane to catch the breeze when the wind shifts to turn the turbine back into the wind. The hole should be between a quarter and a third of the distance from one end of the 2 x 4 to the other, long enough to accommodate attaching the generator to the end closer to the hole, and it should be large enough to thread the wires from the generator through.
3
Attach the generator to the head shaft. You can attach the motor with metal straps and protect it from the elements by encasing it in a section of PVC or metal pipe when attaching it. You may also want to place a smaller block of wood beneath the generator before attaching it to the head shaft.
- Once the wooden pieces are in place, you can paint or stain them to protect them from the elements.
4

Attach the wind vane to the other end of the head shaft. The vane itself can be made from a piece of sheet metal about a third the length of the 2 x 4 used to make the head shaft. The simplest way to attach the vane is to cut a groove in the 2 x 4 about half the thickness of the wood and insert the groove.
5

Screw a 1-inch (2.5-centimeter) iron floor flange to the underside of the head shaft. This will support the shaft bearing.
6

Screw a length of inch-wide (2.5 centimeter-wide) pipe nipple into the flange.The pipe nipple will serve as a bearing to permit the wind turbine to turn freely as the wind changes direction.
7

Attach the blades and hub to the generator shaft. After you do this, lift the assembly and check it for balance. The wind vane section at the long end should rest evenly with the generator section at the short end. If not, add weight to the vane end so that both ends are level.

Method 3 of 4: Building the Wind Turbine Tower

1
Build a strong base. How you build the wind turbine base depends on whether you plan to mount it permanently in one location or move the turbine from one location to another. In either case, the base must support the turbine and keep it from blowing over in a high wind.
- For a permanently mounted wind turbine, the base needs to be wide, strong and heavy. You can either pour a base of concrete or use sandbags to provide the weight for a wooden base, while the base’s horizontal dimensions should be roughly a third of the tower’s height. For a 5-foot-tall (1.5-meter-tall) tower, the base should be about 18 to 20 inches (45 to 50 centimeters) square and weigh about 20 pounds (44 kilograms). Attach a length of 1 inch (2.5-centimeter) diameter pipe to the base (or set it in the concrete before it dries), then attach one of the long ends of a 1-inch tee to the pipe and a length of inch-diameter pipe nipple to the other end.
- For a portable base, cut a disk of heavy plywood. (For a 5-foot-tall tower, a diameter of 24 inches, or 0.6 meters, would be sufficient.) Thread a length of 1-inch (2.5-centimeter) diameter pipe through a 1-inch (2.75-centimeter) diameter pipe tee. Attach an elbow joint to either end of the straight pipe, and attach the ends to the plywood with iron flanges, forming a “U” that the tee can rotate about freely. Attach a reducing fitting to the free opening of the 1-inch tee, then connect one of the long ends of a 1-inch tee to the other end of the reducing fitting. Connect a length of pipe nipple to the other end of the 1-inch tee. You may also want to drill holes in the disk so you can drive stakes to anchor the base.
2

Cut a length of PVC pipe or conduit to serve as the tower. The pipe or conduit should be thicker in diameter than the pipe nipple used as a bearing and a base socket, at least 1 inches (2.75 centimeters). The length of the pipe will determine how tall the tower is.

Method 4 of 4: Erecting the Wind Turbine

1

Connect the charge controller to the battery. Connecting the charge controller to the battery before connecting it to the wind turbine will prevent power spikes from forming and damaging your equipment.
2
Connect insulated wire to the charge controller. This wire will transfer power from the generator to the charge controller and into the battery. Your wire should be like that found in power cords, with two lengths of wire bound in the same insulation. You can use an old extension cord with the plugs removed, if you wish.
- Once you connect the wire to the charge controller, you may want to set it up so that power output is shunted to a dummy load instead of the battery or shorted altogether. This will slow or brake the turbine generator once it’s connected, so the blades won’t spin when raising or lowering the turbine unit.
3

Thread insulated wire through the base and tower shaft. Insert the wire into the side opening formed by the tee and up through the top. Then, thread the wire through the tower shaft. You may need to use a string line or fish tape to help you thread the wire through the pipe.
4

Mount the tower shaft on the base. You may want to attach guy wires to the shaft to help support it.
5
Mount the wind turbine head on the tower shaft. Thread the wires through the bearing to the top of the head assembly and connect them to the generator.
- If your tower is permanently mounted, you may want to remove the blades from the head assembly before putting it in place and then reattach them after everything is hooked up.
6

Connect the other end of the wire to the generator. You can then reconfigure the charge controller so that power output is directed to the battery.