Home ges on a weak stream. Homemade hydroelectric power plant from an old washing machine
I have always been attracted to getting free energy from natural resources. And somehow I had the idea to make a simple mini power plant that would generate electricity from a passing water stream.
It all started with the idea of using the drum of an old washing machine as a water wheel, a miniature homemade hydroelectric power plant.
Straight blades made of moisture-resistant plywood were attached to the drum using metal corners.
Torque from the water wheel is transmitted by a belt to a bicycle dynamo (DC generator). The generated electricity is fed to the LED. It is enough to turn the wheel slightly with your hand, and the LED will start flashing.
The basis of the whole structure is a bicycle frame.
Two bearings allow the water wheel to spin freely.
The first tests on a small river showed that the water wheel on the frame is set too high, which prevents the flow of water from spinning it normally.
After small changes in the frame design, the wheel began to be located lower and the rotation speed increased dramatically. As a result, the dynamo began to rotate and the 4.5 V LED lit up.
This is how a home-made hydroelectric power station turned out from the old trash.
Further, the mini hydroelectric power station assembly was installed on a small stream.
It produces only a few volts, but they are enough to light the LED.
It was a good experiment to start with.
Further improvement in the project
Further improvement of the water wheel should affect:- Build a mini-dam to increase water pressure. At the same time, it is not planned to completely block the river so that the fish can leave in the second stream.
- Under the dam, install a pipe through which water will flow to a makeshift turbine. Arrange a casing from a rubber conveyor belt in the pipe. By blocking the flow of water through the pipe, you can service the mechanisms.
- According to calculations, the turbine will produce about twice as much power as the water wheel. In addition, replacing the water wheel with a turbine should eliminate the problem of freezing in winter.
- The flow of water will spin the turbine, transferring torque to the generator. The turbine will be held on two bearings made of solid wood. With regular lubrication, they will last a long time. The thrust washer will keep the mechanism from lateral displacement.
- Make metal blades, calculating the angle at which they need to be bent (the power of the hydroelectric power plant depends on this parameter). The blades will need to be screwed using rubber gaskets to avoid their separation.
- To transmit torque, use a shaft assembled from pipes.
- Install generator. Install a pulley smaller than the one mounted on the shaft on the generator. This will increase the speed, which is necessary for the efficient operation of the generator.
If a river or even a small stream flows near your home, then with the help of a home-made mini hydroelectric power station you can get free electricity. It may not be a very big budget replenishment, but the realization that you have your own electricity is much more expensive. Well, if, for example, in the country, there is no central power supply, then even small power capacities will be simply necessary. And so, to create a home-made hydroelectric power station, at least two conditions are necessary - the presence of a water resource and desire.
If both are present, then the first thing to do is to measure the flow rate of the river. It is very simple to do this - throw a twig into the river and measure the time during which it swims 10 meters. By dividing meters by seconds, you get the speed of the current 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 rate by artificially narrowing the channel or by making a small dam if you are dealing with a small stream.
As a guide, you can use the ratio between the flow velocity in m/s and the power of the electricity removed from the propeller shaft in kW (propeller diameter 1 meter). These are experimental data, in reality the received 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.
The power of a homemade mini hydroelectric power station is proportional to the cube of the flow rate. As already mentioned, if the flow rate is insufficient, try to artificially increase it, if this is of course possible.
Types of mini hydroelectric power plants
There are several basic options for homemade mini hydroelectric power plants. 
This is a wheel with blades mounted perpendicular to the surface of the water. The wheel is less than half immersed in the stream. Water presses on the blades and rotates the wheel. There are also turbine wheels with special blades optimized for the liquid jet. But these are rather complex designs, rather factory-made than home-made.
It is a vertical axis rotor used to generate electrical energy. A vertical rotor that rotates due to the pressure difference on its blades. The pressure difference is created due to the fluid flow 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 Darier, a French aeronautical engineer, in 1931. It is also often used in the construction of wind turbines.
garland hydroelectric power station consists of light turbines - gidrovingrotors, 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 end rotates the generator rotor. The cable in this case plays the role of a kind of shaft, the rotational movement of which is transmitted to the generator. The flow of water rotates the rotors, the rotors rotate the cable.
Also borrowed from the designs of wind farms, such a "underwater windmill" with a vertical rotor. Unlike an air propeller, an underwater propeller has blades of a minimum width. For water, a blade width of only 2 cm is sufficient. With this width, there will be a minimum resistance and a maximum rotation speed. This width of the blades was chosen for a flow velocity of 0.8-2 meters per second. At high speeds, other sizes may be optimal. The propeller does not move due to water pressure, but due to the occurrence of lift. Just like an airplane wing. The propeller blades move across the flow rather than being carried along by the flow in the direction of the flow.
Advantages and disadvantages of various homemade mini hydroelectric systems
The disadvantages of a stringed hydroelectric power station are obvious: high material consumption, danger to others (a long underwater cable, rotors hidden in the water, blocking the river), low efficiency. Garland HPP is a kind of small dam. It is advisable to use in deserted, remote places with appropriate warning signs. You may need permission from the authorities and environmentalists. The second option is a small stream in your garden.
Rotor Daria - difficult to calculate and manufacture. At the beginning of work, it needs to be untwisted. But it is attractive in that the rotor axis is located vertically and the power take-off can be made above the water, without additional gears. Such a rotor will rotate with any change in the direction of flow - this is a plus.
The most widespread in the construction of home-made hydroelectric power plants were propeller and water wheel schemes. Since these options are relatively simple to manufacture, require minimal calculations and are implemented at minimal cost, have high efficiency, are easy to set up and operate.
An example of the simplest mini-hydroelectric power station
The simplest hydroelectric power station can be quickly built from an ordinary bicycle with a dynamometer for a bicycle headlight. Several blades (2-3) must be prepared from galvanized iron or not thick sheet aluminum. The blades should be 2-4 cm long from the wheel rim to the hub, and 2-4 cm wide. These blades are installed between the spokes in any improvised way or pre-prepared mounts.
If you are using two blades, then set 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 regular intervals. You can experiment with the depth of immersion of a wheel with blades in water. Usually it is immersed from one third to half.
The option of a camping wind farm was considered earlier.
Such a micro hydroelectric power station does not take up much space and will serve perfectly for cyclists - the main thing is the presence of a stream or river - which is usually the case at the campsite. A mini hydropower plant from a bicycle will be able to light a tent and charge cell phones or other gadgets.
I always wanted to get electricity from the stream that flows around the perimeter of my house. About three years ago I installed a temporary turbine to see if a larger turbine wheel would work.
A demo version of this wheel was made from old sanding pads and wooden pallets for blades.
I used an old Ametec drive motor DC tape as a generator. To make everything complete, I used a mini motorcycle chain and sprockets with 70 and 9 teeth (for wheel rotation and on the engine). The cost of all items resulted in about 30 pounds.
It maxed out at 25 watts and lasted for about a year, mainly due to the limitations of the Ametec motor and wheel size, and pushed me to build a bigger turbo.
First of all, I had to dam the water of the stream, so that the water level was about my chest. Without waiting for the end of summer, I diverted water with the help of a bilge pump and made a dam out of cement.
The turbine wheels for me were made by local construction companies from a durable multi-layer material used to create sheathing and decking in shipbuilding, 13 mm thick. From the same material I made the blades. Finally, I coated the discs and blades with a special water repellant to prolong their life.
I built the base for the turbine from oak logs. The oak turned out to be very stiff, and I had to fiddle while I bolted the logs to the stone frame. I had to drill holes, and for this I had to tie the turbine in order to balance it and fit all the dimensions and tighten the bolts.
The next step after installing the wheel was to resolve the issue with the drive and generator.
Initially I used a Minimoto drive but then the small chain began to slip due to tooth spacing and I decided to purchase 3/8 pitch chains and sprockets from a bearing supplier. The generator supplied a Windblue Power Permanent Magnet Generator (PMG). It is capable of producing 12 V at 150 rpm. It is often used as a converted car alternator. A typical alternator only puts out 12 volts at 3000 rpm. I ordered this motor in the US for £135 including postage.
The wheel turned too slowly, and I had to make a stepped tray under the dam, on which the water was collected in a narrow mouth and poured with greater force onto the blades.
In addition, I fastened the main frame rails with 1 cm steel cable, and where possible, strengthened the base with 1 foot long anchor bolts to protect the device from breakage if the dam suddenly breaks or there is a strong gust of wind.
The turbine is fitted with 4x55AH Brand New batteries. With their help, I constantly recharge my laptop. I also bought two military traction lead batteries 2x110Ah Hawker for lighting the garage and the house. The voltage supply to two different types of batteries comes from different wires.
I have been using this system for about a year. Output power - 50 watts, at the peak it produces up to 500 watts. A couple of times the turbine stopped due to a recession in water, as well as due to the blocking of the main flow during floods. And it works all year round.
Translation: Yaroslav Nikolaevich
The regular increase in electricity prices makes many people think about the issue of alternative sources of electricity. One of the best solutions in this case is a hydroelectric power plant. The search for a solution to this issue concerns not only the scale of the country. Increasingly, you can see mini-hydroelectric power plants for the home (cottage). The costs in this case will be only for construction and maintenance. The disadvantage of such a structure is that its construction is possible only under certain conditions. Water flow is required. In addition, the construction of this structure in your yard requires the permission of local authorities.
Scheme of a mini hydroelectric power plant
- Channel, characteristic of the plains. They are installed on rivers with a slight flow.
- Stationary use the energy of water rivers with a fast flow of water.
- Hydroelectric power plants installed in places where the water flow drops. They are most often found in industrial organizations.
- Mobile, which are built using a reinforced sleeve.
For the construction of a hydroelectric power station, even a small stream flowing through the site is enough. Owners of houses with central water supply should not despair.
One of the American companies has developed a station that can be built into the water supply system at home. A small turbine is built into the water supply system, which is set in motion by the flow of water moving by gravity. This reduces the flow rate of water, but reduces the cost of electricity. In addition, this installation is completely safe.
Even mini-hydroelectric power plants are being built in the sewer pipe. But their construction requires the creation of certain conditions. Water through the pipe should flow naturally due to the slope. The second requirement is that the pipe diameter must be suitable for the equipment. And this cannot be done in a detached house.
Classification of mini hydroelectric power plants
Mini hydroelectric power plants (the houses in which they are used are mostly private sector) are most often one of the following types, which differ in the principle of operation:
- The water wheel is the traditional type and is the easiest to make.
- Propeller. Used in cases where the river has a channel with a width of more than ten meters.
- The garland is installed on rivers with a slight flow. To increase the speed of the flow of water, additional structures are used.
- The Darrieus rotor is usually installed in industrial plants.
The prevalence of these options is due to the fact that they do not require the construction of a dam.
Water wheel
This is a classic type of hydroelectric power plant, which is most popular for the private sector. Mini hydroelectric power plants of this type are a large wheel that can rotate. Its blades are lowered into the water. The rest of the structure is above the channel, forcing the whole mechanism to move. Power is transmitted through a hydraulic drive to a generator that generates current.
propeller station
On the frame in a vertical position there is a rotor and an underwater windmill, which is lowered under water. The windmill has blades that rotate under the influence of the flow of water. The best resistance is provided by blades two centimeters wide (with a fast flow, the speed of which, however, does not exceed two meters per second).
In this case, the blades are set in motion due to the emerging and not due to water pressure. Moreover, the direction of movement of the blades is perpendicular to the direction of flow. This process is similar to how wind farms work, only it works underwater.
Garland hydroelectric power station
This type of mini-hydroelectric power station is a cable stretched over the channel and fixed 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 semi-cylinders. Due to the alignment of the axes, when lowered into the water, a torque is created in them. This leads to the fact that the cable bends, stretches and begins to rotate. In this situation, the cable can be compared to a shaft that serves to transmit power. One end of the rope is connected to the gearbox. Power is transferred to it from the rotation of the cable and hydraulic torches.
The presence of several "garlands" will help to increase the power of the station. They can be connected to each other. Even this does not greatly increase the efficiency of this HPP. 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 mandatory.
Rotor Daria
A mini-hydroelectric power plant for a private house of this type is named after its developer, Georges Darier. This design was patented in 1931. It is a rotor with blades on it. For each of the blades, the necessary parameters are selected individually. The rotor is lowered under water in a vertical position. The blades rotate due to the pressure drop that occurs under the action of water flowing over their surface. This process is similar to the lift force that makes airplanes take off.
This type of HPP has a good efficiency index. The second advantage is that the direction of the flow does not matter.
Among the shortcomings of this, one can single out a complex design and difficult installation.
Advantages of a mini hydroelectric power station
Regardless of the type of construction, mini hydroelectric power plants have a number of advantages:
- Environmentally friendly, do not produce substances harmful to the atmosphere.
- The process of obtaining electricity takes place without the formation of noise.
- The water stays clean.
- Electricity is generated constantly, regardless of the time of day or weather conditions.
- Even a small stream is enough to equip the station.
- Surplus electricity can be sold to neighbors.
- You don't need a lot of permissive documentation.
Do-it-yourself mini hydroelectric power station
You can build to generate electricity yourself. For a private house, twenty kilowatts per day is enough. Even a do-it-yourself mini-hydroelectric power station can handle this value. But it should be remembered that this process is characterized by a number of features:
- Precise calculations are difficult to make.
- The dimensions, thickness of the elements are selected "by eye", only empirically.
- Homemade structures do not have protective elements, which leads to frequent breakdowns and associated costs.
Therefore, if there is no experience and certain knowledge in this area, it is better to abandon this kind of idea. It may be cheaper to purchase a ready-made station.
If you still decide to do everything with your own hands, then you need to start by measuring the speed of the flow of water in the river. After all, it depends on the power that can be obtained. If the speed is less than one meter per second, then the construction of a mini-hydroelectric power station in this place will not justify itself.
Another step that should not be omitted is the calculations. It is necessary to carefully calculate the amount of costs that will be spent on the construction of the station. As a result, it may turn out that hydroelectric power is not the best option. Then you should pay attention to other types of alternative electricity.
A mini-hydro power plant can be the best solution for saving energy costs. For its construction, it is necessary to have a river near the house. Depending on the desired characteristics, you can choose the appropriate version of the hydroelectric power station. With the right approach, you can even make such a structure with your own hands.
To begin with, let's define the principle of operation and types of small hydroelectric power plants. The flow of a river or a falling water stream rotates the blades of a turbine and a hydraulic pipeline, which is connected to an electric generator - the latter generates electricity. Modern compact HPPs have automatic control with the ability to instantly switch to manual mode in case of an emergency. The designs of modern factory HPPs make it possible to minimize the construction work during the installation of equipment.
Types of mini hydroelectric power plants
Mini power plants include generating devices with a capacity of 1 to 3000 kW. Basically, the TPP consists of:
- turbines (water intake device);
- generating block;
- control systems.
By the type of water resources used for generation, mini hydroelectric power stations are:
- Channel. Such stations are built on small flat rivers with reservoirs.
- Mountain. Stationary stations that use the energy of a fast mountain current.
- Industrial. Stations using differences in water flow at industrial enterprises.
- Mobile. Stations using reinforced hoses for water flow.
Dam types of stations are characterized by high capacity, but the construction of a dam is expensive, and in this case, permits are indispensable. Contacting officials in our country is not just to complicate your life, but to question the implementation of the best intentions, so we will abandon this idea right away.
How does a mini hydroelectric power station work
The principle scheme of operation of the hydroelectric power station can be selected 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 the bearing, the other is connected to the generator.
- Propeller. An underwater structure resembling a windmill with narrow blades and a vertical rotor. The blade is only 20 mm wide at high rotation speed and will provide minimal resistance. A blade of this width is selected at a flow rate of 0.8–2.0 m per second.
- Water wheel. A wheel with paddles partially submerged in the stream 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 fluid, flowing around the blades, creates a different pressure, due to which rotation occurs.
Pictured is a mini hydroelectric power station based on a water wheel
How to assess the potential capacity of a mini hydroelectric power station
Before building a mini hydroelectric power station with your own hands, you need to determine the power that you can count on. There is a reference relationship between the water flow rate and the power that can be removed from the shaft in kW with a screw diameter of 1 m.
The flow rate is determined by measuring the time it takes for a piece of wood thrown into the water to travel a certain distance. Having made simple calculations, we get the flow rate in meters per second. If in this case the speed is less than 1 m / s, then the construction of a hydroelectric power station will not be economically feasible.
At a flow rate 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 ratio is described by the dependence: the power of the hydroelectric power station is proportional to the cube of the water flow rate. If the flow rate at the site of the proposed construction is low, it can be tried to increase it by a device for a height difference in the flow or by installing a drain pipe with a variable diameter at the outlet of the reservoir. The smaller the diameter of the pipe at the outlet, the greater the flow rate.
How to make a mini hydroelectric power station at home
The principle of operation of a small home-made hydroelectric power station can be understood by the example of a bicycle with a headlight and a dynamo (generator).
- From roofing iron we make three blades with a length equal to the radius of the bicycle wheel (the distance from the central sleeve to the wheel rim) and a width of 3-4 cm.
- We install the blades between the spokes of the wheel, bending the edge of the blade around the spokes for fastening. The blades should be set evenly with the same angles between them.
- 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 the construction of a mini hydroelectric power station
An example is a small hydroelectric power station for a farm with a capacity of 3-5 kW from improvised materials:
- 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 must be welded. The rotor rotates on bearings. Support - metal pipe or corner.
- A chain reducer with a gear ratio (transmission ratio) of 4 must be installed on the rotor. Further, the rotation will be transmitted through the VAZ 2101 cardan shaft. Using the cardan will reduce vibration, and the alignment of the drive and generator when using the shaft will be non-critical.
- You will need a step-up gearbox (coefficient - 40) and a three-phase generator. The rotation speed of the generator 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 for moisture protection and safety. The estimated rotation of the water wheel should be about 20 rpm.
- 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 2x4 cable from the rotor to the farm buildings.
findings
The total cost of production will be about 10-15 thousand rubles. The main item of expenditure is the wages of the welder and the worker who helps to make and assemble the structure.
The main advantages of such equipment are low cost of electricity, environmental safety, inexhaustible source of energy and simplicity of design.