How to make a wind farm with your own hands. Wooden blades for a wind turbine

One of the most available options renewable energy is the use of wind energy. For information on how to independently calculate, assemble and install a windmill, read this article.

Classification of wind generators

Installations are classified based on the following wind turbine criteria:

• location of the axis of rotation;
• number of blades;
• element material;
• screw pitch.

Wind turbines, as a rule, have a design with a horizontal and vertical axis of rotation.

Execution with a horizontal axis - a propeller design with one, two, three or more blades. This is the most common version of air power plants due to its high efficiency.

Vertical axis design - orthogonal and carousel designs on the example of Darrieus and Savonius rotors. The last two concepts should be clarified, since both have a certain significance in the design of wind generators.

The Darrieus rotor is an orthogonal design of a wind turbine, where the aerodynamic blades (two or more) are located symmetrically to each other at a certain distance and are mounted on radial beams. Enough difficult option wind turbine, requiring careful aerodynamic design of the blades.

The Savonius rotor is a carousel-type wind turbine design, where two semi-cylindrical blades are located one against the other, forming a sinusoidal shape as a whole. The efficiency of the structures is low (about 15%), but can be almost doubled if the blades are placed in the direction of the wave not horizontally, but vertically and a multi-tiered version is used with an angular displacement of each pair of blades relative to other pairs.

Advantages and disadvantages of "windmills"

The advantages of these devices are obvious, especially in relation to domestic operating conditions. Users of "windmills" actually get the opportunity to reproduce free electrical energy, except for small costs for construction and maintenance. However, the disadvantages of wind turbines are also obvious.

So in order to achieve effective work installation, the conditions for the stability of wind flows are required. Man cannot create such conditions. This is purely the prerogative of nature. Another one, but already technical disadvantage, noted low quality generated electricity, as a result of which it is necessary to supplement the system with expensive electrical modules (multipliers, chargers, batteries, converters, stabilizers).

Advantages and disadvantages in terms of the features of each of the modifications of wind turbines, perhaps, balance at zero. If the horizontal-axis modifications differ high value Efficiency, then for stable operation they require the use of wind flow direction controllers and hurricane wind protection devices. Vertical-axis modifications have low efficiency, but work stably without a wind direction tracking mechanism. At the same time, such wind turbines are distinguished by a low level of noise, eliminate the effect of "spreading" in conditions of strong winds, and are quite compact.

Homemade wind generators

Making a "windmill" with my own hands- the task is quite solvable. Moreover, a constructive and rational approach to business will help to minimize the inevitable financial expenses. First of all, it is worth sketching a project, carrying out necessary calculations balancing and power. These actions will not only be the key to the successful construction of a wind farm, but also the key to maintaining the integrity of all purchased equipment.

It is recommended to start with the construction of a micro-windmill with a power of several tens of watts. In the future, the experience gained will help create a more powerful design. Creating a home wind generator, you should not focus on obtaining high-quality electricity (220 V, 50 Hz), since this option will require significant financial investments. It is wiser to limit ourselves to using the initially received electricity, which can be successfully used without conversion for other purposes, for example, to support heating and hot water systems built on electric heaters (heaters) - such devices do not require a stable voltage and frequency. This makes it possible to create a simple circuit running directly from the generator.

Most likely, no one will argue that heating and hot water supply in the house are inferior in importance to household appliances and lighting fixtures, for the power of which they often seek to install home windmills. The device of a wind turbine is precisely for the purpose of providing the house with heat and hot water- This minimum costs and simplicity of design.

Generalized project of a home wind turbine

Structurally, a home project largely repeats an industrial installation. True, household solutions are often based on vertical-axis wind turbines and are equipped with low-voltage DC generators. The composition of household wind turbine modules, subject to the receipt of high-quality electricity (220 V, 50 Hz):

• wind turbine;
• wind orientation device;
• multiplier;
• DC generator (12 V, 24 V);
• battery charge module;
• rechargeable batteries (lithium-ion, lithium-polymer, lead-acid);
• DC voltage converter 12 V (24 V) to AC voltage 220 V.

Wind turbine PIC 8-6/2.5

How it works? Just. The wind turns the windmill. The torque is transmitted through the multiplier to the shaft of the DC generator. The energy received at the output of the generator through the charging module is accumulated in the batteries. From the battery terminals, a constant voltage of 12 V (24 V, 48 V) is supplied to the converter, where it is transformed into a voltage suitable for powering household electrical networks.

About generators for home "windmills"

Most residential wind turbine designs are typically constructed using low-speed DC motors. This is the simplest version of the generator that does not require modernization. Optimally - electric motors with permanent magnets, designed for a supply voltage of the order of 60-100 volts. There is a practice of using automotive alternators, but for such a case, the introduction of a multiplier is required, since autogenerators produce the desired voltage only at high (1800-2500) revolutions. One of options– reconstruction induction motor alternating current, but also quite complex, requiring precise calculations, turning, installation of neodymium magnets in the rotor area. There is an option for a three-phase asynchronous motor with the connection of capacitors of the same capacity between the phases. Finally, there is the possibility of making a generator from scratch with your own hands. There are a lot of instructions for this.

Vertical-axis homemade "windmill"

A fairly efficient and, most importantly, inexpensive wind generator can be built on the basis of the Savonius rotor. Here, as an example, a micro-power plant is considered, the power of which does not exceed 20 W. However, this device is quite sufficient, for example, to provide electrical energy some household appliances powered by 12 volts.

Parts set:

1. Aluminum sheet 1.5-2 mm thick.
2. Plastic pipe: diameter 125 mm, length 3000 mm.
3. Aluminum pipe: diameter 32 mm, length 500 mm.
4. DC motor (potential generator), 30-60V, 360-450 rpm, for example, PIK8-6/2.5 electric motor.
5. Voltage controller.
6. Battery.

Making a Savonius rotor

Three "pancakes" with a diameter of 285 mm are cut out of an aluminum sheet. Holes are drilled in the center of each aluminum pipe 32 mm. It turns out something similar to CDs. From plastic pipe two pieces 150 mm long are cut off and cut in half lengthwise. The result is four semicircular blades 125x150 mm. All three aluminum "CDs" are put on a 32 mm pipe and fixed at a distance of 320, 170, 20 mm from top point strictly horizontal, forming two tiers. Blades are inserted between the discs, two per tier and fixed strictly one against the other, forming a sinusoid. In this case, the blades of the upper tier are displaced relative to the blades of the lower tier by an angle of 90 degrees. The result is a four-bladed Savonius rotor. For fastening elements, you can use rivets, self-tapping screws, corners, or use other methods.

Connecting to the engine and mounting on the mast

The shaft of DC motors with the above parameters usually has a diameter of no more than 10-12 mm. In order to connect the motor shaft to the wind turbine pipe, a brass bushing is pressed into the lower part of the pipe, having the required inner diameter. A hole is drilled through the wall of the pipe and the sleeve, a thread is cut to screw in the locking screw. Next, the wind turbine pipe is put on the generator shaft, after which the connection is rigidly fixed with a locking screw.

The rest of the plastic pipe (2800 mm) is the mast of the wind turbine. The generator assembly with the Savonius wheel is mounted at the top of the mast - it is simply inserted into the pipe until it stops. As a stop, a metal disk cover is used, fixed on the front end of the motor, having a diameter slightly larger than the diameter of the mast. Holes are drilled on the periphery of the lid for attaching braces. Since the diameter of the motor housing is smaller than the inner diameter of the pipe, gaskets or stops are used to align the generator in the center. The cable from the generator is passed inside the pipe and out through the window at the bottom. During installation, it is necessary to take into account the design of the generator protection against moisture, using sealing gaskets for this. Again, in order to protect against precipitation, an umbrella cap can be installed above the connection of the wind turbine pipe with the generator shaft.

Installation of the entire structure is carried out in an open, well-ventilated area. A hole 0.5 meters deep is dug under the mast, Bottom part the pipes are lowered into the pit, the structure is leveled with stretch marks, after which the pit is poured with concrete.

Voltage controller (simple charger)

A manufactured wind generator, as a rule, is not capable of delivering a voltage of 12 volts due to the low speed. The maximum frequency of rotation of the wind turbine at a wind speed of 6-8 m / s. reaches a value of 200-250 rpm. At the output, it is possible to obtain a voltage of the order of 5-7 volts. To charge the battery, a voltage of 13.5-15 volts is required. The way out is to use a simple switching voltage converter, assembled, for example, based on the LM2577ADJ voltage regulator. By applying 5 volts DC to the input of the converter, 12-15 volts are obtained at the output, which is quite enough to charge a car battery.

Ready voltage converter on LM2577

This micro-wind generator can certainly be improved. Increase the power of the turbine, change the material and height of the mast, add a DC-to-AC mains voltage converter, etc.

Horizontal-axial wind power plant

Parts set:

1. A plastic pipe with a diameter of 150 mm, an aluminum sheet 1.5-2.5 mm thick, a wooden block 80x40 1 m long, plumbing: flange - 3, corner - 2, tee - 1.
2. DC motor (generator) 30-60 V, 300-470 rpm.
3. Wheel-pulley for an engine with a diameter of 130-150 mm (aluminum, brass, textolite, etc.).
4. Steel pipes with a diameter of 25 mm and 32 mm and a length of 35 mm and 3000 mm, respectively.
5. Charging module for batteries.
6. Batteries.
7. Voltage converter 12 V - 120 V (220 V).

Production of a horizontal-axial "windmill"

Plastic pipe is necessary for the manufacture of wind turbine blades. A segment of such a pipe, 600 mm long, is cut lengthwise into four identical segments. The windmill requires three blades, which are made from the resulting segments by cutting off a piece of material diagonally to the full length, but not exactly from corner to corner, but from bottom corner to top corner, with a slight indent from the latter. The processing of the lower part of the segments is reduced to the formation of a fastening petal on each of the three segments. To do this, a square about 50x50 mm in size is cut along one edge, and the remaining part serves as a mounting petal.

The blades of the wind turbine are fixed on the wheel-pulley with the help of bolted connections. The pulley is mounted directly on the shaft of the DC motor - generator. A simple wooden block with a section of 80x40 mm and a length of 1 m is used as the chassis of the wind turbine. The generator is installed at one end wooden block. At the other end of the bar, a "tail" is mounted, made of aluminum sheet. At the bottom of the bar, fastened metal pipe 25 mm, designed to act as a shaft rotary mechanism. A three-meter metal pipe 32 mm is used as a mast. Top part mast is a sleeve of the rotary mechanism, where the wind turbine pipe is inserted. The mast support is made from a sheet of thick plywood. On this support, in the form of a disk with a diameter of 600 mm, a construction of sanitary parts is assembled, thanks to which the mast can be easily raised or lowered, or mounted or dismantled. Stretch marks are used to fasten the mast.

All electronics of the wind turbine is mounted in a separate module, the interface of which provides for the connection of batteries and consumer loads. The module includes a battery charge controller and a voltage converter. Such devices can be assembled independently with the appropriate experience, or purchased on the market. There are many for sale different solutions, allowing to obtain the desired output values ​​of voltages and currents.

Combined wind turbines

Combined wind turbines are a serious option for a home energy module. Actually, the combination involves the unification of a wind generator in a single system, solar battery, diesel or petrol power plant . You can combine in every possible way, based on the possibilities and needs. Naturally, when there is a three-in-one option, this is the most effective and reliable solution.

Also, under the combination of wind turbines, it is supposed to create wind power plants that have two various modifications. For example, when a Savonius rotor and a traditional three-blade machine work in the same bundle. The first turbine operates at low wind flow speeds, and the second only at nominal ones. Thus, the efficiency of the installation is maintained, unjustified energy losses are excluded, and in the case of asynchronous generators, reactive currents are compensated.

Combined systems are technically complex and costly options for home practice.

Calculation of the power of a wind farm

To calculate the power of a horizontal-axis wind generator, you can use the standard formula:

• N = p S V3 / 2
• N— installation power, W
• p- air density (1.2 kg / m 3)
• S- blown area, m 2
• V— wind flow speed, m/s

For example, the power of an installation with a maximum blade span of 1 meter, with a wind speed of 7 m / s, will be:

• N\u003d 1.2 1 343 / 2 \u003d 205.8 W

An approximate calculation of the power of a wind turbine created on the basis of the Savonius rotor can be calculated using the formula:

• N = p R H V3
• N— installation power, W
• R— impeller radius, m
• V— wind speed, m/s

For example, for the design of a wind power plant with a Savonius rotor mentioned in the text, the power value at a wind speed of 7 m / s. will be:

• N= 1.2 0.142 0.3 343 = 17.5 W

Russia has a dual position regarding wind energy resources. On the one hand, thanks to the huge total area and to the abundance of the plains the wind as a whole is plentiful, and for the most part even. On the other hand, our winds are predominantly low-potential, slow, see fig. On the third, in sparsely populated areas, the winds are violent. Based on this, the task of starting a wind generator on the farm is quite relevant. But, in order to decide whether to buy a fairly expensive device, or make it yourself, you need to think carefully about which type (and there are a lot of them) for what purpose to choose.

Basic concepts

1. KIEV - wind energy utilization factor. If a mechanistic flat wind model is used for calculation (see below), it is equal to the efficiency of the rotor of a wind power plant (APU).
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. The minimum operating wind speed (MPS) is its speed at which the windmill begins to give current to the load.
4. The maximum allowable wind speed (MPS) is its speed at which energy generation 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 stops itself, or the APU simply collapses.
5. Starting wind speed (CWS) - at this speed, the rotor is able to turn without load, spin up and enter the operating mode, after which the generator can be turned on.
6. Negative starting speed (OSS) - this means that the APU (or wind turbine - wind turbine, or WEA, wind power unit) to start at any wind speed requires mandatory spin-up from an external energy source.
7. Starting (initial) moment - the ability of the rotor, forcibly slowed down in the air flow, to create a torque on the shaft.
8. Wind turbine (VD) - part of the APU from the rotor to the shaft of the generator or pump, or other energy consumer.
9. Rotary wind generator - 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 operating speed range of the rotor is the difference between MDS and MRS when operating at rated load.
11. Slow-speed windmill - in it the linear speed of the parts of the rotor in the flow does not significantly exceed the wind speed or below it. The dynamic head 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 lower CIEV than high-speed ones, but they have a starting torque sufficient to spin up the generator without disconnecting the load and zero TCO, i.e. absolutely self-starting and applicable in the lightest winds.
2. Slowness and speed are relative concepts. A household windmill at 300 rpm can be low-speed, and powerful APUs of the EuroWind type, from which the fields of wind farms, wind farms (see Fig.) are recruited 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”, see below.

What generator is needed?

An electric generator for a domestic windmill must generate electricity in a wide range of rotational speeds and have the ability to self-start without automation and external sources nutrition. In the case of using an APU with OSS (windmills with spin-up), 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 alternators or collector alternators with a non-magnetized stator are not suitable at all. With a decrease in wind strength, they will “go out” long before its speed drops to MRS, and then they will not start themselves.

An excellent "heart" of the APU with a power of 0.3 to 1-2 kW is obtained from an alternator with a built-in rectifier; most of them are now. Firstly, they keep the output voltage of 11.6-14.7 V in a fairly wide range of speeds without external electronic stabilizers. Secondly, the silicon gates open when the voltage on the winding reaches about 1.4 V, and before that the generator "does not see" the load. To do this, the generator must already be quite well untwisted.

In most cases, the oscillator can be connected directly, without gear or belt drive, to the high-speed HP shaft by selecting the speed by choosing the number of blades, see below. "Fast-walkers" have a small or zero starting torque, but the rotor, even without disconnecting the load, will have enough time to spin up before the valves open and the generator gives current.

Choice in the wind

Before deciding which wind generator to make, let's decide on the local aerology. in grey-greenish(windless) areas of the wind map, at least some sense will be only from a sailing wind turbine(and 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 VDC to 220/380 VAC 50 Hz. Such an economy will cost no less than $20,000, and it is unlikely that it will be possible to remove a long-term power of more than 3-4 kW. In general, with an inexorable desire for alternative energy, it is better to look for another source of it.

In yellow-green, slightly windy places, if you need electricity up to 2-3 kW, you yourself can take on a low-speed vertical wind generator . They have been developed innumerable, and there are designs that, in terms of KIEV and efficiency, are almost not inferior to industrial-made “blades”.

If you are going to buy a wind turbine for your home, then it is better to focus on a windmill with a sailing rotor. There are many disputes, and in theory not everything is clear yet, but they work. In the Russian Federation, "sailboats" are produced in Taganrog with a capacity of 1-100 kW.

In red, windy, regions, the choice depends on the required power. In the range of 0.5-1.5 kW, self-made "verticals" are justified; 1.5-5 kW - purchased "sailboats". "Vertical" can also be purchased, but it will cost more than the APU horizontal scheme. And, finally, if you need a windmill 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 on your own. Such a set will cost 20-50% cheaper than a ready-made one with installation. But before buying, you need to carefully study the aerology of the intended installation site, 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 solid material weighing 20 g, flying at a speed of 100 m/s, with a “successful” hit, kills a healthy man on the spot. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

In addition, most windmills over 100 watts are quite noisy. Many generate ultra-low (less than 16 Hz) frequency air pressure fluctuations - infrasounds. Infrasounds are inaudible, but detrimental to health, and spread 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. The Indians from the reservation, 200 km from the field of her APU, proved in court that the health disorders that sharply increased in them after the commissioning of the wind farm were due to its infrasounds.

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

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

Wind, aerodynamics, KIEV

Homemade wind generator obeys the same laws of nature as the factory, calculated on a computer. And the do-it-yourselfer needs to understand the basics of his work very well - most often he does not have at his disposal expensive ultra-modern materials and technological equipment. The aerodynamics of the APU is oh so difficult ...

Wind and KIEV

To calculate serial factory APUs, the so-called. flat mechanistic wind model. 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 of a unit volume of air is calculated according to the school formula, assuming the air density under normal conditions is 1.29 kg * cu. 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, it is possible, at 100% efficiency of the entire APU, to remove 650 W. This is a very simplistic approach - everyone knows that the wind is not perfectly even. But this has to be done in order to ensure the 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 reverse situation is also possible: the wind flows to the rotor and the area of ​​the effective surface then turns out to be greater than the swept one, and KIEV is greater than 1 relative to that for a flat wind.

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

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

Theorists did not know what to think, and seriously doubted the law of conservation of energy. In the end, it turned out that the point was the cone of the radar fairing protruding from the air intake. From its toe to the shell, an air seal appeared, 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 measure 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 on flat sails: it was believed that the particles of the oncoming flow give all their momentum to the leading edge of the wing. This made it possible to immediately get rid of the vector quantity - the angular momentum - which generated furious and most often non-analytical mathematics, go to much more convenient scalar purely energy relations, and eventually get the calculated pressure field on the carrier plane, more or less similar to the present one.

Such a 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, carrying capacity and other flight qualities more and more revealed the imperfection of the original aerodynamic theory.

Zhukovsky's idea was this: along the top and bottom surfaces Wing air travels a different path. From the condition of medium continuity (vacuum bubbles do not form in the air by themselves), it follows that the velocities of the upper and lower flows descending from the trailing edge must differ. Due to the albeit 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, as immutable as the law of conservation of energy, is also valid for vector quantities, i.e. must take into account the direction of movement. Therefore, immediately, on the trailing edge, an oppositely rotating vortex with the same torque should form. For what? Due to the energy generated by the engine.

For the practice of aviation, this meant a revolution: by choosing the appropriate wing profile, it was possible to launch an attached vortex around the wing in the form of a circulation Г, increasing its lift. That is, by spending a part, and for high speeds and wing loads - a large part, of the engine power, you can create an air flow around the device, which allows you to achieve better flight qualities.

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

Again KIEV

But the windmill does not have a motor. He, on the contrary, must take energy from the wind and give it to consumers. And here it comes out - he pulled out his legs, his tail got stuck. They let too little wind energy into the rotor's own circulation - it will be weak, the blade thrust will be small, and KIEV and power will be low. Let's give a lot for circulation - the rotor will spin like crazy at idle in a light wind, but consumers again get little: they gave a little load, the rotor slowed down, the wind blew off the circulation, and the rotor stopped.

The law of conservation of energy gives the "golden mean" just in the middle: we give 50% of the energy to the load, and for the remaining 50% we twist the flow to the optimum. Practice confirms the assumptions: if the efficiency of a good pulling propeller is 75-80%, then the KIEV 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 an excess of energy.

Modernity

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

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

The sails that gave rise to the original wing were also significantly affected by the development of the theory. "Live" aerodynamics allowed the yachts with a wind of 8 knots. stand on hydrofoils (see fig.); to disperse such a hulk to the desired speed with a propeller, an engine of at least 100 hp is required. Racing catamarans with the same wind go at a speed of about 30 knots. (55 km/h).

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

Many mysteries of nature have also been solved; in particular, the flight of a beetle. According to classical aerodynamics, it is not capable of flying. Just like the ancestor of the "stealth" F-117 with its diamond-shaped wing, it is also not able to take to the air. And the MIG-29 and Su-27, which can fly tail first for some time, do not fit into any ideas at all.

And why, then, when dealing with wind turbines, not a fun and not a tool for the destruction of their own kind, but a source of a vital resource, it is imperative to dance from the theory of weak flows with its model of a flat wind? Is there really no way to go further?

What to expect from a classic?

However, the classics should not be abandoned in any case. It provides a foundation without leaning on which one cannot rise higher. Just as set theory does not cancel the multiplication table, and quantum chromodynamics does not make apples fly up from trees.

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

To the right of 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. Vertically up - KIEV. And down - again, the relative torque. A single (100%) torque is considered to be that which creates a rotor forcibly decelerated in the flow with 100% KIEV, i.e. when all the energy of the flow is converted into rotational force.

This approach allows us to draw far-reaching conclusions. For example, the number of blades must be chosen 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 outwardly similar carousel and orthogonal have fundamentally different properties.

In general, preference should be given to bladed rotors, except in cases where extreme cheapness, simplicity, maintenance-free self-starting without automation are required, and it is impossible to climb the mast.

Note: we’ll talk about sailing rotors in particular - they don’t seem to fit into the classics.

Vertical lines

APUs with a vertical axis of rotation have an undeniable advantage for everyday life: their components that require maintenance are concentrated at the bottom and there is no need to lift them up. There remains, and even then not always, a self-aligning thrust bearing, but it is strong and durable. Therefore, when designing a simple wind generator, the selection of options must begin with verticals. Their main types are shown in fig.

sun

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

VS for a do-it-yourselfer is good for everyone, except for the "locomotive" KIEV in 10-18%. However, in the USSR a lot of work was done on it, and there are developments. Below we will consider an improved design, not much more complicated, but according to KIEV, it gives odds to the blades.

Note: a two-blade BC does not spin, but jerks; The 4-blade is only slightly smoother, but loses a lot in KIEV. To improve 4-"trough" most often spread over 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 ones increase somewhat, and with a wind of more than 25 m/s, such an APU has a shaft, i.e. without a bearing stretched by the guys above the rotor, “breaks the tower”.

Daria

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

The rotational moment is small, and in the starting positions of the rotor parallel and perpendicular to the wind, it is absent at all, therefore self-promotion is possible only with an odd number of blades (wings?). In any case, the load from the generator must be disconnected for the duration of the promotion.

The Darrieus rotor has two more bad qualities. First, during rotation, the thrust vector of the blade describes a complete revolution relative to its aerodynamic focus, and not smoothly, but jerkily. Therefore, the Darrieus rotor quickly breaks its mechanics even with a flat wind.

Secondly, Daria not only makes noise, but yells and squeals, to the point that the tape is torn. This is due to its vibration. And the more blades, the stronger the roar. So Daria, if they do, then two-blade, from expensive high-strength sound-absorbing materials(carbon fiber, mylar), and for promotion in the middle of the mast-pole, a small aircraft is fitted.

orthogonal

At pos. 3 - orthogonal vertical rotor with profiled blades. Orthogonal because the wings stick out vertically. The transition from the BC to the 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, according to the strength of the wind. Sometimes the blades are made swivel and windcocks are placed on them, automatically holding the alpha, but such structures often break.

The central body (blue in the figure) makes it possible to bring the KIEV to almost 50%. In a three-blade orthogonal, it should have the shape of a triangle in the 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 amount blades gives unambiguously: there should be exactly 3 of them.

Orthogonal refers to high-speed windmills 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

Helicoid rotor, or Gorlov rotor (pos. 4) - a kind of orthogonal that provides uniform rotation; an orthogonal with straight wings "tears" only slightly weaker than a two-bladed aircraft. The bending of the blades along the helicoid avoids the loss of KIEV due to their curvature. Although the curved blade rejects part of the flow without using it, it also rakes a part into the zone of the highest linear speed, compensating for losses. Helicoids are used less often than other windmills, because. due to the complexity of manufacturing, they turn out to be more expensive than counterparts of equal quality.

Barrel-barrel

For 5 pos. – BC type rotor surrounded by a guide vane; its scheme is shown in fig. on right. Rarely found in industrial design, tk. 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 no more than 0.5-1.5 kW is needed, then for him a “barrel-barrel” is a tidbit:

• This type of rotor is absolutely safe, silent, does not create vibrations and can be installed anywhere, even on a playground.
• Bend the "trough" of galvanized and weld the frame of the pipes - the work is nonsense.
• Rotation is absolutely uniform, mechanical parts can be taken from the cheapest or from the trash.
• Not afraid of hurricanes - too strong wind cannot push into the "barrel"; a streamlined vortex cocoon appears around it (we will still encounter this effect).
• And most importantly, since the surface of the "grab" is several times larger than that of the rotor inside, KIEV can also be superunit, and the torque at 3 m / s at a "barrel" of three meters in diameter is such that a 1 kW generator with a maximum load, as It is said that it is better not to twitch.

Video: Lenz wind generator

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

1. roof galvanized rotor;
2. self-aligning double row ball bearing;
3. shrouds - 5 mm steel cable;
4. axle 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 speed;
9. drive pulley - a bicycle wheel without a tire with a chamber;
10. thrust bearing - thrust bearing;
11. driven pulley - regular generator pulley;
12. generator.

Biryukov received several copyright certificates for his APU. First, pay attention to the section of the rotor. When accelerating, it works like a sun, 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 turns into a high-speed orthogonal, with the virtual profile changing according to the strength of the wind.

Secondly, the profiled channel between the blades in the operating speed range works as a central body. If the wind increases, then a vortex cushion is also created in it, which goes beyond the rotor. There is the same vortex cocoon 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 designed primarily for the turbine. He keeps her speed optimal from the point of view of KIEV. And the optimum frequency of rotation of the generator is provided by the choice of the gear ratio of the mechanics.

Note: after publications in the IR for 1965, Biryukov's Armed Forces disappeared into oblivion. The author did not wait for a response from 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.

Lopatniki

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

According to the diagrams in Fig. consider in more detail; positions:

• Fig. BUT:

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

• Fig. B, top view:

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

• Fig. G, current collector:

1. collector with copper continuous ring tires;
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 are we waiting for "stumbling"?

blades

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

Segment 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 time-consuming product that requires painstaking calculations in full theory, blowing in the pipe and field tests.

Generator

When 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. We need an intermediate shaft with a special support bearing and a mechanical transmission from it to the generator. For large windmills, a self-aligning double-row bearing is taken; in best models- three-tier, Fig. D in fig. higher. This allows the rotor shaft to not only bend slightly, but also move slightly from side to side or up and down.

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

emergency weather vane

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

On a windy day, try to hold the lid of boiled water or a large pot by the handle parallel to the wind. Just be careful - the fidgety piece of iron can hit the physiognomy so that it breaks the nose, cuts the lip, and even knocks out the eye.

Flat wind occurs only in theoretical calculations and, with sufficient accuracy for practice, in wind tunnels. In reality, a hurricane windmills with a hurricane shovel distorts more than completely defenseless ones. Still, it's better to change warped blades than to do everything all over again. In industrial settings, it's a different story. There, the pitch of the blades, for each individually, monitors and regulates automation under the control of the on-board computer. And they are made from heavy-duty composites, not from water pipes.

current collector

This is a regularly serviced node. Any power engineer knows that the collector with brushes needs to be cleaned, lubricated, adjusted. And the mast is from water pipe. You won’t climb in, once a month or two you will have to throw the whole windmill to the ground and then raise it again. How long will he last from such "prevention"?

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

Mini and micro

But as the size of the blade decreases, the difficulty decreases with the square of the wheel diameter. It is already possible to manufacture a horizontal bladed APU on its own for a power of up to 100 W. 6-blade will be optimal. With more blades, the diameter of the rotor, designed for the same power, will be smaller, but it will be difficult to firmly fix them on the hub. Rotors with less than 6 blades can be ignored: a 2-blade 100 W needs a rotor with a diameter of 6.34 m, and a 4-blade of the same power - 4.5 m. For a 6-blade 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 will be optimal to count on a power of 10-20 watts. Firstly, a plastic blade with a span of more than 0.8 m without additional measures protection will not withstand winds of more than 20 m / s. 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 the “trough” with a segmented profile from a pipe will already work quite satisfactorily, pos. B in fig. And 10-20 W will provide power to the tablet, recharge the smartphone or light up the housekeeper light bulb.

Next, choose a generator. A Chinese motor is perfect - a wheel hub for electric bicycles, pos. 1 in fig. Its power as a motor is 200-300 watts, but in generator mode it will give up to about 100 watts. But will it fit us in terms of turnover?

The speed factor z for 6 blades is 3. The formula for calculating the speed of rotation under load is N = v / l * z * 60, where N is the speed of rotation, 1 / min, v is the wind speed, and l is the circumference of the rotor. 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 about the same speed, so we will remove our 10-20 watts from a generator that can give 100. You can put the rotor directly on its shaft.

But here the following problem arises: having spent a lot of work and money, at least for a motor, we got ... a toy! What is 10-20, well, 50 watts? And a bladed windmill that can power at least a TV set cannot be made at home. Is it possible to buy a ready-made mini-wind generator, and will it not cost less? Still as possible, and even as cheaper, see pos. 4 and 5. In addition, it will also be mobile. Put it on a stump - and use it.

The second option is if somewhere a stepper motor is lying around from an old 5- or 8-inch drive, 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 cans(pos. 6) is easier than assembling a structure like that shown in pos. 3.

In general, according to the “blades”, the conclusion is unambiguous: home-made - rather in order to make one's heart's content, but not for real long-term energy efficiency.

Video: the simplest wind generator for dacha lighting

sailboats

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

However, a soft sail like the wing of a windmill, it seems, was not so simple. It's not a matter of wind resistance (manufacturers do not limit the maximum allowable wind speed): yachtsmen-sailboats already know that it is almost impossible for the wind to break the panel of a Bermuda sail. Rather, the sheet will rip out, or the mast will break, or the whole vessel will make an “overkill turn”. It's about energy.

Unfortunately, exact test data cannot be found. Based on user feedback, it was possible to compile "synthetic" dependencies for the Taganrog-made wind turbine VEU-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 shown in Fig.

Of course, there can be no guarantees for 100% reliability, but even so it is clear that there is no smell of a flat-mechanistic model here. In no way can a 5-meter wheel in a flat wind of 3 m / s give about 1 kW, at 7 m / s reach a plateau in power and then keep it until a severe storm. Manufacturers, by the way, declare that the nominal 4 kW can be obtained at 3 m / s, but when installed by them according to the results of local aerology studies.

Quantitative theory is also not found; The developers' explanations are unintelligible. However, since people buy Taganrog wind turbines and they work, it remains to be assumed that the declared conical circulation and propulsion effect are not fiction. In any case, they are possible.

Then, it turns out, BEFORE 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 to the rotor, its effective surface it will turn out to be more swept, and KIEV - over unity.

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

Homemade generator

From the foregoing, it is clear that it is better for do-it-yourselfers to take on either verticals or sailboats. But both are very slow, and transferring to a high-speed generator is extra work, extra costs and loss. Is it possible to make an efficient low-speed electric generator yourself?

Yes, you can, on niobium alloy magnets, the 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.

Notice the keyways in the rotor halves. They should be arranged so that the magnets (they are glued to the magnetic circuit with epoxy or acrylic) after assembly converge with opposite poles. "Pancakes" (magnetic circuits) must be made of a magnetically soft ferromagnet; normal structural steel will do. The thickness of the “pancakes” is at least 6 mm.

It's actually better to buy magnets with an axle hole and tighten them with screws; supermagnets are attracted to terrible force. For the same reason, a cylindrical spacer 12 mm high is put on the shaft between the "pancakes".

The windings that make up the stator sections are connected according to the schemes also shown in fig. The soldered ends should not be stretched, but should form loops, otherwise the epoxy, which will be filled with the stator, can break the wires when it hardens.

The stator is cast in the mold to a thickness of 10 mm. It is not necessary to center and balance, the stator does not rotate. The gap between the rotor and the stator is 1 mm on each side. The stator in the generator housing must be securely fixed not only from displacement along the axis, but also from turning; a strong magnetic field with a current in the load will pull it along.

Video: do-it-yourself windmill generator

Conclusion

And what do we have in the end? Interest in "blades" is due rather to their spectacular appearance than valid operational qualities homemade and at low power. A self-made carousel APU will provide “standby” power for charging a car battery or powering a small house.

But with sailing APUs, masters with a creative vein should experiment, especially in a mini version, with a wheel of 1-2 m in diameter. If the developers' assumptions are correct, then it will be possible to remove all of its 200-300 watts from this using the Chinese generator engine described above.

Andrey said:

Thank you for your free consultation ... And the prices “from firms” are not really expensive, and I think that craftsmen from the outback will be able to make generators like yours. And Li-po batteries can be ordered from China, inverters in Chelyabinsk are very good (with a smooth sine). And sails, blades or rotors are another reason for the flight of thoughts 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 detail - an impeller that is exposed to 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”. Setting downwind with a “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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Wind generator - a device for converting kinetic energy wind to mechanical and then to electrical. According to the amount of electricity generated, such devices are divided into large, with a power of more than 100 kW, and small, with a power of less than 100 kW.

Large ones, with a capacity of up to several megawatts, are used as single elements of wind farms that transfer energy to the main power grids for a large number consumers. Are accommodated wind farms on the shores of the seas, large reservoirs and in desert areas. Required attribute when deployed, is the infrastructure for transmitting energy in power lines.

Separate small wind turbines, which will be discussed in this article, have found application for the power supply of private houses and autonomous objects. for various purposes- telecommunication towers, street lighting, elements of control systems road traffic. They are installed next to the object and are often supplemented with a diesel generator.

Principle of operation

The wind generator is a complex of several devices:

The principle of operation of the device is that the pressure (pressure) of the wind rotates the wind wheel, which transmits rotation to the generator rotor. The generator rotor excites alternating current in the stator windings of the generator, which is supplied to the controller. The controller converts this current to DC and charges the battery with it.

All consumers receive energy from the battery through an inverter (220 V) or directly (12, 24, 48 V - depending on the number of batteries). The energy of the windmill is not directly transmitted to consumers, which is associated with the instability of the parameters of the current it receives.

Types of wind farms

There are the following criteria for classifying wind farms:

1. Number of blades. Wind turbines with up to 4 blades are called low-bladed and high-speed. With the number of blades from 4 or more, multi-bladed and slow-moving. The division according to this criterion is due to the fact that the smaller the number of blades, the, ceteris paribus, the wind turbine has a greater number of revolutions.
2. Rated power. The criterion is rather arbitrary, but the following gradation is applied: up to 15 kW household (for private houses, portable), 15-100 kW semi-industrial (for small farms, shops, pumping stations), 100 kW units MW industrial - designed to generate energy used large quantity consumers.
3. The direction of the axis of rotation. This criterion is the most basic, as it affects the main characteristics of the windmill:
   • With a horizontal axis of rotation. Most often two or three-blade, high-speed. The advantages of such devices include: speed, which means a simpler generator; high utilization of wind energy and, as a result, more high efficiency; simplicity of design. The disadvantages include: high level noise, the need for a high mast for installation.
   • With vertical axis of rotation. Many varieties are known design– Savonius wind turbines, Darrieus rotors, helicoid rotor, multi-blade wind turbines. According to the author of the article, the merits of all such structures are highly doubtful. These devices have a complex design, require a complex generator, and have a low wind energy utilization factor (0.18-0.2 versus 0.42 for horizontal ones). The advantages include low noise level, the ability to install at a low height.

A matter of choice

When choosing a device, you need to answer the following questions:

• Required power in kW. It is required to estimate the total consumption per month and select a power plant according to this criterion;
• Equipment manufacturer. It is necessary that the products be certified for use on the territory of the Russian Federation, then you can be sure that the characteristics of the device comply with national standards for noise and electromagnetic interference. Pay attention to the warranty period and the service life of the device, it must be at least 15 years. Learn about after-sales service and warranty repair equipment. It will not be superfluous to find out reviews about the manufacturer and the seller from other users.
• Required place for installation of a windmill. Start from your real opportunities. If it is possible to install a high mast with horizontal type device, give it preference. Otherwise, consider a design with a vertical axis of rotation.
• Price. The more expensive is not always better. Here, as elsewhere, you can overpay for a brand or for features that are completely unnecessary to you. Clearly define your requirements for the device, do not order unnecessary components.

If it is possible to install a high mast with a horizontal type of device, then give it preference

Installation

When installing, it should be remembered that in the Russian Federation there is no ban on the installation of wind farms with a power below 75 kW and they are not taxed. But still, it would be useful to familiarize yourself with the regulations for the installation and use of such devices for each specific area.

What you should pay attention to:

• Permissible mast installation height;
• The presence of power lines near the proposed installation site;
• Permissible noise level in decibels;
• The presence of radio interference from a working power plant.

Permissible height is regulated by local regulations, but it is impossible to place the mast near power lines.

For the last two points, it is necessary to take data from the technical characteristics of the power plant. For suppliers and manufacturers certified in the Russian Federation, these characteristics comply with local legislation.

A good step would be to obtain consent for the installation from the neighbors and the organization serving the territory, if any. Consent must be obtained in writing.

When all the formalities are settled, it is necessary to determine the specific location of the mast. It should be noted that the efficiency will be higher if there are no trees, tall houses nearby and the mast is on a hill. The installation site should be chosen so that nearby buildings and trees are not in front of the windmill. It would also be wrong to place the mast on a hill, in front of a cliff.

The mast must be installed in strict accordance with the manufacturer's instructions. If necessary, qualified specialists and special equipment should be involved.

Price

Wind farms for the home are available on the market with a capacity from 0.4 kW to 75 kW various manufacturers. The range of prices for devices of the same power is quite large.

Consider a table:

Model	power, kWt	Price, rub
EDS Group Condor Home	0,5	89600
EDS Group Condor Home	3	195400
EDS Group Condor Home	5	285000
EDS Group Condor Air	10	770000
EDS Group Condor Air	30	1790000
EDS Group Condor Air	50	2850000
Energospetsservis LLC	1	94000
BEKAR	1	171800
HY 400-L	0,4	66430
Energy stock	3	98000
Energy stock	5	220000
Energy stock	10	414000
Energy stock	30	961000
Energy stock	50	3107000

What's the matter? But the fact is that manufacturers often indicate the price only for part of the required set of equipment. Consider, for example, a 2 kW windmill sold by Energostok. The site says the price is 57,600 rubles, but let's go to detailed description goods.

And there is the price of a complete set of equipment: wind generator, controller, inverter, battery, mast. And the price of a complete set will be 176,800 rubles. Hence the conclusion - be sure to specify the price for the entire set!

Average prices for Russian and Chinese made the following: 1 kW 100-120 tr, 3 kW - 200 tr, 5 kW - 300 tr, 10 kW from half a million, and powerful devices of 20 or more kW will cost more than a million rubles. If you buy equipment from a Western manufacturer or the USA, then prices will be 20-30% higher.

DIY wind farms

If you are going to make a wind generator, then you should pay attention to the resources of the Network, which involve 2 approaches: the first is to assemble all the elements with your own hands, and the second involves the purchase of ready-made components.

When assembling, the greatest difficulty is the manufacture of the wind turbine. It is not easy to manufacture blades for a horizontal axis of rotation design with the required aerodynamic characteristics. There are two ways out: either pay for the production of a workshop with necessary tools and experience, or look towards a design with a vertical axis of rotation, for which the blades can be made from a conventional barrel.

The generator can be purchased used, use the engine washing machine or industrial. Exist big choice ready-made generators and components for their assembly based on neodymium magnets.

The manufacture of the mast is a very important stage, because the safety of operation of the entire structure depends on it. You need to treat it carefully, entrusting the calculations of structural strength to a specialist.

Controllers, inverters and batteries are best purchased ready-made.

Diagram of a wind farm device for self-manufacturing

Install or not

When deciding whether to install a wind farm, you need to obtain the following initial data:

The algorithm for assessing the payback of a windmill is as follows:

• According to the wind map and technical specifications devices to determine the generated power for summer and winter periods or monthly. For example, for the 2 kW device discussed above, the generated power at a speed of 5 m / s will be 400 W;
• Based on the data obtained, determine annual generated capacity;
• Cost per kilowatt hour determine the price of generated electricity;
• Share the cost of the wind turbine kit on the resulting figure and you get a payback in years.

To make adjustments to the calculation, consider:

• Batteries will have to change at least once every three years;
• Service life of modern wind generator 20 years;
• The device needs to be serviced. The cost and terms of service must be clarified with the equipment seller;
• The cost of a kilowatt-hour is growing every year, over the previous 10 years, it has more than tripled. For 2017, tariffs are planned to increase by at least 4%, so we can proceed from this figure of an increase in the cost of electricity.

If the payback figures obtained are not satisfactory, but get hold of alternative source If you want energy or not the ability to connect to a centralized power supply, then you should consider options to increase the efficiency of the windmill and reduce the cost of its installation and maintenance.

The following options are possible:

• Installation of several devices of smaller power instead of one large one. This will reduce the price of the main equipment, reduce installation and maintenance costs, and increase productivity due to the fact that small wind turbines are more efficient at low speeds wind;
• Installation of a special network power management system combined with central system power supply. Such devices are commercially available today.

• for the power supply of even a large private house, a power of 10 kW is enough;
• Assess the capacity of the power plant to generate electricity in your area;
• choose right place wind generator installations;
• control the completeness of the purchased equipment;
• use ways to increase the payback rate of equipment;
• if it's expensive to buy - do it yourself, it's not so difficult.

The price of electricity is constantly growing and, of course, every owner tries to optimize the cost of paying for it. Here, all means are good - starting from savings, equipment with a low energy consumption index, energy-saving lamps, and ending with the use of multi-tariff electricity meters. Nevertheless, the prospect of obtaining electricity not from the state, but from nature will always remain tempting. One of the most effective devices of this kind is the wind generator, which is used in the West almost on a par, if not more widely, than classic thermal power plants or nuclear power plants.

Generator price and efficiency

Naturally, the most practical solution to generate electricity from wind energy, it will become a powerful device capable of generating required amount energy to provide consumers throughout the house. Do-it-yourself wind turbines for 220V can be different power and we will consider the principles of making every possible device from what every diligent owner can have at hand.

But for starters, it is worth at least a preliminary calculation of the wind turbine and its profitability. For example, household appliance for 800 kW Russian assembly will cost one and a half thousand US dollars per kilowatt. Expensive. Chinese products, which are not distinguished by reliability and accuracy of denominations, will cost $ 900 per 1 kW. Also expensive. Note that this is just the generator itself, no peripheral equipment. This is actually an unbearable price for a private trader, so we will try to use everything that is at hand and make our own autonomous system.

How to determine the power of the windmill

Calculating the power of a wind generator is a complex and time-consuming process that is applicable to a specific source generator. The easiest option is to use a dynamo from a tractor or car. Such a device does not actually require modifications and can be used in the power supply system "as is". Of course, you can talk for a long time about devices based on neodymium magnets, only, for example, in the village of Arkhipovka, Oryol region, they have not been in life and never will be, and decommissioned tractors are darkness.

Most important indicator of any generator is its efficiency. Unfortunately, for an autotractor device, it is not too high. For a neodymium generator, it can reach 80%, and for ours - no more than 55-60%, but even with these data, without additional modifications, the device can produce about 300 watts. This is not much, but it is enough to provide DC electricity. LED lights, video surveillance systems, and subject to the use of a current converter, a TV with a low energy consumption class, a single-chamber refrigerator. And that's just one generator set, but no one bothers to make three or five of them. Now about the mover that will rotate the dynamo.

Vertical or rotary wind turbines?

Bladed vertical generators- one of the most popular in the world, however, for their construction, it is necessary to accurately calculate the blade, its shape and size. As the experience of creating such devices by enthusiasts shows, the most efficient blade generators are those with an adjustable blade angle. The average dimensions of each of the six blades are 650x120 mm, and the most effective angle of rotation relative to its axis is about 12 degrees, although experiments can be made in each particular case.

Rotary windmill for the home is performed with horizontal arrangement the axis of the generator on which the rotor is mounted. It can be performed according to several schemes, which are presented below. The easiest option is to make a rotor from a cylindrical container. It could be like plastic barrel, a gas cylinder, after all, a saucepan. The container must be divided into four segments, each of which is attached to the hub. The hub is installed on metal carcass, an approximate drawing of which is shown in the figure.

Parts and consumables, wiring diagram

A low-power windmill for the home can be assembled with a modest set of used devices and parts:

generator;

car battery, the fresher and the larger the capacity, the better;

inverter for 300-700 W;

cylindrical container;

car or tractor charging relay (depending on the generator voltage);

control device (voltmeter);

• For connecting the device to the network electrical network wires with a cross section of at least 4 mm² are used. Finished installation connected according to the diagram shown in the photo through fuses 8, which is opened by switch 9 for maintenance and repair. The value of the resistor 1 is selected empirically, and the ammeter 5 can be installed at the output of the converter 5 as desired. Also, for ease of use of the design, a variable resistor 4 can be used to adjust the voltage. More detailed diagram inverter is shown below.

  In this way, a wind generator can be assembled to ensure a minimum need for electricity. Spend and produce energy wisely, good luck to everyone!

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 house or cottage, have repeatedly encountered interruptions, inconveniences and damage to equipment associated with them.

The listed negative situations, together with the consequences, will no longer complicate the life of lovers of natural spaces. And 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 economy, eliminating energy dependence. According to our advice, an inexperienced person can build a wind generator with his own hands House master. A practical device will help to significantly reduce daily expenses.

Alternative energy sources are the dream of any summer resident or homeowner whose site is located far from the central networks. However, when we receive bills for electricity used in a city apartment, and looking at the increased tariffs, we realize that a wind turbine designed for household needs, we would not interfere.

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, its installation is the only possible way out.

In order not to waste money, effort and time, let's decide: are there any external circumstances that will create obstacles for us in the process of operating a wind turbine?

To provide electricity to cottages or small cottage 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.

In order to determine the feasibility of installing a wind generator, it is necessary to find out the wind energy potential of a particular area (click to enlarge)

No taxation is provided for the production of electricity, which is spent to meet their own domestic needs. Therefore, a low-power windmill can be safely installed, it can be used to generate free electricity without paying any taxes to the state.

However, just in case, you should ask if there are any local regulations regarding individual energy supply that could create obstacles in the installation and operation of this device.

Wind turbines that can meet most of the needs of the average farm can not cause complaints even from the neighbors

Claims may arise from your neighbors if they experience inconvenience associated with the operation of the windmill. Remember that our rights end where other people's rights begin.

Therefore, when buying or independently, you need to pay serious attention to the following parameters:

• Mast height. When assembling a wind turbine, it is necessary to take into account the restrictions on the height of individual buildings that exist in a number of countries of the world, as well as the location own site. Be aware that near bridges, airports and tunnels, buildings that are more than 15 meters high are prohibited.
• Noise from gearbox and blades. The parameters of the generated noise can be set using a special device, after which the measurement results can be documented. It is important that they do not exceed the established noise standards.
• Ether interference. Ideally, when creating a windmill, protection against tele-interference should be provided where your device can provide such trouble.
• environmental claims. This organization can prevent you from operating the facility only if it interferes with the migration of migratory birds. But this is unlikely.

When creating and installing the device yourself, learn these points, and when buying a finished product, pay attention to the parameters that are in its passport. It is better to protect yourself in advance than to be upset later.

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The principle of operation of the wind turbine

A wind generator or wind power plant (WPP) is a device that is used to convert wind flow into mechanical energy. The resulting mechanical energy rotates the rotor and is converted into the electrical form we need.

The structure of the WUE includes:

• blades that form a propeller,
• rotating turbine rotor
• the axis of the generator and the generator itself,
• an inverter that converts alternating current to direct current used to charge batteries,
• battery.

The essence of the device wind turbines simple. As the rotor rotates, a three-phase alternating current is generated, which then passes through the controller and charges the DC battery. Next, the inverter converts the current so that it can be consumed, powering lighting, a radio, a TV, a microwave oven, and so on.

The detailed arrangement of a wind generator with a horizontal axis of rotation allows you to imagine well what elements contribute to the conversion of kinetic energy into mechanical energy, and then into electrical energy.

In general, the principle of operation of a wind generator of any type and design is as follows: in the process of rotation, there are three types of force acting on the blades: braking, impulse and lifting.

This scheme of operation of the wind turbine allows you to understand what happens to the electricity produced by the operation of the wind generator: part of it is accumulated, and the other is consumed

The last two forces overcome the braking force and set the flywheel in motion. On the stationary part of the generator, the rotor generates a magnetic field to electricity went on the wire.

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Classification of types of energy generators

There are several criteria by which wind turbines are classified. How to choose best option devices for suburban property are described in detail in one of our website.

So, windmills differ in:

• the number of blades in the propeller;
• materials for the manufacture of blades;
• the location of the axis of rotation relative to the surface of the earth;
• pitch sign of the screw.

There are models with one, two, three blades and multi-blade.

Products with a large number blades begin to rotate even with a small wind. Usually they are used in such works, when the rotation process itself is more important than generating electricity. For example, to extract water from deep wells.

It turns out that wind turbine blades can be made not only from hard materials but also from affordable fabric

The blades can be sail or rigid. Sailing products are much cheaper than rigid ones, which are made of metal or fiberglass. But they have to be repaired very often: they are fragile.

As for the location of the axis of rotation relative to the earth's surface, there are horizontal models. And in this case, each variety has its own advantages: vertical ones are more sensitive to every breath of wind, but horizontal ones are more powerful.

Wind turbines are divided according to step features into models with a fixed and variable step.

The variable pitch allows you to significantly increase the rotation speed, but this installation is characterized by a complex and massive design. Fixed-pitch wind turbines are simpler and more reliable.

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Rotary wind turbine

Let's figure out how to make a simple windmill with a vertical axis of rotation of the rotary type with your own hands.

Such a model may well meet the needs of electricity garden house, a variety of outbuildings, as well as highlight in the dark adjoining territory and garden paths.

The blades of this rotary type installation with a vertical axis of rotation are clearly made from elements cut from a metal barrel.

Our goal is to manufacture a windmill with a maximum power of 1.5 kW. To do this, we need the following elements and materials:

• car generator for 12 V;
• helium or acid battery 12 V;
• semi-hermetic switch of the “button” variety for 12 V;
• converter 700 W - 1500 W and 12V - 220V;
• bucket, large saucepan or other capacious container made of of stainless steel or aluminum;
• automobile relay of a control lamp of a charge or charging of the accumulator;
• automobile voltmeter (any one is possible);
• bolts with nuts and washers;
• wires with a cross section of 4 square mm and 2.5 square mm;
• two clamps for fixing the generator on the mast.

In the process of doing the work, we will need a grinder or metal shears, a construction pencil or marker, a tape measure, wire cutters, a drill, a drill, keys and a screwdriver.

Starting stage of the plant manufacturing

Manufacturing homemade windmill we start by taking a large metal container of a cylindrical shape. Usually, an old boiling pot, bucket or pan is used for this purpose. It will be the basis for our future WPP.

Using a tape measure and a construction pencil (marker), we will mark up: we will divide our container into four identical parts.

When making cuts in accordance with the instructions contained in the text, in no case cut through the metal to the end

The metal will have to be cut. To do this, you can use the grinder. It is not used to cut a container made of galvanized steel or painted sheet metal, because this type of metal will overheat.

For such cases, it is better to use scissors. We cut out the blades, but do not cut them through to the very end.

Now, along with the continuation of work on the tank, we will redo the generator pulley.

In the bottom of the former pan and in the pulley, you need to mark and drill holes for the bolts. The work at this stage should be taken as carefully as possible: all holes should be located symmetrically so that no imbalance occurs during the rotation of the installation.

This is how the blades of another design with a vertical axis of rotation look like. Each blade is made separately, and then mounted in a common device

We bend the blades so that they do not stick out too much. When we do this part of the work, we must take into account in which direction the generator will rotate.

Usually the direction of its rotation is oriented clockwise. The angle of the blades bend affects the area of ​​influence of air currents and the speed of rotation of the propeller.

Now you need to fix a bucket with on the pulley. We install the generator on the mast, while fixing it with clamps. It remains to connect the wires and assemble the circuit.

Prepare to write down the wiring diagram, wire colors, and pin markings. You will definitely need it later. We fix the wires on the mast of the device.

To connect the battery, you need to use wires with a cross section of 4 mm². It is enough to take a segment with a length of 1 meter. That's enough.

And in order to connect a load to the network, which includes, for example, lighting and electrical devices, wires with a cross section of 2.5 mm² are sufficient. We install the inverter (converter). This will also require a 4 mm² wire.

Advantages and disadvantages of a rotary windmill model

If you did everything carefully and consistently, then this wind generator will work successfully. At the same time, there will be no problems during its operation.

If you use a 1000 W converter and a 75A battery, this installation will provide electricity to both video surveillance devices, and burglar alarm and even street lighting.

The advantages of this model are:

• economical;
• elements can be easily replaced with new ones or repaired;
• special conditions for functioning are not needed;
• reliable in operation;
• provides complete acoustic comfort.

There are also disadvantages, but they are not so many: it is not too high, and it has a significant dependence on sudden gusts of wind. Air currents can simply rip off an impromptu propeller.

Assembly of an axial wind turbine on neodymium magnets

Since neodymium magnets appeared in Russia relatively recently, axial wind turbines with iron-free stators began to be made not so long ago.

The appearance of magnets caused a rush demand, but gradually the market was saturated, and the cost of this product began to decline. It became available to craftsmen, who immediately adapted it to their various needs.

Axial wind turbine on neodymium magnets with a horizontal axis of rotation - more than complex structure which requires not only skill, but also certain knowledge

If you have a hub from an old car with brake discs, then we will take it as the basis of the future axial generator.

It is assumed that this part is not new, but has already been used. In this case, it is necessary to disassemble it, check and lubricate the bearings, carefully clean away sediment deposits and all rust. Do not forget to paint the finished generator.

The hub with brake discs, as a rule, goes to craftsmen as one of the components of an old car that has gone to scrap, therefore it needs to be thoroughly cleaned

Distribution and fixation of magnets

Neodymium magnets must be glued to the rotor disks. For our work, we take 20 magnets 25x8mm.

Of course, you can use a different number of poles, but it is necessary to observe following rules: the number of magnets and poles in a single-phase generator must match, but if we are talking about a three-phase model, then the ratio of poles to coils should be 2/3 or 4/3.

When placing magnets, the poles alternate. It is important not to make a mistake. If you are not sure that you will place the elements correctly, make a hint template or apply sectors directly to the disk itself.

If you have a choice, buy better not round, but rectangular magnets. In rectangular models, the magnetic field is concentrated along the entire length, and in round models, in the center.

The opposing magnets must have different poles. You will not confuse anything if you use a marker to mark them with minus or plus signs. To determine the poles, take the magnets and hold them close to each other.

If the surfaces are attracted, put a plus on them; if they repel, then mark them with minuses. Alternate the poles when placing the magnets on the disks.

Magnets are installed in compliance with the policy alternation rule, along the outer and inner perimeters there are sides made of plasticine: the product is ready for pouring with epoxy resin

For reliable fixing of the magnet, you need to use high-quality and as strong glue as possible.

To enhance the reliability of fixation, you can use epoxy resin. It should be diluted as indicated in the instructions, and fill the disk with it. The resin should cover the disc completely, but not drain from it. You can prevent the possibility of dripping if you wrap the disc with tape or make temporary plasticine fences from a polymer strip around its perimeter.

Single-phase and three-phase generators

If we compare single-phase and three-phase stators, then the latter will be better. A single-phase generator vibrates when loaded. The reason for the vibration is the difference in the amplitude of the current, which occurs due to its inconsistent return over a point in time.

There is no such drawback in the three-phase model. It differs in constant power due to the phases compensating each other: when the current rises in one, it falls in the other.

According to the results of testing, the return of a three-phase model is almost 50% more than that of a single-phase one. Another advantage of this model is that in the absence of unnecessary vibration, acoustic comfort increases when the device is operating under load.

That is, a three-phase generator practically does not buzz during its operation. When vibration is reduced, the service life of the device is logically increased.

In the struggle between three-phase and single-phase devices, three-phase invariably wins, because it does not buzz so much during operation and lasts longer than single-phase

Coil winding rules

If you ask a specialist, he will say that before winding the coils, you need to perform a thorough calculation. The practitioner in this matter will rely on his intuition.

We chose a not too high-speed generator option. Our procedure for charging a twelve-volt battery should begin at 100-150 rpm. Such initial data require that the total number of turns of all coils be 1000-1200 pieces. It remains for us to divide this figure between all the coils and determine how many turns there will be on each.

A windmill at low speeds can be more powerful if the number of poles increases. The frequency of current oscillations in the coils will increase. If a larger wire is used to wind the coils, the resistance will decrease, and the current will increase. Don't lose sight of the fact that more voltage can "eat" the current due to the resistance of the winding.

The winding process can be facilitated and made more efficient if a special machine is used for this purpose.

It is not necessary to do such a routine process as winding coils manually. A little ingenuity and an excellent machine that can easily cope with winding is already there.

For performance homemade generators the thickness and number of magnets that are located on the disks have a great influence. The total final power can be calculated by winding one coil and then spinning it in the generator. The future power of the generator is determined by measuring the voltage at a specific RPM without load.

Let's take an example. With a resistance of 3 ohms and 200 rpm, 30 volts come out. If you subtract 12 volts of battery voltage from this result, you get 18 volts. We divide this result by 3 ohms and we get 6 amperes. The volume is 6 amperes and will go to the battery. Of course, in the calculation we did not take into account the losses in the wires and on the diode bridge: the actual result will be less than the calculated one.

Usually the coils are made round. But, if you stretch them a little, you will get more copper in the sector and the turns will be straighter. If we compare the size of the magnet and the diameter of the inner hole of the coils, then they must match each other or the size of the magnet may be slightly smaller.

Ready-made coils should correspond in size to the magnets: they should be slightly larger than the magnets or equal in size to them

The thickness of the stator that we make must be properly related to the thickness of the magnets. If the stator is made larger by increasing the number of turns in the coils, the interdisk space will increase, and the magnetic flux will decrease. The result may be as follows: the same voltage is formed, but, due to the increased resistance of the coils, we will get less current.

Plywood is used to make the mold for the stator. However, sectors for coils can be marked on paper using plasticine as borders.

If fiberglass is placed on top of the coils at the bottom of the mold, the strength of the product will increase. Before application epoxy resin you need to grease the form with petroleum jelly or wax, then the resin will not stick to the form. Some use tape or film instead of lubrication.

Between themselves, the coils are fixed motionless. In this case, the ends of the phases are brought out. The six wires brought out to the outside should be connected in a star or delta. rotating assembled generator hand, they test it. If the voltage is 40 V, then the current will be approximately 10 amperes.

Final assembly of the device

The length of the finished mast should be approximately 6-12 meters. With such parameters, its base must be concreted. The windmill itself will be fixed to the top of the mast.

So that it can be reached in the event of a breakdown, it is necessary to provide a special mount at the base of the mast, which will allow you to raise and lower the pipe using a manual winch.

The mast rises high with a wind generator attached to it, but the prudent master made a special device that allows, if necessary, to lower the structure to the ground

To make a screw, you can use pvc pipe diameter 160 mm. It will be used to carve out of its surface a two-meter propeller consisting of six blades. It is better to develop the shape of the blades on your own empirically. The goal is to increase torque at low revs.

The propeller should be protected from too strong wind. To solve this problem, a folding tail is used. The generated energy is stored in batteries.

For the attention of our readers, we have provided two options for do-it-yourself wind turbines for 220 V, which enjoy increased attention not only from owners of suburban real estate, but also from ordinary summer residents.

Both models of wind turbines are efficient in their own way. Especially good results these devices are able to demonstrate in the steppe area with frequent and strong winds. And they are not so difficult to build with your own hands.

Conclusions and useful video on the topic

This video shows an example of a wind turbine with a horizontal axis of rotation. The author of the device explains in detail the nuances of the design of a do-it-yourself installation, draws the attention of viewers to mistakes that can be made in the process of self-manufacturing a wind generator, and gives practical advice.

Please note that getting to a device raised to a decent height is not so easy. Reinstalling such a wind turbine will most likely be problematic. Therefore, the folding design of the mast in this case will not be superfluous at all.

This video shows a rotary windmill with a vertical axis of rotation. This installation is located low, made in an original way and is highly sensitive: even a slight wind sets the blades of the device in motion.

If you live in an area where winds are not considered rare, the use of this particular source alternative energy may be the most effective for you. The above examples of self-made windmills prove that it is not so difficult to make them with your own hands. Wind energy is a public and renewable resource that can and should be used.

We invite site visitors interested in the topic of the article to express their opinion in the comments and ask questions that arose during the acquaintance with the material.