The inexhaustible energy that air masses carry with them has always attracted people's attention. Our great-grandfathers learned to harness the wind to the sails and wheels of windmills, after which it rushed aimlessly across the vast expanses of the Earth for two centuries.

Today I found it for him again useful work. A wind generator for a private home goes from being a technical novelty to a real factor in our everyday life.

Let's take a closer look at wind power plants, evaluate the conditions for their profitable use and consider the existing varieties. Home craftsmen will receive food for thought on the topic in our article. self-assembly windmill and devices necessary for its efficient work.

What is a wind generator?

The operating principle of a domestic wind power plant is simple: the air flow rotates the rotor blades mounted on the generator shaft and creates alternating current in its windings. The generated electricity is stored in batteries and used by household appliances as needed. Of course, this is a simplified diagram of how a home windmill works. In practical terms, it is complemented by devices that convert electricity.

Immediately behind the generator in the energy chain there is a controller. It converts three-phase alternating current into direct current and directs it to charge the batteries. Most household appliances cannot operate on constant power, so another device is installed behind the batteries - an inverter. It performs the reverse operation: it converts direct current into household alternating current with a voltage of 220 Volts. It is clear that these transformations do not pass without leaving a trace and take away quite a decent portion of the original energy (15-20%).

If the windmill is paired with solar battery or another electricity generator (petrol, diesel), then the circuit is supplemented circuit breaker(AVR). When the main current source is turned off, it activates the backup one.

For maximum power wind generator should be located along the wind flow. IN simple systems The weather vane principle is implemented. To do this, a vertical blade is attached to the opposite end of the generator, turning it towards the wind.

More powerful installations have a rotating electric motor controlled by a direction sensor.

Main types of wind generators and their features

There are two types of wind generators:

1. With a horizontal rotor.
2. With vertical rotor.

The first type is the most common. It is characterized by high efficiency (40-50%), but has an increased level of noise and vibration. In addition, its installation requires a large free space (100 meters) or a high mast (from 6 meters).

Generators with a vertical rotor are less energetically efficient (the efficiency is almost 3 times lower than that of horizontal ones).

Their advantages include simple installation and reliable design. Low noise makes it possible to install vertical generators on the roofs of houses and even at ground level. These installations are not afraid of icing and hurricanes. They are launched from a weak wind (from 1.0-2.0 m/s) while a horizontal windmill needs air flow medium strength(3.5 m/s and above). Vertical wind generators are very diverse in the shape of the impeller (rotor).

Rotor wheels of vertical wind turbines

Due to the low rotor speed (up to 200 rpm), the mechanical life of such installations significantly exceeds those of horizontal wind generators.

How to calculate and select a wind generator?

The wind is not natural gas, pumped through pipes and not electricity, uninterruptedly supplied through wires to our house. He is capricious and fickle. Today a hurricane tears off roofs and breaks trees, and tomorrow it gives way to complete calm. Therefore, before purchasing or making your own windmill, you need to assess the potential of air energy in your area. To do this, the average annual wind force must be determined. This value can be found on the Internet by request.

Having received such a table, we find the area of ​​​​our residence and look at the intensity of its color, comparing it with the rating scale. If the average annual wind speed is less than 4.0 meters per second, then there is no point in installing a wind turbine. He won't give required quantity energy.

If the wind strength is sufficient to install a wind power plant, then you can proceed to the next step: selecting the generator power.

If we're talking about about autonomous energy supply at home, then the average statistical electricity consumption of 1 family is taken into account. It ranges from 100 to 300 kWh per month. In regions with low annual wind potential (5-8 m/sec), a wind turbine with a power of 2-3 kW can generate this amount of electricity. It should be taken into account that in winter average speed winds are higher, so energy production during this period will be greater than in summer.

Selecting a wind generator. Approximate prices

Prices for vertical domestic wind generators with a capacity of 1.5-2.0 kW are in the range from 90 to 110 thousand rubles. The package at this price includes only a generator with blades, without a mast and additional equipment (controller, inverter, cable, batteries). A complete power plant including installation will cost 40-60% more.

The cost of more powerful wind turbines (3-5 kW) ranges from 350 to 450 thousand rubles (with additional equipment and installation work).

DIY windmill. Fun or real savings?

Let’s say right away that making a wind generator with your own hands that is complete and effective is not easy. Proper calculation of the wind wheel, transmission mechanism, selection of a generator suitable for power and speed is a separate topic. We will give only brief recommendations on the main stages of this process.

Generator

Automotive generators and electric motors from washing machines with direct drive are not suitable for this purpose. They are capable of generating energy from the wind wheel, but it will be insignificant. To operate efficiently, self-generators need very high speeds, which a windmill cannot develop.

Motors for washing machines have another problem. There are ferrite magnets there, but the wind generator needs more efficient ones - neodymium ones. Process them self-installation and winding current-carrying windings requires patience and high precision.

The power of a device assembled by yourself, as a rule, does not exceed 100-200 watts.

IN Lately Motor-wheels for bicycles and scooters are popular among DIYers. From a wind energy standpoint, these are powerful neodymium generators that are optimally suited for working with vertical wind wheels and charging batteries. From such a generator you can extract up to 1 kW of wind energy.

Motor-wheel - a ready-made generator for a homemade wind power plant

Screw

The easiest to manufacture are sail and rotor propellers. The first consists of lightweight curved tubes mounted on a central plate. Blades made of durable fabric are pulled over each tube. The large windage of the propeller requires hinged fastening of the blades so that during a hurricane they fold and do not become deformed.

The rotary wind wheel design is used for vertical generators. It is easy to manufacture and reliable in operation.

Homemade wind generators with a horizontal axis of rotation are powered by a propeller. Home craftsmen assemble it from pipes PVC diameter 160-250 mm. The blades are mounted on a round steel plate with a mounting hole for the generator shaft.

For a long time, humanity has been using the power of the wind for its own purposes. Windmills, sailing ships They are familiar to many; they are written about in books and historical films are made. Nowadays, the wind power generator has not lost its relevance, because with its help you can get free electricity in your dacha, which can come in handy if the power goes out. Let's talk about homemade windmills, which 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 video 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 operating principle of all wind generators is the same - wind energy is converted into electrical energy and accumulated in batteries, and from them is used for human needs. The most common type is horizontal.

He is familiar and recognizable. The advantage of a horizontal wind generator is its higher efficiency compared to others, since the windmill blades are always exposed to air flow. The disadvantages include the high wind requirement - it must be stronger than 5 meters per second. This type of windmill is the easiest to make, which is why home craftsmen often take it as a basis.

If you decide to try your hand at assembling a wind generator yourself, 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. Domestic and imported automobile generators are suitable for this; there is information about the use of stepper motors from printers or other office equipment. You can also use a bicycle wheel motor to make your own windmill to generate electricity. In general, almost any motor or generator can be used, 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 blade assembly. The gearbox can be a part from an angle grinder or a system of belts and rollers.

When the gearbox-generator assembly is assembled, we begin to determine its torque resistance (grams per millimeter). To do this, you need to make an arm with a counterweight on the shaft of the future installation, and using a weight, find out at what weight the arm will go down. An acceptable result is less than 200 grams per meter. The size of the shoulder 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 speeds, and many propellers create greater 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 can spin at more than 1000 rpm in normal winds. You can make the blades of a homemade wind generator from available materials - from plywood and galvanization, to plastic from water pipes (as in the photo below). The main condition is that the material must be light and durable.

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

Next important element, this is the tail. It will keep the wheel in the wind flow, and rotate the structure if its direction changes.

It's up to you to decide whether to make a current collector or not. This will complicate the design, but will eliminate frequent twisting of the wire, which can lead to 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 pose a great danger.

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

The principle of operation of the relay comes down 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 speeds can cause mechanical destruction of wind generator elements. Next 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 craftsmen show how to make a wind generator using powerful magnets yourself. Whether they are as effective as they promise is a moot point. But it’s worth trying to assemble a wind power generating installation for your home, and then decide how to improve it. It is important to gain experience and then you can take a swing at a more serious device. The freedom and variety of homemade windmills is so vast, and the element base is diverse, that there is no point in describing them all, the basic meaning remains the same - the wind flow spins the propeller, the gearbox increases the shaft speed, the generator produces voltage, then the controller maintains the charge level on the battery, and with energy is already being selected for various needs. Using this principle, you can make a wind generator with your own hands at home. We hope ours detailed instructions with photo examples explained to you how to make suitable model windmill for home or cottage. We also recommend that you take a look at the assembly master classes homemade device in video format.

Visual video lessons

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

So we have provided all the simplest and most 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 homemade options: with powerful magnets, with complex blades, etc. These designs should be repeated only if you have some experience in this matter, you should start with simple circuits. If you want to make a wind generator so that it works and is used for its intended purpose, proceed according to the instructions we provide. If you have any questions, leave them in the comments.

It is difficult not to notice how the stability of electricity supplies to suburban facilities differs from the provision of urban buildings and enterprises with electricity. Admit that you, as the owner of a private home or cottage, have more than once encountered interruptions, associated inconveniences and damage to equipment.

The listed negative situations, along with the consequences, will no longer complicate the lives of lovers of natural spaces. Moreover, with minimal labor and financial costs. To do this, you just need to make a wind power generator, which we describe in detail in the article.

We have described in detail the options for manufacturing a system that is useful in the household and eliminates energy dependence. According to our advice, an inexperienced home craftsman can build a wind generator with his own hands. This practical device will help to significantly reduce your daily expenses.

Alternative energy sources are the dream of any summer resident or homeowner whose plot is located far from central networks. However, when we receive bills for electricity consumed in a city apartment and look at the increased tariffs, we realize that a wind generator created for domestic needs would not hurt us.

After reading this article, perhaps you will make your dream come true.

Wind generator – perfect solution to provide a suburban facility with electricity. Moreover, in some cases, installing it is the only possible solution.

In order not to waste money, effort and time, let's decide: are there any external circumstances that will create obstacles for us during the operation of the wind generator?

To provide electricity to a summer house or small cottage, it is enough, the power of which will not exceed 1 kW. Such devices in Russia are equated to household products. Their installation does not require certificates, permits or any additional approvals.

Russia occupies a dual position with regard to wind energy resources. On the one hand, due to the huge total area and the abundance of flat areas, there is generally a lot of wind, and it is mostly even. On the other hand, our winds are predominantly low-potential and slow, see Fig. On the third, in sparsely populated areas the winds are violent. Based on this, the task of installing a wind generator on the farm is quite relevant. But to decide - buy enough expensive device, or make it yourself, you need to think carefully about which type (and there are a lot of them) to choose for what purpose.

Basic Concepts

1. KIEV – wind energy utilization coefficient. When used to calculate a mechanistic model of flat wind (see below), it is equal to the efficiency of the rotor of a wind power plant (WPU).
2. Efficiency – end-to-end efficiency of the APU, from the oncoming wind to the terminals of the electric generator, or to the amount of water pumped into the tank.
3. Minimum operating wind speed (MRS) is the speed at which the windmill begins to supply current to the load.
4. The maximum permissible wind speed (MAS) is the speed at which energy production stops: the automation either turns off the generator, or puts the rotor in a weather vane, or folds it and hides it, or the rotor itself stops, or the APU is simply destroyed.
5. Starting wind speed (SW) - at this speed, the rotor is able to turn without load, spin up and enter operating mode, after which the generator can be turned on.
6. Negative starting speed (OSS) - this means that the APU (or wind turbine - wind power unit, or WEA, wind power unit) to start at any wind speed requires mandatory spin-up from an external energy source.
7. Starting (initial) torque is the ability of a rotor, forcibly braked in the air flow, to create torque on the shaft.
8. Wind turbine (WM) is part of the APU from the rotor to the shaft of the generator or pump, or other energy consumer.
9. Rotary wind generator - an APU in which wind energy is converted into torque on the power take-off shaft by rotating the rotor in the air flow.
10. The range of rotor operating speeds is the difference between MMF and MRS when operating at rated load.
11. Low-speed windmill - in it the linear speed of the rotor parts in the flow does not significantly exceed the wind speed or is lower than it. The dynamic pressure of the flow is directly converted into blade thrust.
12. High-speed windmill - the linear speed of the blades is significantly (up to 20 or more times) higher than the wind speed, and the rotor forms its own air circulation. The cycle of converting flow energy into thrust is complex.

Notes:

1. Low-speed APUs, as a rule, have a KIEV lower than high-speed ones, but have a starting torque sufficient to spin up the generator without disconnecting the load and zero TAC, i.e. Absolutely self-starting and usable in the lightest winds.
2. Slowness and speed are relative concepts. A household windmill at 300 rpm can be low-speed, but powerful APUs of the EuroWind type, from which the fields of wind power plants and wind farms are assembled (see figure) and whose rotors make about 10 rpm, are high-speed, because with such a diameter, the linear speed of the blades and their aerodynamics over most of the span are quite “airplane-like”, see below.

What kind of generator do you need?

An electric generator for a domestic windmill must generate electricity over a wide range of rotation speeds and be able to self-start without automation or external power sources. In the case of using APU with OSS (spin-up wind turbines), which, as a rule, have high KIEV and efficiency, it must also be reversible, i.e. be able to work as an engine. At powers up to 5 kW this condition is satisfied electric cars with permanent magnets based on niobium (supermagnets); on steel or ferrite magnets you can count on no more than 0.5-0.7 kW.

Note: asynchronous generators alternating current or collector ones with a non-magnetized stator are completely unsuitable. When the wind force decreases, they will “go out” long before its speed drops to MPC, and then they will not start themselves.

The excellent “heart” of the APU with a power from 0.3 to 1-2 kW is obtained from an alternating current self-generator with a built-in rectifier; these are the majority now. First, they maintain an output voltage of 11.6-14.7 V over a fairly wide speed range without external electronic stabilizers. Secondly, the silicon valves open when the voltage on the winding reaches approximately 1.4 V, and before that the generator “does not see” the load. To do this, the generator needs to be spun up quite decently.

In most cases, a self-generator can be directly connected, without a gear or belt drive, to the shaft of a high-speed high-pressure engine, selecting the speed by selecting the number of blades, see below. “High-speed trains” have a small or zero starting torque, but the rotor, even without disconnecting the load, will have time to spin sufficiently before the valves open and the generator produces current.

Choosing according to the wind

Before deciding what type of wind generator to make, let’s decide on the local aerology. In gray-greenish(windless) areas of the wind map, only a sailing wind engine will be of any use(We’ll talk about them later). If you need a constant power supply, you will have to add a booster (rectifier with voltage stabilizer), charger, powerful battery, inverter 12/24/36/48 V DC to 220/380 V 50 Hz AC. Such a facility will cost no less than $20,000, and it is unlikely that it will be possible to remove long-term power of more than 3-4 kW. In general, with an unwavering desire for alternative energy, it is better to look for another source.

In yellow-green, low-wind places, if you need electricity up to 2-3 kW, you can use a low-speed vertical wind generator yourself. There are countless of them developed, and there are designs that are almost as good as industrially manufactured “blade blades” in terms of KIEV and efficiency.

If you plan to buy a wind turbine for your home, then it is better to focus on a wind turbine with a sail rotor. There are many controversies, and in theory everything is not yet clear, but they work. In the Russian Federation, “sailboats” are produced in Taganrog with a power of 1-100 kW.

In red, windy regions, the choice depends on the required power. In the range of 0.5-1.5 kW, homemade “verticals” are justified; 1.5-5 kW – purchased “sailboats”. "Vertical" can also be purchased, but will cost more than the APU horizontal scheme. And finally, if you need a wind turbine with a power of 5 kW or more, then you need to choose between horizontal purchased “blades” or “sailboats”.

Note: Many manufacturers, especially the second tier, offer kits of parts from which you can assemble a wind generator with a power of up to 10 kW yourself. Such a kit will cost 20-50% less than a ready-made kit with installation. But before purchasing, you need to carefully study the aerology of the intended installation location, and then select the appropriate type and model according to the specifications.

About security

Parts of a wind turbine for domestic use in operation can have a linear speed exceeding 120 and even 150 m/s, and a piece of any hard material weighing 20 g, flying at a speed of 100 m/s, with a “successful” hit, it kills a healthy man outright. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

In addition, most wind turbines with a power of more than 100 W are quite noisy. Many generate air pressure fluctuations of ultra-low (less than 16 Hz) frequencies - infrasounds. Infrasounds are inaudible, but are harmful to health and travel very far.

Note: in the late 80s there was a scandal in the United States - the largest wind farm in the country at that time had to be closed. Indians from a reservation 200 km from the field of its wind farm proved in court that their health disorders, which sharply increased after the wind farm was put into operation, were caused by its infrasounds.

Due to the above reasons, installation of APUs is allowed at a distance of at least 5 of their heights from the nearest residential buildings. In the courtyards of private households, it is possible to install industrially manufactured windmills that are appropriately certified. It is generally impossible to install APUs on roofs - during their operation, even low-power ones, alternating mechanical loads arise that can cause resonance building structure and its destruction.

Note: The height of the APU is considered to be the highest point of the swept disk (for bladed rotors) or geometric figure (for vertical APUs with a rotor on the shaft). If the APU mast or the rotor axis protrude even higher, the height is calculated by their top - the top.

Wind, aerodynamics, KIEV

A homemade wind generator obeys the same laws of nature as a factory one, calculated on a computer. And a home-made worker needs to understand the basics of his work very well - most often he does not have expensive, cutting-edge materials and technological equipment at his disposal. The aerodynamics of the APU are oh so difficult...

Wind and KIEV

To calculate serial factory APUs, the so-called. flat mechanistic model of wind. It is based on the following assumptions:

• Wind speed and direction are constant within the effective rotor surface.
• Air is a continuous medium.
• The effective surface of the rotor is equal to the swept area.
• The energy of the air flow is purely kinetic.

Under such conditions, the maximum energy per unit volume of air is calculated using the school formula, assuming the air density under normal conditions is 1.29 kg*cubic. m. At a wind speed of 10 m/s, one cube of air carries 65 J, and from one square of the effective surface of the rotor, with 100% efficiency of the entire APU, 650 W can be removed. This is a very simplified approach - everyone knows that the wind is never perfectly even. But this has to be done to ensure repeatability of products - a common thing in technology.

The flat model should not be ignored, it gives a clear minimum of available wind energy. But air, firstly, is compressible, and secondly, it is very fluid (dynamic viscosity is only 17.2 μPa * s). This means that the flow can flow around the swept area, reducing the effective surface and KIEV, which is most often observed. But in principle, the opposite situation is also possible: the wind flows towards the rotor and the effective surface area will then be greater than the swept one, and the KIEV will be greater than 1 relative to it for a flat wind.

Let's give two examples. The first is a pleasure yacht, quite heavy; the yacht can sail not only against the wind, but also faster than it. Wind means external; the apparent wind must still be faster, otherwise how will it pull the ship?

The second one is a classic aviation history. During tests of the MIG-19, it turned out that the interceptor, which was a ton heavier than the front-line fighter, accelerates faster in speed. With the same engines in the same airframe.

The theorists did not know what to think, and seriously doubted the law of conservation of energy. In the end, it turned out that the problem was the cone of the radar radome protruding from the air intake. From its toe to the shell, an air compaction arose, as if raking it from the sides to the engine compressors. Since then, shock waves have become firmly established in theory as useful, and the fantastic flight performance of modern aircraft is due in no small part to their skillful use.

Aerodynamics

The development of aerodynamics is usually divided into two eras - before N. G. Zhukovsky and after. His report “On attached vortices” dated November 15, 1905 was the beginning new era in aviation.

Before Zhukovsky, they flew with flat sails: it was assumed that the particles of the oncoming flow gave all their momentum to the leading edge of the wing. This made it possible to immediately get rid of the vector quantity - angular momentum - which gave rise to tooth-breaking and most often non-analytical mathematics, move to much more convenient scalar purely energy relations, and ultimately obtain a calculated pressure field on the load-bearing plane, more or less similar to the real one.

This mechanistic approach made it possible to create devices that could, at the very least, take to the air and fly from one place to another, without necessarily crashing to the ground somewhere along the way. But the desire to increase speed, load capacity and other flight qualities increasingly revealed the imperfections of the original aerodynamic theory.

Zhukovsky's idea was this: the air travels a different path along the upper and lower surfaces of the wing. From the condition of continuity of the medium (vacuum bubbles by themselves do not form in the air) it follows that the velocities of the upper and lower flows descending from the trailing edge should be different. Due to the small but finite viscosity of the air, a vortex should form there due to the difference in speeds.

The vortex rotates, and the law of conservation of momentum, just as immutable as the law of conservation of energy, is also valid for vector quantities, i.e. must also take into account the direction of movement. Therefore, right there, on the trailing edge, a counter-rotating vortex with the same torque should form. Due to what? Due to the energy generated by the engine.

For aviation practice, this meant a revolution: by choosing the appropriate wing profile, it was possible to send an attached vortex around the wing in the form of a circulation G, increasing its lift. That is, by spending part, and for high speeds and loads on the wing – most of the motor power, you can create an air flow around the device, allowing you to achieve better flight qualities.

This made aviation aviation, and not part of aeronautics: now the aircraft could create for itself the environment necessary for flight and no longer be a toy of air currents. All you need is a more powerful engine, and more and more powerful...

KIEV again

But the windmill does not have a motor. On the contrary, it must take energy from the wind and give it to consumers. And here it turns out - his legs were pulled out, his tail got stuck. We used too little wind energy for the rotor’s own circulation - it will be weak, the thrust of the blades will be low, and the KIEV and power will be low. We give a lot to the circulation - in a weak wind, the rotor will spin like crazy at idle, but consumers again get little: they just put on a load, the rotor slowed down, the wind blew away the circulation, and the rotor stopped working.

The law of conservation of energy gives the “golden mean” right in the middle: we give 50% of the energy to the load, and for the remaining 50% we turn up the flow to the optimum. Practice confirms the assumptions: if the efficiency of a good pulling propeller is 75-80%, then the efficiency of a bladed rotor that is also carefully calculated and blown in a wind tunnel reaches 38-40%, i.e. up to half of what can be achieved with excess energy.

Modernity

Nowadays, aerodynamics, armed with modern mathematics and computers, is increasingly moving away from inevitably simplifying models towards an accurate description of the behavior of a real body in real stream. And here, in addition to the general line - power, power, and once again power! – side paths are discovered, but promising precisely when the amount of energy entering the system is limited.

The famous alternative aviator Paul McCready created an airplane back in the 80s with two chainsaw motors with a power of 16 hp. showing 360 km/h. Moreover, its chassis was tricycle, non-retractable, and its wheels were without fairings. None of McCready's devices went online or went on combat duty, but two - one with piston engines and propellers, and the other a jet - flew around for the first time in history globe without landing at one gas station.

The development of the theory also affected the sails that gave birth to the original wing quite significantly. “Live” aerodynamics allowed the yachts to operate in winds of 8 knots. stand on hydrofoils (see figure); to accelerate such a monster to the required speed with a propeller, an engine of at least 100 hp is required. Racing catamarans sail at a speed of about 30 knots in the same wind. (55 km/h).

There are also finds that are completely non-trivial. Fans of the rarest and most extreme sport - base jumping - wearing a special wing suit, wingsuit, fly without a motor, maneuvering at a speed of more than 200 km/h (picture on the right), and then smoothly land in a pre-selected place. In which fairy tale do people fly on their own?

Many mysteries of nature were also resolved; in particular, the flight of a beetle. According to classical aerodynamics, it is not capable of flying. Just like the founder of the stealth aircraft, the F-117, with its diamond-shaped wing, is also unable to take off. And the MIG-29 and Su-27, which can fly tail first for some time, do not fit into any idea at all.

And why then, when working on wind turbines, not a fun thing and not a tool for destroying their own kind, but a source of a vital resource, do you need to dance away from the theory of weak flows with its flat wind model? Is there really no way to move forward?

What to expect from the classics?

However, one should not abandon the classics under any circumstances. It provides a foundation without which one cannot rise higher without relying on it. Just as set theory does not abolish the multiplication table, and quantum chromodynamics will not make apples fly up from the trees.

So, what can you expect with the classical approach? Let's look at the drawing. On the left are types of rotors; they are depicted conditionally. 1 – vertical carousel, 2 – vertical orthogonal (wind turbine); 2-5 – bladed rotors with different numbers of blades with optimized profiles.

On the right along the horizontal axis is the relative speed of the rotor, i.e., the ratio of the linear speed of the blade to the wind speed. Vertical up - KIEV. And down - again, relative torque. A single (100%) torque is considered to be that which is created by a rotor forcibly braked in the flow with 100% KIEV, i.e. when all the flow energy is converted into rotating force.

This approach allows us to draw far-reaching conclusions. For example, the number of blades must be selected not only and not so much according to the desired rotation speed: 3- and 4-blades immediately lose a lot in terms of KIEV and torque compared to 2- and 6-blades that work well in approximately the same speed range. And the outwardly similar carousel and orthogonal have fundamentally different properties.

In general, preference should be given to bladed rotors, except in cases where extreme low cost, simplicity, maintenance-free self-starting without automation are required, and lifting onto a mast is impossible.

Note: Let's talk about sailing rotors in particular - they don't seem to fit into the classics.

Verticals

APUs with a vertical axis of rotation have an undeniable advantage for everyday life: their components requiring maintenance are concentrated at the bottom and no lifting is required. There remains, and even then not always, a thrust-support self-aligning bearing, but it is strong and durable. Therefore, when designing a simple wind generator, the selection of options should begin with verticals. Their main types are presented in Fig.

Sun

In the first position is the simplest one, most often called the Savonius rotor. In fact, it was invented in 1924 in the USSR by J. A. and A. A. Voronin, and the Finnish industrialist Sigurd Savonius shamelessly appropriated the invention, ignoring the Soviet copyright certificate, and began serial production. But the introduction of an invention in the future means a lot, so in order not to stir up the past and not disturb the ashes of the deceased, we will call this windmill a Voronin-Savonius rotor, or for short, VS.

The aircraft is good for the home-made man, except for the “locomotive” KIEV at 10-18%. However, in the USSR they worked a lot on it, and there are developments. Below we will look at an improved design, not much more complex, but according to KIEV, it gives bladers a head start.

Note: the two-blade aircraft does not spin, but jerks jerkily; The 4-blade is only slightly smoother, but loses a lot in KIEV. To improve, 4-trough blades are most often divided into two floors - a pair of blades below, and another pair, rotated 90 degrees horizontally, above them. KIEV is preserved, and the lateral loads on the mechanics weaken, but the bending loads increase somewhat, and with a wind of more than 25 m/s such an APU is on the shaft, i.e. without a bearing stretched by cables above the rotor, it “tears down the tower.”

Daria

Next is the Daria rotor; KIEV – up to 20%. It is even simpler: the blades are made of a simple elastic tape without any profile. The theory of the Darrieus rotor is not yet sufficiently developed. It is only clear that it begins to unwind due to the difference in the aerodynamic resistance of the hump and the tape pocket, and then it becomes sort of high-speed, forming its own circulation.

The torque is small, and in the starting positions of the rotor parallel and perpendicular to the wind it is completely absent, so self-spin is possible only with an odd number of blades (wings?) In any case, the load from the generator must be disconnected during spin-up.

The Daria rotor has two more bad qualities. Firstly, when rotating, the thrust vector of the blade describes a full rotation relative to its aerodynamic focus, and not smoothly, but jerkily. Therefore, the Darrieus rotor quickly breaks down its mechanics even in a steady wind.

Secondly, Daria not only makes noise, but screams and squeals, to the point that the tape breaks. This happens due to its vibration. And the more blades, the stronger the roar. So, if they make a Daria, it is with two blades, from expensive high-strength sound-absorbing materials (carbon, mylar), and a small aircraft is used for spinning in the middle of the mast-pole.

Orthogonal

At pos. 3 – orthogonal vertical rotor with profiled blades. Orthogonal because the wings stick out vertically. The transition from BC to orthogonal is illustrated in Fig. left.

The angle of installation of the blades relative to the tangent to the circle touching the aerodynamic foci of the wings can be either positive (in the figure) or negative, depending on the wind force. Sometimes the blades are made rotating and weather vanes are placed on them, automatically holding the “alpha”, but such structures often break.

The central body (blue in the figure) allows you to increase the KIEV to almost 50%. In a three-blade orthogonal, it should have the shape of a triangle in cross-section with slightly convex sides and rounded corners, and with a larger number of blades, a simple cylinder is sufficient. But the theory for the orthogonal optimal quantity gives an unambiguous answer: there should be exactly 3 of them.

Orthogonal refers to high-speed wind turbines with OSS, i.e. necessarily requires promotion during commissioning and after calm. According to the orthogonal scheme, serial maintenance-free APUs with a power of up to 20 kW are produced.

Helicoid

Helicoidal rotor, or Gorlov rotor (item 4) is a type of orthogonal that ensures uniform rotation; an orthogonal with straight wings “tears” only slightly weaker than a two-bladed aircraft. Bending the blades along a helicoid allows one to avoid losses of CIEV due to their curvature. Although the curved blade rejects part of the flow without using it, it also scoops part into the zone of highest linear speed, compensating for losses. Helicoids are used less often than other wind turbines, because Due to the complexity of manufacturing, they are more expensive than their counterparts of equal quality.

Barrel raking

For 5 pos. – BC type rotor surrounded by a guide vane; its diagram is shown in Fig. on right. It is rarely found in industrial applications, because expensive land acquisition does not compensate for the increase in capacity, and the material consumption and complexity of production are high. But a do-it-yourselfer who is afraid of work is no longer a master, but a consumer, and if you need no more than 0.5-1.5 kW, then for him a “barrel-raking” is a tidbit:

• A rotor of this type is absolutely safe, silent, does not create vibrations and can be installed anywhere, even on a playground.
• Bending a galvanized “trough” and welding a frame of pipes is nonsense work.
• The rotation is absolutely uniform, the mechanical parts can be taken from the cheapest or from the trash.
• Not afraid of hurricanes - too much strong wind cannot push into the “barrel”; a streamlined vortex cocoon appears around it (we will encounter this effect later).
• And the most important thing is that since the surface of the “barrel” is several times larger than that of the rotor inside, the KIEV can be over-unit, and the rotational moment already at 3 m/s for a “barrel” of three-meter diameter is such that a 1 kW generator with a maximum load of They say it’s better not to twitch.

Video: Lenz wind generator

In the 60s in the USSR, E. S. Biryukov patented a carousel APU with a KIEV of 46%. A little later, V. Blinov achieved 58% KIEV from a design based on the same principle, but there is no data on its testing. And full-scale tests of Biryukov’s APU were carried out by employees of the magazine “Inventor and Innovator”. A two-story rotor with a diameter of 0.75 m and a height of 2 m in a fresh wind spun a 1.2 kW asynchronous generator to full power and withstood 30 m/s without breakdown. Drawings of Biryukov's APU are shown in Fig.

1. rotor made of galvanized roofing;
2. self-aligning double row ball bearing;
3. shrouds – 5 mm steel cable;
4. axis-shaft – steel pipe with a wall thickness of 1.5-2.5 mm;
5. aerodynamic speed control levers;
6. speed control blades – 3-4 mm plywood or sheet plastic;
7. speed control rods;
8. speed controller load, its weight determines the rotation speed;
9. drive pulley - a bicycle wheel without a tire with a tube;
10. thrust bearing - thrust bearing;
11. driven pulley – standard generator pulley;
12. generator.

Biryukov received several copyright certificates for his APU. First, pay attention to the cut of the rotor. When accelerating, it works like an aircraft, creating a large starting torque. As it spins, a vortex cushion is created in the outer pockets of the blades. From the wind's point of view, the blades become profiled and the rotor becomes a high-speed orthogonal, with the virtual profile changing according to the wind strength.

Secondly, the profiled channel between the blades acts as a central body in the operating speed range. If the wind intensifies, then a vortex cushion is also created in it, extending beyond the rotor. The same vortex cocoon appears as around the APU with a guide vane. The energy for its creation is taken from the wind, and it is no longer enough to break the windmill.

Thirdly, the speed controller is intended primarily for the turbine. It keeps its speed optimal from the KIEV point of view. And the optimum generator rotation speed is ensured by the choice of mechanical transmission ratio.

Note: after publications in the IR for 1965, the Armed Forces of Ukraine Biryukova sank into oblivion. The author never received a response from the authorities. The fate of many Soviet inventions. They say that some Japanese became a billionaire by regularly reading Soviet popular-technical magazines and patenting everything worthy of attention.

Lopastniki

As stated, according to the classics, a horizontal wind generator with a bladed rotor is the best. But, firstly, it needs a stable wind of at least medium strength. Secondly, the design for a do-it-yourselfer is fraught with many pitfalls, which is why often the fruit of long hard work, at best, illuminates a toilet, hallway or porch, or even turns out to only be able to unwind itself.

According to the diagrams in Fig. Let's take a closer look; positions:

• Fig. A:

1. rotor blades;
2. generator;
3. generator frame;
4. protective weather vane (hurricane shovel);
5. current collector;
6. chassis;
7. swivel unit;
8. working weather vane;
9. mast;
10. clamp for the shrouds.

• Fig. B, top view:

1. protective weather vane;
2. working weather vane;
3. protective weather vane spring tension regulator.

• Fig. G, current collector:

1. collector with copper continuous ring busbars;
2. spring-loaded copper-graphite brushes.

Note: Hurricane protection for a horizontal blade with a diameter of more than 1 m is absolutely necessary, because he is not capable of creating a vortex cocoon around himself. With smaller sizes, it is possible to achieve a rotor endurance of up to 30 m/s with propylene blades.

So, where do we stumble?

Blades

Expecting to achieve a power on the generator shaft of more than 150-200 W on blades of any size cut from a thick-walled plastic pipe, as is often advised, is the hope of a hopeless amateur. A pipe blade (unless it is so thick that it is simply used as a blank) will have a segmented profile, i.e. its top or both surfaces will be arcs of a circle.

Segmented profiles are suitable for incompressible media, such as hydrofoils or propeller blades. For gases, a blade of variable profile and pitch is needed, for an example, see Fig.; span - 2 m. This will be a complex and labor-intensive product, requiring painstaking calculations in full theory, blowing in a pipe and full-scale testing.

Generator

If the rotor is mounted directly on its shaft, the standard bearing will soon break - there is no equal load on all the blades in windmills. You need an intermediate shaft with a special support bearing and a mechanical transmission from it to the generator. For large windmills, the support bearing is a self-aligning double-row one; in the best models - three-tiered, Fig. D in Fig. higher. This allows the rotor shaft not only to bend slightly, but also to move slightly from side to side or up and down.

Note: It took about 30 years to develop a support bearing for the EuroWind type APU.

Emergency weather vane

The principle of its operation is shown in Fig. B. The wind, intensifying, puts pressure on the shovel, the spring stretches, the rotor warps, its speed drops and eventually it becomes parallel to the flow. Everything seems to be fine, but it was smooth on paper...

On a windy day, try holding a boiler lid or a large saucepan by the handle parallel to the wind. Just be careful - the fidgety piece of iron can hit you in the face so hard that it breaks your nose, cuts your lip, or even knocks out your eye.

Flat wind occurs only in theoretical calculations and, with sufficient accuracy for practice, in wind tunnels. In reality, a hurricane damages windmills with a hurricane shovel more than completely defenseless ones. It’s better to change damaged blades than to do everything again. IN industrial installations- another thing. There, the pitch of the blades, each individually, is monitored and adjusted by automation under the control of the on-board computer. And they are made from heavy-duty composites, not water pipes.

Current collector

This is a regularly serviced unit. Any power engineer knows that the commutator with brushes needs to be cleaned, lubricated, and adjusted. And the mast is from water pipe. If you can’t climb, once every month or two you’ll have to throw the entire windmill down to the ground and then pick it up again. How long will he last from such “prevention”?

Video: bladed wind generator + solar panel for power supply to a dacha

Mini and micro

But as the size of the paddle decreases, the difficulties fall according to the square of the wheel diameter. It is already possible to manufacture a horizontal bladed APU on your own with a power of up to 100 W. A 6-bladed one would be optimal. With more blades, the diameter of the rotor designed for the same power will be smaller, but they will be difficult to firmly attach to the hub. Rotors with less than 6 blades need not be taken into account: a 2-blade 100 W rotor needs a rotor with a diameter of 6.34 m, and a 4-blade of the same power needs 4.5 m. For a 6-blade, the power-diameter relationship is expressed as follows :

• 10 W – 1.16 m.
• 20 W – 1.64 m.
• 30 W – 2 m.
• 40 W – 2.32 m.
• 50 W – 2.6 m.
• 60 W – 2.84 m.
• 70 W – 3.08 m.
• 80 W – 3.28 m.
• 90 W – 3.48 m.
• 100 W – 3.68 m.
• 300 W – 6.34 m.

It would be optimal to count on a power of 10-20 W. Firstly, a plastic blade with a span of more than 0.8 m will not withstand winds of more than 20 m/s without additional protection measures. Secondly, with a blade span of up to the same 0.8 m, the linear speed of its ends will not exceed the wind speed by more than three times, and the requirements for profiling with twist are reduced by orders of magnitude; here a “trough” with a segmented pipe profile, pos. B in Fig. And 10-20 W will provide power to a tablet, recharge a smartphone, or illuminate a house-saving light bulb.

Next, select a generator. A Chinese motor is perfect - wheel hub for electric bicycles, pos. 1 in Fig. Its power as a motor is 200-300 W, but in generator mode it will give up to about 100 W. But will it suit us in terms of speed?

The speed index z for 6 blades is 3. The formula for calculating the rotation speed under load is N = v/l*z*60, where N is the rotation speed, 1/min, v is the wind speed, and l is the rotor circumference. With a blade span of 0.8 m and a wind of 5 m/s, we get 72 rpm; at 20 m/s – 288 rpm. A bicycle wheel also rotates at approximately the same speed, so we will take off our 10-20 W from a generator capable of producing 100. You can place the rotor directly on its shaft.

But here the following problem arises: after spending a lot of work and money, at least on a motor, we got... a toy! What is 10-20, well, 50 W? But you can’t make a bladed windmill capable of powering even a TV at home. Is it possible to buy a ready-made mini-wind generator, and wouldn’t it be cheaper? As much as possible, and as cheaply as possible, see pos. 4 and 5. In addition, it will also be mobile. Place it on a stump and use it.

The second option is if a stepper motor from an old 5- or 8-inch floppy drive is lying around somewhere, or from a paper drive or carriage of an unusable inkjet or dot matrix printer. It can work as a generator, and attach a carousel rotor to it from tin cans(pos. 6) is easier than assembling a structure like the one shown in pos. 3.

In general, the conclusion regarding “blade blades” is clear: homemade ones are more likely for tinkering to your heart’s content, but not for real long-term energy output.

Video: the simplest wind generator for lighting a dacha

Sailboats

The sailing wind generator has been known for a long time, but soft panels on its blades (see figure) began to be made with the advent of high-strength, wear-resistant synthetic fabrics and films. Multi-bladed windmills with rigid sails have spread widely around the world as a drive for low-power automatic water pumps, but their technical specifications are lower even than those of carousels.

However, a soft sail like a windmill wing, it seems, turned out to be not so simple. The point is not about wind resistance (manufacturers do not limit the maximum permissible wind speed): sailboat sailors already know that it is almost impossible for the wind to tear the panel of a Bermuda sail. Most likely, the sheet will be torn out, or the mast will be broken, or the whole vessel will make an “overkill turn.” It's about energy.

Unfortunately, exact test data cannot be found. Based on user reviews, it was possible to create “synthetic” dependencies for the installation of a Taganrog-made wind turbine-4.380/220.50 with a wind wheel diameter of 5 m, a wind head weight of 160 kg and a rotation speed of up to 40 1/min; they are presented in Fig.

Of course, there can be no guarantees for 100% reliability, but it is clear that there is no smell of a flat-mechanistic model here. There is no way a 5-meter wheel in a flat wind of 3 m/s can produce about 1 kW, at 7 m/s reach a plateau in power and then maintain it until a severe storm. Manufacturers, by the way, state that the nominal 4 kW can be obtained at 3 m/s, but when installed by forces based on the results of studies of local aerology.

There is also no quantitative theory to be found; The developers' explanations are unclear. However, since people buy Taganrog wind turbines and they work, we can only assume that the declared conical circulation and propulsive effect are not a fiction. In any case, they are possible.

Then, it turns out, IN FRONT of the rotor, according to the law of conservation of momentum, a conical vortex should also arise, but expanding and slow. And such a funnel will drive the wind towards the rotor, its effective surface will be more swept, and the KIEV will be more than unity.

Field measurements of the pressure field in front of the rotor, even with a household aneroid, could shed light on this issue. If it turns out to be higher than on the sides, then, indeed, the sailing APUs work like a beetle flies.

Homemade generator

From what has been said above, it is clear that it is better for homemade craftsmen to take on either verticals or sailboats. But both are very slow, and transmission to a high-speed generator is extra work, unnecessary costs and losses. Is it possible to make an efficient low-speed electric generator yourself?

Yes, you can, on magnets made of niobium alloy, so-called. supermagnets. The manufacturing process of the main parts is shown in Fig. Coils - each of 55 turns of 1 mm copper wire in heat-resistant high-strength enamel insulation, PEMM, PETV, etc. The height of the windings is 9 mm.

Pay attention to the grooves for the keys in the rotor halves. They must be positioned so that the magnets (they are glued to the magnetic core with epoxy or acrylic) converge with opposite poles after assembly. “Pancakes” (magnetic cores) must be made of a soft magnetic ferromagnet; Regular structural steel will do. The thickness of the “pancakes” is at least 6 mm.

In general, it is better to buy magnets with an axial hole and tighten them with screws; supermagnets attract with terrible force. For the same reason, a cylindrical spacer 12 mm high is placed on the shaft between the “pancakes”.

The windings that make up the stator sections are connected according to the diagrams also shown in Fig. The soldered ends should not be stretched, but should form loops, otherwise the epoxy with which the stator will be filled may harden and break the wires.

The stator is poured into the mold to a thickness of 10 mm. There is no need to center or balance, the stator does not rotate. The gap between the rotor and stator is 1 mm on each side. The stator in the generator housing must be securely secured not only from displacement along the axis, but also from rotation; a strong magnetic field with current in the load will pull it along with it.

Video: DIY windmill generator

Conclusion

And what do we have in the end? The interest in “blade blades” is explained rather by their spectacular appearance, than actual performance in a home-made version and at low power. A homemade carousel APU will provide “standby” power for charging a car battery or powering a small house.

But with sailing APUs it is worth experimenting with craftsmen with a creative streak, especially in the mini version, with a wheel 1-2 m in diameter. If the developers’ assumptions are correct, then it will be possible to remove all 200-300 W from this one, using the Chinese engine-generator described above.

Andrey said:

Thank you for your free consultation... And the prices “from companies” are not really expensive, and I think that craftsmen from the outback will be able to make generators similar to yours. And Li-po batteries can be ordered from China, inverters in Chelyabinsk make very good ones (with smooth sine). And sails, blades or rotors are another reason for the flight of thought of our handy Russian men.

Ivan said:

question:
For windmills with a vertical axis (position 1) and the “Lenz” option, it is possible to add an additional part - an impeller that points in the direction of the wind, and covers the useless side from it (going towards the wind). That is, the wind will not slow down the blade, but this “screen”. Positioning downwind with the “tail” located behind the windmill itself below and above the blades (ridges). I read the article and an idea was born.

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The activities of both individual people and all of today's humanity are practically impossible without electricity. Unfortunately, the rapidly increasing consumption of oil and gas, coal and peat is leading to a decrease in the reserves of these resources on the planet. What can be done while earthlings still have all this? According to the conclusions of experts, it is the development of energy complexes that can solve the problems of global economic and financial crises. Therefore, the search and use of fuel-free energy sources is becoming the most urgent.

Renewable, ecological, green

Perhaps it is not worth reminding that everything new is well forgotten old. People learned to use the power of river flow and wind speed to generate mechanical energy a very long time ago. The sun heats our water and moves cars and powers spaceships. Wheels installed in the beds of streams and small rivers supplied water to fields back in the Middle Ages. One could provide flour to several surrounding villages.

At the moment we are interested in a simple question: how to provide your home with cheap light and heat, how to make a windmill with your own hands? 5 kW power or a little less, the main thing is that you can supply your home with current to operate electrical appliances.

Interestingly, in the world there is a classification of buildings according to the level of resource efficiency:

• conventional, built before 1980-1995;
• with low and ultra-low energy consumption - up to 45-90 kWh per 1 kW/m;
• passive and non-volatile, receiving current from renewable sources (for example, by installing a rotary wind generator (5 kW) with your own hands or a system of solar panels, you can solve this problem);
• energy-efficient buildings that generate more electricity than they need earn money by passing it on to other consumers through the grid.

It turns out that your own home mini-stations, installed on roofs and in courtyards, can eventually become a kind of competition to large power suppliers. Yes and governments different countries strongly encourage the creation and active use

How to determine the profitability of your own power plant

Researchers have proven that the reserve capacity of winds is much greater than all the accumulated fuel reserves of centuries. Among the methods of obtaining energy from renewable sources, windmills have a special place, since their production is simpler than the creation of solar panels. In fact, you can assemble a 5 kW wind generator with your own hands, having the necessary components, including magnets, copper wire, plywood and metal for the blades.

Experts say that the design can become productive and, accordingly, profitable not only correct form, but also built in right place. This means that it is necessary to take into account the presence, constancy and even speed of air flows in each individual case and even in a specific region. If the area periodically experiences calm, calm and windless days, installing a mast with a generator will not bring any benefit.

Before you start making a windmill with your own hands (5 kW), you need to think about its model and type. You should not expect a large energy output from a weak design. And vice versa, when you only need to power a couple of light bulbs in your dacha, there is no point in building a huge windmill with your own hands. 5 kW is a power sufficient to provide electricity to almost the entire lighting system and household appliances. If there is a constant wind, there will be light.

How to make a wind generator with your own hands: sequence of actions

At the location chosen for the high mast, the windmill itself with the generator attached to it is strengthened. The generated energy is transmitted through the wires to the right room. It is believed that the higher the mast design, the larger the diameter of the wind wheel and the stronger the air flow, the higher the efficiency of the entire device. In reality, everything is not quite like that:

• for example, a strong hurricane can easily break the blades;
• some models can be installed on the roof of a regular house;
• a properly selected turbine starts easily and works perfectly even in very low wind speeds.

Main types of wind turbines

Designs with a horizontal axis of rotation of the rotor are considered classic. They usually have 2-3 blades and are installed at a high height from the ground. The greatest efficiency of such an installation is manifested at a constant direction and its speed of 10 m/s. A significant disadvantage of this blade design is the failure of the rotation of the blades during frequently changing, gusty conditions. This leads to either unproductive operation or destruction of the entire installation. To start such a generator after stopping, a forced initial rotation of the blades is necessary. In addition, when the blades actively rotate, they produce specific sounds that are unpleasant to the human ear.

Vertical wind generator(“Top” 5 kW or another) has a different rotor placement. H-shaped or barrel-shaped turbines capture wind from any direction. These designs are smaller in size and start even at the weakest air currents(at 1.5-3 m/s), do not require high masts, they can be used even in urban environments. In addition, self-assembled windmills (5 kW - this is real) reach their rated power at wind speeds of 3-4 m/s.

Sails are not on ships, but on land

One of the popular trends in wind energy now is the creation of a horizontal generator with soft blades. The main difference is both the material of manufacture and the shape itself: do-it-yourself windmills (5 kW, sail type) have 4-6 triangular fabric blades. Moreover, unlike traditional structures, their cross-section increases in the direction from the center to the periphery. This feature allows you not only to “catch” weak winds, but also to avoid losses during hurricane air flow.

The advantages of sailboats include the following indicators:

• high power at slow rotation;
• independent orientation and adjustment to any wind;
• high weathervane and low inertia;
• no need to force the wheel to spin;
• completely silent rotation even at high speeds;
• absence of vibrations and sound disturbances;
• relative cheapness of construction.

DIY windmills

The 5 kW of required electricity can be obtained in several ways:

• build a simple rotor structure;
• assemble a complex of several sailing wheels arranged in series on the same axis;
• use an axle design with neodymium magnets.

It is important to remember that the power of a wind wheel is proportional to the cubic value of the wind speed multiplied by the swept area of ​​the turbine. So, how to make a 5 kW wind generator? Instructions below.

You can use a car hub and brake discs as a basis. 32 magnets (25 by 8 mm) are placed parallel in a circle on the future rotor disks (the moving part of the generator), 16 pieces per disk, and the pluses must alternate with the minuses. Opposing magnets must have different meanings poles. After marking and placement, everything on the circle is filled with epoxy.

Coils of copper wire are placed on the stator. Their number should be less than the number of magnets, that is, 12. First, all the wires are taken out and connected to each other in a star or triangle, then they are also filled with epoxy glue. It is recommended to insert pieces of plasticine inside the coils before pouring. After the resin has hardened and been removed, there will be holes left that are needed for ventilation and cooling of the stator.

How does it all work

The rotor disks, rotating relative to the stator, form a magnetic field, and an electric current arises in the coils. And the windmill, connected through a pulley system, is needed in order to move these parts of the working structure. How to make a wind generator with your own hands? Some people start building their own power station by assembling a generator. Others - from the creation of a rotating blade part.

The shaft from the windmill is engaged by a sliding connection with one of the rotor disks. The lower, second disk with magnets is placed on a strong bearing. The stator is located in the middle. All parts are attached to the plywood circle using long bolts and secured with nuts. Between all the “pancakes”, minimum gaps must be left for free rotation of the rotor disks. The result is a 3-phase generator.

"Barrel"

All that remains is to make windmills. You can make a 5 kW rotating structure with your own hands from 3 circles of plywood and a sheet of the thinnest and lightest duralumin. Metal rectangular wings are attached to the plywood with bolts and angles. First, guide grooves in the shape of a wave are hollowed out in each plane of the circle, into which the sheets are inserted. The resulting double-decker rotor has 4 wavy blades attached to each other at right angles. That is, between each two plywood pancakes fastened to the hubs there are 2 duralumin blades curved in the shape of a wave.

This structure is mounted in the center on a steel pin, which will transmit torque to the generator. Self-made windmills (5 kW) of this design weigh approximately 16-18 kg with a height of 160-170 cm and a base diameter of 80-90 cm.

Things to consider

A “barrel” windmill can even be installed on the roof of a building, although a tower 3-4 meters high is sufficient. However, it is imperative to protect the generator housing from natural precipitation. It is also recommended to install a battery energy storage device.

To obtain alternating current from direct 3-phase current, a converter must also be included in the circuit.

If there are enough windy days in the region, a self-assembled windmill (5 kW) can provide current not only to a TV and light bulbs, but also to a video surveillance system, air conditioning, refrigerator and other electrical equipment.