If there is a river or even a small stream flowing near your home, then with the help of a homemade mini hydroelectric power station you can get free electricity. Perhaps this will not be a very large addition to the budget, but the realization that you have your own electricity costs much more. Well, if, for example, at a dacha, there is no central power supply, then even small amounts of electricity will be simply necessary. And so, to create a homemade hydroelectric power station, at least two conditions are required - the availability of a water resource and desire.

If both are present, then the first thing to do is measure the speed of the river flow. This is very simple to do - throw a twig into the river and measure the time during which it floats 10 meters. Dividing meters by seconds gives you the current speed in m/s. If the speed is less than 1 m/s, then a productive mini hydroelectric power station will not work. In this case, you can try to increase the flow speed by artificially narrowing the channel or making a small dam if you are dealing with a small stream.

As a guide, you can use the relationship between the flow speed in m/s and the power of electricity removed from the propeller shaft in kW (screw diameter 1 meter). The data is experimental; in reality, the resulting power depends on many factors, but it is suitable for evaluation. So:

0.5 m/s – 0.03 kW,
0.7 m/s – 0.07 kW,
1 m/s – 0.14 kW,
1.5 m/s – 0.31 kW,
2 m/s – 0.55 kW,
2.5 m/s – 0.86 kW,
3 m/s -1.24 kW,
4 m/s – 2.2 kW, etc.

Power homemade mini hydroelectric power station proportional to the cube of the flow velocity. As already indicated, if the flow speed is insufficient, try to artificially increase it, if this is of course possible.

Types of mini-hydroelectric power plants

There are several main options for homemade mini hydroelectric power plants.

Water wheel

This is a wheel with blades mounted perpendicular to the surface of the water. The wheel is less than half immersed in the flow. Water presses on the blades and rotates the wheel. There are also turbine wheels with special blades optimized for liquid flow. But that's enough complex designs more factory-made than home-made.

Rotor Daria

This is a vertical axis rotor used to generate electrical energy. Vertical rotor, which rotates due to the pressure difference on its blades. The pressure difference is created due to the flow of liquid around complex surfaces. The effect is similar to the lift of a hydrofoil or the lift of an airplane wing. This design was patented by Georges Jean-Marie Darrieux, a French aeronautical engineer in 1931. Also often used in wind turbine designs.

Garlyandnaya hydroelectric power station

A hydroelectric power station consists of light turbines - hydraulic propellers, strung and rigidly fixed in the form of a garland on a cable thrown across the river. One end of the cable is fixed in the support bearing, the other rotates the generator rotor. In this case, the cable plays the role of a kind of shaft, the rotational motion of which is transmitted to the generator. The flow of water rotates the rotors, the rotors rotate the cable.

Propeller

Also borrowed from the designs of wind power plants, a kind of “underwater wind turbine” with a vertical rotor. Unlike an air propeller, an underwater propeller has blades of minimal width. For water, a blade width of only 2 cm is sufficient. With such a width there will be minimal resistance and maximum speed rotation. This width of the blades was chosen for a flow speed of 0.8-2 meters per second. At higher speeds, other sizes may be optimal. The propeller moves not due to water pressure, but due to the generation of lifting force. Just like an airplane wing. The propeller blades move across the flow rather than being dragged in the direction of the flow.

Advantages and disadvantages of various homemade mini hydroelectric power station systems

Flaws garland hydroelectric power station obvious: high material consumption, danger to others (long underwater cable, rotors hidden in the water, blocking the river), low efficiency. The Garland hydroelectric power station is a kind of small dam. It is advisable to use in uninhabited, remote areas with appropriate warning signs. Permission from authorities and environmentalists may be required. The second option is a small stream in your garden.
Rotor Daria- difficult to calculate and manufacture. Before starting work, you need to unwind it. But it is attractive because the rotor axis is located vertically and power can be taken off over water, without additional gears. Such a rotor will rotate with any change in flow direction - this is a plus.

Most common when building homemade hydroelectric power plants received schematics of the propeller and water wheel. Since these options are relatively simple to manufacture, they require minimum payments and are implemented at minimum costs, have high efficiency, are easy to set up and operate.

If you do not have a water energy resource, you can make your own home wind power station.

P an example of the simplest mini-hydroelectric power station

The simplest hydroelectric power station can be quickly built from an ordinary bicycle with a dynamic headlight. Several blades (2-3) must be prepared from galvanized iron or thin sheet aluminum. The blades should be the length from the wheel rim to the hub, and 2-4 cm wide. These blades are installed between the spokes using any available method or using pre-prepared fasteners.
If you are using two blades, place them opposite each other. If you want to add more blades, then divide the circumference of the wheel by the number of blades and install them at equal intervals. You can experiment with the depth of immersion of the wheel with blades in the water. It is usually one-third to one-half immersed.
The option of a traveling wind power plant was considered earlier.

Such a micro hydroelectric power station does not take up much space and will serve cyclists perfectly - the main thing is the presence of a stream or rivulet - which is usually the place where the camp is set up. A mini hydroelectric power station from a bicycle will be able to illuminate a tent and charge Cell Phones or other gadgets.

The power of water flow is renewable natural resource, allowing you to get practically free electricity. Energy donated by nature will provide an opportunity to save on utilities and solve the problem with recharging equipment.

If there is a stream or river running near your home, it is worth taking advantage of it. They will be able to provide electricity to the site and the house. And if you build a hydroelectric power station with your own hands, the economic effect increases significantly.

The presented article describes in detail the manufacturing technologies of private hydraulic structures. We talked about what is required to set up the system and connect it to consumers. Here you will learn about all the options for miniature energy suppliers assembled from scrap materials.

Hydroelectric power plants are structures that can convert the energy of water movement into electricity. so far they are actively exploited only in the West. In our country, this promising industry is only taking its first timid steps.

Image gallery

Next in line are designs, the prototype of which was the free-flow (model 1964) garland hydroelectric power station of V. Blinov.

The hydroelectric power plants that will be discussed are free-flow, with a rather original turbine made of so-called Savonius rotors, strung on a common (maybe flexible, composite) working shaft. They do not require dams or other large-scale hydraulic structures for their installation. They are able to work with full efficiency even in shallow water, which, combined with the simplicity, compactness and reliability of the design, makes these hydroelectric power stations very promising for those farmers and gardeners whose plots of land are located near small watercourses (rivers, streams and ditches).

Unlike dams, free-flow hydropower plants, as is known, use only the kinetic energy of flowing water. To determine power there is a formula:

N=0.5*p*V3*F*n (1),

N - power on the working shaft (W),
- p - density of water (1000 kt/m3),
- V - river flow speed (m/s),
- F - cross-sectional area of ​​the active (submersible) part of the working body of the hydraulic machine (m2),
- n - energy conversion efficiency.

As can be seen from formula 1, at a river speed of 1 m/s per one square meter The cross section of the active part of the hydraulic machine ideally (when n=1) has a power equal to only 500 W. This value is clearly small for industrial use, but quite sufficient for a farmer’s or summer resident’s subsidiary plot. Moreover, it can be increased through the parallel operation of several “hydroenergy garlands”.

And one more subtlety. The speed of the river in its different sections is different. Therefore, before starting the construction of a mini-hydroelectric power station, it is necessary to determine the energy potential of your river using the simple method outlined. Let us only recall that the distance traveled by the measuring float and divided by the time it passes will correspond to the average flow speed in this area. It should also be noted: this parameter will change depending on the time of year.

Therefore, design calculations should be made based on the average (over the planned period of operation of the mini-hydroelectric power station) river flow speed.

Fig.1. Savonius rotors for homemade garland mini-hydroelectric power plants:

a, b - blades; 1 - transverse, 2 - end.

Next, you need to determine the size of the active part of the hydraulic machine and its type. Since the entire mini-hydroelectric power station should be as simple and uncomplicated to manufacture as possible, the most suitable type The converter is a Savonius rotor of end-end design. When working with complete immersion in water, the value F can be taken equal to the product rotor diameter D by its length L, and n=0.5. The rotation frequency f is determined with an accuracy acceptable for practice using the formula:

f=48V/3.14D (rpm) (2).

To make the hydroelectric power plant as compact as possible, the power specified in the calculation should be correlated with the actual load, the power supply of which should be provided by the mini-hydroelectric power station (since, unlike a wind turbine, the current will be continuously supplied to the consumer network). As a rule, this electricity is used for lighting, powering the TV, radio, and refrigerator. Moreover, only the latter is constantly put into operation throughout the day. The rest of the electrical appliances work mainly in the evening. Based on this, it is advisable to focus on the maximum power from one “hydroenergy garland” of about 250-300 W, covering the peak load with the help of a battery charged from a mini-hydroelectric power station.

The transmission of torque from the working shaft of a hydraulic power plant to the pulley of an electric generator is usually carried out using an intermediate transmission. However, this element, strictly speaking, can be excluded if the generator used in the design of a microhydroelectric power station has an operating rotation speed of less than 750 rpm. However, you often have to refuse direct communication. Indeed, for the vast majority of generators domestic production working speed rotation at the beginning of “distribution” of power lies in the range of 1500-3000 rpm. This means that additional coordination is needed between the shafts of the hydropower plant and the electric generator.

Well, now that the preliminary theoretical part is behind us, let’s look at specific designs. Each of them has its own advantages.

Here, for example, is a semi-stationary free-flow mini-hydroelectric power station with a horizontal arrangement of two coaxial, rotated 90° relative to each other (to facilitate self-starting) and rigidly connected transverse-type Savonius rotors. Moreover, the main parts and components of this homemade hydropower plant are made of wood as the most affordable and “obedient” building material.

The proposed mini-hydroelectric power station is submersible. That is, its supporting frame is located across the watercourse at the bottom and is strengthened with guy ropes or poles (if, for example, there are walkways, a boat dock, etc. nearby). This is done in order to avoid the structure being carried away by the watercourse itself.

Fig.2. Submersible mini hydroelectric power station with horizontal transverse rotors:
1 - base spar (beam 150x100, 2 pcs.), 2 - lower cross member (board 150x45, 2 pcs.), 3 - middle cross member (beam 150x120, 2 pcs.), 4 - riser (round timber with a diameter of 100, 4 pcs. .), 5 upper spar (board 150x45, 2 pcs.), 6 - upper cross member (board 100x40, 4 pcs.), 7 - intermediate shaft (stainless steel, rod with a diameter of 30), 8 - pulley block, 9 - constant generator current, 10 - “gander” with a porcelain roller and two-core insulated wire, 11 - base plate (board 200x40), 12 - drive pulley, 13 - wooden bearing assembly (2 pcs.), 14 - “hydroenergy garland” rotor (D600, L1000, 2 pcs.), 15 disk (from knocked into a shield boards 20-40 mm thick, 3 pcs.); metal elements fastenings (including braces, hubs of outer discs) are not shown.

Of course, the depth of the river at the installation site of the mini hydroelectric power station should be less than the height of the support frame. Otherwise, it is very difficult (if not impossible) to avoid water getting into the electric generator. Well, if the place where the mini hydroelectric power station is supposed to be located has a depth of more than 1.5 m or there is a large amount of water and flow speed that varies greatly throughout the year (which, by the way, is quite typical for snow-fed watercourses), then this design It is recommended to equip with floats. This will also allow it to be easily moved when installed on a river.

The supporting frame of a mini hydroelectric power station is a rectangular frame made of timber, boards and small logs, fastened with nails and wire (cables). Metal parts of the structure (nails, bolts, clamps, angles, etc.) should, if possible, be made of of stainless steel or other corrosion-resistant alloys.

Well, since the operation of such a mini hydroelectric power station is often possible in Russian conditions only seasonally (due to the freezing of most rivers), then after the expiration of the operation period, the entire structure pulled ashore is subject to thorough inspection. Rotten ones are replaced in a timely manner wooden elements, rusty, despite Taken measures precautions, metal parts.

One of the main components of our mini-hydroelectric power station is a “hydroenergy garland” of two rigidly fixed (and forming a single whole on the working shaft) rotors. Their disks can be easily made from boards 20-30 mm thick. To do this, making a shield out of them, use a compass to build a circle with a diameter of 600 mm. After which, each of the boards is cut according to the curve obtained on it. Having knocked the workpieces together on two strips (to give the required rigidity), they repeat everything three times - according to the number of required disks.

As for the blades, it is advisable to make them from roofing iron. Or better yet, from cylindrical stainless containers (barrels) that are suitable in size and cut in half (along the axis), in which agricultural fertilizers and other aggressive materials are usually stored and transported. In extreme cases, the blades can be made of wood. But their weight (especially after a long stay in water) will increase significantly. And this should be remembered when creating mini-hydroelectric power plants on floats.

Spiked supports are attached to the ends of the “hydroenergy garland”. Essentially, these are short cylinders with a wide flange and an end slot for a key. The flange is attached to the corresponding rotor disk with four bolts.

To reduce friction, there are bearings located on the middle crossbars. And since ordinary ball or roller bearings are unsuitable for working in water, they use... homemade wooden ones. The design of each of them consists of two clamps and insert boards with a hole for the passage of a tenon support. Moreover, the middle bearing shells are positioned so that the wood fibers run parallel to the shaft. In addition, special measures are taken to ensure that the insert boards are firmly fixed against lateral movement. This is done using tightening bolts.

Fig.3. Sliding bearing assembly:
1 - crimp bracket (St3, strip 50x8, 4 pcs.), 2 - middle frame cross member, 3 - crimp insert (made of hard wood, 2 pcs.), 4 replaceable insert (made of hard wood, 2 pcs.) , 5 - M10 bolt with Grover nut and washer (4 sets), 6 - M8 stud with two nuts and washers (2 pcs.).

Any automobile generator is used as an electric generator in the microhydroelectric power station under consideration. They produce 12-14 V DC and can be easily connected to both battery and electrical appliances. The power of these machines is about 300 W.

Quite acceptable for self-made and the design of a portable mini hydroelectric power station with a vertical arrangement of a “garland” and a generator. Such a hydroelectric station, according to the author of the development, is the least material-intensive. The supporting structure of the installation, which fixes its position in the river bed, is a hollow steel rod (for example, from pipe sections). Its length is chosen based on the nature of the bottom of the watercourse and the speed of the flow. Moreover, such that the sharp end of the rod, driven into the bottom, would guarantee the stability of the mini-hydroelectric power station and its non-disruption by the current. Possibly additional use stretch marks.
Having determined the active surface of the rotor using formula (1) and measuring the depth of the river at the installation site of the mini hydroelectric power station, it is easy to calculate the diameter of the Savonius rotors used here. To make the design simple and self-starting, it is advisable to make a “hydroenergy garland” of two rotors connected so that the blades of the first are offset by 90° relative to the second (along the axis of rotation). Moreover, to increase operating efficiency, the structure on the side of the oncoming flow is equipped with a shield that plays the role of a guide vane. Well, the working shaft is mounted in the sliding bearings of the upper and lower supports. In principle, for a short period of operation of a mini hydroelectric power station (for example, on a hiking trip), ball bearings can also be used large diameter. However, if there is sand or silt in the water, these units will have to be washed in clean water after each use.

Rice. 4. Mini hydroelectric power station with a vertical arrangement of end-type rotors:
1 - support rod, 2 - lower bearing assembly, 3 - "hydroenergy garland" disk (3 pcs.), 4 - rotor (D600, 2 pcs.), 5 - upper bearing assembly, 6 - working shaft, 7 - transmission, 8 - electric generator, 9 - “gander” with a porcelain roller and two-core insulated wire, 10 - generator mounting clamp, 11 - movable guide panel; a, b - blades: the braces at the upper end of the support rod are not shown.

The supports are bolted and welded to the rod, depending on the weight of the “hydroenergy garland” and the need to disassemble it into parts. The upper end of the working shaft of the hydraulic machine is also the input shaft of the multiplier, which (as the simplest and most technologically advanced) can be used as a belt one.

The electric generator is again taken from a car. It is easy to attach it to the support rod with a clamp. And the wires themselves coming from the generator must have reliable waterproofing. In the illustrations, the exact geometric proportions of the intermediate transmission are not shown, as they depend on the parameters of the specific generator you have. Well, transmission belts can be made from an old car inner tube, cutting it into strips 20 mm wide and then twisting it into bundles.

For power supply to small villages, a garland mini-hydroelectric power station designed by V. Blinov is suitable, which is nothing more than a chain of barrel-shaped Savonius rotors with a diameter of 300-400 mm, attached to a flexible cable stretched across the river. One end of the cable is attached to the hinged support, and the other through a simple multiplier to the generator shaft. At a flow speed of 1.5-2.0 m/s, the chain of rotors makes up to 90 rpm. And the small size of the elements of the “hydroenergy garland” makes it possible to operate this micro-hydroelectric power station on rivers with a depth of less than one meter.

It must be said that before 1964, V. Blinov managed to create several portable and stationary mini hydroelectric power stations of his own design, the largest of which was a hydroelectric power station built near the village of Porozhki (Tver region). A pair of garlands here drove two standard automobile and tractor generators with a total power of 3.5 kW.

MK 10 1997 I. Dokunin

The most common among alternative sources energy sources are wind generators, but they are largely dependent on weather conditions. In the absence of wind or weak wind flow, they are ineffective. For normal operation Such generators are suitable for areas where the average annual wind speed is not lower than 5-6 m/s and higher.

In Russia there are not many areas with intense winds, the steppes and the Black Sea coast of Kuban, the Far Eastern coast and up to a dozen uninhabited or small areas.

IN middle lane, in the mountains of the Caucasus, Urals, Altai and other regions where there are small but fast-moving rivers, tributaries, streams, people forget about the possibility of using hydroelectric generators.

It is not rational to refuse to use them; this is a guaranteed source of electricity, because a river with a stable level and flow is much more reliable than a changeable wind.

Power calculation and design selection

In essence, the electrical part of a wind generator is no different from a hydrogenerator; the principle is similar to convert mechanical rotational energy into electrical energy.

The difference in the driving force is wind or water, the drive devices will be fundamentally different. Instead of a propeller, hydrogenerators use wheels drum type with blades.

It is not difficult to assemble a hydraulic generator with your own, if they grow from the right place; if you have a wind generator, all that remains is to design and assemble a hydraulic drive for its rotation.

In such cases, in order for the generator to rotate with the required speed, it is often necessary to use gearboxes to change the force and speed of rotation, which depend on the water flow.

It is calculated that the power of the filling wheel is significantly greater than that of the filling wheel; filling is when the flow of water falls on the blades of the drive wheel from above, the filling wheel rotates with the flow from below.

Therefore, based on your conditions, use the filling wheel design whenever possible. However, such a wheel also has its disadvantages:

• spin it slower
• requires the construction of additional structures

The photo above uses a direct drive filling wheel on a homemade permanent magnet disk generator, the design of which will be discussed below.

Vehicle elements can be used in drive mechanism designs:

• disks
• stars
• gears
• chains and belts

In some cases, even gearboxes from mopeds and motorcycles are used, and blades are welded onto the disks of large tractor wheels.

Options for generators used and load connections

Generators can be used for automobiles, buses, and best of all low-speed tractors for permanent magnets.

They are more reliable, easier to operate and repair, and they do not have brushes.

1. generator G250-G1 2. P362 relay-regulator 3. car battery 4. ammeter 5 and 6 switches 7 fuse 8 fuel supply.

Depending on your conditions and capabilities, you can use 24V generators.

1. Generator G-228 2. voltage regulator 11.3702 3. 12V batteries connected in series 4. Ammeter for measuring charging current 5 and 6 switches 7. load.

In the simplest case, you can use 6ST-75 batteries, but for reliability it is of course better to install new lithium-ion starter batteries. They are of course more expensive, but lighter in weight than lead-acid ones, smaller in size, larger in A/H capacity, service life much longer, and superior to lead ones in all respects.

This is decided by everyone for themselves, depending on the purpose of the generator, operating conditions and financial capabilities.

If you are going to use a hydro generator to power household electrical appliances designed to power an industrial network 220/50Hz, you will have to use voltage and current converters.

These devices D.C. batteries at 12 or 24 V are converted into alternating current voltage 220V. They come in different capacities; you need to choose depending on the current what maximum load you are going to use.

They are connected according to the above diagram instead of the load; the simplest converter of low power can be assembled yourself.

This circuit has been tested for years, works like a clock, is simple, and does not require configuration. The disadvantage is that it is low-power 100W.

Use economical fluorescent lamps of 13-15 W or LED lamps of 5-10 W are enough to illuminate a private house, garage and even a yard at night. 15 W lamps are as bright as 80 W incandescent lamps.

If you need more power to fully operate the power grid, you can buy industrial converters. There is a large assortment of 12/220V on sale; 24/220V; 48/220V, power up to 5 kW or more.

The Pulso IMU-800 inverter converts 12V direct current into 220V/50Hz alternating current. maximum output power 800W. This is enough
enough for lighting, connecting a TV, refrigerator; for irons and boilers, more powerful inverters will be needed.

Assembling a homemade magnet generator

Many people make a hydroelectric generator with their own hands, using the method of assembling a generator using neodymium magnets. You can take a car wheel hub with a brake disc as the basis on which the entire structure will be mounted.

Factory assembled, reliable and well balanced; disks with permanent magnets are attached to the rotating part, between which the disk with the rotor windings will be fixed.

The advantage of a permanent magnet generator is that the magnetic field is controlled, this is achieved:

• minimum gap between rotor and stator
• through a magnetically conductive disk power lines all magnets are connected to each other

Therefore, the disks of the rotating rotor must be magnetically conductive; with a different material, the generator power will be halved. We draw the disks into 12 identical sectors and then glue them evenly along the perimeter of the disk in each sector. super glue magnets with a diameter of 25mm and a thickness of 5mm.

The poles of the magnets alternate through one (S-N-S-N....) and so on in a circle. You can increase the number of magnets and windings, there will be more poles, this will allow you to achieve more power at lower speeds.

But in our case, 12 magnets, windings with 08-1 mm wire, 100 turns each, generate sufficient power to charge a 12 V starter battery.

A wheel with a diameter of 5 m, rotating at a speed of 150 rpm, produces a current of at least 1A; at 200 rpm, the charging current reaches 4A, this is quite enough.

Winding connection diagram

We make the diameter of the disk 30-35 cm, depending on the size of the hub you have chosen.

In our version, the magnets are round, but it is better to install rectangular ones 35x25x5mm, the greater the magnetic flux, and therefore the greater the power of the generator.

At the same time, the stator windings are made oval, the size of magnets. When installing the stator, the magnets must coincide with the center of the windings.

The thickness of the stator disk with windings must be the same as the thickness of the disks with magnets. We place the windings on a plywood disk and connect them in series with each other according to the specified star circuit.

After connecting and insulating the contacts, the wires are carefully laid along internal diameter so that they do not touch the rotating parts of the structure. After which they are filled epoxy resin. For reliability, you can cover the poured surface with fiberglass, press it a little, then once again generously saturate the fiberglass with epoxy resin on top.

Such measures exclude mechanical damage windings and moisture ingress. After drying, we assemble the generator plates on the hub platform.

Through the mounting holes, we put the first disk on the long bolts of the rotating disk of the hub, fixing the magnets outward with clamping nuts.

Next, the stator disk with windings is put on, and lastly, the second disk is put on with magnets inside. The discs are fixed with tension nuts so that the gap between them is uniform over the entire plane and is no more than 3 mm. After assembly, rotate to check for vibration and runout, and adjust if necessary.

When assembling a hydrogen generator with your own hands at home, you should understand that direct connection of the generator to the wheel simplifies the design, but this is not always the case ideal conditions supplying water flow to the wheel.

In some places it is necessary to use torque transmission schemes through a system of additional shafts, gears or belt drives, this reduces power.

For those who don’t want to do a lot of fiddling, drilling and gluing, there is absolutely simple options you can buy a reliable Chinese generator, manual drive, or rather foot drive. Such generators are used in cycling simulators, they combine business with pleasure, and are convenient in emergency situations.

Generators NJB-800-12 are very practical, have Beautiful design, compact.

At a rotation speed of 250 rpm, the output power is 500W, at 500 rpm, 800W. 12V.

It is convenient to transport it in the trunk of a car to a campsite for use water resources You only need to attach the blades to the wheel.

Everything is good, but there is one drawback: it costs almost 30 thousand rubles, not everyone can afford it. If there is a suitable water source, modern technologies allow you to independently make a reliable hydrogenerator, the most main element in this project it is your desire. How to make a manual generator on video:

First, let's define the operating principle and types of small hydroelectric power plants. The flow of a river or a falling water stream rotates the turbine blades and a hydraulic pipeline, which is connected to an electric generator - the latter generates electricity. Modern compact hydroelectric power plants have automatic control with the ability to instantly switch to manual mode in case emergency situation. The designs of modern factory hydroelectric power plants allow production to be minimized construction work when installing equipment.

Types of mini hydroelectric power plants

Mini power plants include generating devices with a capacity from 1 to 3000 kW. Fundamentally, the thermal power plant consists of:

1. turbines (water intake device);
2. generating block;
3. control systems.

According to the type of water resources used for generation, mini hydroelectric power stations are:

• Channel rivers. Such stations are built on small lowland rivers with reservoirs.
• Mountain. Stationary stations that use the energy of fast mountain currents.
• Industrial. Stations that use differences in water flow at industrial enterprises.
• Mobile. Stations using reinforced hoses for water flow.

Dam types of stations are characterized by high power, but the construction of a dam is expensive, and in this case it is impossible to do without permits. To get involved with officials in our country is not just to complicate your life, but to call into question the implementation of the most good intentions, so let’s abandon this idea right away.

How does a mini hydroelectric power station work?

The principle diagram of the operation of a hydroelectric power station can be chosen from several options:

• Garland hydroelectric power station. From one bank of the river to the other, a cable with rotors strung on it is laid under water. The current rotates the rotors and, accordingly, the cable itself. One end of the cable is in a bearing, the other is connected to the generator.
• Propeller. An underwater structure resembling a wind turbine with narrow blades and a vertical rotor. A blade with a width of only 20 mm at a high rotation speed will provide minimal resistance. A blade of this width is selected at a flow speed of 0.8–2.0 m per second.
• Water wheel. A wheel with blades, partially submerged in the flow, and located at right angles to the surface of the water. The flow of water presses on the blades, rotating the wheel.
• Rotor Daria. Vertical rotor with complex blade surfaces. The liquid flowing around the blades creates different pressures, causing rotation.

The photo shows a mini hydroelectric power station based on a water wheel

How to estimate the potential capacity of mini hydroelectric power stations

Before building a mini hydroelectric power station with your own hands, you need to determine the power you can count on. There is a reference relationship between the speed of water flow and the power that can be removed from the shaft in kW with a screw diameter of 1 m.

The speed of the flow is determined by measuring the time it takes for a chip thrown into water to travel a certain distance. Having made simple calculations, we obtain the flow speed in meters per second. If in in this case speed is less than 1 m/sec, then the construction of a hydroelectric power station will not be economically feasible.

At a flow speed of 2.5 m/s, the power will be 0.86 kW, at 3 m/s - 1.24 kW, at 4 m/s - 2.2 kW. The relationship is described by the dependence: the power of a hydroelectric power station is proportional to the cube of the water flow velocity. If the flow velocity at the proposed construction site is low, you can try to increase it by installing a difference in flow heights or by installing a drain pipe with a variable diameter at the outlet of the reservoir. The smaller the outlet diameter of the pipe, the higher the flow rate.

How to make a mini hydroelectric power station at home

The operating principle of a small homemade hydroelectric power station can be understood using the example of a bicycle with a headlight and a dynamo (generator).

1. From roofing iron we make three blades with a length equal to the radius of a bicycle wheel (the distance from the central hub to the wheel rim) and a width of 3-4 cm.
2. We install the blades between the spokes of the wheel, bending the edge of the blade around the spokes to secure it. The blades should be aligned evenly while maintaining the same angles between them.
3. We immerse the wheel with blades in a fast river to a depth of one third to half the diameter of the wheel. The generated electricity will be enough, for example, to light a tent.

Drawing of one of the options for constructing a mini hydroelectric power station

An example would be a small hydroelectric power station for farm power 3-5 kW from scrap materials:

1. The rotor can be made from an old metal cable drum with a diameter of 2.2 m. Using a grinder and welding at an angle of 45 degrees to the radius, 18 blades need to be welded. The rotor rotates on bearings. Support – metal pipe or angle.
2. On the rotor you need to install a chain gearbox with a gear ratio (gear ratio) of 4. Next, the rotation will be transmitted through the VAZ 2101 driveshaft. The use of a driveshaft will reduce vibration, and the coaxiality of the drive and generator when using the shaft will be uncritical.
3. You will need a step-up gearbox (coefficient - 40) and a three-phase generator. The generator rotation speed is about 3000 rpm. The total reduction ratio of the two gearboxes will be 40 x 4 = 160. The generator should be covered with a casing to protect it from moisture and safety. The estimated rotation of the water wheel should be about 20 revolutions per minute.
4. An asynchronous motor can be adapted for the generator, and the control unit can be taken from any small machine. You will need a VVG NG cable 2x4 long from the rotor to farm buildings.

conclusions

The total manufacturing costs will be about 10-15 thousand rubles. The main expense item is wage welder and worker helping to make and assemble the structure.

The main advantages of such equipment are the low cost of electricity, environmental Safety, inexhaustibility of the energy source and simplicity of design.