Conditions for installing a hydroelectric power station
Despite the tempting cheapness of the energy generated by a hydro generator, it is important to take into account the characteristics of the water source whose resources you plan to use for your own needs.
After all, not every watercourse is suitable for operating a mini-hydroelectric power station, especially year-round, so it doesn’t hurt to have in reserve the ability to connect to a centralized main line. After all, not every watercourse is suitable for operating a mini-hydroelectric power station, especially year-round, so it doesn’t hurt to have a reserve option connection to a centralized highway.
A few pros and cons
The main advantages of an individual hydroelectric power station are obvious: inexpensive equipment that generates cheap electricity, and also does not harm nature (unlike dams that block the flow of a river). Although the system cannot be called absolutely safe, the rotating elements of the turbines can still cause injuries to the inhabitants of the underwater world and even people.
To prevent accidents, the hydroelectric station must be fenced, and if the system is completely hidden by water, a warning sign must be installed on the shore
Advantages of mini-hydroelectric power stations:
- Unlike other “free” energy sources (solar panels, wind generators), hydraulic systems can operate regardless of the time of day and weather. The only thing that can stop them is the freezing of the reservoir.
- To install a hydrogenerator, it is not necessary to have a large river - the same water wheels can be successfully used even in small (but fast!) streams.
- The units do not emit harmful substances, do not pollute water and operate almost silently.
- To install a mini-hydroelectric power station with a capacity of up to 100 kW, you do not need to obtain permits (although everything depends on the local authorities and the type of installation).
- Excess electricity can be sold to neighboring houses.
As for the disadvantages, insufficient current strength can become a serious obstacle to the productive operation of the equipment. In this case, it will be necessary to build auxiliary structures, which entails additional costs.
If the potential energy of a nearby river, based on rough calculations, is not enough to generate electricity in a volume sufficient for practical use, it is worth paying attention to methods for constructing wind generators. A windmill will serve as an effective addition
Measuring the strength of water flow
The first thing you need to do to think about the type and method of installation of the station is to measure the speed of water flow at your favorite source.
The easiest way is to lower any light object (for example, a tennis ball, a piece of foam plastic, or a fishing float) onto the rapids and use a stopwatch to measure the time it takes for it to swim the distance to some landmark. The standard distance for the “swim” is 10 meters.
If the reservoir is located far from the house, you can build a diversion channel or pipeline, and at the same time take care of height differences
Now you need to divide the distance traveled in meters by the number of seconds - this will be the speed of the current. But if the resulting value is less than 1 m/sec, it will be necessary to erect artificial structures to speed up the flow due to elevation changes.
This can be done with the help of a collapsible dam or a narrow drain pipe. But without a good flow, the idea of a hydroelectric station will have to be abandoned.
Hydroelectric power plants for non-industrial purposes
Hydroelectric power plants are structures that can convert the energy of water movement into electricity. Alternative “green” electricity suppliers are so far only actively used in the West. In our country, this promising industry is only taking its first timid steps.
Small private hydroelectric power plants can be dams on large rivers, generating from ten to several hundred megawatts, or mini-hydroelectric power plants with a maximum power of 100 kW, which is quite enough for the needs of a private home. Let’s find out more about the latter.
Garland station with hydraulic screws
The structure consists of a chain of rotors attached to a flexible steel cable stretched across the river. The cable itself plays the role of a rotation shaft, one end of which is fixed on the support bearing, and the other activates the generator shaft.
Each hydraulic rotor of the “garland” is capable of generating about 2 kW of energy, however, the water flow speed for this must be at least 2.5 meters per second, and the depth of the reservoir should not exceed 1.5 m.
The principle of operation of a garland hydroelectric power station is simple: the water pressure spins the hydraulic screws, which rotate the cable and force the generator to produce energy
Garland stations were successfully used back in the middle of the last century, but the role of propellers was then played by homemade propellers and even tin cans. Today, manufacturers offer several types of rotors for various operating conditions.
They are equipped with blades of different sizes, made of sheet metal, and allow you to obtain maximum efficiency from the operation of the station.
But although this hydrogenerator is quite simple to manufacture, its operation requires a number of special conditions that are not always feasible in real life. Such structures block the river bed, and it is unlikely that your neighbors along the bank, not to mention representatives of environmental services, will allow you to use the energy of the stream for your purposes.
In addition, in winter, the installation can only be used on non-freezing reservoirs, and in harsh climates it can be preserved or dismantled. Therefore, garland stations are erected temporarily and mainly in deserted areas (for example, near summer pastures).
Rotary stations with a capacity of 1 to 15 kW/hour generate up to 9.3 MW per month and allow you to independently solve the problem of electrification in regions remote from centralized highways
A modern analogue of a garland installation is submersible or floating frame stations with transverse rotors. Unlike their garland predecessor, these structures do not block the entire river, but use only part of the riverbed, and they can be installed on a pontoon/raft or even lowered to the bottom of the reservoir.
Vertical Daria rotor
The Darrieus rotor is a turbine device that was named after its inventor in 1931. The system consists of several aerodynamic blades fixed on radial beams and operates by differential pressure using the “lifting wing” principle, which is widely used in shipbuilding and aviation.
Although such installations are mostly used to create wind generators, they can also work with water. But in this case, precise calculations are needed to select the thickness and width of the blades in accordance with the strength of the water flow.
The Daria rotor resembles a “windmill”, only installed under water, and it can operate regardless of seasonal fluctuations in flow speed
Vertical rotors are rarely used to create local hydroelectric power stations. Despite the good efficiency indicators and the apparent simplicity of the design, the equipment is quite complex to operate.
Before starting work, the system needs to be “spinned up”, but only the freezing of the reservoir can stop the running station. Therefore, the Darrieus rotor is used mainly in industrial enterprises.
An interesting solution in the field of designing small hydroelectric power plants with a vertically operating turbine was proposed by the Austrian inventor Franz Zotleterer:
A significant advantage of whirlpool stations is quite rightly considered to be the preservation of fish resources. The operation of a vertical turbine does not harm living organisms of the river. In addition, mud does not linger on the walls of structures due to the specific movement of water flow.
Underwater screw propeller
In fact, this is the simplest air windmill, only it is installed under water. The dimensions of the blades, in order to ensure maximum rotation speed and minimum resistance, are calculated depending on the force of the flow. For example, if the current speed does not exceed 2 m/sec, then the width of the blade should be within 2-3 cm.
An underwater propeller is easy to make with your own hands, but it is only suitable for deep and fast rivers - in a shallow body of water, rotating blades can cause injury to fishermen, swimmers, waterfowl and animals
Such a windmill is installed “towards” the flow, but its blades operate not due to the pressure of the water pressure, but due to the generation of lifting force (on the principle of an airplane wing or a ship’s propeller).
Water wheel with blades
A water wheel is one of the simplest versions of a hydraulic engine, known since the times of the Roman Empire. The efficiency of its operation largely depends on the type of source on which it is installed.
The pouring wheel can rotate only due to the speed of the flow, and the filling wheel can rotate only with the help of the pressure and weight of the water falling from above onto the blades
Depending on the depth and bed of the watercourse, different types of wheels can be installed:
- Submerged (or bottom-flowing) - suitable for shallow rivers with fast currents.
- Medium-flow - located in channels with natural cascades so that the flow falls approximately in the middle of the rotating drum.
- Flood (or top-mounted) - installed under a dam, pipe or at the bottom of a natural threshold so that the falling water continues its path through the top of the wheel.
But the principle of operation for all options is the same: water falls on the blades and drives a wheel, which causes the generator for the mini-power station to rotate.
Manufacturers of hydraulic equipment offer ready-made turbines, the blades of which are specially adapted to a certain speed of water flow. But home craftsmen make drum structures the old fashioned way - from scrap materials.
The following photo selection will help you get acquainted with the steps of constructing the simplest version of a mini hydroelectric power station:
Perhaps the lack of optimization will affect efficiency indicators, but the cost of homemade equipment will be several times cheaper than a purchased analogue. Therefore, a water wheel is the most popular option for organizing your own mini-hydroelectric power station.
Do-it-yourself mini hydroelectric power station
The design of a hydroelectric power station is quite complex, so it will be possible to build only a small station on your own, which will save on electricity or provide energy to a modest household. Below are two examples of the implementation of a homemade hydroelectric power station.
How to make a mini hydroelectric power station from a bicycle
This version of the hydroelectric power station is ideal for cycling trips. It is compact and lightweight, but can provide energy to a small camp set up on the banks of a stream or river. The resulting electricity will be enough for evening lighting and charging mobile devices.
To install the station you will need:
- Front wheel from a bicycle.
- A bicycle generator that is used to power bicycle lights.
- Homemade blades. They are cut out in advance from sheet aluminum. The width of the blades should be from two to four centimeters, and the length should be from the wheel hub to its rim. There can be any number of blades; they need to be placed at the same distance from each other.
To launch such a station, it is enough to immerse the wheel in water. The immersion depth is determined experimentally, approximately from a third to a half of the wheel.
How to build a mini-hydroelectric power station based on a water wheel
To build a more powerful station for permanent use, more durable materials will be needed. Metal and plastic elements, which are easier to protect from exposure to the aquatic environment, are best suited. But wooden parts are also suitable if you soak them in a special solution and paint them with waterproof paint.
The station requires the following elements:
- Steel cable drum (2.2 meters in diameter). The rotor-wheel is made from it. To do this, the drum is cut into pieces and welded again at a distance of 30 centimeters. Blades (18 pieces) are made from the remains of the drum. They are welded to a radius at an angle of 45 degrees. To support the entire structure, a frame is made from angles or pipes. The wheel rotates on bearings.
- A chain gear is installed on the wheel (the gear ratio should be four). To make it easier to bring the axes of the drive and generator together, as well as to reduce vibration, rotation is transmitted through the cardan from the old car.
- An asynchronous motor is suitable for the generator. To it should be added another gear reducer with a coefficient of about 40. Then for a three-phase generator with 3000 revolutions per second with a total reduction coefficient of 160, the number of revolutions will decrease to 20 revolutions per minute.
- Place all electrical items in a waterproof container.
The described starting materials can easily be found in a landfill or from friends. You can pay specialists for cutting a steel drum with a grinder and for welding (or do everything yourself). As a result, a hydroelectric power station with a capacity of up to 5 kW will cost a small amount.
Generating electricity from water is not that difficult. It is more difficult to build an autonomous power supply system based on a homemade hydroelectric power station, maintain the station in working order and ensure the safety of people and animals around it.
Turbine assembly
To assemble the turbine, we must pierce the center of the plug from 3 to 5 cm with a 1/4 “drill. Place the cork on the template using a pencil and mark where the spoons will be placed.
Using a knife, drill holes in the marked locations. Cut 8 plastic spoons, leaving a centimeter from the handle. Secure the spoons into the cork and adjust the angle and depth of each spoon so that they have the same angle relative to the cork. Secure all spoons with silicone. Take a 4 liter rectangular plastic bottle, cut it with scissors or a sharp knife, as shown in the photo.
Using a ruler, measure the center on one of the sides. Mark this point with a permanent marker. Repeat on the opposite side. Drill through both sides with a 1/4 drill bit at the mark you made. Using scissors, cut 2 1/4" PVC pipes. The tube should pass through the center of the plastic container, the stator and the shaft as shown in Fig.
The dowel is inserted through the turbine and container as shown in the picture above. The turbine is located inside the container so that the spoons are below the bottleneck. We also adjust the position of the vinyl hose so that they do not touch the inside of the container. Now place the second tube after installing the stator. The tubes help keep all parts of the turbine in place as it spins. We turn on the turbine to check that the turbine does not fall inside the container. Insert the rotor onto the shaft. The magnets should be about 2 or 3mm from the coils. Rotate the shaft to check that the magnets are not caught on the coils. Adjust the angle of the disk if necessary. If the rotor rotates smoothly, it locks the position of placing the hot glue on the dowel. Place the container next to the pipe and rotate the turbine with water. Use a multimeter to measure the energy they produce. Here are some video examples on creating a home hydroelectric power station:
Areas and advantages of application
An alternative to using oil stations is to use compressor-type units. However, if we compare installations of these types, then hydraulic power stations for hydraulic drives have a number of advantages.
- Due to the more compact size of such equipment, you have to spend significantly less money on its transportation, installation and operation.
- When operating hydraulic oil stations, significantly less energy resources are consumed, which also leads to a reduction in financial costs.
- Oil stations, compared to compressor equipment, have higher productivity and efficiency of use.
- The wide versatility of such equipment allows it to be connected to devices of various types and power.
- Compared to compressor equipment, oil stations produce significantly less noise during operation.
- Due to the ease of use and maintenance, specially trained, highly qualified personnel are not required to work with such equipment.
Pumping station as part of a hydraulic pipe bender
Hydraulic stations, naturally, are used to equip equipment on which a hydraulic drive is installed. In fact, with the help of such devices it is possible to operate a mechanism for almost any purpose. That is why hydraulic oil stations are successfully used in many areas. The technical capabilities and versatility of such devices allow them to be used for:
- static type hydraulic tools;
- electrical installation equipment;
- dynamic type hydraulic tools;
- equipment for railway and construction purposes;
- pumps and slurry pumps;
- equipment for drilling operations;
- injection molding machines;
- press equipment;
- devices used to lift and move large and heavy loads;
- equipping test stands;
- technological equipment for various purposes.
Oil station of lathe
Using hydraulic oil stations, they pump and purify oil, as well as lubricate and cool working elements of equipment for various purposes. Oil stations are used quite actively in cases where it is necessary to test pipeline systems, hydraulic equipment, hydraulic cylinders and various equipment.
If we talk about the areas of activity in which hydraulic oil stations are most actively used, then this should include:
- mechanical engineering;
- metallurgy;
- energy;
- construction;
- Agriculture;
- transport sector.
Finding the right water
Recently I saw a short video that showed how, in an ordinary Indian village, students from one of the Western colleges decided to build a mini hydroelectric power station. There is no electricity in that wilderness, young people are fleeing to the cities, but what will happen if you give the residents electricity? There is no river as such in the village, but there is a reservoir. A natural bowl with a huge amount of water is located slightly above the village level. What did the students come up with?
With their smart heads they realized that since there is no flow from Nature here, it can be created! By the hands of hired workers, a covered long pipe with a diameter of a meter was installed, and one end of it was closed onto a reservoir, and the other, below, went into a small and slow-moving river. Due to the difference in height, water from the reservoir rushed down through the pipe, accelerating more and more, and at the exit a rather powerful flow was already created, which rested against the blades of the mini hydroelectric power station. The pipe in which the water of the reservoir is enclosed runs down the hillside so picturesquely that it seems as if a huge python is slowly crawling from top to bottom and instills terror in the local residents with its size. You want to touch it with your hands, feel it, feel its power.
If something similar is being created in an Indian village, then why not try to do the same in a Russian village? If there is no fast-flowing river nearby, but there is a reservoir, then the construction of a mini hydroelectric power station is also possible. You just need to look at the terrain, but one thing is clear: the reservoir - be it natural or artificial - must be located higher than the place where the hydroelectric power station will be installed. If the height difference is significant, even better! The flow of water will run stronger from top to bottom, which means that the possible power of the generated electricity will increase.
It is not necessary to buy expensive pipes to organize an artificial water flow. You can make a kind of gutter with your own hands, and let the water from the reservoir accelerate through it. To begin with, it is better to take any available means, old pipes, albeit of small diameter for now, and build a trial version of draining water from the reservoir located above. This way it will be possible to measure the flow speed (I already wrote how to do this earlier). If there is a fast-flowing river nearby, then there is no need to build either dams, gutters, or artificially create a flow of water. Mini hydroelectric power stations in the form of a garland, propeller, Dardieu rotor or water wheel can be installed in such places without any problems.
It will be important to protect the structure. How? A protective screen made of mesh or a diffuser should be installed in front of the mini hydroelectric power station so that fragments of trees, or even whole logs, floating along the river, as well as live and dead fish, and all kinds of debris, do not fall on the turbine blades, but float past
Turbine assembly
To assemble the turbine, we must pierce the center of the plug from 3 to 5 cm with a 1/4 “drill. Place the cork on the template using a pencil and mark where the spoons will be placed.
Using a knife, drill holes in the marked locations. Cut 8 plastic spoons, leaving a centimeter from the handle. Secure the spoons into the cork and adjust the angle and depth of each spoon so that they have the same angle relative to the cork. Secure all spoons with silicone. Take a 4 liter rectangular plastic bottle, cut it with scissors or a sharp knife, as shown in the photo.
Using a ruler, measure the center on one of the sides. Mark this point with a permanent marker. Repeat on the opposite side. Drill through both sides with a 1/4 drill bit at the mark you made. Using scissors, cut 2 1/4" PVC pipes. The tube should pass through the center of the plastic container, the stator and the shaft as shown in Fig.
The dowel is inserted through the turbine and container as shown in the picture above. The turbine is located inside the container so that the spoons are below the bottleneck. We also adjust the position of the vinyl hose so that they do not touch the inside of the container. Now place the second tube after installing the stator. The tubes help keep all parts of the turbine in place as it spins. We turn on the turbine to check that the turbine does not fall inside the container. Insert the rotor onto the shaft. The magnets should be about 2 or 3mm from the coils. Rotate the shaft to check that the magnets are not caught on the coils. Adjust the angle of the disk if necessary. If the rotor rotates smoothly, it locks the position of placing the hot glue on the dowel. Place the container next to the pipe and rotate the turbine with water. Use a multimeter to measure the energy they produce. Here are some video examples on creating a home hydroelectric power station:
There are various options for installing a water wheel. At the same time, the difference in height of the water flow can be organized artificially in order to increase the productivity of mini-hydroelectric power plants.
Water wheel installation options:
- Bottom water wheel (installed directly into the water flow);
- Medium water wheel (installed at the point where the height of the water flow differs so that the falling water flow falls approximately in the middle of the wheel);
- Top water wheel (installed at the point where the height of the water flow differs so that the falling water flow hits the top of the wheel)
Manufacturers of equipment for mini-hydroelectric power plants offer special turbine wheels equipped with blades optimized for a particular speed of water flow. Craftsmen make water wheels in the same way as their ancestors built water mills, that is, without any optimization. On the one hand, this reduces the efficiency of the installation, on the other hand, it is much cheaper than purchasing “store-bought” equipment.
Garlyandnaya hydroelectric power station
This type of mini-hydroelectric power station consists of a cable stretched over a river bed and secured in a support bearing. Turbines of small size and weight (hydraulic rotors) are hung and rigidly fixed on it in the form of a garland. They consist of two half-cylinders. Due to the alignment of the axes when lowered into the water, a torque is created in them. This causes the cable to bend, stretch and begin to rotate. In this situation, the cable can be compared to a shaft that serves to transmit power. One of the ends of the cable is connected to the gearbox. The power from the rotation of the cable and hydraulic propellers is transmitted to it.
The presence of several “garlands” will help increase the power of the station. They can be connected to each other. Even this does not greatly increase the efficiency of this hydroelectric power station. This is one of the disadvantages of such a structure.
Another disadvantage of this species is the danger it creates for others. This kind of station can only be used in deserted places. Warning signs are required.
A simple alternative
Mini-hydroelectric power plants are generally one of the best solutions regarding alternative sources of electricity. They can be installed in a country house or country house. The disadvantage of such structures is that their construction is possible only under certain conditions - the presence of a water flow is necessary. In addition, the construction of this structure in your yard requires permission from local authorities.
The operating principle of a mini-hydroelectric power station for the home is quite simple. Water falls on the turbine, causing the blades to rotate. They, in turn, drive the hydraulic drive due to torque or pressure difference. The received power is transferred from it to an electric generator, which produces electricity.
Components of mini hydroelectric power station
- Hydraulic turbine with blades connected by a shaft to a generator
- Generator. Designed to generate alternating current. Attached to the turbine shaft. The parameters of the generated current are relatively unstable, but nothing similar to power surges occurs during wind generation;
- The hydraulic turbine control unit provides start and stop of the hydraulic unit, automatic synchronization of the generator when connected to the power system, control of the operating modes of the hydraulic unit, and emergency stop.
- The ballast load unit, designed to dissipate power that is currently unused by the consumer, avoids failure of the electric generator and the monitoring and control system.
- Charge controller/stabilizer: designed to control battery charge, control blade rotation and voltage conversion.
- Battery bank: a storage tank, the size of which determines the duration of the autonomous operation of the object powered by it.
- Inverter, Many hydro generation systems use inverter systems. If there is a battery bank and a charge controller, hydraulic systems are not much different from other systems using renewable energy sources.
Mini pumped storage power plant
In the middle of the last century, British inventor Alvin Smith proposed an original design for a small wave pumped storage power station. The installation is based on two floats that can move relative to each other. The upper one is swayed by the waves, the lower one is connected to the seabed with a chain and an anchor. There is an automatic adjustment of the height of the upper float depending on the sea level, which is constantly changing due to the ebb and flow of the tides, using a telescopic pipe that expands and folds under the influence of Archimedes forces and gravity. Between the floats is a “pumping station” (a cylinder with a double-acting piston that pumps water as it moves up and down). It supplies water to the land, to the mountains. A pool is built in the mountains, in which water is accumulated and released back into the sea during peak load hours, rotating a water turbine along the way.
The installation is capable of lifting sea water to a height of up to 200 m and generating a power of 0.25 MW.
* * *
Natural conditions in Russia are very favorable for the development of small hydropower, and with the current level of availability of information and all kinds of materials, craftsmen can make a mini-hydroelectric power station even with their own hands, if only there was a suitable river or stream. Therefore, small hydroelectric power stations as alternative energy sources have every chance to become widespread again in our country.
Typical hydraulic station diagram
- Tank
- Pump
- Pressure filter
- Suction filter
- Drain filter
- Safety valve
- Hydraulic distributor
Tank
The hydraulic tank serves to store the working fluid circulating in the hydraulic system, release air from it and partially cool it. When designing a tank, normal conditions for suction and deaeration of the working fluid must be ensured. The size and shape of the tank are closely related to the temperature regime in the hydraulic drive, since some of the thermal energy released during the operation of the hydraulic system is transferred to the environment through the walls of the tank. During the production process, all tanks undergo mandatory leak testing and subsequent painting using special technologies and materials that are resistant to hot oil. To monitor the fluid level in the hydraulic tank, there is a visual level indicator. The fluid is drained through a drain hole or tap located at the bottom of the hydraulic tank. We have developed hydraulic tanks of various designs and sizes, which you can familiarize yourself with in the corresponding section of the catalog.
Pump
Hydraulic pumps are power elements of a hydraulic drive that convert the mechanical energy of rotation of the drive shaft into the hydraulic energy of the flow of working fluid, which is supplied through pipelines to the hydraulic motors. The most common type of pump unit for pumping hydraulic fluid into the system is made on the basis of a gear pump. Operating pressure range from 2 to 310 bar, flow rates from 0.5 to 100 l/min (standard range of pumps) and above 100 l/min. up to 5000 l/min. (supplied upon request). Such solutions are widely used in mobile and industrial technology. The next type of pumping units is with vane pumps. This type of pump provides more uniform flow compared to gear pumps and greater productivity. The operating pressure range is somewhat lower and rarely exceeds 160 bar (the imported industry produces pumps of 210 bar or more). Vane pumps can be produced as single- and double-flow, with fixed and adjustable performance, as well as a through shaft for installing an additional pump, for example, a gear pump. This type of pump is common in machine tools and hydraulic drives for a wide range of applications. Pumping units with axial piston pumps are characterized by compactness and the resulting minimum weight. Due to the use of working bodies with small radial dimensions and, therefore, a relatively small moment of inertia, such machines make it possible to quickly regulate the rotation speed. In addition, the advantages of axial piston pumps include the ability to operate at high pressures (up to 400 bar) and high efficiency values (up to 95%). Among the disadvantages of machines of this type, it should be noted the considerable cost, complexity of the design, as well as significant feed pulsation. Axial piston pumps are most widely used in hydraulic drives of machines operating under medium and heavy external load conditions with high switching frequencies. It is possible to manufacture units with 2-3 in-line pumps driven by one electric motor, which makes it possible to reduce the size of the system and use various combinations of performance and pressure to solve a wide range of problems.
Advantages and disadvantages of microhydropower
The advantages of a mini hydroelectric power station for the home include:
- Environmental safety (with reservations for juvenile fish) of equipment and the absence of the need to flood large areas with colossal material damage;
- Ecological purity of the energy produced. There is no effect on the properties and quality of water. Reservoirs can be used both for fishing activities and as sources of water supply for the population;
- Low cost of generated electricity, which is several times cheaper than that generated at thermal power plants;
- Simplicity and reliability of the equipment used, and the possibility of its operation in autonomous mode (both within and outside the power supply network). The electric current they generate meets GOST requirements for frequency and voltage;
- The full service life of the station is at least 40 years (at least 5 years before major repairs);
- inexhaustibility of resources used to generate energy.
The main disadvantage of micro-hydroelectric power stations is the relative danger for the inhabitants of aquatic fauna, because Rotating turbine blades, especially in high-speed flows, can pose a threat to fish or fry. The limited application of the technology can also be considered a disadvantage.
About the types of mini-hydroelectric power stations
Small hydropower is developing today, and this is an excellent solution for saving energy resources. A generator for a mini-hydroelectric power station can be purchased at a store, or you can make it yourself.
There are several options for manufacturing small hydroelectric power stations:
- Water wheel. It is a large drum with blades placed between round surfaces. Installed perpendicular to the water flow. Immersed in water approximately half the width of the blade. There are designs of turbine wheels with blades designed for a given water flow, but these designs are complex and are best purchased in a store.
- Rotor Daria. A mini-hydroelectric power plant of this kind is equipped with a mechanism with a vertical axis of rotation. Used to convert electricity. Due to the flow of fluid between structural elements, pressure is created. The effect of its operation is reminiscent of seaworthy hydrofoils. This principle is used in the design of wind generators.
- Garland hydroelectric power station. Light turbines resembling garlands in appearance are placed on a cable located perpendicular to the river. The cable performs the function of a shaft, and the rotational movement is transmitted to the generator. The flow created by the water causes the rotors to rotate, and the rotors cause the cable to rotate.
- Propeller. The rotor is located vertically, like in wind-powered power plant designs, and plays the role of a propeller. Unlike an air device, the blades of this device are small in width and their size can be only 2 cm. This will ensure high rotation speed and minimal resistance. For high-speed water flows, other sizes can also be used. The movement of the propeller is ensured by the force of rising water, and not by its pressure. It can be compared to an airplane wing. The movement of the blades, relative to the flow, is perpendicular, and not along the flow of water.
Portable hydroelectric power stations are easy to use and their designs are simple.
Advantages of mini-hydroelectric power stations
Small hydropower plants have a number of advantages:
- The mini-hydraulic turbine operates quietly, without noise;
- there are no emissions of harmful substances into the atmosphere during operation;
- does not in any way affect the quality characteristics of water;
- does not depend on external conditions;
- small hydroelectric power stations generate energy continuously throughout the day;
- To ensure work, you can use even a small stream;
- if there is surplus energy, it can be sold and generated income;
- There is no need to obtain a permit to ensure energy production from hydroelectric power stations.
Today, small hydroelectric power plants in Russia are enjoying unprecedented popularity. They are easy to do yourself, or can be purchased at the store. Small hydropower is a profitable business.
Flaws
Along with their advantages, small hydroelectric power plants have some disadvantages:
- A garland small hydroelectric power station poses a danger to others: the moving parts are hidden in the water, the cable is long.
- Low efficiency.
- Rotor Daria. This water generator is difficult to manufacture.
It is recommended to install small hydroelectric power stations after weighing all the positive and negative aspects
It is important to make the right choice: which design to make so that the effect of the work is ensured
Production of hydroelectric power station based on a water wheel
Of course, assembling and erecting a colossus designed to serve an enterprise or settlement of even a dozen houses is an idea from the realm of science fiction. But building a mini-hydroelectric power station with your own hands to save electricity is quite possible. Moreover, you can use both ready-made components and improvised materials.
Therefore, we will consider step by step the manufacture of the simplest structure - a water wheel.
Required materials and tools
To make a mini-hydroelectric power station with your own hands, you need to prepare a welding machine, an angle grinder, a drill and a set of auxiliary tools - a hammer, a screwdriver, a ruler.
Materials you will need:
Wheel assembly and nozzle manufacturing
But if metal is not found in the materials at hand, you can cut circles from waterproof plywood, although the strength and service life of even treated wood cannot be compared with steel. Then you need to cut a round hole on one of the disks for installing the generator.
After this, the blades are made, and at least 16 pieces will be needed. To do this, galvanized pipes are cut lengthwise into two or four parts (depending on the diameter). Then the cutting areas and the surface of the blades themselves must be polished to reduce energy loss due to friction.
The blades are installed at an angle of approximately 40-45 degrees - this will help increase the surface area that will be affected by the flow force
The distance between the two side discs should be as close as possible to the length of the blades. To mark the location for future hubs, it is recommended to make a template from plywood, which will mark the location for each part and the hole for fixing the wheel to the generator. The finished markings can be attached to the outside of one of the disks.
The circles are then installed parallel to each other using solid threaded rods, and the blades are welded or bolted in the desired positions. The drum will rotate on bearings, and a frame made of angles or small diameter pipes is used as a support.
At this stage, the assembly of the drum can be considered complete; all that remains is to equip it with a homemade generator and a nozzle that directs the flow of water
The nozzle is designed for cascade-type water sources - such an installation will allow you to use the flow energy to the maximum. This auxiliary element is made by bending sheet metal, followed by welding the seams, and then mounted on a pipe.
However, if your area has a flat river without rapids or other high-altitude obstacles, this detail is not necessary.
It is important that the width of the nozzle outlet corresponds to the width of the wheel itself, otherwise part of the flow will go “idle” and not reach the blades
Now the wheel needs to be mounted on the axle and mounted on a support made of welded or bolted corners. All that remains is to make a generator (or install a ready-made one) and you can go to the river.
Mini hydroelectric power station for a private house
Rising electricity tariffs and the lack of sufficient capacity make urgent questions about the use of free energy from renewable sources in households. Compared to other sources of renewable energy sources, mini hydroelectric power stations are of interest, since with equal power to a windmill and a solar battery, they are capable of delivering much more energy in an equal period of time. A natural limitation on their use is the lack of a river
If a small river, stream flows near your house, or there are elevation changes on lake spillways, then you have all the conditions for installing a mini hydroelectric power station. The money spent on its purchase will quickly pay for itself - you will be provided with cheap electricity at any time of the year, regardless of weather conditions and other external factors.
The main indicator that indicates the efficiency of using SHPPs is the flow rate of the reservoir. If the speed is less than 1 m/s, then it is necessary to take additional measures to accelerate it, for example, make a bypass channel of variable cross-section or organize an artificial height difference.
Next, the power required by the farm and the geometric features of the channel are determined. All these indicators are taken into account when choosing the type and design of the installed micro-hydroelectric power station.
Flow speed and ways to enhance it
When designing a mini-hydroelectric power station for use as an alternative source of energy for your own home, the following factors should be decisive:
- Proximity of the river to the house. There is no point in installing a homemade station away from home. The further away the installation, the lower its efficiency, because some of the energy will be lost during transmission. In addition, it is more difficult to protect your hydroelectric power station from theft or damage.
- Sufficient flow speed or the possibility of increasing it. The power of the station increases exponentially with increasing water speed.
It's easy to find out the speed. Throw a piece of foam or a tennis ball into the water and time the time it takes for it to swim a certain distance. Then divide the meters by seconds and you will know the speed. The minimum sufficient water speed for a homemade hydroelectric power station is 1 m/s.
If the flow rate of your river or stream is below this value, then it will be increased by a small dam or narrowing pipe. But these options can cause additional difficulties. The construction of a dam requires permission from the authorities, as well as the consent of neighbors.