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 station. The search for a solution to this issue concerns not only the scale of the country. Increasingly, you can see mini-hydroelectric power for the house (cottages). 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 in certain conditions. Water flow required. In addition, the construction of this structure in his yard requires the permission of local authorities.
Scheme of a mini hydroelectric power station
The principle of operation of a hydroelectric power station for a house is quite simple. The construction scheme is as follows. Water falls on the turbine, causing the blades to rotate. They, in turn, due to the torque or pressure drop set the hydraulic actuator in motion. The received power is transferred from it to the electric generator, which generates electricity.
Currently, a hydropower plant scheme is most often equipped with a control system. This allows the design to work in automatic mode. If necessary (for example, an accident), there is the possibility of switching to manual control.
Varieties of mini-hydro
It should be understood that mini-hydroelectric power stations allow you to receive no more than three thousand kilowatts. This is the maximum power of such a structure. The exact value will depend on the type of HPP and the design of the equipment used.
Depending on the type of water flow, the following types of stations are distinguished:
- Channel, characteristic of the plains. They are installed on rivers with a low flow.
- Stationary use the energy of water rivers with a fast flow of water.
- Hydroelectric power plants installed in places of the difference in water flow. They are found most often in industrial organizations.
- Mobile, which are built using reinforced sleeves.
For the construction of a hydroelectric 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, which is set in motion due to 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 stations are installed in the sewer. But their construction requires the creation of certain conditions. Water through the pipe should drain naturally due to slope. The second requirement is the diameter of the pipe must be suitable for the installation of equipment. And this is impossible to do in a detached house.
Classification of mini hydropower plants
Mini-hydroelectric power plants (the houses in which they are used mostly belong to the private sector) most often belong to one of the following types, which differ in the way they work:
- The water wheel is the traditional type, which is the simplest in execution.
- Propeller. Use in cases where the river has a channel with a width of more than ten meters.
- Garland is set on rivers with a low flow. To enhance the speed of the water flow, additional structures are used.
- The Darier rotor is usually installed in industrial enterprises.
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 station, which is most popular for the private sector. Mini-hydro power plants of this type are a large wheel that can rotate. Its blades sink into the water. The rest of the structure is above the bed, forcing the entire mechanism to move. Power is transmitted through a hydraulic actuator to a current-generating generator.
Propeller station
On the frame in a vertical position is a rotor and an underwater windmill, lowered under water. The windmill has blades that rotate under the influence of a stream of water. Two centimeters wide blades have the best resistance (with a fast flow, the speed of which, however, does not exceed two meters per second).
In this case, the blades are driven by the resulting lifting force, and not due to the pressure of the water. Moreover, the direction of motion of the blades is perpendicular to the direction of flow. This process is similar to the operation of wind farms, only works under water.
Garland hydroelectric power station
This type of mini-hydroelectric power station is a cable stretched over the channel and fixed in a thrust bearing. Small turbines of small size and weight (hydro-rotors) are hung and rigidly fixed on it. They consist of two half cylinders. Due to the alignment of the axles when lowered into the water, a torque is created in them. This leads to the fact that the cable bends, stretches and starts to rotate. In this situation, the cable can be compared with a shaft that serves to transmit power. One end of the cable is connected to the gearbox. Power is transmitted to it from the rotation of the cable and hydro-rotors.
The presence of several "garlands" will help to increase the power of the station. They can be interconnected. Even this does not greatly increase the efficiency of this hydroelectric power station. This is one of the minuses of such a structure.
Another disadvantage of this type is the danger it creates for others. Such stations can only be used in uninhabited places. Warning signs are required.
Rotor darya
A mini-hydroelectric power station for a private house of this type is named after its developer, Georges Darier. This design was patented back in 1931. It is a rotor on which the blades are located. For each of the blades, the necessary parameters are individually selected. The rotor is lowered into the water in an upright position. The blades rotate due to the pressure drop arising from the action of water flowing along their surface. This process is similar to lift, forcing planes to take off.
This type of hydroelectric station has a good indicator of efficiency. The third advantage is that the flow direction does not matter.
Among the shortcomings of this type of power plants can distinguish a complex structure and difficult installation.
Benefits of Mini Hydro
Regardless of the type of construction, mini-hydroelectric power plants have several advantages:
- Environmentally friendly, do not produce substances harmful to the atmosphere.
- The process of generating electricity is without noise.
- The water remains clean.
- Electricity is generated continuously, regardless of the time of day or weather conditions.
- To equip the station, even a small stream is enough.
- Surplus electricity can be sold to neighbors.
- You do not need a lot of permissive documentation.
DIY hydropower station
You can build a water station to receive electricity yourself. For a private house, twenty kilowatts per day is enough. Even mini-hydropower plants assembled by themselves can cope with such a value. But it should be remembered that this process is characterized by a number of features:
- Accurate calculations are difficult enough.
- Dimensions, thickness of the elements is chosen "by eye", only empirically.
- Home-made structures do not have protective elements, which leads to frequent breakdowns and the associated costs.
Therefore, if there is no experience and certain knowledge in this area, it is better to abandon the idea of this kind. Cheaper may be the purchase of a finished station.
If you still decide to do it yourself, you need to start by measuring the speed of the water flow in the river. After all, the power that can be obtained depends on this. 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 cannot be omitted is calculations. It is necessary to carefully calculate the amount of expenses that will be spent on the construction of the station. As a result, it may turn out that a hydroelectric power station is not the best option. Then it is worth paying attention to other types of alternative electricity.
A mini-hydroelectric power station may be the best solution for saving energy costs. For its construction requires a river near the house. Depending on the desired characteristics, you can choose the appropriate option for the hydroelectric power station. With the right approach, you can even perform such a construction with your own hands.