Buzz
A wind turbine is a simple mechanical device, much like a traditional windmill. The flow of air pushes the turbine blades, and the resulting mechanical energy is transferred along the turbine's axis. This axis then powers other components of the generator, producing clean (renewable) energy for your home and reducing electricity costs. Additionally, turbines can be built using basic materials available at hardware stores.
Steps
Plan the installation of the wind turbine
Determine the average wind speed at the site where you plan to install the turbine. For effective power generation, the turbine needs a wind speed of at least 11-16 km/h. Most turbines work best at wind speeds between 19-32 km/h. To find the average wind speed for your area, you can consult an online wind map that provides the average wind speed.
- You can also purchase an anemometer to measure the wind speed at the turbine site. Take readings daily over a period of time.
- If the wind speed at your location is relatively stable, a month's worth of data should be sufficient, even though wind speed fluctuates seasonally. Then you can calculate the average value of the data to determine if it's reasonable to install the turbine there.
Check the local building laws related to wind turbines. Each region has different construction regulations, so it's important to consult with local authorities to ensure your turbine complies with the law. Some regulations may specify the minimum distance between turbines or the distance from the turbine to property boundaries. Local laws may also impose height restrictions to consider when designing your turbine.
- It's advisable to discuss the turbine installation with your neighbors before investing too much time in design and construction. This way, you can address their concerns about wind turbines and dispel misconceptions about noise and potential interference with radio waves (broadcasting and television).
Evaluate the space for installing the turbine. While the turbine itself doesn't require much space, to avoid conflicts with neighbors, it's recommended to allocate at least 0.2 hectares for a 3-kilowatt turbine and 0.4 hectares for a turbine with a capacity up to 10 kilowatts. The space's height should also be sufficient to ensure that buildings and trees do not obstruct the wind flow.
Use pre-made or homemade turbine blades. The type and design of the turbine blades can affect the overall turbine design. Traditional farm windmills essentially have small sails attached to a rotating shaft, but wind turbines are like giant propellers with large blades shaped like teardrops. The blades must be appropriately sized and spaced to operate efficiently.
- If you're making your own blades, you can craft them from wood or PVC pipe sections. You can find guides online by searching for 'DIY wind turbine blades'.
- Whether you buy or make the blades, typically you'll need three blades for the wind turbine. Using an even number, like two or four, can cause the turbine to wobble when spinning. Increasing the number of blades increases torque but may slow the turbine's rotation.
- Turbine blades can also be made from household items, like a sturdy shovel. If you go this route, choose a solid shovel and replace the wooden handle with a more durable material, like metal.
Select a generator. You need to connect your wind turbine to a generator to produce electricity. Most generators are direct current (DC), meaning you'll need to connect the generator to an inverter to convert the electricity into alternating current (AC) for household use.
- You can use a DC motor as a generator, though the magnetic flux may not be strong enough to produce a substantial electric field.
- Generators depend on rotational movement (in this case, the motion of the turbine blades) and magnetic forces to generate electricity. Pre-made generators are the easiest option for beginners, but you can also build your own by searching for 'build a wind turbine generator' online.
- If you decide to buy a DC generator, choose one with a high voltage rating, high current, and a low rotation speed (a few hundred RPM instead of a few thousand). You should aim for a minimum continuous output of 12 volts.
- The generator must be connected to a battery storage system and a charge controller positioned between the generator and the inverter to protect both the inverter and battery from voltage spikes. This also helps provide power to the inverter during low wind conditions.
- Avoid using car generators for wind turbines. They require much higher rotation speeds than wind turbines provide.
Assemble the rotating shaft and hand crank for a vertical-axis wind turbine
Assemble the rotating shaft. You will need to weld the rotating shaft to the shaft base, although many pre-made wind turbines already have these parts welded together. If you're assembling the turbine from purchased components or surplus parts, remember to wear protective gear such as goggles, gloves, protective clothing, and boots before starting the welding process.
- Once the rotating shaft is assembled, you can proceed by attaching the remaining components to the shaft in sequence. This method is typically the most efficient for assembling the turbine if you're doing the project by yourself.
Slide the sprocket onto the rotating shaft. To prevent friction and damage between the rotating shaft and sprocket, it's a good idea to install a bearing between them. Place the bearing on the tapered end of the shaft protruding from the base, and slide it towards the base until it settles into the thicker section of the shaft. Then, slide the sprocket onto the bearing, ensuring that the sprocket's teeth are facing upward.
- The distance from the bearing to the shaft base is approximately 10.2 cm. When the wind blows strongly, the turbine may bend, causing the blades to collide and potentially damage the shaft.
- If you’re not using a full set and need to make your own sprocket, consider using a 4 on 4 (4 bolts - 4 inches) sprocket from a trailer, available at trailer parts stores, like those for automotive parts.
Attach the lower rotating disc to the sprocket. The rotating disc should have holes to slide over the protruding pins on the sprocket, and it should have tabs to connect the cranks. Fit the rotating disc onto the sprocket pins and secure it in place. After aligning the disc evenly on the sprocket, tighten it using wheel nuts, first by hand and then using a socket wrench for a firmer hold.
Connect the cranks. You will need two cranks for each turbine blade, meaning there are six cranks for a turbine with three blades. You will need bolts to connect the cranks to the tabs on the lower rotating disc, and washers to separate the lower cranks from the upper cranks. Then:
- Slide a bolt into a hole on the tab of the rotating disc, fit the crank onto the bolt, push the washer onto the bolt, fit the second crank onto the bolt, and use the upper rotating disc to clamp the two cranks together with the washer. The lower and upper rotating discs must be identical in shape, with matching tabs for the cranks.
- Hand-tighten the bolt into the upper rotating disc to hold it in place, then tighten the remaining bolts of the first crank assembly. Repeat this process for all cranks.
- Once all cranks are clamped between the lower and upper rotating discs, use a socket wrench to tighten the bolts further. After tightening the bolts, the lower rotating disc, upper rotating disc, and cranks should be ready to rotate smoothly with the sprocket on the bearing.
- Since the turbine structure will be continuously affected by wind and environmental factors, the connection between the bolts and cranks must be secure. To ensure a firm bond, use thread-locking fluid available at hardware stores.
Attach four pins to the upper rotating disc. These pins should have threads and each should be 6 cm in length and 0.635 cm in thickness. You may need to use a hacksaw to cut the pins to the required length. Then, screw the pins into the upper surface of the upper rotating disc, distributing them evenly around the rotating shaft.
- Only screw the pins into the disc deep enough so that each pin stands straight and securely. All pins should protrude equally from the rotating disc.
- If you use a hacksaw to cut the pins, be cautious not to damage the threads. Damaged threads will prevent you from attaching other components.
- Ensure that the pins, as well as the bolts connecting the cranks, are securely fastened. Finally, apply thread-locking fluid to the pins.
Install the magnets of the vertical axis wind turbine
Install the lower rotor magnets onto the pins. You can either create your own lower and upper rotors using rotor discs, epoxy resin, and neodymium magnets (5cm x 2.5cm x 1.25cm), or purchase pre-made rotor parts that come with the wind turbine kit, or directly from the wind turbine parts supplier. Point the magnets upwards, and fit the lower rotor disc into the four pins that you’ve securely fastened to the rotating disc.
- Whether you make your own rotor magnets or use pre-made ones, always exercise caution when handling the magnets or rotor discs. Their magnetic fields are powerful and can cause serious injuries if mishandled.
- Neodymium magnets are quite brittle. You will need 24 magnets, 12 for the upper rotor and 12 for the lower rotor, but it’s recommended to purchase extra magnets in case any break during installation. These magnets are available online.
Create the rotor magnets if necessary. If you’ve purchased a complete set with a rotor disc, simply install it onto the pins as described above. For a homemade rotor, you’ll need to evenly space the magnets around the rotor disc’s edge. To avoid placing magnets incorrectly and damaging the rotor, it’s helpful to sketch the magnet placement on cardboard or regular paper.
- This paper will be placed in the center of the rotor, marking the area where magnets should not be placed. Lines drawn from the center to the paper’s edge will show where to position the magnets. You can tape the paper down and use sample templates found online.
- It’s also important to mark the poles of the magnets before installation. If the magnets are attracted to each other and it’s hard to tell the poles apart, make a simple testing tool by attaching a small magnet to a popsicle stick.
- Slide the "N" pole of your test tool along the neodymium magnet. If you feel a repelling force, that side is the same pole. If you feel an attraction, it’s the opposite pole.
- Use a small amount of epoxy resin, roughly the size of a pea, to secure each magnet. Apply the resin to the magnet before placing it on the rotor disc.
- Be cautious and keep your fingers away from the gap between the magnet and the rotor disc, gently move the magnet to the designated area on the disc. The magnet should adhere to the surface before you slide it into the correct position according to the marked lines on the template.
Install the spacers onto the pins. You can use metal tubing with a thickness of 0.375cm, cutting it into 3.175cm long pieces to create the spacers. The more accurately you cut the spacer lengths, the better. Slide the spacers onto the pins that extend from the surface of the rotor disc.
- Uneven spacer sizes can cause the rotor to tilt, which is dangerous and could negatively affect the wind turbine’s performance.
- The length of the pin above the spacer should be no more than 2.5cm. This extra length allows you to attach the bolt tightening the upper rotor disc and all the parts between the two rotors.
Place the stator onto the lower rotor magnets. The stator consists of multiple metal wire coils and plays a crucial role in the generator. It is available in wind turbine kits, or you can purchase it from the turbine parts supplier, or even create your own. The pins around the central rotating axis will fit into the stator, and you must align it carefully with the rotating axis.
- The stator consists of three bundles, each with three coils of 24-gauge copper wire, each coil containing 320 turns of copper wire. Crafting a stator can be time-consuming and challenging.
- If you choose to make your own stator, you can find tutorials online by searching for the phrase "how to make a wind turbine stator".
Build a stator winding machine at home. You can create a stator winding machine using scrap wood and nails. Join two pieces of plywood with four nails so that there is a 2.5cm gap between the two pieces. The nails should be positioned in a rectangular pattern corresponding to the size of the magnet. After this, you can easily wind copper wire to form the stator.
- While making the stator, ensure you monitor when each coil starts and ends. Each coil should be wound in the same direction. It’s a good idea to place a piece of colored electrical tape at the start of each winding.
- To prevent the coils from unraveling after winding, wrap the coils with electrical tape and then apply two layers of epoxy resin. Once the epoxy has been applied, let the stator dry on wax paper for the time indicated on the resin label.
Install the upper rotor magnets. Exercise extreme caution, as this is one of the most dangerous components of the wind turbine structure. Place four pieces of wood on top of the stator on both sides of the rotating axis, using thick wood at the bottom and thinner wood on top. The top wood should measure 2 x 4.
- Hold the upper rotor carefully, keeping your fingers within the gap between the stacked pieces of wood, and slowly place the upper rotor onto the lower rotor. Try to align the upper rotor with the pins as you install it.
- The magnetic field will hold the upper rotor disc and attract it to the previously placed pieces of wood. Then, lower the upper rotor onto the pins by gradually sliding each piece of wood out.
- Repeat this process with the lower pieces of wood to properly position the upper rotor. Afterward, tighten the hex bolts onto the pins to secure the rotor. Once completed, the upper rotor should sit on the spacers and the pins, with only a small gap left above.
- You may need to wiggle the pieces of wood to remove them from the upper rotor due to the strong magnetic forces involved.
Complete the main structure of the turbine
Remove the turbine structure from the rotating axis. Next, you will attach the rotating axis to the tower. If you leave the turbine structure attached to the rotating axis while trying to install it on the tower, it will be very difficult. At this point, you need to invert the structure to fit it onto the tower.
- Lift the entire turbine structure (including the sprocket, crank, rotor magnets, stator, and all related components) off the rotating axis in a vertical motion. Then, move the turbine structure to another location, with the sprocket facing upward.
Weld the rotating axis base to the tower. If you have a complete kit (usually sold pre-made), weld the rotating axis base to the tower. However, the tower may be made from a sheet of metal attached to the top of a thick metal pipe. Be sure to use a pipe that’s thick enough to withstand the wind forces acting on the turbine.
- The tower must be installed on a stable foundation. It’s recommended to pour concrete at the base of the tower installation to increase stability.
Install the support bracket for the rotating axis and stator. This bracket must fit snugly on the rotating axis, similar to a collar. Then, secure it with bolts to the tower. Next, cut a 0.375cm thick threaded rod into four 11cm sections. First, apply thread-locking solution, then use nuts and washers to connect the threaded rods to the outer part of the bracket, with the rods facing upwards.
- You should tighten the nuts onto the threaded rods until they are approximately three-quarters of the way down from the top of the rods. The nuts will allow you to adjust the position of the stator while the threaded rods keep it securely in place.
Install the tapered bearing onto the rotating axis. Before installation, apply plenty of regular bearing grease to the tapered bearing. After greasing, slide the bearing onto the rotating axis until it reaches the base of the shaft.
- You can use your fingers to apply grease to the bearing. Be sure to have paper towels or rags nearby to clean your hands after greasing the bearing and installing it onto the rotating axis.
Assemble the main turbine structure. Lift the main structure with the sprocket facing upward and place it onto the rotating axis, which has the tapered bearing installed below. The holes for the stator should align with the threaded rods you previously secured to the bracket.
- Once the structure is in position, you need to install another tapered bearing onto the sprocket cap. Be sure to apply regular bearing grease to the bearing before installation.
- Tighten the flower nut at the top of the bearing, which can be done easily by hand.
- If you find it difficult to tighten the nut by hand, loosen it until the gap in the nut aligns with the hole in the rotating axis. Slide a locking pin into this hole, and use pliers to bend the pin legs to securely lock the flower nut.
Tighten the stator and install the grease cap to complete the turbine structure. Use a hex nut for each threaded rod to secure the stator to the structure. Then, use two wrenches to adjust the nuts, positioning the stator precisely between the two magnet rotors.
- Once the stator is correctly aligned, the remaining step is to install the grease cap on top of the sprocket, thus completing the turbine assembly.
Install the electrical components of the turbine
Connect the charge controller to the battery or electrical circuit. Connecting the charge controller to the battery before attaching it to the wind turbine prevents the generation of excessive voltage, thus avoiding potential damage to the equipment.
Connect the insulated electrical wires to the charge controller. These wires will transmit electricity from the generator to the charge controller, which then feeds it into the battery or electrical circuit.
- It is recommended to use power cables with two similarly insulated sections, or you can use wires from a mobile outlet and cut off the plug if preferred.
Thread the electrical wires from the base and through the tower shaft. Run the wires from the bottom of the tower to the top of the turbine structure. You may need to use a guiding rope or tape measure to help route the wires through the tower. Afterward, connect the wires to the generator.
Connect to the battery or electrical circuit. Once the generator is connected to the charge controller and the wiring is routed through the tower legs, you are ready to link the home's electrical circuit to the turbine's wiring. Whenever connecting an external power source to a household circuit, it's advisable to consult a licensed electrician. In many regions, this task requires professional electrical expertise.
Advice
- You should enclose the charge controller to prevent moisture from the air, and consider connecting it to a voltmeter to monitor the output current.
- Research the migratory bird patterns in your area. If migratory birds frequent the area, it is not advisable to build a wind turbine there.
Warning
- If you plan to sell electricity to the power company, be aware that they sell electricity to you at retail prices but purchase it at wholesale rates. You will need to install a synchronous rectifier compatible with the alternating current frequency of the company’s power lines, along with a special inverter. It is likely you won't generate enough power to recoup the installation costs, let alone make a profit.
What You Will Need
- 2 x 4 wooden pieces
- Bolts, nuts, and washers
- Flower nuts
- Charge controller
- Key locks
- DC generator or AC motor (optional)
- Maintenance battery (recommended)
- General bearing grease
- Grease cover (for gearbox)
- Metal saw
- Gearbox
- Insulated electrical wires
- Iron floor flange (2.5 cm diameter)
- Iron pipe (2.5 cm diameter)
- Magnet rotor/rotor disk
- Metal tube (3/8"/0.95 cm width)
- Nuts
- Pipe wrench
- Crank handle
- Stator
- Stator bracket
- Cone bearings (2 pieces)
- Thread locker solution
- Thread rods (3/8"/0.375 cm thickness)
- Thread rods (0.635 cm thickness)
- Voltmeter (optional)
- Washers
- Welding machine
- Adjustable wrench
