ADVANTAGES OF HPP:

Flexibility

Hydropower is a flexible source of electricity because hydroelectric power plants can very quickly adapt to changing energy demands, increasing or decreasing electricity production. A hydraulic turbine has a startup time of the order of several minutes. It takes 60 to 90 seconds to bring the device from cold start to full load; this is much less than for gas turbines or steam plants. Electricity production can also be quickly reduced when there is excess power.

Ffestiniog power station can produce 360 ​​MW in 60 seconds

Low energy costs

The main advantage of hydroelectric power is the absence of fuel costs. The cost of operating a hydroelectric power plant is almost immune to increases in the cost of fossil fuels such as oil, natural gas or coal, and no imports are required. The average cost of electricity from a hydroelectric power plant larger than 10 megawatts is 3 to 5 US cents per kilowatt-hour.

Hydroelectric power plants have a long service life, some hydroelectric power plants still provide electricity after 50-100 years of operation.

Operational maintenance costs are low, few people are required to control the operation of the hydroelectric power station.

The dam can be used for several purposes at once: accumulate water for hydroelectric power stations, protect territories from floods, create a reservoir.

Suitability for industrial use

While many hydroelectric dams supply energy to public utility networks, some are created to serve specific industrial plants. For example, in New Zealand, a power station was built to supply electricity to the Tiwai Point aluminum smelter.

Reduced CO 2 emissions

Hydroelectric power plants do not burn fossil fuels and do not directly produce carbon dioxide. Although some carbon dioxide is generated during the production and construction process of the project. According to research by Paul Scherrer from the University of Stuttgart, hydropower produces the least carbon dioxide among other energy sources. Wind was in second place, nuclear energy was third, solar energy was in 4th place.

Other uses of the reservoir

Hydroelectric reservoirs often provide opportunities for water sports and become tourist attractions themselves. In some countries, aquaculture in reservoirs is common. Water from reservoirs can be used to irrigate crops, and fish can be raised in it. Dams also help prevent flooding.

DISADVANTAGES OF HYDRO POWER PLANT:

Ecosystem damage and land loss

The large reservoirs required to operate hydroelectric dams flood vast areas of land upstream from the dam, destroying forest valleys and swamps. Land loss is often compounded by habitat destruction in the surrounding areas occupied by the reservoir.
Hydroelectric power plants can lead to the destruction of ecosystems, as water passing through turbinescleared of natural sediments. Hydroelectric power stations on large rivers are especially dangerous, as they lead to serious changes in the environment.

The photo shows a reservoir resulting from the construction of a dam.

Siltation

When water flows, heavier particles float downstream.
This has a negative impact on dams and subsequently their power plants, especially on rivers or in catchments with high levels of siltation. Silt can fill the reservoir and reduce its ability to control floods, causing additional horizontal pressure on the dam. Reducing the river bed can lead to a decrease in electricity production. In addition, even a hot summer or low rainfall can lead to a decrease in the river.

Methane emissions (from reservoirs)

Hydroelectric power plants in tropical regions have the greatest impact; reservoirs of power plants in tropical regions produce significant amounts of methane. This is due to the presence of plant material in flooded areas that decays in an anaerobic environment and produces methane and a greenhouse gas. According to the report of the World Commission on Dams, in cases where the reservoir is large compared to the generating capacity (less than 100 watts per square meter of surface area) and the forests in the area of ​​the reservoir have not been cleared. Then greenhouse gas emissions in the reservoir may be higher than those of a conventional thermal power plant.

Novosibirsk State University

Graduate College of Informatics

Abstract on life safety

Topic: “Safety and environmental friendliness of hydropower”

Student: Kisarova Valentina

Group: 803C

Teacher: Khegay E.G.

Introduction

Energy is divided into traditional and non-traditional. Traditional energy is based on the use of fossil fuels or nuclear fuel and water energy from large rivers. It is divided into thermal power engineering, electric power engineering, nuclear power engineering and hydropower engineering.

For many millennia, the energy contained in flowing water has served man faithfully. Its reserves on Earth are colossal. It is not without reason that some scientists believe that it would be more correct to call our planet not Earth, but Water - after all, about three-quarters of the planet’s surface is covered with water. The World Ocean serves as a huge energy accumulator, absorbing most of it coming from the Sun. Waves splash here, tides ebb and flow, and powerful ocean currents arise. Mighty rivers are born, carrying huge masses of water into the seas and oceans. It is clear that humanity, in its search for energy, could not pass by such gigantic reserves. First of all, people learned to use the energy of rivers.

The invention of the steam engine seemed to stop the centuries-long triumphal march of water wheels. Small chugging engines that could be installed anywhere, not just on the river bank, set in motion machine tools and forge hammers and fulling mills, and even encroached on the eternal purpose of water wheels - to irrigate fields. One after another, the giant water wheels were scrapped; it seemed that the centuries-old history of water energy was nearing its end. But when the golden age of electricity arrived, the water wheel was revived, albeit in a different guise - in the form of a water turbine. Electric generators that produced energy needed to be rotated, and water could do this quite successfully.

A little history

Hydropower, as well as solar energy, has been used for a very long time. Mention of the use of water energy in water mills for grinding grain and blowing air when smelting metal dates back to the end of the 2nd century. BC e. Over the centuries, water wheels have increased in size and efficiency. In the 11th century in England and France there was one mill for every 250 people. At this time, the scope of application of mills expanded. They began to be used in the cloth production, brewing beer, sawing wood, for operating pumps, and in oil mills. Modern hydropower can be considered to have been born in 1891. This year, the Russian engineer Mikhail Osipovich Dolivo-Dobrovolsky, who emigrated to Germany due to “political unreliability,” was supposed to demonstrate the alternating current motor he invented at the electrical exhibition in Frankfurt am Main. This engine, with a power of about 100 kilowatts in the era of the dominance of direct electric current, itself should have become the highlight of the exhibition, but the inventor decided to build a completely unexpected structure for its power at that time - a hydroelectric power station. In the small town of Lauffen, Dolivo-Dobrovolsky installed a three-phase current generator, which was rotated by a small water turbine. Electrical energy was transmitted to the exhibition territory via transmission lines that were incredibly long for those years, 175 kilometers long (nowadays transmission lines thousands of kilometers long do not surprise anyone, but at that time such construction was unanimously recognized as impossible). Just a few years before this event, the most prominent English engineer and physicist Osborne Reynolds, in his Cantor Lectures, seemingly irrefutably proved that when transmitting energy by means of transmission, the energy loss is only 1.4% per mile, while when transmitting electric energy losses along wires over the same distance will be 6%. Based on experimental data, he concluded that when using electric current at the other end of the transmission line, it is unlikely that it will be possible to have more than 15-20% of the initial power. At the same time, he believed, you can be sure that when energy is transferred by the drive cable, 90% of the power will be retained. This “indisputable” conclusion was successfully refuted by the work of the first-born hydroelectric power industry in Lauffen.

But the era of hydropower had not yet arrived. The advantages of hydroelectric power plants are obvious - a supply of energy constantly renewed by nature itself, ease of operation, and lack of environmental pollution. And the experience of building and operating water wheels could be of great help to hydropower engineers. However, building a dam for a large hydroelectric power station turned out to be a much more difficult task than building a small dam to turn a mill wheel. To drive powerful hydraulic turbines, you need to accumulate a huge supply of water behind the turbine. To build a dam, it is necessary to lay down so much material that the volume of the giant Egyptian pyramids will seem insignificant in comparison. Therefore, at the beginning of the twentieth century, only a few hydroelectric power plants were built. This was just the beginning. The development of hydropower resources was carried out at a rapid pace, and in the 30s of the twentieth century, the implementation of such large projects as the Hoover hydroelectric power station in the USA with a capacity of 1.3 Gigowatts was completed. The construction of such powerful hydroelectric power plants caused an increase in energy use in industrialized countries, and this, in turn, gave impetus to programs for the development of large hydropower potentials.

Currently, the use of water energy is still relevant, and the main direction is the production of electricity.

Hydropower - pros and cons

Hydroelectric power plants, or HPPs for short, are built primarily on large rivers. And they have a lot of positive and negative sides.

The positive ones include the fact that they use renewable natural resources, “save” fuel resources (including money for their extraction and transportation), require 15-20 times less maintenance personnel than thermal power plants (thermal power plants), significant Efficiency (over 80%), low cost (5-6 times less than thermal power plants), allow you to regulate water flow, protect adjacent areas from catastrophic floods, improve conditions for navigation of the country (territory), and create conditions for the development of mass cultural recreation.

The disadvantages include 100% attachment to large rivers, flooding of a significant part of the land (meadows, forested settlements), a gradual change in the microclimate of the surrounding areas, herds of valuable fish are declining, and blue-green algae are developing.

Another representative of hydroelectric power plants are pumped storage power plants or pumped storage power plants, which are built only in the largest industrial densely populated areas where a large number of electricity consumers are located. They significantly reduce the problem of shortage of electricity (especially during the daytime), are built mainly on artificial reservoirs, therefore cause minor harm to the surrounding flora and fauna, are justified in terms of financial costs, but are economically unprofitable (unprofitable), because During their work, they consume slightly more electricity than they produce themselves.

When using hydropower resources, the environmental aspect is very important. Hydropower resources are the energy reserves of the flowing water of river streams and reservoirs located above sea level (as well as the energy of sea tides). The construction of hydroelectric power stations in many cases is accompanied by the construction of reservoirs, which sometimes have a negative impact on the environmental situation and introduce a number of changes to nature. The hydropower industry of the future should, with minimal negative impact on the natural environment, maximally satisfy people's needs for electricity. Therefore, today more and more attention is being paid to the problems of preserving the natural and social environment during hydraulic engineering construction. In modern conditions, a correct forecast of the consequences of such construction is especially important. The result of the forecast should be recommendations for mitigating and overcoming unfavorable environmental situations during the construction of hydroelectric power stations, a comparative assessment of the environmental efficiency of created or designed hydroelectric power stations. Thus, we can talk about the feasibility of forming a new, narrower and more complex category of hydropower resources - an environmentally effective part, differentiated by the degree of environmental load caused by the use of a certain share of hydropower potential. Unfortunately, at the moment, there is practically no development of methods for determining environmental energy potential, but it is obvious that the development of hydropower without detailed environmental assessments of hydropower projects can undermine the already fragile ecological balance in the world.

In the wake of interest in renewable energy sources around the world, hydroelectric dams are being built here and there, some of them are amazing in their grandeur. But while paying tribute to bold engineering solutions, it should be remembered that the huge masses of water held by dams are fraught with terrible destructive power.

Hydropower facilities have a significant impact on the natural environment. This influence is local. However, the construction of cascades of large reservoirs, planning the transfer of part of the flow of Siberian rivers to Central Asia and other major water management measures can change natural conditions on a regional scale.

During operation, hydropower facilities have a diverse impact on the environment. Reservoirs have the most significant impact on nature:

1. The creation of reservoirs leads to flooding of the territory. The flood zone may include agricultural lands, mineral deposits, industrial and civil buildings, ancient monuments, roads, forests, permanent habitats of animals and plants, etc. The riverbed areas and areas at the mouths of tributaries are the most populated and developed. There is little agricultural land on the mountain slopes, and there are usually no industrial facilities there. Therefore, the creation of reservoirs in mountainous conditions causes significantly less damage than on the plains.

1. Flooding. Flooding of lands adjacent to the reservoir occurs due to rising groundwater levels. In an area of ​​excessive moisture, flooding entails negative consequences - waterlogging of plant roots and their death. With a change in the water-air regime of the soil, waterlogging and gleying of the soil can occur, which deteriorates the quality of the soil and reduces its productivity. In arid areas, flooding improves the conditions for plant growth at appropriate depths of soil water. In unfavorable conditions, soil salinization may occur.
2. Bank processing. Due to the rise and fall of the water level in the reservoir, when regulating runoff and wave phenomena, the banks of the reservoir are processed. This involves the erosion and collapse of steep slopes, the cutting off of capes and spits. The extent of bank reworking depends on their geological structure, the regime of water levels and the depth of the reservoir, the configuration of the banks, prevailing winds, etc. Relative stabilization of the banks occurs 5-20 years after the filling of the reservoir.
3. Water quality. Due to a decrease in flow speed and a decrease in water movement in depth, the physicochemical characteristics change significantly. The quality of the years in the reservoir is affected by the population of the flood zone, the species and age composition of the forest, undergrowth and forest litter, the presence of tributaries, the regime and depth of the reservoir, etc. When creating reservoirs, it is necessary to carefully study the combined influence of all factors, taking into account the prospects for the construction of cascades hydroelectric power station and take measures to maintain water quality. Water quality is a characteristic of the composition and properties of water that determines its suitability for specific types of water use. Wastewater entering the reservoir must be thoroughly treated. It is necessary to use the adjacent lands in agriculture using advanced agricultural techniques that limit the removal of fertilizers into the reservoir.
4. The influence of reservoirs on the microclimate. Reservoirs increase air humidity, change the wind regime of the coastal zone, as well as the temperature and ice conditions of the watercourse. This leads to changes in natural conditions, as well as the life and economic activities of the population, the habitat of animals and fish. The degree of influence of large reservoirs on the microclimate varies for individual regions of the country.
5. The influence of reservoirs on fauna. Many animals from the flood zone are forced to migrate to areas with higher elevations. At the same time, the species composition and number of animals decreases significantly. In a number of cases, reservoirs contribute to the enrichment of the fauna with new species of waterfowl and especially fish: crucian carp, carp, pike, etc. When the reservoir is drained early after the spring flood, shallow waters are drained, which negatively affects the spawning of fish in the upper pool.

Hydraulic structures also affect the environment. The construction of hydraulic dams leads to a rise in water levels in the upper pool and the formation of reservoirs. Dams blocking rivers make it difficult for fish to reach natural spawning grounds in the upper reaches of rivers. But platinums, hydroelectric power station buildings, locks, canals, etc., successfully integrated into the terrain and well architecturally designed, together with the upstream water area, create monumental and picturesque ensembles.

Nature conservation activities . Work on the construction of hydropower facilities should be designed with minimal damage to nature. When developing construction plans, it is necessary to rationally choose quarries, the location of roads, etc. By the time construction is completed, the necessary work must be carried out to reclaim land disturbances and landscaping the area. For a reservoir, the most effective environmental protection measure is engineering protection. For example, the construction of embankment dams reduces the area of ​​flooding and preserves land and mineral deposits for economic use, reduces the area of ​​shallow waters and improves the sanitary conditions of the reservoir, and preserves natural complexes. If the construction of dams is not economically justified, then shallow waters can be used for bird breeding and for other economic needs. If the required water levels are maintained, shallow waters can be used for fisheries, as spawning grounds and a food supply.

To prevent or reduce the processing of banks, bank protection is carried out. Enterprises, railways, residential and utility buildings, and ancient monuments are removed from the flood zone.

To ensure high water quality, sanitary cleaning of the reservoir bed is necessary before it is flooded with water. For this purpose, agrotechnical measures are taken to reduce polluted surface runoff and wastewater treatment plants are built.

If necessary, reserves, wildlife sanctuaries are organized, animals are captured and moved, and forest plantings are carried out. For the purpose of fish farming, artificial spawning grounds, spawning and nursery farms are created, fish passage structures are built for the passage of fish for spawning from the lower pool to the upper one. Extensive engineering protection work is being carried out in the downstream.

Conclusion

The state of the hydropower sector of any country largely depends on the ratio of the reserves of its hydropower resources, or, to put it differently, on the hydropower potential of its rivers, as well as on the scale and level of their development.

Technical potential, or in other words, what can be further used by generating electricity at hydroelectric power plants or other available technical methods, is usually calculated in billions of kWh/year. However, in this case, the economic feasibility of constructing and, of course, operating small hydroelectric power plants will be taken into account first of all. In other words, the higher the price of fuel consumed, the greater the benefits of using hydropower.

Bibliography

1. Andrizhievsky A.A., Volodin V.I. "Energy saving and energy management." - Mn: “Higher School” 2005
2. Volodin V.V., Khazanovsky P.M. "Energy, twenty-first century: Scientific and fiction literature." - M.: Det. lit., 1989
3. Baburin V.N. "Hydropower and integrated use of water resources", M: Nauka, 1986.
4. Avakyan A.B. "Integrated use and protection of water resources", M: 1990.

Electric power plants are a vital part of every person's life as they convert energy into electricity. One station represents a whole complex of 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:

1. The process of extracting and processing a primary energy source.
2. Delivery to the power plant.
3. The process of converting primary energy into secondary energy.
4. 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 power plant is a complex of buildings, structures and equipment designed to generate electrical energy. That is, power plants convert various types of energy into electricity. The most common types of power plants are:

— hydroelectric power stations;
— thermal;
- atomic.

A hydroelectric power plant (HPP) is a power plant that converts the energy of moving water into electrical energy. Hydroelectric power stations are being installed on rivers. With the help of a dam, a difference in water heights is created (before and after the dam). The resulting water pressure sets the turbine blades in motion. The turbine drives generators that produce electricity.

Depending on the power, hydroelectric power plants are divided into: small (up to 5 MW), medium (5-25 MW) and powerful (over 25 MW). According to the maximum used pressure, they are divided into: low-pressure (maximum pressure - from 3 to 25 m), medium-pressure (25-60 m) and high-pressure (over 60 m). Hydroelectric power stations are also classified according to the principle of use of natural resources: dam, near-dam, diversion and pumped storage.

Advantages of hydroelectric power plants are: generation of cheap electricity, use of renewable energy, ease of control, quick access to operating mode. In addition, hydroelectric power plants do not pollute the atmosphere. Disadvantages: attachment to water bodies, possible flooding of arable land, detrimental effect on river ecosystems. Hydroelectric power stations can only be built on lowland rivers (due to the seismic danger of mountains).

Thermal power plant (TPP) generates electricity by converting thermal energy obtained as a result of fuel combustion. The fuel for thermal power plants is: natural gas, coal, fuel oil, peat or hot shale.

As a result of fuel combustion in the furnaces of steam boilers, feed water is converted into superheated steam. This steam at a certain temperature and pressure is supplied through a steam line to a turbogenerator, where electrical energy is generated.

Thermal power plants are divided into:

— gas turbine;

— boiler-turbine;

- combined cycle;

— based on combined cycle gas plants;
- based on piston engines.

Boiler-turbine thermal power plants, in turn, are divided into condensing (CPS or GRES) and combined heat and power plants (CHP).

Advantages of thermal power plants

— low financial costs;

— high speed of construction;

— possibility of stable work regardless of the season.

Disadvantages of thermal power plants

— work on non-renewable resources;

— slow return to operating mode;

- receiving waste.

Nuclear power plant (NPP)- a station in which electricity (or thermal energy) is generated through the operation of a nuclear reactor. For 2015, almost 11% of electricity.

During operation, a nuclear reactor transfers energy to the primary coolant. This coolant enters the steam generator, where it heats the secondary circuit water. In the steam generator, water is converted into steam, which enters the turbine and drives electric generators. The steam after the turbine enters the condenser, where it is cooled with water from the reservoir. Mainly water is used as the primary coolant. However, lead, sodium and other liquid metal coolants can also be used for this purpose. The number of circuits may vary.

Nuclear power plants are classified according to the type of reactor used. Nuclear power plants use two types of reactors: thermal and fast neutrons. Reactors of the first type are divided into: boiling water, water-water, heavy water, gas-cooled, graphite-water.

Depending on the type of energy received, nuclear power plants are of two types:

Stations designed to generate electricity.

Stations designed to generate electrical and thermal energy (CHP).

Advantages of nuclear power plants:

— independence from fuel sources;

— environmental cleanliness;

The main disadvantage of stations of this type- severe consequences in case of emergency situations.

In addition to the listed power plants, there are also: diesel, solar, tidal, wind, geothermal.

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 return it to the system when necessary, 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 construction of the station. German scientist Paul Scherrer, after conducting research, came to the conclusion that hydropower ranks first in terms of minimal carbon dioxide production, followed by wind, nuclear power and solar energy.

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 various types of 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 produce large volumes of methane due to the huge amount of decaying plant material. 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.