Air masses have inexhaustible reserves of energy that mankind used in ancient times. Basically, the force of the wind ensured the movement of ships under sail and the operation of windmills. After the invention of steam engines, this type of energy lost its relevance.
Only in modern conditions, wind energy has again become in demand as a driving force applied to electric generators. They are not yet widely used on an industrial scale, but are becoming increasingly popular in the private sector. Sometimes it is simply impossible to connect to the power line. In such situations, many owners design and manufacture a wind generator for a private house with their own hands from improvised materials. In the future, they are used as the main or auxiliary sources of electricity.
The theory of an ideal windmill
This theory was developed at different times by scientists and specialists in the field of mechanics. It was first developed by V.P. Vetchinkin in 1914, and the theory of an ideal propeller was used as a basis. In these studies, the utilization factor of wind energy by an ideal wind turbine was first derived.
Work in this area was continued by N.E. Zhukovsky, who deduced the maximum value of this coefficient, equal to 0.593. In the later works of another professor - Sabinin G.Kh. the corrected value of the coefficient was 0.687.
According to the developed theories, an ideal wind wheel should have the following parameters:
- The axis of rotation of the wheel must be parallel to the speed of the wind flow.
- The number of blades is infinitely large, with a very small width.
- Zero profile resistance of the wings in the presence of constant circulation along the blades.
- The entire swept surface of the windmill has a constant lost airflow velocity on the wheel.
- The tendency of the angular velocity to infinity.
Wind turbine selection
When choosing a wind turbine model for a private house, one should take into account the necessary power that ensures the operation of instruments and equipment, taking into account the schedule and frequency of switching on. It is determined by monthly metering of consumed electricity. Additionally, the power value can be determined in accordance with the technical characteristics of consumers.
It should also be taken into account that the power of all electrical appliances is not carried out directly from the wind generator, but from the inverter and a set of batteries. Thus, a generator with a power of 1 kW is able to ensure the normal functioning of the batteries that feed the four-kilowatt inverter. As a result, household appliances with a similar capacity are provided with electricity in full. Choosing the right batteries is important. Particular attention should be paid to parameters such as charging current.
When choosing a wind turbine design, the following factors are taken into account:
- The direction of rotation of the wind wheel is vertical or horizontal.
- The shape of the blades for the fan can be in the form of a sail, with a straight or curved surface. In some cases, combined options are used.
- Material for blades and technology of their manufacture.
- Placement of fan blades with different slopes relative to the flow of passing air.
- The number of blades included in the fan.
- The required power transferred from the wind turbine to the generator.
In addition, it is necessary to take into account the average annual wind speed for a particular area, specified in the meteorological service. It is not necessary to specify the direction of the wind, since modern designs of wind turbines independently turn in the other direction.
For most areas of the Russian Federation, the best option would be the horizontal orientation of the axis of rotation, the surface of the blades is curved concave, which the air flow flows around at an acute angle. The amount of power taken from the wind is affected by the area of the blade. For an ordinary house, an area of \u200b\u200b1.25 m 2 is enough.
The speed of a windmill depends on the number of blades. Wind turbines with one blade rotate the fastest. In such designs, a counterweight is used for balancing. It should also be taken into account that at low wind speeds, below 3 m/s, wind turbines become unable to take energy. In order for the unit to perceive a weak wind, the area of its blades must be increased to at least 2 m 2.
Calculation of a wind generator
Before choosing a wind generator, it is necessary to determine the wind speed and direction that are most characteristic at the place of intended installation. It should be remembered that the rotation of the blades starts at a minimum wind speed of 2 m/s. The maximum efficiency can be achieved when this indicator reaches a value from 9 to 12 m / s. That is, in order to provide electricity to a small country house, you will need a generator with a minimum power of 1 kW / h and wind at a speed of at least 8 m / s.
Wind speed and propeller diameter have a direct impact on the power generated by a wind turbine. It is possible to accurately calculate the performance characteristics of a particular model using the following formulas:
- Calculations in accordance with the area of rotation are performed as follows: P = 0.6 x S x V 3, where S is the area perpendicular to the direction of the wind (m 2), V is the wind speed (m / s), P is the power of the generator set ( kW).
- To calculate the electrical installation by the diameter of the screw, the formula is used: P \u003d D 2 x V 3 / 7000, in which D is the screw diameter (m), V is the wind speed (m / s), P is the generator power (kW).
- More complex calculations take into account the density of the air flow. For these purposes, there is a formula: P \u003d ξ x π x R 2 x 0.5 x V 3 x ρ x η red x η gene, where ξ is the coefficient of wind energy use (a measureless value), π = 3.14, R - rotor radius (m), V - air flow velocity (m / s), ρ - air density (kg / m 3), η ed - reducer efficiency (%), η gene - generator efficiency (%).
Thus, the electricity produced by the wind generator increases quantitatively in a cubic ratio with the increasing speed of the wind flow. For example, with an increase in wind speed by 2 times, the production of kinetic energy by the rotor will increase by 8 times.
When choosing a place to install a wind turbine, it is necessary to give preference to areas without large buildings and tall trees that create a barrier to the wind. The minimum distance from residential buildings is from 25 to 30 meters, otherwise the noise during work will create inconvenience and discomfort. The wind turbine rotor must be located at a height exceeding the nearest buildings by at least 3-5 m.
If it is not planned to connect a country house to a common network, in this case, you can use the options of combined systems. The operation of the wind turbine will be much more efficient when used in conjunction with a diesel generator or a solar battery.
How to make a wind generator with your own hands
Regardless of the type and design of the wind turbine, each device is equipped with similar elements as a basis. All models are equipped with generators, blades of various materials, lifts to provide the desired level of installation, as well as additional batteries and an electronic control system. The most simple to manufacture are rotary-type units or axial structures using magnets.
Option 1. Rotary design of the wind generator.
The design of a rotary wind generator uses two, four or more blades. Such wind generators are not able to fully provide electricity to large country houses. They are mainly used as an auxiliary source of electricity.
Depending on the design power of the windmill, the necessary materials and components are selected:
- 12 volt car alternator and car battery.
- Voltage regulator that converts alternating current from 12 to 220 volts.
- Large sized container. An aluminum bucket or stainless steel pot works best.
- As a charger, you can use the relay removed from the car.
- You will need a 12 V switch, a charge lamp with a controller, bolts with nuts and washers, and metal clamps with rubberized gaskets.
- A three-core cable with a minimum cross section of 2.5 mm 2 and a conventional voltmeter taken from any measuring device.
First of all, the rotor is prepared from an existing metal container - a pot or bucket. It is divided into four equal parts, holes are made at the ends of the lines to facilitate separation into component parts. Then the container is cut with scissors for metal or a grinder. Rotor blades are cut out of the resulting blanks. All measurements must be carefully checked for dimensional conformity, otherwise the design will not work properly.
Next, the side of rotation of the generator pulley is determined. As a rule, it rotates clockwise, but it is better to check this. After that, the rotor part is connected to the generator. To avoid imbalance in the movement of the rotor, the mounting holes in both designs must be symmetrical.
To increase the speed of rotation, the edges of the blades should be slightly bent. As the bending angle increases, the air flows will be more effectively perceived by the rotary unit. As blades, not only elements of a cut container are used, but also individual parts connected to a metal blank having the shape of a circle.
After attaching the container to the generator, the entire resulting structure must be fully installed on the mast using metal clamps. Then the wiring is mounted and assembled. Each pin must be connected to its own connector. After connection, the wiring is attached to the mast with wire.
At the end of the assembly, the inverter, battery and load are connected. The battery is connected with a cable with a cross section of 3 mm 2, for all other connections a cross section of 2 mm 2 is sufficient. After that, the wind generator can be operated.
Option 2. Axial construction of a wind generator using magnets.
Axial windmills for the home are a design, one of the main elements of which are neodymium magnets. In terms of their performance, they are significantly ahead of conventional rotary units.
The rotor is the main element of the entire design of the wind turbine. For its manufacture, the hub of an automobile wheel complete with brake discs is best suited. The part that was in operation should be prepared - cleaned of dirt and rust, lubricated bearings.
Next, you need to correctly distribute and fix the magnets. In total, you will need 20 pieces, 25 x 8 mm in size. The magnetic field in them is located along the length. Even magnets will be poles, they are located on the entire plane of the disk, alternating through one. Then the pros and cons are determined. One magnet alternately touches the other magnets on the disc. If they attract, then the pole is positive.
With an increased number of poles, certain rules must be observed. In single-phase generators, the number of poles is the same as the number of magnets. Three-phase generators have a 4/3 ratio between magnets and poles and a 2/3 ratio between poles and coils. The installation of magnets is carried out perpendicular to the circumference of the disc. A paper template is used to evenly distribute them. First, the magnets are fixed with strong glue, and then finally fixed with epoxy.
If we compare single-phase and three-phase generators, then the performance of the former will be somewhat worse compared to the latter. This is due to high amplitude fluctuations in the network due to unstable current output. Therefore, vibration occurs in single-phase devices. In three-phase designs, this disadvantage is compensated by current loads from one phase to another. As a result, a constant power value is always ensured in the network. Due to vibration, the service life of single-phase systems is significantly shorter than that of three-phase systems. In addition, three-phase models have no noise during operation.
The height of the mast is approximately 6-12 m. It is installed in the center of the formwork and poured with concrete. Then a finished structure is installed on the mast, on which the screw is attached. The mast itself is fastened with cables.
Wind turbine blades
The efficiency of wind power installations largely depends on the design of the blades. First of all, this is their number and size, as well as the material from which the blades for the wind turbine will be made.
Factors affecting blade design:
- Even the weakest wind can set the long blades in motion. However, too much length can slow down the speed of the wind wheel.
- Increasing the total number of blades makes the wind wheel more responsive. That is, the more blades, the better the rotation starts. However, the power and speed will decrease, making such a device unsuitable for power generation.
- The diameter and speed of rotation of the wind wheel affects the noise level generated by the device.
The number of blades must be combined with the installation site of the entire structure. Under the most optimal conditions, properly selected blades can provide maximum output from the wind turbine.
First of all, you need to determine in advance the required power and functionality of the device. To properly manufacture a wind turbine, you need to study the possible designs, as well as the climatic conditions in which it will be operated.
In addition to the total power, it is recommended to determine the value of the output power, also known as peak load. It represents the total number of appliances and equipment that will be turned on simultaneously with the operation of the wind turbine. If you need to increase this figure, it is recommended to use several inverters at once.
DIY wind generator 24v - 2500 watts
Electricity is steadily rising in price. To feel comfortable outside the city in hot summer weather and a frosty winter day, you need to either spend a lot of money or look for alternative energy sources. Russia is a huge country with large flat areas. Although slow winds prevail in most of our regions, strong and violent air currents blow over the sparsely populated area. Therefore, the presence of a wind generator in the farm of the owner of suburban real estate is most often justified. The appropriate model is chosen based on the area of application and the actual purpose of use.
Wind turbine #1 - rotary type design
You can make a simple rotary windmill with your own hands. Of course, he is unlikely to be able to supply electricity to a large cottage, but it is quite possible to provide electricity to a modest garden house. With it, you can supply light in the evening to outbuildings, illuminate garden paths and the local area.
You can read more about other types of alternative energy sources in this article:
So, or almost so, a do-it-yourself rotary wind generator looks like. As you can see, there is nothing super complicated in the design of this equipment.
Preparation of parts and consumables
To assemble a wind generator, the power of which will not exceed 1.5 kW, we will need:
- generator from car 12 V;
- acid or gel battery 12 V;
- converter 12V - 220V to 700 W - 1500 W;
- a large container made of aluminum or stainless steel: a bucket or a voluminous pan;
- automotive battery charging relay and charge control lamp;
- semi-hermetic "button" switch for 12 V;
- voltmeter from any unnecessary measuring device, you can automobile;
- bolts with washers and nuts;
- wires with a cross section of 2.5 mm 2 and 4 mm 2;
- two clamps with which the generator will be attached to the mast.
To do the work, we will need metal scissors or a grinder, a tape measure, a marker or a construction pencil, a screwdriver, keys, a drill, a drill, wire cutters.
Most owners of private houses do not recognize the use of geothermal heating, but such a system has promise. You can read more about the advantages and disadvantages of this complex in the following material:
Progress of design work
We are going to make a rotor and remake the alternator pulley. To get started, we need a metal container of a cylindrical shape. Most often, a pot or bucket is adapted for these purposes. Take a tape measure and a marker or construction pencil and divide the container into four equal parts. If we cut metal with scissors, then in order to insert them, you must first make holes. You can also use a grinder if the bucket is not made of painted tin or galvanized steel. In these cases, the metal will inevitably overheat. Cut out the blades without cutting through them to the end.
In order not to be mistaken with the dimensions of the blades that we cut in the tank, it is necessary to make careful measurements and carefully recalculate everything.
In the bottom and in the pulley we mark and drill holes for the bolts. At this stage, it is important to take your time and arrange the holes symmetrically to avoid imbalance during rotation. The blades should be bent, but not too much. When performing this part of the work, we take into account the direction of rotation of the generator. It usually rotates in a clockwise direction. Depending on the angle of the bend, the area of influence of wind flows increases, and, therefore, the speed of rotation.
This is another option for blades. In this case, each part exists separately, and not as part of the container from which it was cut.
Since each of the windmill blades exists separately, you need to screw each one. The advantage of this design is its increased maintainability
The bucket with finished blades should be fixed to the pulley using bolts. We install the generator on the mast using clamps, then we connect the wires and assemble the circuit. It is better to rewrite the diagram, wire colors and contact markings in advance. The wires also need to be fixed on the mast.
To connect the battery, we use wires 4 mm 2, the length of which should not be more than 1 meter. We connect the load (electrical appliances and lighting) using wires with a cross section of 2.5 mm 2. Do not forget to put the converter (inverter). It is connected to the network to contacts 7.8 with a 4 mm 2 wire.
The design of the wind turbine consists of a resistor (1), a generator starter winding (2), a generator rotor (3), a voltage regulator (4), a reverse current relay (5), an ammeter (6), a battery (7), a fuse (8) , switch (9)
Advantages and disadvantages of such a model
If everything is done correctly, this wind generator will work without creating problems for you. With a 75A battery and a 1000 W converter, it can power street lighting, video surveillance devices, etc.
The scheme of the installation clearly demonstrates exactly how wind energy is converted into electricity and how it is used for its intended purpose.
The advantages of such a model are obvious: it is a very economical product, easy to repair, does not require special conditions for its operation, works reliably and does not violate your acoustic comfort. The disadvantages include low productivity and a significant dependence on strong gusts of wind: the blades can be torn off by air currents.
Windmill #2 - axial design with magnets
Until recently, axial windmills with iron-free stators on neodymium magnets have not been made in Russia due to the inaccessibility of the latter. But now they are in our country, and they are cheaper than originally. Therefore, our craftsmen began to manufacture wind turbines of this type.
Over time, when the capabilities of a rotary wind generator will no longer provide all the needs of the economy, you can make an axial model on neodymium magnets
What needs to be prepared?
For the basis of the axial generator, you need to take the hub from the car with brake discs. If this part was in operation, it must be disassembled, the bearings checked and lubricated, rust cleaned off. The finished generator will be painted.
To qualitatively clean the hub from rust, use a metal brush that can be mounted on an electric drill. The hub will look great again
Distribution and fixation of magnets
We have to stick magnets on the rotor discs. In this case, 20 magnets with a size of 25x8mm are used. If you decide to make a different number of poles, then use the rule: in a single-phase generator there must be as many poles as there are magnets, and in a three-phase generator, the ratio of 4/3 or 2/3 poles to coils must be observed. Magnets should be placed by alternating poles. To ensure that their location is correct, use a template with sectors printed on paper or on the disc itself.
If possible, it is better to use rectangular magnets rather than round ones, because round ones have a magnetic field concentrated in the center, and rectangular ones along their length. The opposing magnets must have different poles. In order not to confuse anything, use a marker to put “+” or “-” on their surface. To determine the pole, take one magnet and bring others to it. Put plus on attracting surfaces, and minus on repulsive ones. On the disks, the poles must alternate.
The magnets are correctly placed. Before fixing them with epoxy resin, it is necessary to make plasticine sides so that the adhesive mass can harden, and not glass on the table or floor
To fix the magnets, you need to use a strong glue, after which the bonding strength is further enhanced with epoxy resin. It is filled with magnets. To prevent the resin from spreading, you can make plasticine borders or simply wrap the disc with tape.
Three-phase and single-phase generators
A single-phase stator is worse than a three-phase one, because it vibrates when loaded. This is due to the difference in the amplitude of the current, which occurs due to its non-constant return for a moment in time. The three-phase model does not suffer from this disadvantage. The power in it is always constant, because the phases compensate for each other: if the current drops in one, it increases in the other.
In a dispute between single-phase and three-phase options, the latter comes out the winner, because additional vibration does not extend the life of the equipment and irritates the ear.
As a result, the output of a three-phase model is 50% higher than that of a single-phase one. Another advantage of the absence of unnecessary vibration is the acoustic comfort when working under load: the generator does not hum during its operation. In addition, vibration always puts the wind generator out of action before the expiration of its service life.
Coil winding process
Any specialist will tell you that before winding the coils, you need to make a careful calculation. And any practitioner will do everything intuitively. Our generator will not be too fast. We want the 12 volt battery to start charging at 100-150 rpm. With such initial data, the total number of turns in all coils should be 1000-1200 pieces. It remains to divide this figure by the number of coils and find out how many turns there will be in each.
To make the wind generator more powerful at low speeds, you need to increase the number of poles. In this case, the frequency of current oscillations in the coils will increase. For winding coils, it is better to use a thick wire. This will reduce the resistance, which means that the current will increase. It should be noted that at high voltage, the current may be "eaten" by the resistance of the winding. A simple homemade machine will help you quickly and accurately wind high-quality coils.
The stator is marked, the coils are laid in their places. For their fixation, epoxy resin is used, the runoff of which is again resisted by plasticine bumpers.
Due to the number and thickness of the magnets located on the disks, generators can vary considerably in performance. To find out what power to expect as a result, you can wind one coil and scroll it in the generator. To determine future power, you should measure the voltage at certain speeds without load.
For example, at 200 rpm, 30 volts is obtained with a resistance of 3 ohms. We subtract from 30 volts the battery voltage of 12 volts, and divide the resulting 18 volts by 3 ohms. The result is 6 amps. This is the volume that will go to the battery. Although in practice, of course, it turns out less due to losses in the diode bridge and in the wires.
Most often, the coils are made round, but it is better to stretch them a little. At the same time, there is more copper in the sector, and the turns of the coils are straighter. The diameter of the inner hole of the coil should match the size of the magnet or be slightly larger than it.
Preliminary tests of the resulting equipment are carried out, which confirm its excellent performance. Over time, this model can be improved.
When making the stator, keep in mind that its thickness must match the thickness of the magnets. If the number of turns in the coils is increased and the stator is made thicker, the interdisk space will increase and the magnetic flux will decrease. As a result, the same voltage can be generated, but less current due to the increased resistance of the coils.
Plywood is used as a form for the stator, but you can mark sectors for coils on paper, and make borders from plasticine. The strength of the product will increase the fiberglass placed on the bottom of the mold and on top of the coils. The epoxy must not stick to the mold. To do this, it is lubricated with wax or petroleum jelly. For the same purpose, you can use a film or tape. The coils are fixed to each other motionlessly, the ends of the phases are brought out. Then all six wires are connected by a triangle or a star.
The generator assembly is tested using hand rotation. The resulting voltage is 40 volts, while the current strength is approximately 10 amperes.
Final stage - mast and propeller
The actual height of the finished mast was 6 meters, but it would be better to make it 10-12 meters. The base for it needs to be concreted. It is necessary to make such a fastening so that the pipe can be raised and lowered using a hand winch. A screw is attached to the top of the pipe.
PVC pipe is a reliable and fairly light material, using which you can make a windmill propeller with a predetermined bend
For the manufacture of the screw, a PVC pipe is needed, the diameter of which is 160 mm. A six-blade two-meter screw is to be cut out of it. It makes sense to experiment with the shape of the blades in order to increase the torque at low revs. From a strong wind, the screw must be removed. This function is performed using a folding tail. The generated energy is stored in batteries.
The mast must be raised and lowered with a hand winch. Additional structural stability can be given using tension cables.
Your attention is given to two options for wind turbines, which are most often used by summer residents and owners of suburban real estate. Each of them is effective in its own way. Especially the result of using such equipment is manifested in areas with strong winds. In any case, such an assistant in the household will never hurt.
Until recently, wind turbines were considered a rarity, but today this area is rapidly developing, and many have gained experience in creating wind turbines to generate electricity. Such devices can be used in a variety of areas - for water supply, electrification of private houses, operation of agricultural units (for example, crushers) or heating water to heat a home.
Industrial models have a lot of advantages, except for the cost. Therefore, today we will find out how to make a wind generator with our own hands and what materials / tools will be needed for this.
Design features and mechanics of a wind generator
The principle of operation of a wind generator is to convert kinetic energy into electricity. The device consists of a number of system elements, each of which has its own function. Let's try to figure this out.
Note! Wind generators can be rotary (vertical) and classical (horizontal). The latter have a higher efficiency, which is why they are made more often than others.
It is worth noting that vertical windmills must be turned towards the wind, because they are simply unable to function with a side stream. Horizontal generators have other advantages as well. Let's get acquainted with them.
- Turbines of rotary devices will "catch" the wind, regardless of which side it blows. Which is extremely convenient in case of unstable / variable wind in the region.
- It is much easier to build a horizontal windmill than a horizontal one.
- The structure can be located directly on the ground, but provided that there is enough wind there.
As for the disadvantages, a horizontal wind generator has only one - a rather low efficiency.
We calculate the power of the future wind generator
First you need to find out how much power a wind generator should have with your own hands, what are the functions and loads that it will face. As a rule, alternative sources of electricity are used as auxiliary, that is, designed to help the main power supply. Therefore, if the power of the system is even from 500 watts, this is already quite good.
Note! To heat a private house of medium size, you will need about two to three kilowatts.
However, the final power of the wind turbine depends on other factors, including:
- wind speed;
- number of blades.
To find out the appropriate ratio for horizontal type fixtures, we recommend that you familiarize yourself with the table below. The numbers in it at the intersection are the required power (indicated in watts).
Table. Calculation of the required power for horizontal wind generators.
| 1m | 3 | 8 | 15 | 27 | 42 | 63 | 90 | 122 | 143 |
| 2m | 13 | 31 | 63 | 107 | 168 | 250 | 357 | 490 | 650 |
| 3m | 30 | 71 | 137 | 236 | 376 | 564 | 804 | 1102 | 1467 |
| 4m | 53 | 128 | 245 | 423 | 672 | 1000 | 1423 | 1960 | 2600 |
| 5m | 83 | 166 | 383 | 662 | 1050 | 1570 | 2233 | 3063 | 4076 |
| 6m | 120 | 283 | 551 | 953 | 1513 | 2258 | 3215 | 4410 | 5866 |
| 7m | 162 | 384 | 750 | 1300 | 2060 | 3070 | 4310 | 6000 | 8000 |
| 8m | 212 | 502 | 980 | 1693 | 2689 | 4014 | 5715 | 7840 | 10435 |
| 9m | 268 | 653 | 1240 | 2140 | 3403 | 5080 | 7230 | 9923 | 13207 |
For example, if in your region the wind speed is predominantly from 5 to 8 meters per second, and the required power of the wind generator is 1.5-2 kilowatts, then the diameter of the structure should correspond to about 6 meters or more.
What should be the blades?
The shape of the blades can be:
- sailing;
- winged.
As for the sail-type blades, they are flat, and therefore less efficient. They do not take into account aerodynamics, but spin exclusively under the pressure of the wind flow. As a result, no more than 10 percent of all energy is converted into electrical energy. But for winged blades, the area of \u200b\u200bthe inner and outer surfaces is different. It is also worth noting that such blades should be located at an angle of 7-10 degrees relative to the wind.
Now a few words about the material from which the blades should be. For ancient windmills, tonic wood frames were used, consisting of poles and lintels. On such frames, special "wings" made of fabric were stretched. In case of wear of the fabric, it was simply replaced with a new one. Although there is an alternative option - to take dense materials for these purposes (for example, a tarpaulin).
Although with your own hands you can make blades from more modern materials.
- If the propeller is small, then PVC pipes cut into pieces can serve as blades for it.
- You can also use light metals (for example, duralumin).
- If you plan to use "sails", then they can be cut out of plywood.
- Finally, for a large unit, the blades can be made from boards (even if they are heavy, it doesn’t matter, you just need them to balance each other).
Note! In the case of a predominance of gusty winds in the region, it is better to give preference to weighty blades - this will ensure a more stable functioning of the entire system.
As for the diameter of the pipes, it should correspond to 1/5 of their total length. Each of these pipes is cut lengthwise into four pieces, and at the base it is necessary to cut a 5x5 rectangle (there will be fasteners), and after that, make an oblique cut, due to which each blade will taper from the base. Emery is used to process a torn edge.
Making a vertical wind generator at home
And now let's find out how, in fact, a wind generator is made by hand. The procedure consists of several stages, we will get acquainted with the features of each of them.
Stage one. We prepare tools and materials
There are no requirements regarding the size of the turbine - the larger it is, the better for the system itself. And in the example given in this article, the diameter of the turbine is 60 centimeters.
To make a vertical turbine yourself, prepare in advance:
- a pipe with diameters of 60 centimeters, made of stainless steel;
- screws, nuts and other fasteners;
- a pair of plastic disks with a diameter of 60 centimeters (it is important that the plastic is durable);
- hub from the car for the base;
- corners with which the blades will be attached (for each element - six pieces; that is, 36 copies in total).
In addition, take care of the following tools first:
- keys;
- jigsaw;
- mask;
- protective gloves;
- Bulgarian;
- screwdriver;
- electric drill.
Magnets or small metal plates can be used to balance the blades. If the imbalance is slight, then you can simply drill holes in the appropriate places.
Stage two. Draws up a drawing
You definitely can't do without a drawing. You can use the one below or create your own.
Stage three. Making a vertical windmill
Step 1. First, take a metal pipe and cut it lengthwise so that you end up with six blades of the same size.
Step 2 Cut out a pair of identical circles with a diameter of 60 centimeters from plastic. They will serve as supports for the lower and upper parts of the turbine.
Step 3 You can cut a small hole in the upper support (about 30 centimeters in diameter), which will make the construction somewhat easier.
Step 4 Mark the holes on the car hub with the same holes in the lower plastic support needed for the fasteners. Use a drill to make holes.
Step 5 Mark the location of the blades in accordance with the template (you should get a pair of triangles that seem to form a star). Mark the places for fixing the corners. On both supports, everything should be the same.
Step 6 Cut off the blades. You can cut several of them at once using a grinder.
Step 7 Mark the attachment points on the blades and corners. Make all these holes.
Step 8 Connect the blades to the bases using angles, bolts and nuts.
Note! The power of the device largely depends on the length of the blades, but if the latter are large, it will be much more difficult to balance them. Moreover, the structure can "loose" under the influence of a strong wind.
Stage four. We make a generator
The generator in this case must be self-excited, and always on permanent magnets. If you take a conventional generator from a car, then here the voltage winding functions from a battery, in other words, in the absence of voltage, there will be no excitation. Therefore, if you use a simple generator in tandem with a battery, and the wind is relatively weak for a long time, the battery will soon simply be discharged, and later, when the wind resumes, the wind generator will not start up again.
You can also make a system on neodymium magnets. This kind of device will produce from 1.5 kilowatts (if the wind is weak) to 3.5 kilowatts (if the wind is strong). A step-by-step instruction for creating such a generator is as follows.
Step 1. Make a couple of metal pancakes, each of which would be about 50 centimeters long.
Step 2 Using superglue, glue neodymium magnets measuring 2.5x5.0.12 centimeters to the pancakes around the entire perimeter (twelve pieces for each).
Step 3 Place the pancakes opposite each other, do not forget about the polarity.
Step 4 Place a self-made stator between them (make 9 coils from a wire with a cross section of 0.3 centimeters, each with 70 turns). Connect the coils with an "asterisk" (as shown in the image), then fill with polymer resin. At the same time, it is important that the coils are wound in one direction, you can mark the end / beginning of the winding with a colored insulating tape - it will be more convenient.
Step 5 The stator should be about 2 centimeters thick. The winding should come out by means of bolts with nuts. The distance between the rotor and the stator must be 2 mm.
The magnets will attract quite strongly, and for a smooth connection, you need to make holes in them and cut the threads for the studs. Immediately align the rotors, then using the wrenches, lower the top to the bottom. Then you can remove the temporary hairpins.
Note! The generator described above can be used not only for vertical, but also for horizontal windmills.
Stage five. Assembling the whole structure
First, install a special bracket on the mast, through which the stator will be attached (which, in turn, can have either three or six blades). Fix the hub above the bracket using the same nuts. Screw on the four studs that are at the hub, the finished generator. After that, connect the stator to the bracket, which is fixed to the mast. Attach the turbine to the second rotor plate. Connect the stator wires to the voltage regulator using the terminals.
Stage six. We install a unit that can turn wind into electricity
To install the entire wind turbine with your own hands, you must follow the steps that are given below in the form of step-by-step instructions.
Step 1. Concrete in the ground a reliable and solid foundation.
Step 2 When pouring concrete mortar there, add the studs necessary to attach the massive hinge (all this is easily done with your own hands).
Step 3 When the concrete has completely hardened, put the hinge on the studs and fix with nuts.
Step 4 Install the mast in the movable part of the hinge.
Step 5 Attach 3 or 4 guy wires to the top of the mast (you can use a flange or weld). You will also need a steel cable.
Step 6 Raise the mast on the hinge using one of the prepared cables (you can pull with a car).
Step 7 The verticality of the entire mast is strictly fixed with braces.
Where can such a wind generator be installed?
The efficiency of its operation largely depends on how correctly you choose a place to install a wind generator. The place should be such that the blades of the system get as much wind as possible. The site should be open and elevated (for example, the roof of a house, but as far as possible from trees and other structures). Tellingly, the reason for this lies not only in interference, but also in the production of some noise by the device during operation, which the neighbors or the owners themselves may not like.
For a more detailed acquaintance with the problem, we recommend that you watch the thematic video below.
Video - How to make a wind generator using a household fan
Rotary (horizontal) wind generator
Such a device will cope with the provision of electricity to a small house or several outbuildings. The maximum power of the wind generator will not exceed 1.5 kilowatts.
Prepare for work:
- car generator 12 watts;
- relay, battery control light;
- the battery itself is 12 watts;
- current converter;
- a large pot or bucket made of duralumin or stainless steel;
- a pair of clamps for attaching the generator to the mast;
- switch;
- wire, 0.4 and 0.25 centimeters;
- bolts, nuts, washers;
- voltmeter.
The tools required are the same as in the previous case. First, take a pot (or bucket) and, using a marker with a tape measure, divide it into four identical parts. Cut out the blades, but do not cut all the way (as shown in the picture).
Make holes for the bolts in the bottom, then bend the blades, but not very much. Take into account the fact how the generator will rotate (clockwise or counterclockwise).
Next, fix the pan with the already prepared blades on the pulley, secure with bolts. Install the generator on the mast, fixed in advance (for this, use the supplied clamps), then connect all the cables and assemble the circuit. Rewrite the entire circuit, fix the wires on the support.
Use a 4 mm cable with a maximum length of 1 meter to connect the battery. Use a smaller cable to connect the load. Also install an inverter. Below is an example connection diagram.
As you can see, it is quite possible to build a wind generator with your own hands. The design can be of two types, but if you have the skills and due zeal, you can even cope with the work alone. That's all, good luck!
We have developed a design of a wind turbine with a vertical axis of rotation. Below is a detailed guide for its manufacture, carefully reading which, you can make a vertical wind generator yourself.
The wind generator turned out to be quite reliable, with low maintenance costs, inexpensive and easy to manufacture. It is not necessary to follow the list of details below, you can make some adjustments of your own, improve something, use your own, because. Not everywhere you can find exactly what is on the list. We tried to use inexpensive and high-quality parts.
Used materials and equipment:
| Name | Qty | Note |
| List of used parts and materials for the rotor: | ||
| Pre-cut metal sheet | 1 | Cut from 1/4" thick steel using waterjet, laser, etc. cutting |
| Hub from car (Hub) | 1 | Should contain 4 holes, about 4 inches in diameter |
| 2" x 1" x 1/2" neodymium magnet | 26 | Very fragile, it is better to order additionally |
| 1/2"-13tpi x 3" stud | 1 | TPI - number of threads per inch |
| 1/2" nut | 16 | |
| 1/2" washer | 16 | |
| 1/2" grower | 16 | |
| 1/2".-13tpi cap nut | 16 | |
| 1" washer | 4 | In order to maintain the gap between the rotors |
| List of used parts and materials for the turbine: | ||
| 3" x 60" Galvanized pipe | 6 | |
| ABS plastic 3/8" (1.2x1.2m) | 1 | |
| Balancing magnets | If needed | If the blades are not balanced, then the magnets are attached to balance |
| 1/4" screw | 48 | |
| 1/4" washer | 48 | |
| 1/4" grower | 48 | |
| 1/4" nut | 48 | |
| 2" x 5/8" corners | 24 | |
| 1" corners | 12 (optional) | If the blades do not hold their shape, then you can add extra. corners |
| screws, nuts, washers and grovers for 1" angle | 12 (optional) | |
| List of used parts and materials for the stator: | ||
| Epoxy with hardener | 2 l | |
| 1/4" screw st. | 3 | |
| 1/4" washer st. | 3 | |
| 1/4" nut ss. | 3 | |
| 1/4" ring tip | 3 | For e-mail connections |
| 1/2"-13tpi x 3" stud st. | 1 | stainless steel steel is not a ferromagnet, so it will not "brake" the rotor |
| 1/2" nut | 6 | |
| fiberglass | If needed | |
| 0.51mm enamel. the wire | 24AWG | |
| List of used parts and materials for installation: | ||
| 1/4" x 3/4" bolt | 6 | |
| 1-1/4" pipe flange | 1 | |
| 1-1/4" galvanized pipe L-18" | 1 | |
| Tools and equipment: | ||
| 1/2"-13tpi x 36" stud | 2 | Used for jacking |
| 1/2" bolt | 8 | |
| Anemometer | If needed | |
| 1" aluminum sheet | 1 | For making spacers if needed |
| green paint | 1 | For painting plastic holders. Color is not important |
| Blue paint ball. | 1 | For painting the rotor and other parts. Color is not important |
| multimeter | 1 | |
| Soldering iron and solder | 1 | |
| Drill | 1 | |
| Hacksaw | 1 | |
| Kern | 1 | |
| Mask | 1 | |
| Protective glasses | 1 | |
| Gloves | 1 | |
Wind turbines with a vertical axis of rotation are not as efficient as their horizontal counterparts, however, vertical wind turbines are less demanding on their installation site.
Turbine manufacturing
1. Connecting element - designed to connect the rotor to the wind turbine blades.
2. The layout of the blades - two opposite equilateral triangles. According to this drawing, it will then be easier to arrange the corners of the blades.
If you are not sure about something, cardboard templates will help you avoid mistakes and further alterations.
The sequence of steps for manufacturing a turbine:
- Production of the lower and upper supports (bases) of the blades. Mark and use a jigsaw to cut out a circle from ABS plastic. Then circle it and cut out the second support. You should get two absolutely identical circles.
- In the center of one support, cut a hole with a diameter of 30 cm. This will be the top support of the blades.
- Take the hub (hub from the car) and mark and drill four holes on the bottom support for attaching the hub.
- Make a template for the location of the blades (fig. above) and mark on the lower support the attachment points for the corners that will connect the support and the blades.
- Stack the blades, tie them tightly and cut to the desired length. In this design, the blades are 116 cm long. The longer the blades, the more wind energy they receive, but the downside is instability in strong winds.
- Mark the blades for attaching the corners. Pierce and then drill holes in them.
- Using the paddle pattern shown in the picture above, attach the paddles to the support using the angle brackets.
Rotor manufacturing
The sequence of actions for the manufacture of the rotor:
- Lay the two rotor bases on top of each other, align the holes and make a small mark on the sides with a file or marker. In the future, this will help to correctly orient them relative to each other.
- Make two paper magnet placement templates and glue them to the bases.
- Mark the polarity of all magnets with a marker. As a "polarity tester" you can use a small magnet wrapped in a rag or electrical tape. By passing it over a large magnet, it will be clearly visible whether it is repelled or attracted.
- Prepare epoxy resin (by adding hardener to it). And apply it evenly on the bottom of the magnet.
- Very carefully bring the magnet to the edge of the rotor base and move it to its position. If the magnet is installed on top of the rotor, then the high power of the magnet can sharply magnetize it and it can break. And never stick your fingers or other body parts between two magnets or a magnet and iron. Neodymium magnets are very powerful!
- Continue gluing the magnets to the rotor (don't forget to lubricate with epoxy), alternating their poles. If the magnets move under the influence of magnetic force, then use a piece of wood, placing it between them for insurance.
- After one rotor is finished, move on to the second. Using the mark you made earlier, position the magnets exactly opposite the first rotor, but in a different polarity.
- Put the rotors away from each other (so that they do not get magnetized, otherwise you will not pull it off later).
The manufacture of a stator is a very laborious process. Of course, you can buy a ready-made stator (try to find them with us) or a generator, but it’s not a fact that they are suitable for a particular windmill with their own individual characteristics.
The wind generator stator is an electrical component consisting of 9 coils. The stator coil is shown in the photo above. The coils are divided into 3 groups, 3 coils in each group. Each coil is wound with 24AWG (0.51mm) wire and contains 320 turns. More turns but thinner wire will give higher voltage but less current. Therefore, the parameters of the coils can be changed, depending on what voltage you require at the output of the wind generator. The following table will help you decide:
320 turns, 0.51mm (24AWG) = 100V @ 120 rpm.
160 turns, 0.0508mm (16AWG) = 48V @ 140 rpm.
60 turns, 0.0571 mm (15AWG) = 24V @ 120 rpm.
Winding coils by hand is a boring and difficult task. Therefore, in order to facilitate the winding process, I would advise you to make a simple device - a winding machine. Moreover, its design is quite simple and it can be made from improvised materials.
The turns of all coils must be wound in the same way, in the same direction, and pay attention or mark where the beginning and where the end of the coil is. To prevent unwinding of the coils, they are wrapped with electrical tape and smeared with epoxy.
The fixture is made from two pieces of plywood, a bent hairpin, a piece of PVC pipe and nails. Before bending the hairpin, heat it with a torch.
A small piece of pipe between the planks provides the desired thickness, and four nails provide the required dimensions for the coils.
You can come up with your own design of the winding machine, or maybe you already have a ready-made one.
After all the coils are wound, they must be checked for identity to each other. This can be done using scales, and you also need to measure the resistance of the coils with a multimeter.
Do not connect household consumers directly from the wind turbine! Also observe the safety precautions when handling electricity!
Coil connection process:
- Sand the ends of the leads on each coil.
- Connect the coils as shown in the picture above. You should get 3 groups, 3 coils in each group. With this connection scheme, a three-phase alternating current will be obtained. Solder the ends of the coils, or use clamps.
- Choose from the following configurations:
A. Configuration" star". In order to get a large output voltage, connect the X, Y and Z pins together.
B. Delta configuration. To get a high current, connect X to B, Y to C, Z to A.
C. In order to make it possible to change the configuration in the future, grow all six conductors and bring them out. - On a large sheet of paper, draw a diagram of the location and connection of the coils. All coils must be evenly distributed and match the location of the rotor magnets.
- Attach the spools with tape to the paper. Prepare epoxy resin with hardener for casting the stator.
- Use a paint brush to apply epoxy to fiberglass. If necessary, add small pieces of fiberglass. Do not fill the center of the coils to ensure sufficient cooling during operation. Try to avoid the formation of bubbles. The purpose of this operation is to secure the coils in place and flatten the stator, which will be located between the two rotors. The stator will not be a loaded node and will not rotate.
In order to make it more clear, consider the whole process in pictures:
The finished coils are placed on waxed paper with the layout drawn. Three small circles in the corners in the photo above are the holes for mounting the stator bracket. The ring in the center prevents the epoxy from getting into the center circle.
The coils are fixed in place. Fiberglass, in small pieces, is placed around the coils. The coil leads can be brought inside or outside the stator. Be sure to leave enough lead length. Be sure to double-check all connections and ring with a multimeter.
The stator is almost ready. The holes for mounting the bracket are drilled in the stator. When drilling holes, be careful not to hit the coil leads. After completing the operation, cut off the excess fiberglass and, if necessary, clean the surface of the stator with sandpaper.
stator bracket
The pipe for attaching the hub axle was cut to the desired size. Holes were drilled and threaded in it. In the future, bolts will be screwed into them that will hold the axle.
The figure above shows the bracket to which the stator will be attached, located between the two rotors.
The photo above shows a stud with nuts and a sleeve. Four of these studs provide the necessary clearance between the rotors. Instead of a bushing, you can use larger nuts, or cut your own aluminum washers.
Generator. final assembly
A small clarification: a small air gap between the rotor-stator-rotor bundle (which is set by a pin with a bushing) provides a higher power output, but the risk of damage to the stator or rotor increases when the axis is misaligned, which can occur in strong winds.
The left picture below shows a rotor with 4 clearance studs and two aluminum plates (which will be removed later).
The right picture shows the assembled and green painted stator in place.
Assembly process:
1. Drill 4 holes in the top rotor plate and thread them for the stud. This is necessary to smoothly lower the rotor into place. Rest 4 studs in the aluminum plates glued earlier and install the top rotor on the studs.
The rotors will be attracted to each other with a very large force, which is why such a device is needed. Immediately align the rotors relative to each other according to the marks on the ends set earlier.
2-4. Alternately rotating the studs with a wrench, evenly lower the rotor.
5. Once the rotor has rested against the hub (providing clearance), unscrew the studs and remove the aluminum plates.
6. Install the hub (hub) and screw it on.
The generator is ready!
After installing the studs (1) and the flange (2), your generator should look something like this (see the figure above)
Stainless steel bolts serve to provide electrical contact. It is convenient to use ring lugs on wires.
Cap nuts and washers are used to fasten the connections. boards and blade supports to the generator. So, the wind generator is fully assembled and ready for tests.
To begin with, it is best to spin the windmill with your hand and measure the parameters. If all three output terminals are shorted together, then the windmill should rotate very tightly. This can be used to stop the wind turbine for service or safety reasons.
A wind turbine can be used for more than just providing electricity to your home. For example, this instance is made so that the stator generates a large voltage, which is then used for heating.
The generator considered above produces a 3-phase voltage with different frequencies (depending on the strength of the wind), and for example, in Russia a single-phase 220-230V network is used, with a fixed network frequency of 50 Hz. This does not mean that this generator is not suitable for powering household appliances. Alternating current from this generator can be converted to direct current, with a fixed voltage. And direct current can already be used to power lamps, heat water, charge batteries, or a converter can be supplied to convert direct current to alternating current. But this is already beyond the scope of this article.
In the figure above, a simple circuit of a bridge rectifier, consisting of 6 diodes. It converts AC to DC.
Location of the wind generator
The wind generator described here is mounted on a 4-meter support on the edge of a mountain. The pipe flange, which is installed at the bottom of the generator, provides an easy and quick installation of the wind generator - it is enough to fasten 4 bolts. Although for reliability, it is better to weld.
Usually, horizontal wind turbines "like" when the wind blows from one direction, unlike vertical wind turbines, where due to the weather vane, they can turn and they do not care about the direction of the wind. Because Since this windmill is installed on the shore of a cliff, the wind there creates turbulent flows from different directions, which is not very effective for this design.
Another factor to consider when choosing a location is the strength of the wind. An archive of wind strength data for your area can be found on the Internet, although this will be very approximate, because. it all depends on the location.
Also, an anemometer (a device for measuring wind force) will help in choosing the location of the installation of the wind generator.
A little about the mechanics of the wind generator
As you know, the wind occurs due to the difference in temperature of the earth's surface. When the wind rotates the turbines of a wind generator, it creates three forces: lifting, braking and impulse. The lifting force usually occurs over a convex surface and is a consequence of the pressure difference. The wind braking force occurs behind the blades of the wind generator, it is undesirable and slows down the windmill. The impulse force comes from the curved shape of the blades. When air molecules push the blades from behind, they have nowhere to go and they gather behind them. As a result, they push the blades in the direction of the wind. The greater the lifting and impulse forces and the less braking force, the faster the blades will rotate. Accordingly, the rotor rotates, which creates a magnetic field on the stator. As a result, electrical energy is generated.
Download the layout of the magnets.
Often, owners of private houses have an idea about the implementation backup power systems. The simplest and most affordable way is, of course, or a generator, but many people are turning their eyes to more complex ways of converting the so-called free energy (radiation, energy of flowing water or wind) into.
Each of these methods has its own advantages and disadvantages. If everything is clear with the use of water flow (mini-hydroelectric power station) - this is available only in the immediate vicinity of a fairly fast-flowing river, then sunlight or wind can be used almost everywhere. Both of these methods will have a common disadvantage - if a water turbine can work around the clock, then a solar battery or a wind generator is only effective for a while, which makes it necessary to include batteries in the structure of the home electrical network.
Since the conditions in Russia (short daylight hours for most of the year, frequent precipitation) make the use of solar panels inefficient at their current cost and efficiency, the most profitable is the design of a wind generator. Consider its principle of operation and possible design options.
Since no homemade device is like another, this an article is not a step-by-step instruction, but a description of the basic principles of designing a wind turbine.General principle of operation
The main working body of the wind generator is the blades, which rotate the wind. Depending on the location of the axis of rotation, wind turbines are divided into horizontal and vertical:
- Horizontal wind turbines the most widespread. Their blades have a design similar to an aircraft propeller: in the first approximation, these are plates inclined relative to the plane of rotation, which convert part of the load from wind pressure into rotation. An important feature of a horizontal wind generator is the need to ensure the rotation of the blade assembly in accordance with the direction of the wind, since maximum efficiency is ensured when the direction of the wind is perpendicular to the plane of rotation.
- blades vertical wind generator have a convex-concave shape. Since the streamlining of the convex side is greater than the concave side, such a wind generator always rotates in the same direction, regardless of the direction of the wind, which makes the rotary mechanism unnecessary, unlike horizontal windmills. At the same time, due to the fact that at any time only a part of the blades performs useful work, and the rest only oppose rotation, The efficiency of a vertical windmill is much lower than that of a horizontal one.: if for a three-blade horizontal wind generator this figure reaches 45%, then for a vertical one it will not exceed 25%.
Since the average wind speed in Russia is low, even a large windmill will rotate quite slowly most of the time. To ensure sufficient power supply, it must be connected to the generator through a step-up gearbox, belt or gear. In a horizontal windmill, the blade-gear-generator assembly is mounted on a pivoting head that enables them to follow the direction of the wind. It is important to consider that the swivel head must have a limiter that prevents it from making a full turn, since otherwise the wiring from the generator will be cut off (the option using contact washers that allow the head to rotate freely is more complicated). To ensure rotation, the wind generator is supplemented by a working weather vane directed along the axis of rotation.
The most common blade material is large diameter PVC pipe cut lengthwise. Along the edge, metal plates are riveted to them, welded to the hub of the blade assembly. Drawings of this kind of blades are the most widely distributed on the Internet.
The video tells about a wind generator made by hand
Calculation of a bladed wind generator
Since we have already found out that a horizontal wind generator is much more efficient, we will consider the calculation of its design.
Wind energy can be determined by the formula
P=0.6*S*V³, where S is the area of the circle described by the ends of the propeller blades (sweeping area), expressed in square meters, and V is the estimated wind speed in meters per second. You also need to take into account the efficiency of the windmill itself, which for a three-bladed horizontal circuit will average 40%, as well as the efficiency of the generator set, which at the peak of the current-speed characteristic is 80% for a generator with excitation from permanent magnets and 60% for a generator with excitation winding. On average, another 20% of the power will be consumed by a step-up gearbox (multiplier). Thus, the final calculation of the radius of the windmill (that is, the length of its blade) for a given power of a permanent magnet generator looks like this:
R=√(P/(0.483*V³))
Example: Let's take the required power of the wind power plant as 500 W, and the average wind speed as 2 m/s. Then, according to our formula, we will have to use blades with a length of at least 11 meters. As you can see, even such a small power will require the creation of a wind generator of colossal dimensions. For more or less rational constructions with a blade length of no more than one and a half meters, the wind generator will be able to produce only 80-90 watts of power even in strong winds.
Not enough power? In fact, everything is somewhat different, since in fact the load of the wind generator is powered by batteries, the windmill only charges them to the best of its ability. Therefore, the power of the wind turbine determines the frequency with which it will be able to supply energy.