Do-it-yourself vertical windmill (5 kW). How to make a wind farm with your own hands Wind generator from

General working principle

The main working body of the wind generator is the blades, which are rotated by the wind. Depending on the location of the axis of rotation, wind turbines are divided into horizontal and vertical:

• Horizontal wind turbines 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 the maximum efficiency is ensured when the direction of the wind is perpendicular to the plane of rotation.
• Blades vertical wind turbine have a convex-concave shape. Since the streamlining of the convex side is greater than the concave side, such a wind turbine always rotates in one direction regardless of the direction of the wind, which makes the swing mechanism unnecessary, unlike horizontal wind turbines. At the same time, due to the fact that at any given 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 not high, even a large wind turbine will rotate rather slowly most of the time. To ensure sufficient power, the power supply must be connected to the generator through a speed-up reducer, belt or gear. In a horizontal windmill, the blade-reducer-generator unit is mounted on a swivel head, which enables them to follow the direction of the wind. It is important to take into account 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 with a working weather vane directed along the axis of rotation.

The most common blade material is large diameter PVC pipes 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 widespread on the Internet.

The video tells about a self-made wind generator

Calculation of a bladed wind turbine

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 tips of the rotor blades (throwing area), expressed in square meters, and V is the design wind speed in meters per second. You also need to take into account the efficiency of the windmill itself, which for a three-blade 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 permanent magnet excitation and 60% for a generator with an excitation winding. On average, another 20% of the power will be consumed by the step-up gear (multiplier). Thus, the final calculation of the radius of the wind turbine (that is, the length of its blade) for a given power of the permanent magnet generator looks like this:
R = √ (P / (0.483 * V³))

Example: Let's assume the required power of the wind farm is 500 W, and the average wind speed is 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 structures with a blade length of no more than one and a half meters in the conditions of do-it-yourself manufacturing, 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 fed by the batteries, the wind turbine only charges them to the best of its capabilities. Consequently, the power of a wind turbine determines the frequency with which it can supply energy.

For a long time, humanity has been using the power of the wind for its own purposes. Windmills and sailing ships are familiar to many, they write about them in books and make historical films. In our time, the wind power generator has not lost its relevance, because with its help, you can get free electricity in the country, which can come in handy if the lights are turned off. Let's talk about homemade wind turbines that can be assembled from scrap materials and available parts at a minimum cost. For you, we have provided one detailed instruction with pictures, as well as a video of ideas for several more assembly options. So, let's look at how to make a wind generator with your own hands at home.

Assembly instructions

There are several types of wind turbines, namely horizontal, vertical and turbine. They have fundamental differences, their pros and cons. However, the principle of operation of all wind generators is the same - wind energy is converted into electrical energy and accumulates in batteries, and already from them goes to human needs. The most common view is horizontal.

He is familiar and recognizable. The advantage of a horizontal wind turbine is a higher efficiency compared to others, since the blades of the wind turbine are always under the influence of the air flow. The disadvantages include a high wind requirement - it must be stronger than 5 meters per second. This type of windmill is the easiest to make, so it is often taken as a basis by DIYers.

If you decide to try your hand at assembling a wind turbine with your own hands, here are some recommendations.

You need to start with the generator - this is the heart of the system; the design of the screw assembly will depend on its parameters. For this, automobile generators of domestic and foreign production are suitable, there is information about the use of stepper motors from printers or other office equipment. A bicycle wheel motor can also be used to make your own wind turbine to generate electricity. In general, almost any motor or generator can work, but it must be tested for efficiency.

Having decided on the energy converter, you need to assemble a gear unit to increase the speed on the generator shaft. One revolution of the propeller should be equal to 4-5 revolutions on the shaft of the generator unit. However, these parameters are selected individually, based on the power and characteristics of your generator and vane unit. A part from a grinder or a system of belts and rollers can act as a reducer.

When the gear-generator assembly is assembled, they begin to find out its resistance to torque (grams per millimeter). To do this, you need to make a shoulder with a counterweight on the shaft of the future installation, and with the help of a weight, find out at what weight the shoulder will go down. An acceptable result is less than 200 grams per meter. The shoulder size in this case is taken as the length of the blade.

Many people think that the more blades the better. This is not entirely true. We need high rpm, and many screws create more wind resistance, since we make them at home, as a result of which at some point the oncoming flow slows down the propeller and the efficiency of the installation drops. You can use a two-blade propeller. Such a propeller in normal wind can spin more than 1000 rpm. You can make the blades of a homemade wind generator from available tools - from plywood and galvanized steel, to plastic from water pipes (as in the photo below). The main condition is that the material must be lightweight and durable.

The lightweight propeller will increase the efficiency of the windmill and the sensitivity to air flow. Do not forget to balance the air wheel and remove any irregularities, otherwise during the operation of the generator you will hear howling and howling, and vibrations will lead to rapid wear of parts.

The next important element is the tail. He will keep the wheel in the flow of the wind, and turn the structure in case of a change in its direction.

Whether or not to make a slip ring is up to you. This will complicate the design, however, it will save you from frequent twisting of the wire, which is fraught with cable breaks. Of course, in its absence, you will sometimes have to unwind the wire yourself. During the test run of the wind generator, do not forget about safety precautions, spinning blades are a great danger.

A tuned and balanced wind turbine is installed on a mast with a height of at least 7 meters from the ground, secured with spacer cables. Further, an equally important unit is the storage battery. The most commonly used car battery. You cannot connect the output of a homemade wind generator directly to the battery; this must be done through a charging relay or a controller, which you can assemble yourself or purchase a ready-made one.

The principle of operation of the relay is reduced to monitoring the charge and load. If the battery is fully charged, it switches the generator and battery to load ballast, the system strives to always be charged, preventing overcharging, and does not leave the generator without load. A windmill without load can spin up quite strongly and damage the insulation in the windings with the generated potential. In addition, high speed can cause mechanical destruction of the elements of the wind generator. Next, there is a voltage converter from 12 to 220 volts 50 Hz for connecting household appliances.

Now the Internet is full of diagrams and drawings where masters show how to make a wind generator with powerful magnets on their own. Whether they are as effective as they promise is a moot point. But it is worth trying to assemble a wind power generating installation for a home, and then decide how to improve it. It is important to gain experience and then you can already swing at a more serious apparatus. The freedom and variety of home-made wind turbines is so extensive, and the element base is diverse that it makes no sense to describe them all, the main meaning remains the same - the wind flow spins the screw, the gearbox increases the shaft speed, the generator gives out voltage, then the controller keeps the charge level on the battery, and with it is already taking energy for various needs. By this principle, you can make a wind generator with your own hands at home. We hope our detailed instructions with photo examples have explained to you how to make a suitable model of a windmill for your home or summer cottage. We also recommend that you familiarize yourself with the master classes on assembling a homemade device in video format.

Visual video tutorials

To easily make a wind generator for generating electricity at home, we recommend that you familiarize yourself with ready-made ideas in video examples:

So we have provided all the most simple and affordable ideas for assembling a homemade windmill. As you can see, even a child can easily make some models of devices. There are many other options for homemade products: with powerful magnets, with complex blades, etc. These constructions should be repeated only if you have some experience in this matter, you should start with simple schemes. If you want to make a wind generator so that it works and is used for its intended purpose, proceed according to the instructions provided by us. If you have any questions, leave them in the comments.

Air masses have inexhaustible reserves of energy, which mankind used in ancient times. Basically, the force of the wind provided the movement of ships under sail and the operation of windmills. After the invention of steam engines, this type of energy has lost its relevance.

It is only in modern conditions that wind energy again became in demand as a driving force applied to electric generators. They are not yet widely used on an industrial scale, but are becoming more and more 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 scrap materials. In the future, they are used as the main or auxiliary sources of electricity.

The ideal wind turbine theory

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 wind energy utilization rate of 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 updated value of the coefficient was 0.687.

In accordance with 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 value of the profile drag of the wings in the presence of constant circulation along the blades.
• The entire swept surface of the wind turbine has a constant lost air speed at the wheel.
• The aspiration of the angular velocity to infinity.

Choosing a wind turbine

When choosing a model of a wind generator for a private house, one should take into account the required power to ensure the operation of devices 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 borne in mind that the power of all electrical appliances is carried out not directly from the wind generator, but from the inverter and a set of batteries. Thus, a generator with a capacity of 1 kW is able to ensure the normal functioning of the batteries supplying the four-kilowatt inverter. As a result, household appliances with a similar capacity are fully supplied with electricity. The correct choice of batteries is essential. 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 fan blades can be sail-shaped, with a straight or curved surface. In some cases, combined options are used.
• Material for blades and technology for their manufacture.
• Placement of fan blades with different inclination 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 specific area, as specified by the meteorological service. It is not necessary to clarify the direction of the wind, since modern designs of wind generators independently turn in the other direction.

For most areas of the Russian Federation, the most optimal option would be a horizontal orientation of the axis of rotation, the surface of the blades is curved and concave, which the air stream flows around at an acute angle. The amount of power taken from the wind is influenced by the area of ​​the blade. For an ordinary house, an area of ​​1.25 m 2 is quite enough.

The number of revolutions of the wind turbine 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 borne in mind that at a low wind speed, below 3 m / s, wind turbines become unable to take energy. In order for the unit to perceive weak wind, the area of ​​its blades must be increased to at least 2 m 2.

Wind turbine calculation

Before choosing a wind generator, it is necessary to determine the wind speed and direction, which are most characteristic in the place of the proposed installation. It should be remembered that the rotation of the blades starts at a minimum wind speed of 2 m / s. The maximum efficiency is 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, a generator with a minimum power of 1 kW / h and a wind speed of at least 8 m / s will be required.

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:

1. 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 wind direction (m 2), V is the wind speed (m / s), P is the power of the generator set ( kW).
2. For calculations of an electrical installation by the diameter of the screw, the formula is used: P = D 2 x V 3/7000, in which D is the diameter of the screw (m), V is the wind speed (m / s), P is the power of the generator (kW).
3. More complex calculations take into account the airflow density. For these purposes, there is a formula: P = ξ x π x R 2 x 0.5 x V 3 x ρ x η ed x η gen, where ξ is the coefficient of wind energy use (immeasurable value), π = 3.14, R - rotor radius (m), V - air flow speed (m / s), ρ - air density (kg / m 3), η red - reducer efficiency (%), η gen - generator efficiency (%).

Thus, the electricity produced by the wind generator increases quantitatively in a cubic ratio with the increasing wind speed. For example, if the wind speed doubles, the kinetic energy generation by the rotor will increase 8 times.

When choosing a place to install a wind generator, 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 25 to 30 meters, otherwise noise during operation will create inconvenience and discomfort. The rotor of the windmill must be located at a height that exceeds the nearest buildings by at least 3-5 m.

If you do not plan to connect the country house to a common network, in this case, you can use the options for combined systems. The operation of a wind turbine will be much more efficient when used in conjunction with a diesel generator or solar battery.

How to make a wind generator with your own hands

Regardless of the type and design of the wind generator, each device as a base is equipped with similar elements. All models are equipped with generators, blades in a variety of materials, lifts to ensure the desired level of installation, as well as additional batteries and electronic control system. Rotary-type units or axial structures using magnets are considered the easiest to manufacture.

Option 1. Rotary design of the wind turbine.

The design of a rotary wind turbine uses two, four or more blades. Such wind generators are not able to fully provide electricity to large country houses. They are used primarily as an auxiliary source of electricity.

Depending on the design power of the wind turbine, the necessary materials and components are selected:

• Generator from a car for 12 volts and a car battery.
• Voltage regulator converting alternating current from 12 to 220 volts.
• Large container. An aluminum bucket or stainless steel pot works best.
• A relay removed from the vehicle can be used as a charger.
• You will need a 12 V switch, a charge lamp with a controller, bolts with nuts and washers, as well as metal clamps with rubberized gaskets.
• Three-core cable with a minimum cross-section of 2.5 mm 2 and a conventional voltmeter removed from any measuring device.

First of all, the rotor is prepared from an existing metal container - a saucepan or bucket. It is marked 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 metal scissors or a grinder. The rotor blades are cut from the resulting blanks. All measurements must be carefully checked for compliance with the dimensions, otherwise the structure will not work correctly.

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 structures must be symmetrically positioned.

To increase the speed of rotation, the edges of the blades should be slightly bent. With an increase in the bending angle, the air flows will be more effectively perceived by the rotary installation. As blades, not only elements of the cut container are used, but also individual parts connected to a metal workpiece in the shape of a circle.

After attaching the container to the generator, the entire resulting structure must be completely installed on the mast using metal clamps. Then the wiring is mounted and assembled. Each pin must be plugged into its own connector. Once connected, 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. Then the wind generator can be operated.

Option 2. Axial design of a wind generator using magnets.

Axial windmills for home are a structure, one of the main elements of which is neodymium magnets. In terms of their performance, they are significantly ahead of conventional rotary units.

The rotor is the main element of the entire structure of the wind turbine. For its manufacture, a car wheel hub complete with brake discs is best suited. A part that has been in operation should be prepared - cleaned of dirt and rust, lubricate the bearings.

Next, you need to properly 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 along 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 followed. In single-phase generators, the number of poles is the same as the number of magnets. In three-phase generators, a 4/3 ratio between magnets and poles and a 2/3 ratio between poles and coils are respected. The magnets are installed perpendicular to the disc circumference. A paper template is used to distribute them evenly. 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 slightly 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 for by current loads from one phase to another. This ensures that a constant power value is always provided in the network. Due to vibration, the service life of single-phase systems is significantly lower than that of three-phase systems. In addition, the 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 ready-made 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 turbines is largely dependent 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 generator will be made.

Factors affecting blade design:

• Even the lightest wind can propel long blades. However, too long a length can slow down the rotation 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, 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 should be compatible with the installation location of the entire structure. In the most optimal conditions, correctly selected blades are able to provide the maximum output of 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 generator, 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 instruments and equipment that will be turned on simultaneously with the operation of the wind generator. If it is necessary to increase this indicator, it is recommended to use several inverters at once.

DIY wind generator 24v - 2500 watts