Homemade wind generator for home. How to assemble a wind generator with your own hands for your home

This article examines in detail this type of equipment, such as a wind generator for a private home: design features, its purpose and scope of application, internal structure and classification. In the text you can find useful information, which will help you decide on a quality windmill, average prices for popular types equipment, as well as detailed description manufacturing technologies.

Wind power plants for private homes are widely used as alternative sources of electrical energy to achieve savings. Often such devices are installed in summer cottages.

Most often they are used in areas remote from main power grids. However, this is far from the only reason in favor of buying a wind generator for a private home. Most land owners use these structures to achieve autonomy and savings.

Not every site is suitable for installing such devices, since not all conditions meet the requirements of this equipment. First of all, this concerns wind speed. In order for a wind power plant to function normally, the average wind speed must be at least 4-4.5 m/s. Only in this case will the installation of the structure be economically justified.

To find out the average annual wind speed, you can use a wind map. It reflects approximate data by region. More accurate indicators can be obtained using a special device - an anemometer, as well as a device for reading its signals.

Note! The device for measuring data must be installed very high, otherwise trees and buildings will distort the result.

Operating principle and structure of a wind generator

A wind generator is a special type of equipment that converts the kinetic energy of the wind into mechanical energy. It drives the rotor blades mounted on the generator. As a result, alternating current is created in its windings. The generated electrical energy is stored in batteries, from where it is supplied to household appliances.

The described scheme of work is simplified. Of course, the design of a wind generator is much more complicated. There is also a controller in the energy chain. Its function is to convert three-phase alternating current into direct current. After which it goes to charge the batteries.

Most household appliances are not able to be powered by direct current. Therefore, an inverter is installed in the chain behind the battery. It converts direct current into alternating current, the voltage of which is 220V. All these operations take away part of the initial energy - approximately 15-20%.

The building can be recharged not only from wind farm, but also from solar panels, as well as from a gasoline or diesel generator. If these elements are present in the chain, then the circuit is supplemented with another component - a circuit breaker. When the main current source is turned off, it starts the backup ones.

The wind power plant consists of the following components:

• a rotor with blades (depending on the features of the model, there may be several blades for a wind generator, usually 2 or 3, although there are also multi-blade options);
• a gearbox or gearbox that controls the speed between the generator and the rotor;
• a protective casing that protects structural parts from the negative influence of external factors;
• “tail”, ensuring the rotation of the structure following the direction of the wind;
• storage battery that stores a certain amount of energy;
• inverter installation that converts one type of current into another.

What kind of wind power plant can you buy: classification of equipment

There are several classifications according to which wind power plants are divided into groups:

1. Towards rotational movement blades – horizontal and vertical windmills.
2. By the number of blades - two-, three- and multi-bladed devices.
3. According to the type of material used for the production of blades - designs with sail and rigid blades.
4. According to the control method - windmills with fixed or adjustable blade pitch.

Helpful advice! In most cases, experts recommend that country house owners buy a windmill with a fixed blade pitch, since adjustable devices are too difficult to operate.

A wind power plant with a horizontal axis is placed perpendicular to the air flow. The design has a similar structure and functions on the same principle as a conventional weather vane. Windmills with a rotary generator have high efficiency, and they are affordable. The operation of these devices is based on air flow resistance.

Vertical axis wind turbines, or orthogonal wind turbines, have a compact design, but their price is much higher. Thanks to the special structure, this type of equipment is completely independent of the wind direction. The blades have the appearance of turbines, which significantly reduces the load on the axial part. It would be advisable to buy a vertical wind generator in cases where the wind in the area constantly changes its direction.

Advantages and disadvantages of wind power plants for home

Like any other type of equipment, wind power plants have both advantages and disadvantages. To decide to buy this device, it is advisable to weigh its strengths and weaknesses.

Why is it profitable to buy a wind generator (220V) for a private home:

1. There are no additional costs, since the device does not require fuel to operate.
2. There is no need for constant monitoring. The structure generates electricity on its own every time the wind blows.
3. A relatively silent and completely environmentally friendly way of generating electricity.
4. The device can be used in almost any climatic conditions.
5. Part wear is minimal.

Installing a wind generator for a home is accompanied by the following disadvantages:

• the cost of purchasing equipment pays off in 5-6 years;
• relatively low efficiency indicator, which is reflected in power;
• high price of wind generators;
• to compensate for device inactivity on windless days, it is required optional equipment: generator and storage battery (the cost of these elements is very high);
• in some modes, windmills for home use infrasounds (the same thing happens if the equipment is installed incorrectly);
• Regular preventative maintenance is required;
• a hurricane can seriously damage equipment.

Helpful advice! You definitely need to calculate the profitability before buying a wind generator for your home; the price of the equipment may be too high, and the cost of purchasing it will not pay off. To do this it is necessary to calculate average power of the house (the power of all electrical appliances is taken into account), assess the area where the equipment will be installed, and find out the number of windy days per year.

Feasibility of purchase: prices of wind generators for a private home

The cost of wind turbines for private homes is quite high. The cost of purchasing equipment will only pay off if the area has suitable conditions.

Installation of a wind power plant is justified in the following cases:

• the terrain meets the equipment requirements;
• the region in which the site is located is characterized by strong winds;
• there is no possibility of using other alternative sources of electrical energy.

In other cases, the cost of purchasing a wind generator for your home will not pay off. If the number of windy days per year is small, these devices can be supplemented with solar panels or generators running on diesel or gasoline.

How to increase the profitability of a wind turbine for a private home

Coastal areas, as well as open areas in mountainous areas, are ideal for installing wind equipment. In these regions, the wind speed is more than 60-70 m/s. Residents of these areas can completely abandon central power supply systems and switch to wind power plants. In flat areas, wind flows are more uniform, but their strength is not enough to fully provide the house with electricity.

It is highly undesirable to install equipment near forests and plantings. Trees will retain some of the energy, which will reduce the profitability of wind turbines. The power of the air flow increases with distance from the ground. This means that the higher the wind farm mast, the greater the impulse the device can capture. On the other hand, an excessively high structure requires additional reinforcement. It will be easier for strong gusts of wind to knock it down than wind turbines with a mast that reaches 5-7 m.

1. By concreting the base.
2. Using metal guy wires.

To concrete the base of the windmill, you will need to dig four deep wells with a small diameter. The mast guy wires are immersed in them, after which they are poured cement mortar. This process is quite labor-intensive and expensive, but it is highly reliable. Even with strong gusts of wind, the mast will remain motionless. The only risk is that the blades break.

Fixing the mast with guy wires involves using a metal cable. It is pulled until the windmill is positioned strictly perpendicular to the surface of the earth. After this, the cable extensions are securely fixed in the ground.

Important! Wind turbines with high masts need to be grounded.

Which is the best wind generator to buy for your home: manufacturers and cost

The choice of a wind power plant must be approached carefully. The main criteria are the power of the equipment, the type of axis (horizontal or vertical), and the manufacturer. Before purchasing, you must carefully study the technical specifications and compare products from different manufacturers.

Prices for Russian-made wind generators:

Manufacturer	Price, thousand rubles
Wind energy company	30-300
Rkraft	65-908
Wind power	78-130
Sapsan-Energy	149-319
GRC-Vertical	204-600

Many of these organizations are engaged in the production of equipment for individual orders, and also provide assistance in design and calculations.

The prices of foreign-made wind turbines for homes are much higher. The minimum cost of installations is 120 thousand rubles. Products of foreign companies are different high level quality thanks to the use of high-tech equipment in production. However, repairing such installations will be expensive, and purchasing spare parts may be difficult.

Advantages of factory-made wind turbines:

• the opportunity to purchase a complete device and even order its professional installation;
• a wide selection of manufacturers and modifications with different characteristics;
• quality assurance;
• the ability to call a qualified specialist to carry out repair work.

Taking into account high cost factory equipment many owners suburban areas They prefer hand-made designs. It takes about 3,000-5,000 rubles to make a homemade wind generator. Most of this amount is spent on purchasing a high-quality battery that can hold a charge for a long time.

Advantages of self-made wind power plants:

• significant savings;
• when creating a homemade windmill, the designer will know all the features of its structure;
• the ability to make the main parts and blades for a wind generator with your own hands from scrap materials.

Homemade structures, unlike factory-made wind power plants, fail much more often.

Note! To install a factory structure, it is better to call a specialist. Otherwise, any error made during the installation process will void the warranty.

How to make a windmill with your own hands: technology and recommendations

Exploitation homemade device on the site may cause resentment from neighbors. Therefore, before making a wind generator with your own hands, you need to take care to follow several rules.

All individual buildings are subject to height restrictions. Installation of a wind turbine with a mast height of more than 15 m is prohibited if the following objects are located nearby:

• tunnels;
• bridges;
• airports.

The wind turbine must not create airborne interference. To prevent their occurrence, it is recommended to use special protection. In addition, you should monitor the level of noise emitted by the blades and keep it within normal limits.

Materials needed to make a vertical wind generator with your own hands

A vertical axis wind farm can be used to provide electrical energy various outbuildings or a small garden house. Its power is enough to illuminate the surrounding area in dark time days.

To create a wind generator with your own hands from a car generator, you will need the following materials:

• 12V battery (acid or gel);
• spacious capacity cylindrical made of aluminum or stainless steel (pan, bucket);
• automobile generator (12V);
• voltmeter;
• semi-hermetic switch button (12V);
• automotive battery charging relay or charge warning lamp;
• converters (12-220V and 700-1500W);
• wires with cross-sectional sizes of 2.5 and 4 mm;
• clamp for fixing the generator on the mast (2 pcs.).

To complete the work you will need the following tools and equipment:

• grinder (you can use metal scissors);
• marker or construction pencil;
• wire cutters and tape measure;
• drill with a set of drills;
• screwdriver and set of keys.

Technology for manufacturing a wind generator from a car generator

A cylindrical container will be used as a base, for example, a bucket, old boiling water or a saucepan. Using a pencil and tape measure, you need to mark it so that it is divided into 4 equal parts. According to the marks, cuts are made using a grinder so that vertical blade plates are obtained. It is very important not to cut the metal to the end.

Note! If the container is made of painted tin or galvanized steel, you cannot use a grinder for cutting, otherwise the metal will overheat. In this case, it is advisable to use scissors.

Holes for bolts should be made in the pulley, as well as in the bottom of the container. At this stage of creating a wind generator for a private house with your own hands, you need to be extremely careful and careful about symmetry. Any inaccuracies in hole placement will cause the structure to become unbalanced during rotation.

The blades should be bent, but they should not stick out too much. When performing this work, it is necessary to take into account the direction of rotational movement of the generator. Most often, the windmill is oriented clockwise. The rotational speed and contact area of ​​the air flows with the structure will depend on the selected bending angle of the blades.

Next, a container with blades is attached to the pulley. The generator is installed on the mast, after which it is fixed with clamps. All that remains is to connect all the wires and assemble the circuit. All cables are fixed to the windmill mast. To connect the storage battery, use wires with a cross-sectional area of ​​4 mm. For this, a piece 100 cm long will be enough. Connection to the network of household and lighting devices is carried out using wires with a cross-sectional size of 2.5 mm. The inverter or converter requires a wire with a cross section of 4 mm.

How to make a wind generator from a washing machine

To create a wind generator with your own hands from washing machine a list of certain parts will be required. Some of them can be removed from old ones household appliances, and the rest will have to be bought.

The wind turbine design will consist of the following elements:

• gearbox for adjusting rotational speed;
• rotor with blades;
• protective casing;
• storage battery;
• tail section;
• inverter;
• masts for fixing the generator.

The design generator is made from an electric motor from a washing machine. Its power must be at least 1.5 kW.

In addition you will need:

• sandpaper and adhesive;
• neodymium magnets 5 and 12 mm (32 pcs.);
• epoxy resin or cold welding.

Neodymium magnets will be installed on the rotor. They can be purchased at many brick-and-mortar or online stores. The cores must be removed from the rotor of an asynchronous motor. After this, these parts are partially cut off. The cutting depth should not exceed 2 mm. You can use a lathe for this. Next, it is necessary to make grooves in the cores, the depth of which is 5 mm.

At the next stage of making a wind generator for your home, you install magnets with your own hands. To begin with, a hard coating is mounted on the core. After this, magnets are placed at the appropriate places at equal distances. It is very important to keep a distance, otherwise in the future the magnets will stick together, which will negatively affect the power of the wind farm. It is better to use superglue to fix these parts. It is advisable to wear safety glasses while working, since the magnets may bounce off during the gluing process.

When the template with magnets is completely ready, it is placed on the rotor. The resulting gaps must be filled using epoxy resin or cold welding. At the end of the work, the rotor is carefully clamped in a vice, and its surface is treated with sandpaper. Before starting the windmill, all bearings and bolted connections should be checked for strength. You should not use even partially worn parts to assemble the structure; it is better to buy new ones.

To create an impeller, it is better to choose a lightweight material with a high margin of safety. Fiberglass is suitable for these purposes. As a result, the blades are light and wear-resistant. It is better to make the mast from steel pipes. Optimal size diameter is 32 mm.

Anyone who has an understanding of how electrical circuits work can assemble a windmill. The main thing is to pay attention to all the details and carefully check all your actions. To eliminate the possibility of errors, you can use visual videos that describe in detail the entire process of manufacturing parts and their further assembly.

How to make a 220V (4 kW) wind generator with your own hands: video

Russia occupies a dual position with regard to wind energy resources. On the one hand, due to the huge total area and the abundance of flat areas, there is generally a lot of wind, and it is mostly even. On the other hand, our winds are predominantly low-potential and slow, see Fig. On the third, in sparsely populated areas the winds are violent. Based on this, the task of installing a wind generator on the farm is quite relevant. But 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) to choose for what purpose.

Basic Concepts

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

Notes:

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

What kind of generator do you need?

An electric generator for a domestic windmill must generate electricity over a wide range of rotation speeds and be able to self-start without automation or external power sources. In the case of using APU with OSS (spin-up wind turbines), which, as a rule, have high KIEV and efficiency, it must also be reversible, i.e. be able to work as an engine. At powers up to 5 kW, this condition is satisfied by electric machines 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 alternating current generators or collector ones with a non-magnetized stator are completely unsuitable. When the wind force decreases, they will “go out” long before its speed drops to MPC, and then they will not start themselves.

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

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

Choosing according to the wind

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

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

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

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

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

About security

The parts of a wind turbine for household 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, will kill a healthy man outright. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

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

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

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

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

Wind, aerodynamics, KIEV

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

Wind and KIEV

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

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

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

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

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

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

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

Aerodynamics

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

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

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

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

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

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

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

KIEV again

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

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

Modernity

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

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

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

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

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

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

What to expect from the classics?

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

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

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

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

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

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

Verticals

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

Sun

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

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

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

Daria

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

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

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

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

Orthogonal

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

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

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

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

Helicoid

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

Barrel raking

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

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

Video: Lenz wind generator

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

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

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

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

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

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

Lopastniki

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

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

• Fig. A:

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

• Fig. B, top view:

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

• Fig. G, current collector:

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

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

So, where do we stumble?

Blades

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

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

Generator

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

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

Emergency weather vane

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

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

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

Current collector

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

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

Mini and micro

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

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

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

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

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

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

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

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

Video: the simplest wind generator for lighting a dacha

Sailboats

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

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

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

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

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

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

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

Homemade generator

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

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

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

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

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

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

Video: DIY windmill generator

Conclusion

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

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

Andrey said:

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

Ivan said:

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

By clicking the “Add comment” button, I agree with the site.

With rising prices for electricity, the search and development of alternative sources is underway everywhere. In most regions of the country, it is advisable to use wind generators. To fully provide electricity a private house, a fairly powerful and expensive installation is required.

Wind generator for home

If you make a small wind generator, you can use electric current to heat water or use it for part of the lighting, for example, outbuildings, garden paths and porch. Heating water for household needs or heating is the simplest option for using wind energy without its accumulation and conversion. Here the question is more about whether there will be enough power for heating.

Before making a generator, you should first find out the wind patterns in the region.

A large wind generator is not suitable for many places in the Russian climate due to frequent changes in the intensity and direction of air flows. With a power above 1 kW, it will be inertial and will not be able to fully spin up when the wind changes. Inertia in the plane of rotation leads to overloads from cross winds, leading to its failure.

With the advent of low-power energy consumers, it makes sense to use small homemade wind generators of no more than 12 volts to illuminate the dacha LED lamps or charge telephone batteries when there is no electricity in the house. When this is not necessary, an electric generator can be used to heat water.

Wind generator type

Only suitable for windless areas sailing wind generator. To ensure a constant power supply, you will need a battery of at least 12V, a charger, an inverter, a stabilizer and a rectifier.

For low-wind areas, you can independently make a vertical wind generator with a power of no more than 2-3 kW. There are many options and they are almost as good as industrial designs. It is advisable to buy wind turbines with a sail rotor. Reliable models with power from 1 to 100 kilowatts are produced in Taganrog.

In windy regions, you can make a vertical generator for your home with your own hands if the required power is 0.5-1.5 kilowatts. Blades can be made from available materials, for example, from a barrel. It is advisable to buy more productive devices. The cheapest are “sailboats”. A vertical windmill is more expensive, but it works more reliably in strong winds.

Do-it-yourself low-power windmill

It is not difficult to make a small homemade wind generator at home. To start working in the field of creating alternative energy sources and gaining valuable experience in this, how to assemble a generator, you can make a simple device yourself by adapting a motor from a computer or printer.

12V Wind Generator with Horizontal Axis

To make a low-power windmill with your own hands, you must first prepare drawings or sketches.

At a rotation speed of 200-300 rpm. the voltage can be raised to 12 volts, and the generated power will be about 3 watts. It can be used to charge a small battery. For other generators, the power must be increased to 1000 rpm. Only in this case will they be effective. But here you will need a gearbox, which creates significant resistance and also has a high cost.

Electrical part

To assemble an electric generator, you need the following components:

1. a small motor from an old printer, disk drive or scanner;
2. 8 diodes type 1N4007 for two rectifier bridges;
3. capacitor with a capacity of 1000 microfarads;
4. PVC pipe and plastic parts;
5. aluminum plates.

The figure below shows the generator circuit.

Stepper motor: connection diagram to the rectifier and stabilizer

Diode bridges are connected to each motor winding, of which there are two. After the bridges, the LM7805 stabilizer is connected. The resulting output is a voltage that is typically applied to a 12-volt battery.

Electric generators using neodymium magnets with extremely high adhesive force have become very popular. They should be used carefully. With a strong impact or heating to a temperature of 80-250 0 C (depending on the type), neodymium magnets demagnetize.

You can take a car hub as the basis for a self-made generator.

Rotor with neodymium magnets

Approximately 20 pieces of neodymium magnets with a diameter of about 25 mm are glued onto the hub with superglue. Single-phase electric generators are made with an equal number of poles and magnets.

Magnets located opposite each other must attract, that is, they are turned with opposite poles. After gluing the neodymium magnets, they are filled with epoxy resin.

The coils are wound round, and the total number of turns is 1000-1200. The power of the neodymium magnet generator is selected so that it can be used as a direct current source, about 6A, for charging a 12 V battery.

Mechanical part

The blades are made from plastic pipe. Blanks 10 cm wide and 50 cm long are drawn on it and then cut out. A bushing is made for the engine shaft with a flange to which the blades are attached with screws. Their number can be from two to four. Plastic will not last long, but it will be enough for the first time. Nowadays, quite wear-resistant materials have appeared, for example, carbon and polypropylene. Stronger blades can then be made from aluminum alloy.

The blades are balanced by cutting off excess parts at the ends, and the angle of inclination is created by heating them and bending them.

The generator is bolted to a piece of plastic pipe with a vertical axis welded to it. An aluminum alloy weather vane is also installed coaxially on the pipe. The axle is inserted into the vertical pipe of the mast. A thrust bearing is installed between them. The entire structure can rotate freely in a horizontal plane.

The electrical board can be placed on the rotating part, and the voltage can be transmitted to the consumer through two slip rings with brushes. If the board with the rectifier is installed separately, then the number of rings will be equal to six, the same number of pins as the stepper motor has.

The windmill is mounted at a height of 5-8 m.

If the device generates energy efficiently, it can be improved by making it vertical-axial, for example, from a barrel. The structure is less susceptible to lateral overloads than horizontal ones. The figure below shows a rotor with blades made from fragments of a barrel, mounted on an axis inside the frame and not subject to overturning force.

Windmill with a vertical axis and a barrel rotor

The profiled surface of the barrel creates additional rigidity, due to which thinner sheet metal can be used.

Wind generator with a capacity of more than 1 kilowatt

The device must provide tangible benefits and provide a voltage of 220 V so that some electrical appliances can be turned on. To do this, it must start independently and generate electricity over a wide range.

To make a wind generator with your own hands, you must first determine the design. It depends on how strong the wind is. If it is weak, then the only option may be a sailing version of the rotor. You cannot get more than 2-3 kilowatts of energy here. In addition, it will require a gearbox and a powerful battery with a charger.

The price of all equipment is high, so you should find out whether it will be beneficial for your home.

In areas with strong winds, a homemade wind generator can produce 1.5-5 kilowatts of power. Then it can be connected to a 220V home network. Device with more power It's difficult to do on your own.

Electric generator from a DC motor

As a generator, you can use a low-speed motor that generates electric current at 400-500 rpm: PIK8-6/2.5 36V 0.3Nm 1600min-1. Case length 143 mm, diameter – 80 mm, shaft diameter – 12 mm.

What does a DC motor look like?

It requires a multiplier with a gear ratio of 1:12. With one revolution of the windmill blades, the electric generator will make 12 revolutions. The figure below shows a diagram of the device.

Wind turbine design diagram

The gearbox creates an additional load, but it is still less than for a car generator or starter, where a gear ratio of at least 1:25 is required.

It is advisable to make the blades from aluminum sheet measuring 60x12x2. If you install 6 of them on the motor, the device will not be so fast and will not spin during large gusts of wind. The possibility of balancing should be provided. To do this, the blades are soldered to bushings with the ability to screw onto the rotor so that they can be moved further or closer from its center.

The power of a generator using permanent magnets made of ferrite or steel does not exceed 0.5-0.7 kilowatts. It can be increased only with special neodymium magnets.

A generator with a non-magnetized stator is not suitable for operation. When there is a slight wind, it stops, and after that it will not be able to start on its own.

Constant heating during the cold season requires a lot of energy, and heating a large house is a problem. In this regard, it can be useful for a dacha when you have to go there no more than once a week. If you weigh everything correctly, the heating system in the country only works for a few hours. The rest of the time the owners are in nature. Using a windmill as a source of direct current to charge the battery, in 1-2 weeks you can accumulate electricity to heat the premises for such a period of time, and thus create sufficient comfort for yourself.

To make a generator from an AC motor or car starter, they need to be redone. The motor can be upgraded to become a generator if the rotor is made with neodymium magnets, machined to their thickness. It is made with the same number of poles as the stator, alternating with each other. The rotor with neodymium magnets glued to its surface should not stick when rotating.

Rotor types

Rotor designs vary. Common options are shown in the figure below, which shows the values ​​of the wind energy utilization factor (WEI).

Types and designs of wind turbine rotors

For rotation, windmills are made with a vertical or horizontal axis. The vertical option has the advantage of ease of maintenance when the main components are located at the bottom. The support bearing is self-aligning and has a long service life.

The two blades of the Savonius rotor create jerks, which is not very convenient. For this reason, it is made of two pairs of blades, spaced apart by 2 levels with one rotated relative to the other by 90 0. Barrels, buckets, and pans can be used as blanks.

The Daria rotor, the blades of which are made of elastic tape, is easy to manufacture. To facilitate promotion, their number should be odd. The movement occurs in jerks, which is why the mechanical part quickly breaks. In addition, the tape vibrates when rotating, making a roar. This design is not very suitable for permanent use, although the blades are sometimes made of sound-absorbing materials.
In an orthogonal rotor, the wings are made profiled. The optimal number of blades is three. The device is fast, but it must be untwisted when starting.

The helicoid rotor has high efficiency due to the complex curvature of the blades, which reduces losses. It is used less often than other wind turbines due to its high cost.

The horizontal blade rotor design is the most efficient. But it requires stable average winds and also requires hurricane protection. Blades can be made from propylene when their diameter is less than 1 m.

If you cut the blades from a thick-walled plastic pipe or barrel, you will not be able to achieve a power higher than 200 W. A profile in the form of a segment is not suitable for a compressible gaseous medium. This requires a complex profile.

The diameter of the rotor depends on how much power is required, as well as the number of blades. A 10 W two-blade requires a rotor with a diameter of 1.16 m, and a 100 W rotor needs 6.34 m. For a four- and six-blade, the diameter will be 4.5 m and 3.68 m, respectively.

If you place the rotor directly on the generator shaft, its bearing will not last long, since the load on all the blades is uneven. The support bearing for the windmill shaft must be self-aligning, with two or three tiers. Then the rotor shaft will not be afraid of bending and displacement during rotation.

A major role in the operation of a windmill is played by the current collector, which must be regularly maintained: lubricated, cleaned, adjusted. The possibility of its prevention should be provided, although this is difficult to do.

Safety

Windmills with power exceeding 100 W are noisy devices. An industrial wind turbine can be installed in the courtyard of a private house, if it is certified. Its height should be higher than the nearest houses. Even a low-power windmill cannot be installed on the roof. Mechanical vibrations from its operation can create resonance and lead to the destruction of the structure.

High rotation speeds of a wind generator require high-quality manufacturing. Otherwise, if the device is destroyed, there is a danger that its parts may fly away over long distances and cause injury to people or pets. This should be especially taken into account when making a windmill with your own hands from scrap materials.

Video. DIY wind generator.

The use of wind generators is not advisable in all regions, since it depends on climatic conditions. In addition, it makes no sense to make them yourself without some experience and knowledge. To begin with, you can start creating a simple design with a power of several watts and a voltage of up to 12 volts, with which you can charge your phone or light an energy-saving lamp. The use of neodymium magnets in the generator can significantly increase its power.

It is better to purchase powerful wind turbines that take over a significant portion of the home’s power supply, producing industrial ones that create a voltage of 220V, carefully weighing all the pros and cons. If you combine them with other types of alternative energy sources, there may be enough electricity for all household needs, including the home heating system.

The issue of wind energy in our innovative times is of interest to many people. Those who have ever visited European countries by car have probably seen huge wind farms.
Hundreds of generators are found along the way.

Observing this picture, many begin to believe that generating electricity using wind is very promising and profitable occupation. Wise Europeans cannot make mistakes.

At the same time, for some reason the fact is ignored that in other places in Europe there are practically no such wind power plants. Why did it happen?
This is exactly what this article will discuss, when, where and how it is profitable to use wind turbines and when it is not.

Autonomy

Surely, after the next increase in the price of electricity, you have thought about installing a wind generator on your site. Thus, providing, if not all, then most of your electricity needs.

Some are even thinking about becoming independent from power grids in this way. How realistic and possible is this? Unfortunately, for 90% of private home owners, these dreams will remain dreams.

And so that you don’t waste your money, we’ll tell you, laying out all the numbers, why this is exactly so.

Wind speed

Unfortunately, there are not many regions in our country where the wind speed is at least 5-7 meters per second. The data is taken on average per year. In the vast majority of latitudes suitable for habitation, this same speed is a maximum of 2-4 m/s.

This means that your wind turbine will simply not work most of the time. For stable generation of electricity, it needs a wind of about 10 m/s.

If the wind in your area is 7 m/s, then the generator will operate at a maximum of 50% of its nominal value. And if it’s only 2 m/s, then by 5%.

In fact, in an hour, a 2kW generator will give you no more than 100W.

You will also encounter another wind problem that manufacturers are silent about. Near the ground, its speed is much lower than at the top, where industrial installations with a height of 25-30m are installed.

You will install your unit at a maximum of ten meters. Therefore, do not even rely on wind tables from different sites. This data is not suitable for you.

Manufacturers modestly keep silent about the fact that for their wind resource maps, measurements are made at an altitude of 50 to 70 meters! In addition, data on turbulence and eddies are not taken into account.

If you try to raise it higher than 10m, you will definitely think about lightning protection. Blades electrified by air friction, a very tasty bait for discharges!

In addition, for some reason everyone only worries about such a parameter as wind speed, and at the same time forgets about its density or pressure. And the difference for energy is quite significant. The dependence of electricity generation on wind pressure is disproportionate.

So, when the wind pressure doubles, the generated power increases eight times!

In addition, there is a certain slyness in these technical specifications generators.

Of course, you can trust them, but only under ideal conditions. Because:

• and in laminar flow with constant direction and increased density

On your summer cottage The wind speed may be such that it will not be possible to even rotate the shaft, let alone generate energy.

And this is in spring or autumn. It is during this period that the most active movements of air masses occur.

Do not forget that the windmill does not operate in the mode idle move turntables, but must spin the generator rotor surrounded by neodymium magnets.

And this is only as long as the electrical potential of the windmill is lower than the battery voltage. When the voltage is sufficient to begin charging, the battery turns into a load.

If you use low-speed designs with a vertical axis of rotation, then there is already a step-up gearbox. Have you tried to spin up the boost gearbox? This design becomes more complicated, increasing weight, windage, and cost.

Even at the lighthouses of the Northern Fleet, given the constant winds and polar night, experts prefer to use solar panels. When asked why this is so, the answer is simple – there are fewer problems!

Batteries for wind turbines

Large industrial wind turbines can transmit energy directly to the grid, bypassing any batteries.

But you won’t be able to do without them. Without a battery, neither the TV nor the refrigerator will work. Even the lighting will shine in fits and starts, depending on gusts of wind.

Moreover, over 12-15 years of operation of the generator, you will be required to change 3-4 sets of batteries, thereby doubling your initial costs. Moreover, we take almost the ideal option, when the batteries will be discharged no more than half of their capacity.

Of course, you can buy cheap battery models, but this will not reduce your costs. Just going to the store for new batteries will be done not 4 times, but 8 times.

Where is the best place to install

Another thing worth seriously thinking about is the availability free space. Moreover, in area it can extend 100 meters or more in each direction from the mast.

The wind should move freely along the blades and reach them from all sides without interference. It turns out that you must live either in the steppe or near the sea (preferably directly on its shore).

The ideal location would be on top of a hill. Where, from an aerodynamics perspective, the air flow is compressed with a corresponding increase in wind speed and pressure.

Forget about your neighbors nearby. Their gardens and two-three-story mansions will “drink your blood” great, blocking the tailwind every time. As well as neighboring forest plantations.

The same industrial windmills are not placed directly next to each other, but are mounted diagonally. Each subsequent one should not cover the previous one.

Price per 1 kW of power

4th reason – high price. Don't be fooled by sellers' prices on price lists. They never show the actual cost of all the equipment needed.
Therefore, always multiply prices by 2, even when choosing so-called ready-made kits.

But that's not all. Don't forget about operating costs, reaching up to 70% of the cost of wind turbines. Try to repair the generator at height, or dismantle and disassemble and reassemble the mast each time.

Don't forget to periodically replace the battery. Therefore, do not expect that a windmill can cost you 1 dollar per 1 kW of electricity.

When you calculate all the real costs, it turns out that every kilowatt of power from such a wind generator cost you at least 5 bucks.

Payback period and savings calculation

The fifth reason is inextricably linked with the first four. This is the payback period.

For your individual wind installation, this period is NEVER.

The cost of a windmill, mast and additional equipment for 2-kilowatt high-quality models will reach an average of 200 thousand rubles. The productivity of such installations is from 100 to 200 kW per month, no more. And this is in good weather conditions.

Even precipitation reduces the power of wind turbines. Rain by 20%, snow by 30%.

So your entire savings turns out to be 500 rubles. In 12 months of continuous work, a little more will accumulate – 6 thousand.

But if you remember the initial expenses of 200 thousand, then you will return it in thirty-two years!

And all this without taking into account operating costs. And if you estimate that the average service life of a good windmill is about 20 years, then it turns out that it will completely and irreparably break down even before it reaches its payback period.

At the same time, a 2-kilowatt unit will not cover 100% of your needs. Maximum by a third! If you want to connect everything entirely from it, then take a 10-kilowatt model, no less. This will not change the payback period.

But here there will be completely different dimensions and weight.

And simply attaching it to a pipe through the attic of your roof will definitely not work.

However, some are still convinced that due to the endless rise in price of electricity, a wind generator will one day become profitable.

When should you buy a windmill?

Of course, electricity becomes more expensive every year. For example, 10 years ago, its price was 70% lower. Let's make approximate calculations and find out the prospects for the windmill to break even, taking into account the sharp increase in the cost of electricity.

We will consider a 2 kW generator.

As we found out earlier, the cost of such a model is about 200 thousand. But taking into account all the additional expenses, you need to multiply it by two. The result will be at least 400 thousand rubles. costs, with a service life of twenty years.

That is, in a year it turns out to be 20 thousand. In fact, this year the unit will give you a maximum of 900 kW. Due to the coefficient installed capacity (for small wind turbines it does not exceed five percent), in a month you will generate 75 kW.

Even if we take 1000 kW per year for simplicity of calculations, the cost of 1 kW/h obtained from a wind turbine will be 20 rubles for you. Even if we assume that electricity from thermal power plants will rise in price by 4 times, then this will not happen tomorrow, and not even in 5 years.

Which wind turbines to choose

Well, for those who live far from substations and 0.4 kV overhead lines, it is worth purchasing the most powerful models of wind turbines that you can afford. Since you will get no more than 15% of the power indicated in the pictures.

Another category of consumers, quite rightly, makes a choice not in favor of Chinese factory models, but, on the contrary, prefers homemade windmills from self-taught craftsmen. This also has its benefits.

For the most part, the inventors of such devices are competent and responsible guys. And in almost 100% of cases, you can return the installation to them without any problems if something goes wrong or it needs to be repaired. There will certainly be no problems with this.

At industrial Chinese windmills, appearance Of course it's prettier. And if you still decide to buy it, immediately after checking it with an electric drill, do preventative repairs and replace Chinese scrap metal with bearings with high-quality lubricant.

If there are large nesting birds near you, it won’t hurt to purchase additional kit blades.

Chicks sometimes get caught in the spinning “mini mill”. Plastic blades break and metal blades bend.

And I would like to end with wisdom from those users who did not listen to all the arguments and came face to face with all the problems described above. Remember, the most expensive weather vane for a home is a wind generator!

One of the most affordable options for using renewable energy sources is the use of wind energy. To learn how to make calculations, assemble and install a windmill yourself, 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;
• propeller pitch.

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

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

Version with a vertical axis - orthogonal and carousel designs using the example of Darrieus and Savonius rotors. The last two concepts should be clarified, since both have some significance in the design of wind generators.

Darrieus rotor is an orthogonal wind turbine design, where aerodynamic blades (two or more) are located symmetrically to each other at a certain distance and mounted on radial beams. A rather complex version of a wind turbine that requires careful aerodynamic design of the blades.

Savonius rotor is a carousel-type wind turbine design, where two semi-cylindrical blades are located one against the other, overall forming a sinusoidal shape. 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-tier design is used with the angular displacement of each pair of blades relative to the other pairs.

Advantages and disadvantages of wind turbines

The advantages of these devices are obvious, especially in relation to domestic operating conditions. Users of wind turbines actually have the opportunity to generate free electrical energy, not counting the small costs of construction and maintenance. However, the disadvantages of wind power plants are also obvious.

So in order to achieve efficient work installation, the conditions for stability of wind flows must be met. Man cannot create such conditions. This is purely the prerogative of nature. One more, but already technical defect, there is a low quality of generated electricity, as a result of which it is necessary to supplement the system with expensive electrical modules(cartoonists, chargers, batteries, converters, stabilizers).

The advantages and disadvantages in terms of the features of each modification of wind turbines, perhaps, balance at zero. If the horizontal-axial modifications are different 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 mechanism for tracking wind direction. At the same time, such wind turbines are distinguished by a low noise level, eliminate the “spreading” effect in strong winds, and are quite compact.

Homemade wind generators

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

It is recommended to start by building a micro-windmill with a power of several tens of watts. In the future, the experience gained will help create a more powerful design. When 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 makes more sense to limit ourselves to the use of initially obtained electricity, which can be successfully used without conversion for other purposes, for example, to support heating and hot water supply systems built on electric heaters (TEH) - such devices do not require stable voltage and frequency. This makes it possible to create a simple circuit that operates 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, to power which they often try to install home windmills. The construction of wind turbines is precisely for the purpose of providing the house with heat and hot water- minimum costs and simplicity of design.

Generalized design of a home wind turbine

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

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

Wind generator PIC 8-6/2.5

How it works? Just. The wind turns the wind turbine. The torque is transmitted through the multiplier to the shaft of the DC generator. The energy received at the output of the generator is accumulated in batteries through the charging module. 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 domestic wind turbine designs are typically constructed using low-speed DC motors. This is the simplest generator option that does not require modernization. Optimally - electric motors with permanent magnets, designed for a supply voltage of about 60-100 volts. There is a practice of using car generators, but for this case the introduction of a multiplier is required, since car generators produce the required voltage only at high (1800-2500) speeds. One of the possible options is the reconstruction of an AC asynchronous motor, but it is also quite complex, requiring precise calculations, turning, and 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 on this matter.

Vertical-axis homemade “windmill”

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

Set of parts:

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, electric motor model PIK8-6/2.5.
5. Voltage controller.
6. Battery.

Manufacturing of the 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. Two pieces 150 mm long are cut from a plastic pipe 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 the top point strictly horizontally, forming two tiers. Blades are inserted between the disks, two per tier, and fixed strictly one against the other, forming a sinusoid. In this case, the blades of the upper tier are shifted relative to the blades of the lower tier at an angle of 90 degrees. The result is a four-bladed Savonius rotor. To fasten elements, you can use rivets, self-tapping screws, corners, or other methods.

Connection to engine and installation on 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 having the required internal diameter is pressed into the lower part of the pipe. A hole is drilled through the wall of the pipe and the bushing, and 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 remaining part 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. A metal disk cover mounted on the front end of the motor, having a diameter slightly larger than the diameter of the mast, is used as a stop. Holes are drilled on the periphery of the cover for attaching guy wires. Since the motor housing diameter is smaller internal diameter pipes, spacers or stops are used to align the generator in the center. The cable from the generator is passed inside the pipe and exited through the window at the bottom. During installation, it is necessary to take into account the protection of the generator from moisture by using sealing gaskets. Again, for the purpose of protection from precipitation, an umbrella cap can be installed above the connection of the wind turbine pipe with the generator shaft.

The entire structure is installed in an open, well-ventilated area. A hole 0.5 meters deep is dug under the mast, the lower part of the pipe is lowered into the hole, the structure is leveled with guy wires, after which the hole is filled with concrete.

Voltage controller (simple charger)

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

Ready-made voltage converter based on LM2577

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

Horizontal-axis wind power plant

Set of parts:

1. Plastic pipe with a diameter of 150 mm, aluminum sheet 1.5-2.5 mm thick, wooden block 80x40 1 m long, plumbing: flange - 3, angle - 2, tee - 1.
2. DC electric 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).

Manufacturing of a horizontal-axis “windmill”

A plastic pipe is needed to make wind turbine blades. A section of such a pipe, 600 mm long, is cut lengthwise into four identical segments. A windmill requires three blades, which are made from the resulting segments by cutting part of the material diagonally along the entire length, but not exactly from corner to corner, but from bottom corner to the top corner, with a slight indentation from the last. Processing 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 measuring approximately 50x50 mm is cut along one edge, and the remaining part serves as a fastening petal.

The wind turbine blades are secured to the wheel-pulley using bolted connections. The pulley is mounted directly on the shaft of a DC electric motor - generator. A simple wooden block with a cross-section of 80x40 mm and a length of 1 m is used as a wind turbine chassis. The generator is installed at one end wooden block. At the other end of the bar, a “tail” made of an aluminum sheet is mounted. At the bottom of the block, a 25 mm metal pipe is attached, intended to act as the shaft of the rotating mechanism. A three-meter 32 mm metal pipe is used as a mast. The upper part of the mast is the bushing of the rotating mechanism, into which 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 structure is assembled from plumbing parts, thanks to which the mast can be easily raised or lowered, or mounted or dismantled. Guys are used to secure the mast.

All wind turbine electronics are mounted in a separate module, the interface of which provides for connecting batteries and consumer loads. The module includes a battery charge controller and a voltage converter. Similar devices You can collect it yourself if you have the appropriate experience, or purchase it on the market. There are many different solutions on the market that allow you to obtain the desired output voltages and currents.

Combined wind turbines

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

Also, the combination of wind turbines involves the creation of wind power plants that include two different modifications at once. For example, when a Savonius rotor and a traditional three-blade machine work in one combination. The first turbine operates at low wind speeds, and the second only at nominal ones. This preserves the efficiency of the installation, eliminates unjustified energy losses, and in the case of asynchronous generators, compensates for reactive currents.

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

Calculation of the power of a wind power plant

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

• N = p S V3 / 2
• N— installation power, W
• p- air density (1.2 kg/m3)
• S— blown area, m2
• V— wind flow speed, m/sec

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

• N= 1.2 1 343 / 2 = 205.8 W

An approximate calculation of the power of a wind turbine created on the basis of a 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/sec

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/sec. will be:

• N= 1.2 · 0.142 · 0.3 · 343 = 17.5 W

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