Pros and cons of hydroelectric power plant construction. Electric stations: advantages and disadvantages. Novosibirsk State University
I am sure that if the average person is asked about the differences between hydraulic and thermal power plants, he will answer: one runs on hydraulics, the other on fuel. But I think the answer is more complicated...
Types of power plants
Today there are three main types of power plants: hydraulic, thermal and nuclear.
The efficiency of nuclear power plants is the highest in relation to the cost of producing electricity. When used correctly and wisely nuclear power will hold a leading position in the near future.
There are also wind or solar power plants, but their productivity today is negligible and can only provide people with electricity at the household level.
Advantages of hydraulic power plants
Among the advantages of hydraulic power plants over thermal power plants are the following:
- lower cost of electricity;
- less damage caused environment;
- renewable source of energy conversion.
To produce electricity using water flow, less money is needed than to produce electricity by burning fuel: there is no need to carry out costly mining of minerals and build logistics for their transportation.
A hydraulic power plant causes less damage to the environment during operation. There are no emissions of by-products into the atmosphere or hydrosphere. harmful substances from the production of electricity - gases, solid toxic waste and the like.
Due to the natural water cycle, the source of electricity production (water) can be used repeatedly, in contrast to the one-time combustion of fuel.
Disadvantages of hydraulic power plants
Hydraulic power plants also have disadvantages:
- low efficiency compared to fuel ones;
- costs for the construction of significant power transmission lines;
- are located in a certain place on the banks of large rivers, at a distance from industrial centers, which complicates the repair work of units and the delivery of bulky equipment to them.
These are the features of the production of these two types of power plants.
Electric power plants are a vital part of every person's life as they convert energy into electricity. One station is the whole complex activities, artificial and natural subsystems that serve for the transformation and distribution of all types of energy sources. The whole process can be divided into several stages:
- The process of extracting and processing a primary energy source.
- Delivery to the power plant.
- The process of converting primary energy into secondary energy.
- Distribution of secondary (electrical or between consumers.
Electric power involves the production of energy at a station and its subsequent delivery through power lines. The most important elements of this chain, such as power plants, differ in the type of primary sources that are available in a given region.
Let us consider some types of transformation processes in more detail, as well as the advantages and disadvantages of each of them.
They belong to the group of traditional energy and occupy a significant share of global electricity generation (approximately 40%). The advantages and disadvantages of thermal power plants are given in the following table:
For example, reservoirs and rivers are used as a primary source of energy. The advantages and disadvantages of hydroelectric power stations are also summarized in the table.
Nuclear power plants (NPPs) are a complex of installations and activities intended for which, as a result of the fission of atomic nuclei, into heat, and then into the The most important element of this system is also a complex of related devices. The table below shows the advantages and disadvantages of nuclear power plants.
An equally important stage is the transportation of fuel resources to the power plant. This process can be carried out in several ways, each of which has its own advantages and disadvantages. Consider the main methods of transportation:
- Water transport. Delivery is carried out using tankers and bunkers.
- Automobile transport. Transportation is carried out in tanks. The ability to transport only liquid or gaseous fuel determines the existing advantages and disadvantages of road transport.
- Railway transport. Delivery in tanks and open wagons over long distances.
- Suspended and rarely used and only for very short distances.
A hydroelectric power plant is an electrical station that uses the energy of water discharge as a source of energy. They are most often erected on existing reservoirs, constructing artificial dams and reservoirs to store the required volume of water.
To effectively obtain electricity at this kind of station, two main requirements must be met: a year-round continuous supply of water and the presence of sharp river slopes.
Electricity generation technology hydroelectric power stations represents the transformation of the mechanical energy of water, due to the presence of different heights through the use of engines and generators.
Today there are the following types of hydroelectric power plants, which differ from each other in the way they supply water - dam, diversion and pumped storage stations.
Dam hydroelectric power plants are the most popular and powerful type of station. A reservoir is created by erecting artificial partitions to retain the flow of the river. Water is released for two reasons - when there is a need for electricity and to create the required level in the reservoir.
The diversion type is different in that it does not use the entire flow of the river, but with the help of pipes and a drainage system, the required volume of water is taken, which is then sent to the turbine.
Pumped storage stations are installations that store electrical energy and returns it to the system if necessary; it is used to level out the daily heterogeneity of the electrical load schedule.
Marine stations are also used, which operate using the energy of tides and waves.
Advantages of hydroelectric power
Flexibility. Hydropower is recognized as a flexible source of electricity because a hydroelectric power plant can easily and quickly adapt to changing energy needs, increasing or slowing down the output of electricity. The existing turbine starts up within just a few minutes.
Low energy costs. The main advantage of the hydroelectric power station is the absence of fuel costs and complete independence from fossil fuels. All such stations have a long service life; even today, hydroelectric power stations that were built about 100 years ago operate, and moreover, they do not require many employees to maintain them.
Use for industrial purposes. Hydroelectric power is used both to serve the population and to provide electricity to certain factories.
Minimal carbon emissions. Hydroelectric power plants themselves are not capable of producing carbon dioxide, which most often can only be formed during the implementation of construction work stations. The German scientist Paul Scherrer, after conducting research, came to the conclusion that hydropower ranks first in terms of minimum production carbon dioxide, followed by wind, nuclear power and solar power.
Benefits of creating a reservoir. Constructed reservoirs are often excellent options for water sports, and some are even considered attractions for visiting guests. Also, the water from them is perfect for irrigation or for breeding in it. various types fish Plus, artificial dams help prevent flooding.
Disadvantages of hydroelectric power plants
Environmental damage and loss of land. The huge reservoirs that are required for the operation of hydroelectric power plants cause the flooding of colossal areas of land located upstream of the dam, which means the destruction of forests, fields, swamps and their inhabitants.
Siltation. The flow of water brings with it various particles and residues that harm both the dam and the power plant. Such deposits can reduce the size of the reservoir and impair the ability to prevent flooding. And also reduce electricity production.
Methane emissions. Hydroelectric power plants located in tropical regions due to huge amount decomposing plant material produces large volumes of methane. Therefore, before constructing a hydroelectric power station and a dam, it is necessary to clear the area of forests in the area where the artificial reservoir is formed.
Relocation. Many researchers include the need to resettle the population living in the area of the future reservoir as a significant disadvantage of the construction of hydroelectric power stations. At the beginning of the 21st century, the World Commission on Dams published its statistics, the data of which showed that due to the construction of dams, almost 80 million people around the world had to leave their places of residence.
One of the main advantages of small hydropower facilities is environmental safety. During their construction and subsequent operation there are no harmful effects on the properties and quality of water. Reservoirs can be used for fishing activities and as sources of water supply for the population. However, in addition to this, micro and small hydroelectric power stations have many advantages. Modern stations are simple in design and fully automated, i.e. do not require human presence during operation. The electric current they generate meets GOST requirements for frequency and voltage, and the stations can operate in autonomous mode, i.e. outside the power grid of the power system of the region or region, and as part of this power grid. And the full service life of the station is at least 40 years (at least 5 years before major repairs). Well, and most importantly, small-scale energy facilities do not require the organization of large reservoirs with corresponding flooding of the territory and colossal material damage.
During the construction and operation of SHPPs, the natural landscape is preserved and there is virtually no load on the ecosystem. The advantages of small hydropower - compared to power plants using fossil fuels - also include: low cost of electricity and operating costs, relatively inexpensive replacement of equipment, longer service life of hydroelectric power plants (40-50 years), integrated use of water resources (electricity, water supply, reclamation, water protection, fisheries).
Many of the small hydroelectric power plants do not always provide guaranteed energy production, being seasonal power plants. In winter, their energy output drops sharply, snow cover and ice phenomena (ice and sludge), as well as summer low water and drying up of rivers, can completely stop their work. The seasonality of small hydropower plants requires backup energy sources; a large number of them can lead to a loss of reliability of energy supply. Therefore, in many areas, the power of small hydroelectric power stations is considered not as the main one, but as a backup one.
Reservoirs of small hydroelectric power stations, especially in mountainous and foothill areas, have a very acute problem of their siltation and the associated problem of rising water levels, flooding and flooding, reducing the hydropower potential of rivers and generating electricity. It is known, for example, that the reservoir of the Zemonechal hydroelectric power station on the Kura River was silted by 60% within 5 years.
For fisheries, small hydroelectric dams are less dangerous than medium and large ones, which block the migration routes of anadromous and semi-anadromous fish and block spawning grounds. Although, in general, the creation of waterworks does not completely eliminate the damage to the fish stock on the main rivers, because A river basin is a single ecological system and violations of its individual links inevitably affect the system as a whole.
