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Integrated lesson (physics + ecology) on the topic: “Matter - without which life is impossible”

Physics lesson.

Today in class we are working on a mini-project - Water. Ecological aspects of aquatic ecosystems.

The purpose of our work is to clarify the importance of water for the life of living organisms, its influence and the influence of the environment on water and, accordingly, on life. Let's get to work.

To correctly answer the questions in the lesson, you must carefully read the content of the theoretical material. All questions in the lesson relate specifically to the part that preceded it.

If any question causes difficulty, carefully re-read the theory again.

First, let's find out how water affects living organisms, its importance in our lives, remember its physical and chemical characteristics and how they are related to this influence.

Nature protection is not only a general state task, but also the cause of the entire people. Thinking about the future, a person must treat nature today with care and love, and first of all its water resources.

Today in class we will repeat what we know about water and try to answer the question.

Why is it so necessary to care about the state of aquatic ecosystems?

What environmental problems are individual ecosystems experiencing?

What solutions have already been found?

And also try to suggest your own ways to solve these problems.

Water plays a big role in our life. It’s hard to imagine what humanity would do without water. Apparently, it simply would not exist. Not only life and climate are connected with water on our planet, but also the work of most sectors of the national economy, especially water transport. Water is the richest source of energy - river hydropower, tidal energy, geothermal and thermonuclear energy.

It is thanks to water that the most interesting and diverse phenomena arise in nature, such as rainbows, haloes, halos, crowns, “whispers of stars” and others.

Some people associate various superstitions and signs with them. But scientists have solved and found an explanation for these mysterious natural phenomena. Some of them are caused by water, its vapor and ice.

Water plays a huge role in nature. In fact, it was the sea that was the first arena of life on Earth.

Ammonia and carbohydrates dissolved in sea water in contact with certain minerals at a sufficiently high pressure and exposure to powerful electrical discharges could provide the formation of protein substances, on the basis of which the simplest organisms subsequently arose.

According to K. E. Tsiolkovsky, the aquatic environment helped protect fragile and initially imperfect organisms from mechanical damage. Land and atmosphere subsequently became the second arena of life.

We can say that all living things consist of water and organic substances. Without water, a person, for example, could live no more than 2-3 days, but without nutrients he can live for several weeks.

To ensure normal existence, a person must introduce into the body approximately 2 times more water by weight than nutrients.

Loss of more than 10% of water by the human body can lead to death.

On average, the body of plants and animals contains more than 50% water, in the body of a jellyfish it is up to 96%, in algae 95-99%, in spores and seeds from 7 to 15%.

The soil contains at least 20% water, while in the human body water makes up about 65% (in the body of a newborn up to 75%, in an adult 60%).

Different parts of the human body contain unequal amounts of water: the vitreous body of the eye consists of 99% water, the blood contains 83%, adipose tissue 29%, the skeleton 22%, and even tooth enamel 0.2%.

In the primary water shell of the globe there was much less water than now (no more than 10% of the total amount of water in reservoirs and rivers at present). An additional amount of water appeared subsequently as a result of the release of water that was part of the earth's interior.

According to experts, the Earth's mantle contains 10-12 times more water than the World Ocean. With an average depth of 4 km, the oceans cover about 71% of the planet's surface and contain 97.6% of the world's known free water reserves.

Rivers and lakes contain 0.3% of the world's free water.

Glaciers are also large reservoirs of moisture; they contain up to 2.1% of the world's water reserves. If all the glaciers melted, the water level on Earth would rise by 64 m, which means that about 1/8 of the land surface would be flooded with water.

During the era of glaciation in Europe, Canada and Siberia, the thickness of the ice cover in mountainous areas reached 2 km. Currently, due to the warming of the Earth's climate, the boundaries of glaciers are gradually retreating. This causes water levels in the oceans to slowly rise.

About 86% of water vapor enters the atmosphere through evaporation from the surface of seas and oceans, and only 14% through evaporation from the land surface. As a result, 0.0005% of the total supply of free water is concentrated in the atmosphere. The amount of water vapor in the surface air is variable. Under particularly favorable conditions, evaporation from the underlying surface can reach 2%.

Despite this, the kinetic energy of water movement in the seas is no more than 2% of the kinetic energy of air currents. This happens because more than a third of the solar heat absorbed by the Earth is spent on evaporation and goes into the atmosphere. In addition, a significant amount of energy enters the atmosphere due to the absorption of solar radiation passing through it and the reflection of this radiation from the earth's surface.

The radiant energy of the Sun and the vault of heaven passing through the water surface decreases in intensity by half already in the upper half meter of water due to strong absorption in the infrared part of the spectrum.

Of great importance in the life of nature is the fact that the highest density of water is observed at a temperature of 4 ° C. When fresh water bodies cool in winter, as the temperature of the surface layers decreases, denser masses of water sink down, and in their place warmer and less dense masses rise from below. dense.

This happens until the water in the deep layers reaches a temperature of 4 ° C. In this case, convection stops, since there will be heavier water below. Further cooling of water occurs only from the surface, which explains the formation of ice in the surface layer of reservoirs. Thanks to this, life under the ice does not stop, because... The pond does not freeze completely.

1. What is convection?

Vertical mixing of sea water is carried out due to the action of wind, tides and changes in density with height. Wind mixing of water occurs from top to bottom, while tidal mixing occurs from bottom to top. Density mixing occurs due to cooling of surface waters. Wind and tidal mixing extend to a depth of up to 50 m; at greater depths, only density mixing can affect it. The air dissolved in water is rich in oxygen, which contributes to the development of life processes in it.

2. In which waters are there more fish: cold or warm?

Water has a high specific heat capacity and low thermal conductivity, which also plays an important role for the life of living organisms in it.

3. Determine how many degrees the water temperature will change if the air temperature of the same mass changes by 10 degrees.

The high heat capacity of water also affects the climate of the globe.

4. The climate of the islands is more moderate and equal than the climate of the larger continents. Why?

Water has more resistance than air. This is due to the fact that it has a high density. High density of water is associated with high pressure. Adaptation to different pressures in layers of water can also explain the body shape of fish.

5. How do the body shapes of stingrays and breams differ and why?

Among the liquids present on Earth, the surface tension of water is second only to mercury. The optical properties of water vapor also play a significant role in plant life. Water vapor strongly absorbs infrared rays, which is important for protecting the soil from frost. An even more effective remedy for frost is dew and fog.

6. Why?

7. Calculate how much heat is released during the condensation of water vapor with a volume of 100 cubic meters.

Knowing the physical properties of water and ice, people have long used them in their practical activities.

8. How can you explain the laying of bare electrical wires on ice?

9. Which sea can serve as a standard for water transparency?

A water molecule consists of two hydrogen atoms and one oxygen atom. Water is a universal solvent.

10. What is the name of water in which less than 1 g of minerals are dissolved per 1 liter?

11.Find the mass of this water.

12. What is water with a high content of gypsum and lime called?

13. Why do crayfish live only in hard water?

Let's summarize the first part of our lesson.

14. List the main physical and chemical properties of water. How do they affect the life of living organisms?

We have repeated the influence of water on the life of living organisms. Now you are starting the second part of your work: you need to find out how life, or rather people, influences the state of water and how this affects the environment and people. Since living organisms receive substances dissolved in it with water, its most important characteristic is its quality, which sharply deteriorates as a result of pollution. In an ecology lesson, you will talk about types of water pollution and prepare abstracts for the press conference "Ecological problems of aquatic ecosystems."

Ecology lesson.

In physics class, you talked about the importance of water for the life of living organisms. What physical and chemical properties of water affect the state of life of organisms in it? You and I already know that the capacity of the ocean, as a natural limitless purifier, is not limitless, that water is an ideal solvent, and accordingly, not only useful, but also harmful substances enter our body. Because water pollution occurs. Since only the boundary layers of water, constituting no more than 2-3% of the World Ocean, have a self-purification effect, its ecosystems are no longer able to cope with the pollution that causes their degradation. Saving aquatic ecosystems is one of the most important tasks. Your task in this lesson is to find information, prepare abstracts for a press conference and draw up a map of the “Ecological state of aquatic ecosystems”. We will search for information in groups. The tasks for each group are given on the board. The result of our work should be the most complete picture of the “Ecological state of aquatic ecosystems” at the moment, and the homework is to develop your proposals for improving the state of aquatic ecosystems and monitoring the condition of the Kuzminsky ponds. Check out the lesson plan.

The group is looking for information on the Internet	The group works with the large encyclopedia of Cyril and Methodius (CD-ROM)	Group working with magazine "Ecology and life" and encyclopedias
1. Log in to the Rubricon search engine. 2. Find the right encyclopedia 3. Find data about seas and lakes. 5. Log in to the Yandex search engine 6. Find information on environmental problems of the seas and ways to solve them. 7. Log in to the Aport search system and use the advanced search to find information. 8. Write abstracts for the press conference 9. Mark on the contour map, using Photoshop, the areas of pollution associated with water pollution	1. Using encyclopedia material, find information on the ecological state of rivers and lakes and their characteristics. 2. Mark on the contour map, using Photoshop, the areas of pollution associated with the pollution of aquatic ecosystems. 3. Compose abstracts for the press conference and tasks for use in physics lessons. 4. Report the results of your work to the teacher by E-mail:	1.Using magazines and encyclopedias to find the necessary information. 2. Compose abstracts for the press conference and material under the heading “Interesting facts” for use in biology lessons in .doc format. 3.Send your work in .zip format to the teacher by E-mail: 4. Mark on the contour map the areas of pollution associated with the pollution of aquatic ecosystems.

When drawing up a map, pay attention to the fact that not a single encyclopedia will give you a complete map or information. To correctly draw a map, you need to apply knowledge of physics, geography, ecology and biology.

I remind you of your homework. Develop your proposals for improving the condition of aquatic ecosystems, taking into account the information received, and monitor the condition of nearby lakes.

Gonchar Elena Leonidovna

Physics teacher,

teacher-methodologist

Municipal educational institution "School No. 26 in Donetsk"

PHYSICS LESSON-CONVERSATION “ENERGY SAVING FOR EVERYONE”

ANNOTATION: the lesson is aimed at cultivating environmental consciousness in students, should promote the organization of skills in an environmentally sustainable and safe lifestyle, draw attention to the problems of energy use, saving energy and energy resources, and environmental protection; The proposed material creates motivation for saving resources and energy, involves schoolchildren in useful activities for energy and resource conservation, and stimulates interest in scientific research and the practical application of knowledge.

KEYWORDS: energy saving, environment, energy, electrical appliances, energy sources, safety precautions.

Tasks:

To help schoolchildren understand the importance of ecology as a science, to teach how to carefully manage the Earth's resources, to cultivate a friendly attitude towards the environment, to teach them to make the right decisions on environmental issues and take meaningful actions.

Lesson Objectives: educational:

Create conditions for students to become familiar with the types of electrical appliances, the purpose of an electric meter, and the structure of an iron;

To promote the development of the ability to calculate the amount of electricity consumed and its cost;

Create conditions for the formation of initial skills in the correct operation of electrical appliances and knowledge of safety rules when using them.

developing:

To promote the development in schoolchildren of the ability to highlight the main thing in what they are studying;

Contribute to the development of analytical thinking and broadening your horizons;

To develop the ability to perform operations of analysis, synthesis, classification, the ability to observe, draw conclusions, identify essential features of an object, put forward hypotheses and apply them when solving problems of different levels.

educational:

Contribute to the development of economic thinking in students;

Development of independence and communication at work;

Develop a careful attitude towards energy resources and household appliances.

Lesson type: combined.

Forms of teaching a lesson: dialogue, conversation, explanation, practical work, exercises, instruction, work with technical documentation, career guidance activities.

Forms of organizing educational and cognitive activities of students: group work, individual, whole-class, work with text.

Lesson Plan

I. Organizing time.

II. Updating the basic knowledge and skills of students. Repetition of occupational safety rules. Creating a problematic situation: “All energy resources have been exhausted. How to find a way out of this situation?”

III. Learning new material.

1. The concept of an electric meter. Calculation of the cost of consumed electricity.

2.Use of energy-saving technologies in everyday life.

3.Types of household electrical appliances.

4. Arrangement of electrical appliances.

During the classes

І . Teacher's opening speech.

In the recent past, low-power power plants running on coal and oil had difficulty meeting human needs. But the needs were very modest. Naturally, there was no question that the Earth could exhaust its resources. But the number of inhabitants of the Earth is growing exponentially and thereby the need for energy is increasing. Scientists are trying to solve this problem. International conferences, scientific books, and studies are devoted to finding cheap, accessible, environmentally friendly solutions. Today in class we will talk about this topic. How do we understand this problem, what can we do to preserve the wealth of our planet?

ІІ . Updating the basic knowledge and skills of students.

Conversation.

1.Tell what role electric current plays in our lives.

2.What elements of an electrical circuit do you know?

3.What is conductor resistance? In what units is it measured?

4.How can we express the work of electric current in terms of power and time?

5.What is the general purpose of all electrical appliances?

6.Name electrical appliances used in everyday life.

7.What kind of lamps are installed in your apartment? Try to determine their types and purpose. What lamps do you use most often?

8.What is a necessary condition for the operation of the listed devices?

9.Which device shows us the amount of energy consumed?

ІІІ. Discussion of the topic.

Teacher: What is energy?

Energy is a branch of the economy that covers energy resources, production, transformation, transmission and use of various types of energy.

How long ago did people start using energy?

Teacher: About 500 thousand years ago, man first mastered the energy of fire - thermal energy from the combustion of wood.

10 thousand years ago, with the advent of agriculture, the need for energy resources increased, and people began to build mills powered by water and wind energy. But with the growth of industrial production and the increase in the population of the Earth, people are building thermal power plants based on coal, oil and natural gas. River hydroelectric power is being widely developed. At the end of the 20th century, nuclear energy was mastered, but this no longer satisfies human needs. But there are also unconventional sources of energy - wind power plants (wind power is used, causing turbines to rotate and thus producing electricity), solar power plants - solar energy, geothermal (steam from water, heated deep in the Earth, is used to turn turbines connected to electric generators. ) Man is trying to use the energy of ebbs and flows, sea currents, liquid hydrogen, and synthetic fuel. But what about the environmental problems when using certain sources of energy?

Teacher: The use of thermal energy is a priority. But! Also D.I. Mendeleev said that using oil is the same as burning money in a furnace, although oil in its pure form is not used, but only fuel oil, a product of its processing. And when burning any fuel, a large amount of oxygen is consumed and carbon dioxide is released in such quantities that it leads to an environmental problem - the “greenhouse effect” is created. This leads to climate warming and as the consequences of flooding (we are very familiar with natural disasters in Europe.) When fuel is burned, the environment is polluted, this harms animals (they either leave their places, or die, or mutations occur in development), and the quality of drinking water changes. water, excessive flowering and overgrowing of water bodies. This leads to environmental disasters. This, of course, cannot continue indefinitely. We need an alternative, and you and I know that thermal resources are not endless.

Name exhaustible and inexhaustible sources of energy.

Calculation of the cost of consumed electricity.

Example 1. There is an electric lamp rated for a current of 100 W. The lamp burns for 6 hours every day. Find the current work for one month (30 days) and the cost of energy consumed at a tariff of 2.45 hryvnia per 1 kWh.

Using energy-saving technologies in everyday life.

Does energy consumption depend on the time of year?

Guys, do we need to use electricity rationally and carefully? Creating a problem situation

What ways to save energy can you suggest?

Do not turn on lighting and electric heating devices unless necessary;

Use the economical mode of operation of household electrical appliances (washing machines, electric stoves, vacuum cleaners);

When leaving the apartment, make sure that all electrical appliances are turned off (this rule is also a fire safety rule).

Depending on their purpose, electrical appliances are conventionally divided into the following groups:

For cooking (stoves, mixers, vegetable cutters, juicers, coffee makers, toasters, blenders, etc.);

Heating liquids (kettles, samovars, boilers, water heaters);

Additional heating and ventilation of premises (radiators, fireplaces, convectors, fans, air conditioners);

Personal hygiene (irons, hair dryers, heating pads);

Leisure activities (music centers, tape recorders, televisions);

Household appliances (washing machines, refrigerators, vacuum cleaners);

Communication means (telephones, radiotelephones);

Power tools (soldering irons, burners, polishers, drills, etc.).

Each electrical appliance has a technical passport, which indicates the voltage, power, standard number, year of manufacture, the name of the manufacturer, which is located on the device body in the form of a plate, as well as instructions for use, which indicate operating rules, features of caring for the device, possible malfunctions and the reasons for their elimination, warranty obligations.

IV. Installation of electric heating devices.

Teacher: exhaustible energy sources are oil, gas, coal, uranium. The fact that they can run out is one problem, but the waste from these stations is deadly to humans. Inexhaustible sources of energy are the energy of biomass, wind, sun, sea waves and currents, and the heat of the earth. What consequences can a nuclear power plant accident lead to?

Teacher: Even without an accident, there is a radioactive background around the reactor, which leads to gene mutations and cancer.

But is the use of wind, sun and water so harmless?

Teacher: While there are many advantages, there are disadvantages. The dependence of wind farms on the weather creates noise pollution. Animals leave, which upsets the ecological balance in the area. The person feels depressed. And with all this, the power of such stations is small. In Germany, wind parks have been created on the southern coast of the Jutland Peninsula, and near the village of Kulikovo, Kaliningrad region. Geothermal energy is used in Iceland and Kamchatka... But hot water is not pumped back anywhere, this will lead to soil pollution and environmental damage. There are still very few solar power plants. These are solar installations that capture and convert the sun's energy. But this is dependent on climatic conditions and is very expensive. This type of energy is used in Brazil and California on the roofs of high-rise buildings.

Is it possible to somehow change the situation?

Teacher: The most important thing is to learn to save energy. It is elementary to save electricity in our apartments and insulate windows for greater heat retention. Efficient use of energy resources, compliance with environmental protection requirements so that the ecological balance in nature is not disturbed, and reduce resource consumption. Install means of regulating energy consumption (switches and switches.)

V. Consolidating new knowledge and skills of students (reflection).

1. The first group draws up safety rules using the particle NOT, the second group draws up, based on the safety rules of group 1, without using the particle not, i.e. explains what to do in a given situation.

2. Solve a crossword puzzle on the topic “Electrical appliances”

1) Household kitchen electrical appliance.

2) Household electrical appliance for washing floors

3) Household electrical appliance for cleaning the premises

4) Electrical appliance

5) Thermal electrical appliance

6) Household electrical appliance used for space heating

7) Household electrical appliance

8) Kitchen electrical appliance for extracting juice

9) Outer shell of the electrical appliance

10) Part connecting the electric heating device to the cord

11) Device that automatically maintains temperature

12) Part of the thermostat related to hairstyle

13).An important component of the refrigerator

14) Oven with infrared heating

VI. Summing up the lesson.

VII. Homework: Calculate the electricity consumption in your home for a week.

LIST OF SOURCES USED

1) http://boltishki.grodno.unibel.by/main.aspx?uid=872

2) Bushuev V.V. Troitsky A.A. Energy efficiency and the economy of Russia.// Energy: technology, economics, ecology. 2004. No. 5.

3) Lisienko V.G. Shchelokov Ya.M. Reader on energy saving. Reference publication. In 2 books. - M.: “Teploenergetik”, 2002. - 688 p.

Integrated lesson (chemistry - physics) Fuel energy. Heat of combustion of fuel. Purpose of the lesson: To study the use of internal energy of fuel. Study questions about the release of heat during fuel combustion. Derive a formula to calculate the amount of heat released during fuel combustion. Consider environmental issues related to the combustion process.

Stages of the lesson: 1-repetition The guys remember questions about types of energy. (potential and kinetic, internal) 2-explanation of new material (the study of new material takes the form of questions and answers during a conversation. At the same time, students compile a background note and do practical work) 3-conclusion and homework

Pedagogical technologies used in the classroom. Information technology: -used when explaining material in the form of watching the video “The Origin of Life on Earth” Health-saving technology: -used during moments of relaxation when reading a poem and watching a candle burn -this promotes emotional mood Communication technology

"ENERGY AND ECOLOGY"

Lesson on working in basic-crossover groups

I use my knowledge

and I recognize their importance.

I contribute my understanding

And I feel included.

Based on a Chinese proverb

Target. Summarize and systematize students’ knowledge about various types of power plants, the principle of their operation, energy transformations; continue to develop the ability to analyze, compare, draw independent conclusions, and work with scientific literature; to cultivate economic and environmental thinking, the ability to work in a team, tolerance, and the desire to expand knowledge.

Lesson type. Lesson of generalization and systematization of knowledge.

Equipment. A tape recorder, an electric kettle, posters with schematic images of different types of power plants, tables for comparative characteristics of different types of power plants, colored markers, didactic material with information about a specific type of power plant, atlases “Economic and social geography of the world,” numbered color cards.

Methodical advice. Activities that teach children to formulate and express their thoughts, listen to others, and make decisions based on rational thought help teach democratic thinking. Research suggests that introducing group work methods is effective in preventing disengagement among students. It is advisable to divide into groups in the previous lesson, and give each group homework to find and process materials about a certain type of power plant. In the classroom, student activity should predominate; they should work with instruments, reference books, and diagrams, because it is precisely this kind of activity that is associated with active thinking.

By using new teaching methods alongside traditional ones, we can help students develop their thinking while teaching them to respect the rights of others and work together to achieve a common goal. “Knowledge is only knowledge when it is acquired through the efforts of one’s mind, and not through memory” (L. Tolstoy).

The lesson involves the use of active learning methods, in particular, the method of working in basic-cross groups and the “decision tree” method.

Basic-cross group method. The teacher divides them into basic groups in which students work through material of a certain type (each group is different). After this, the teacher forms new cross-groups so that they include representatives from each previous basic group. In these groups, students teach each other, passing on the knowledge acquired in basic groups.

Division into groups can be done in various ways. For example, give students cards of different colors, on which the numbers 1, 2, 3, 4, 5, 6 are written. Basic groups are formed by the colors of the cards, cross groups - by numbers. You can write the symbols A1, A2, A3, A4, A5, A6, B1, B2,... etc. on small sheets of paper. to E6. Basic groups are formed by letters, cross groups - by numbers. The number of group members should not exceed 6 people.

Decision tree method. Each group receives large format tables with a drawn “solution tree” of the problem that is being considered) and felt-tip pens to fill out. As they work, group members write down the disadvantages and advantages of each option, and then decide on how to solve the problem. After completion of the work, representatives of each group report the results of the work of their groups.

During the classes

I. Updating students’ basic knowledge

(Music is playing quietly in the classroom, there is an electric kettle with water heating on the demonstration table, a lamp is burning above the chalkboard, student tables are arranged for group work.)

Teacher. Dear friends, today we will start our lesson in an unusual way. First we'll drink tea and then we'll work. Our laboratory assistant turned on the electric kettle a long time ago, and the water is about to boil. (Suddenly the lights go out, the music stops, the kettle turns off. The laboratory assistant approaches the teacher and quietly says something to him.)

Teacher. What's happened?

Students. There is no current in the network.

Teacher. It's a pity... We won't be able to drink tea now. Tell me, please, where does the current in the electrical network of our class, our apartments come from?

Students. Produced in power plants.

Teacher. Right. What power plants do you know?

Students. Hydroelectric power plants, thermal power plants, nuclear power plants, alternative (solar, wind, tidal, geothermal, biogas).

(When students name a certain type of power plant, the teacher or assistant puts up posters on the board with a diagram of that type of power plant.)

II. Motivation for learning activities

Teacher. Energy is the basis of life in human society and its progressive development is associated with a direct increase in energy consumption. This consumption increased during the 20th century. more than 100 times, while many times more organic fuel was burned than in all previous times. What prospects await us in the 21st century?

Humanity is increasingly aware of its responsibility for preserving the environment and for the cleanliness of our planet. Scientific and technological progress, increased living comfort and the associated increase in energy consumption are objective things. But this does not mean that they should be achieved at any cost. Using only traditional energy sources (oil, gas, nuclear fuel) destroys and pollutes land, water resources and air. At the same time, more than 1 kW per square meter constantly provides us during the day with the light of an inexhaustible, environmentally impeccable and publicly accessible natural source - the Sun. Advances in technology already make it possible to use it to generate electricity, the cost of which is approaching traditional ones. Wind energy and biomass energy, which are related to solar energy, are also intensively developing in many countries. Today, undoubtedly, the main economic problem in the world is the energy crisis. The socio-economic development of each country, in particular Ukraine, depends on the state of its energy sector.

So, there are methods for generating electricity from organic and nuclear fuel (coal, oil, natural gas, uranium) and using renewable energy sources (hydraulic, solar, wind, tidal, geothermal and others). Which one should you prefer? The topic of our lesson is “Energy and Ecology”.

III. Generalization and systematization of knowledge

At this stage of the lesson we will work in this way. Last year, you and I formed groups, each of which received homework: to prepare a report on a certain type of power plant. So, I ask you to now sit down in groups at tables (there are signs of different colors on the tables). You will receive additional information for the messages you prepared at home (see appendix). Your task is to process this material, discuss it and answer the following questions (the questions are written on the board or in the form of a poster).

1. What is the operating principle of the power plant?

2. What energy transformations occur in this ES?

3. The impact of this ES on the environment?

4. In what places are power plants of this type mainly located?

8 minutes are allotted to complete this work.

(While the students are working, the teacher monitors their work and provides assistance if necessary.)

Teacher (in 8 minutes). Please stop the discussion. We carry out our further work as follows. Your colored cards have different numbers written on them. So, I will ask the students to look at what number is written on the card and sit at the table with the corresponding number.

Now you must tell each other about the type of ES that you learned in the previous group. Then fill out the table you receive and make a decision: which station is the most economical and environmentally friendly? You have 15 minutes to complete this task.

(After 15 minutes, the groups post their tables on the board with the solution covered with a strip of paper.)

Teacher. I ask one of the group members to comment on their table without reading the solution.

(Groups take turns presenting tables. When all groups have reported, the teacher reveals all the solutions and reads them out. Based on these solutions, students make generalizations about which power plant is the most economical and environmentally friendly.)

Teacher. Consequently, electrical energy is a consequence of the development of civilization. It gives us the opportunity to watch TV shows, listen to the radio, and use many devices. But tell me, what should we always remember when taking advantage of any achievement of civilization?

Students. About the impact of these achievements on the environment.

Teacher. Now I want to propose an interesting experiment. Let's find out which of you can give up the benefits of civilization for the sake of preserving the environment. I ask everyone to close their eyes and raise their hand if they are ready to do this. Thank you.

(The teacher evaluates and comments on the students’ work, their ability to work with scientific material, analyze, draw conclusions, notes active work in the lesson, interesting and meaningful messages. Assigns homework.)

Application

Hydroelectric power station (HPP)

Energy - a branch of the economy that produces energy - is important for the development of the economy, science and culture of the country. Nowadays, mechanical energy sources - hydroelectric power plants - have a significant share of electricity generation. For the first time, man used the energy of water with the help of a water wheel. In a modern hydroelectric power station, water rushes at a significant speed onto the turbine blades. Water flows through a protective mesh and a control valve through a steel pipeline to the turbine, above which the generator is installed. The mechanical energy of water is transmitted through a turbine to generators, in which electrical energy is converted. After the work is completed (the turbine rotates), the water flows into the river through a tunnel and gradually expands.

The costs of building a hydroelectric power station are serious, but they are compensated by the fact that they do not pay (at least explicitly) for the energy source - water. The power of modern hydroelectric power plants exceeds 100 MW, and the efficiency is 95%. Such power is achieved at low rotor speeds, which is why modern hydraulic turbines are striking in their size. A turbine is an energetically very beneficial machine, since water easily and simply changes translational motion to rotational motion.

The construction of a dam on a river makes it possible to create a significant difference in the lower and higher water levels from the hydroelectric power station along the river, that is, between the upper and lower pools. Sometimes this level difference reaches more than 100 m. The upstream water falls from a considerable height onto the blades of the hydraulic turbine, rotates it, and with it rotates the electricity generator, which is connected to the turbine. The power of any hydroelectric power station depends on the difference in water levels between the upper and lower pools and on! the number of cubic meters of water passing through the blades of the station’s turbines in 1 second: the larger it is, the more powerful the hydroelectric power station.

One of the principles of hydroelectric power generation is the maximum use of river hydropower. According to this principle, not individual hydroelectric power stations are built on rivers, but cascades of such stations and reservoirs are created to regulate the annual flow of water. The flow of most rivers is uneven throughout the year. So, in the Dnieper, during the spring flood, that is, for about one month, half of all the river’s water reserves flowed into the sea; in the summer months, the water level dropped sharply. As a result, the hydroelectric power station operated at half capacity in the summer. The creation of a large reservoir near the hydroelectric power station dramatically changed the situation. Now the spring waters of the Dnieper no longer flow uselessly into the sea, but are stored in the reservoir, and then systematically used throughout the year by hydroelectric power stations. This made it possible not only to increase electricity production, but also to relieve peak loads in the energy system of the area where the hydroelectric power station is located. Modern hydroelectric power stations are built in such a way that they can be used to comprehensively solve the problems of generating electricity, irrigating land, water supply, and the like.

Note that hydroelectric power plants have at least two advantages over thermal power plants and nuclear power plants:

1. absence of fuel costs during operation, as a result of which their electricity is 4-8 times cheaper than electricity produced at thermal power plants and nuclear power plants;

2. The hydropower of rivers, which is used at hydroelectric power stations, is reproduced naturally, but fossil energy resources are not reproduced.

Hydropower technologies have many advantages, but there are also significant disadvantages. For example, low water resources during droughts can seriously affect the amount of energy produced. This can be a significant problem where hydropower forms a significant part of the country's energy mix; The construction of dams causes many problems: resettlement of residents, siltation of reservoirs, water disputes between neighboring countries, and the significant cost of these projects. The construction of hydroelectric power stations on lowland rivers leads to the flooding of large areas. A significant part of the area of ​​the reservoirs formed is shallow. In the summer, due to solar radiation, aquatic vegetation actively develops in them, and the so-called “blooming” of water occurs.

Dams prevent fish migration. The rich cascade hydroelectric power stations turn rivers into a series of lakes where swamps appear. Fish die in these rivers, and the microclimate around them changes, further destroying natural ecosystems.

Thermal power plant (TPP)

Human energy has long been aimed at finding means to facilitate the performance of work necessary for its existence. For this, all kinds of tools and mechanisms, tamed animals were used, but only the heat engine dramatically expanded human capabilities and accelerated technical progress.

A heat engine is a system that allows you to convert thermal energy into other forms of energy - mechanical, electrical.

In thermal ES, the energy that is released during the combustion of various types of fuel - coal, gas, oil, peat, oil shale with the help of electric generators driven by steam and gas turbines or internal combustion engines, is converted into electrical energy. Most modern powerful thermal power plants are steam turbine. In a steam turbine, heated (up to 500-560°C) and compressed (up to 2.4·107 Pa) steam leaves the nozzle and expands. The volume of steam increases, and the pressure correspondingly drops, while the potential energy of the compressed steam is converted into kinetic energy. The steam leaves the nozzle at considerable speed, hits the blades of the turbine disk mounted on the shaft, and quickly rotates them, while the kinetic energy of the steam is transferred to the turbine rotor. The turbine shaft is rigidly connected to the electric generator shaft, and therefore the turbine rotates the generator rotor, as a result of which electrical energy is produced.

Most of the fuel's energy is lost along with the hot (waste) steam. This hot steam-water mixture, exhausted from turbines, is used for heating residential premises and industrial needs, which increases the efficiency of thermal power plants (CHP). It should be noted that at thermal power plants 80% of fuel combustion energy is used efficiently.

During the combustion of fuel in heat engines, harmful substances are released: carbon (IV) oxide, nitrogen compounds, lead compounds, and a significant amount of heat is also released into the atmosphere. In addition, the use of steam turbines at thermal power plants requires the allocation of large areas for ponds in which the exhaust steam is cooled. Every year, 5 billion tons of coal and 13.2 billion tons of oil are burned in the world, this is accompanied by the release of 2·1010 J of heat into the atmosphere. Organic fuel reserves on Earth are distributed extremely unevenly, and at the current rate of consumption, coal will last for 150-200 years, oil for 40-50 years, and gas for about 60 years. The entire cycle of work associated with the extraction, transportation and combustion of organic fuel (mainly coal), as well as the generation of waste, is accompanied by the release of a significant amount of chemical pollutants. Coal mining is associated with significant salinization of water reservoirs where water from mines is discharged. In addition, the pumped water contains the isotopes Radium and Radon. The thermal power plant, although it has modern systems for purifying coal combustion products, emits into the atmosphere per year, according to various estimates, from 10 to 120 thousand tons of sulfur oxides, 2-20 thousand tons of nitrogen oxides. In addition, more than 300 thousand tons of ash are formed, which contains about 400 tons of toxic metals (arsenic, cadmium, lead).

It can be noted that coal-fired thermal power plants emit more radioactive substances into the atmosphere than nuclear power plants of the same power. This is due to the release of various radioactive elements contained in coal in the form of inclusions (radium, thorium, polonium, etc.). To quantify the impact of radiation, the concept of “collective dose” is introduced, i.e. the product of the dose value by the number of the population that was exposed to radiation (it is expressed in man-sieverts). It turned out that in the early 90s of the last century, the annual collective radiation dose to the population of Ukraine due to thermal energy was 767 man stars. and due to nuclear power - 188 star stars.

Nowadays, 20-30 billion tons of carbon monoxide are emitted into the atmosphere annually. Projections indicate that if this rate continues in the future, by mid-century the average temperature on Earth could rise by several degrees, which will lead to unforeseen global climate changes.

When comparing the environmental effects of various energy sources, it is necessary to take into account their impact on human health. The high risk for workers when using coal is associated with its extraction in mines, transportation and the environmental impact of its combustion products. The last two reasons relate to oil and gas and affect the entire population. It has been established that the global impact of emissions from the combustion of coal and oil on human health is approximately the same as an accident like Chernobyl, which is repeated once a year. This is a “silent Chernobyl”, the consequences of which are directly invisible, but constantly affect the environment. The concentration of toxic impurities in chemical waste is stable, and eventually they will all end up in the ecosphere.

Nuclear power plant (NPP)

The basis of nuclear energy is nuclear power plants that convert nuclear energy into electrical energy. Nuclear power plants use the heat released in a nuclear reactor as a result of a chain reaction of fission of nuclei of heavy elements, mainly 235U, 238U, 239Pb. Then, as in conventional thermal power plants, thermal energy is converted into electrical energy. The final fission of 1 g of an isotope of uranium or plutonium releases approximately 22.5 MWh. energy, which is equivalent to the energy of 2.8 tons of standard fuel.

The operating principle of a nuclear power plant is as follows: a nuclear reactor, protected by concrete, contains cylinders (rods) containing uranium inside. Uranium rod blocks are located in water, which is both a moderator and a coolant. Water is under high pressure and can therefore be heated to very high temperatures (about 300°C). This hot water from the top of the reactor core is piped into the steam generator (which is also filled with water, which evaporates), cooled, and returned through the pipeline to the reactor. Saturated steam from the steam generator enters the steam turbine through a pipeline and, after exhaustion, is returned back through another pipeline. The turbine rotates an electric generator, the current from which flows into the switchgear and then into the external electrical circuit. The course of the chain reaction is regulated by rods made of substances that absorb neutrons well.

More than 45 years have passed since the commissioning of the first nuclear power plant. During this time, serious changes occurred in nuclear power plant technology: the power of nuclear reactors increased sharply, and the technical and economic indicators of nuclear power plants increased. Now for areas remote from chemical fuel resources, the cost is 1 kW hour. for nuclear power plants is less than for thermal power plants. Therefore, despite the slightly higher cost of equipment for nuclear power plants, their overall economic performance under these conditions is better than for thermal power plants. Nuclear fuel reserves in energy equivalent are hundreds of times greater than organic fuel. Nuclear power plants practically do not emit chemical pollutants into the atmosphere. If their normal operation is understood to be such an operating mode in which the additional radiation dose from the station does not exceed the values ​​of natural background fluctuations, then, as a rule, this condition is met. In general, the actual radiation impact of nuclear power plants on the natural environment is significantly (10 times or more) less than permissible. If we take into account the environmental impact of various energy sources on human health, then among non-renewable energy sources the risk from nuclear power plants that operate normally is minimal, both for workers whose activities are associated with various stages of the nuclear fuel cycle, and for the population. The global radiation contribution of nuclear energy at all stages of the nuclear fuel cycle is currently about 0.1% of the natural background and will not exceed 1% even with its intensive development in the future.

Mining and processing of uranium ores is also associated with adverse environmental effects. But the main problem remains the disposal of high-level waste. The volume of especially hazardous radioactive waste is about one hundred thousandth of the total amount of waste, including highly toxic chemical elements and their stable compounds. Methods are being developed for their concentration, reliable binding and placement in stable geological formations, where, according to experts, they can be retained for thousands of years.

A serious disadvantage of nuclear energy is the radioactivity of the fuel used and its fission products. This requires the creation of protection from various types of radioactive radiation, which significantly increases the cost of energy generated by nuclear power plants. In addition, another disadvantage of nuclear power plants is thermal pollution of water, that is, its heating.

It is interesting to note that, according to a group of English doctors, persons who worked during 1946-1988. workers in the British nuclear industry live longer on average and have significantly lower mortality rates from all causes, including cancer. If we take into account the actual levels of radiation and the concentration of chemicals in the atmosphere, then it can be argued that the influence of the latter on the flora as a whole is quite significant compared to the impact of radiation.

The data presented indicate that during normal operation of power plants, the environmental impact of nuclear energy is tens of times lower than thermal energy.

The Chernobyl tragedy remains an irreparable disaster for Ukraine. But it concerns more the social system that gave birth to it than nuclear energy.

Alternative power plants

The growing use of electrical energy and the aggravation of environmental problems have significantly intensified the search for environmentally friendly methods of generating electricity. Methods of using fuel renewable energy are being intensively developed - solar, wind, geothermal, wave energy, tidal energy, biogas energy and the like. The sources of these types of energy are inexhaustible, but you need to reasonably assess whether they can satisfy all the needs of humanity.

Wind power plants (WPP)

According to various authors, the total wind energy potential of the Earth is 1200 TW, but the possibilities of using this type of energy in different regions of the Earth are not the same. The latest research is aimed primarily at generating electrical energy from wind energy. Wind farms are being built mainly with direct current. The wind wheel drives a dynamo - an electric current generator, which simultaneously charges batteries connected in parallel.

Today, wind-electric units reliably supply oil workers with electricity; they successfully work in hard-to-reach areas, on remote islands, in the Arctic, on thousands of agricultural farms where there are no large settlements or power plants nearby. The widespread use of wind-electric units under normal conditions is still hampered by their high cost. When using wind, a serious problem arises:

excess energy in windy weather and lack of it in calm periods. The use of wind energy is complicated by the fact that the wind has a low energy density, and its strength and direction also change. Wind turbines are usually used in places where there is good wind conditions. To create high-power wind turbines, it is necessary that the wind turbine be large in size, in addition, the propeller must be raised to a sufficient height, since at higher altitudes the wind is more stable and has a higher speed. Only one power plant running on fossil fuel can replace (in terms of the amount of energy produced) thousands of wind turbines. In Ukraine, the best conditions for the construction of wind farms are in Crimea.

Energy of ebbs and flows

For centuries, people have speculated about the cause of sea tides. Today we know for sure that a powerful natural phenomenon - the rhythmic movement of sea waters is caused by the gravitational forces of the Moon and the Sun. Tidal energy is enormous, its total power on Earth is about 1 billion kW, which is more than the total power of all the rivers in the world.

The operating principle of tidal power plants is very simple. During high tide, water rotates the hydraulic turbine rotor and fills the reservoir, and after low tide it leaves the reservoir into the ocean, again rotating the turbine rotor. The main thing is to find a convenient place to install the dam, where the tide height would be significant. Constructing and operating offshore power plants is a complex task. Sea water causes corrosion of most metals, and parts of installations become overgrown with algae. In Ukraine there are no conditions for using tidal energy.

Energy of sun

The heat flux of solar radiation that reaches the Earth is very large. It is more than a thousand times higher than the total use of all types of fuel and energy resources in the world.

Among the advantages of solar energy is exceptional environmental friendliness. Solar energy reaches the entire surface of the Earth, only the polar regions of the planet suffer from its lack. That is, almost all over the globe, only clouds and night prevent it from being used constantly. This general availability makes this type of energy impossible to monopolize, unlike oil and gas. Of course, the cost is 1 kW hour. solar energy is significantly higher than that obtained by the traditional method. Only a fifth of sunlight is converted into electrical current, but this share is growing thanks to the efforts of scientists and engineers.

Since solar radiation energy is distributed over a large area (in other words, has a low density), any installation for direct solar energy use must have a collecting device with a sufficient surface area. The simplest device of this kind is a flat-plate collector - a black plate well insulated from below.

It is covered with glass or plastic, which allows light to pass through, but does not allow infrared thermal radiation to pass through. In the space between the stove and the glass, black tubes are most often placed in which water, oil, air, sulfur oxide (IV) and the like flow. The sun's rays, penetrating through glass or plastic into the collector, are absorbed by black tubes and the stove and heat the working substance in the tubes. Thermal radiation cannot escape from the collector, so the temperature in it is much higher (200-3000C) than the ambient temperature. This is where the so-called greenhouse effect manifests itself. A more complex collector, the cost of which is much higher, is a concave mirror that concentrates the incident radiation in a small volume around a certain geometric point - the focus. Thanks to special mechanisms, collectors of this type are constantly turned towards the Sun. This makes it possible to collect a significant amount of sunlight. The temperature in the working space of mirror collectors reaches 3000°C and higher. There are power plants of a slightly different type. According to experts, the most attractive idea for converting solar energy is the use of the photoelectric effect in semiconductors. However, the surface area of ​​solar panels to provide sufficient power must be quite large (a daily output of 500 MW requires a surface area of ​​500,000 m2), which is quite expensive. Solar energy is one of the most material-intensive types of energy production. Large-scale use of solar energy entails a gigantic increase in the need for materials, and, consequently, in labor resources for the extraction of raw materials, obtaining materials, manufacturing heliostats, collectors, other equipment, and their transportation. The efficiency of solar power plants in areas far from the equator is quite low due to unstable atmospheric conditions, relatively weak intensity of solar radiation, as well as its fluctuations due to the alternation of day and night.

Geothermal energy

Geothermal energy uses the high temperatures of the earth's crust to generate thermal energy. In some places on Earth, especially at the edges of tectonic plates, heat comes to the surface in the form of hot springs - geysers and volcanoes. In other areas, underwater hot springs flow through underground formations, and this heat can be harnessed through heat exchange systems. Iceland is an example of a country where geothermal energy is widely used.

Biogas. Biotechnology

Technologies have now been developed that make it possible to extract flammable gases from biological raw materials as a result of the chemical reaction of the decomposition of high molecular weight compounds into low molecular weight ones due to the activity of special bacteria (which take part in the reaction without access to oxygen from the air).

Reaction scheme: biomass + bacteria => combustible gases + other gases + fertilizers.

Biomass is waste from agricultural production (livestock farming, processing industry). The main raw material for biogas production is manure, which is delivered to the biogas station. The main product of a biogas station is a mixture of combustible gases (90% of the mixture is methane). This mixture is supplied to power plants.

Renewable sources (except for water energy, which falls) have a common drawback: their energy is very weakly concentrated, and this creates considerable difficulties for practical use. The cost of renewable sources (not counting hydroelectric power stations) is significantly higher than traditional ones. Both solar and wind and other types of energy can be successfully used to generate electricity in the power range from several to tens of kilowatts. But these types of energy are not promising for creating powerful industrial energy sources.

Lesson - lecture (physics – 11th grade)

Lesson topic: “HUMANITY AND ENERGY”

Target: consider ways to solve the inevitable global energy crisis.

Tasks:

Highlight energy as one of the priority areas of economic, scientific and technical development of Russia in the 21st century.

Consider alternative energy sources as possible options for overcoming the energy crisis, identifying their advantages and disadvantages.

Pay attention to the environmental component of each alternative energy source.

Study questions:

The inevitability of a global energy crisis.

Alternative energy sources:

a) Solar energy;

b) Wind energy;

c) Ocean energy;

d) Geothermal energy.

3. What will help solve the global energy crisis?

During the classes.

Organizational moment.

Formulation of the problem:

Learning new material :

Lesson summary . Reflection

Homework

S. Studying new material

First study question:

Where is the beginning of the end with which the beginning ends?

K. Prutkov

Back in 1996, the Prime Minister of Russia approved the priority directions for the development of domestic science and technology, as well as critical technologies at the federal level, determined by the government commission on scientific and technological policy. These include areas and technologies that are recognized as the most promising from the point of view of economic, scientific and technical development of Russia in the 21st century. and which the state undertakes to oversee and finance. The list of priorities is:

• Basic Research;

  Information technology and electronics;

  Manufacturing technologies;

  New materials and chemical products;

  Technologies of living systems;

  Transport;

  Fuel and energy;

  Ecology and rational use of natural resources.

Given the importance of the issue raised, I propose to talk about one of the listed priorities – energy.

It is generally accepted that the main factor determining the development of material culture is the creation and use of energy sources. Energy is the most important carrier of technological progress and improving human living standards.

According to the UN, the current average level of energy consumption per year per person is about 5 kW per person, the current level in the most developed countries is 14 kW.

The production, transformation and conservation of energy are fundamental processes studied in various branches of science. The main pattern that physics has established is the law of conservation of energy. Based on this law, a global crisis in energy production is predicted. The inevitability of a global energy crisis is now fully realized, and therefore the energy problem for science and technology has become problem number one. Currently, organic fuels are used as the main energy resources: oil, natural gas, coal, peat. The reserves of chemical energy in fossil fuels have been accumulated over a long period of the Earth's existence due to biological processes. Therefore, based on the law of conservation of energy, humanity, if it does not find other sources of energy, will be faced with the need to limit its consumption. And this will lead to a decrease in the level of material well-being of mankind.

The era of mineral energy, having barely begun, will most likely soon end. There are at least three reasons that support this prediction:

The number of minerals is limited,

Their use pollutes the environment,

Their reserves are irreplaceable.

For example, it is believed that coal, oil and gas are non-renewable energy sources only insofar as the current rate of their use is millions of times higher than the rate of formation.

Academician A.E. Sheindlin believes that “there are three ways to solve the global energy problems of the future: finding new energy sources, more efficient use of existing ones, and finally, rational use of extracted energy.”

Recently, attention to the use of renewable energy sources has been increasing everywhere: solar energy, wind energy, seas and oceans, geothermal heat from underground sources, i.e. deep heat of the Earth.

Strictly speaking, hydropower resources are also a type of renewable energy source. Electricity production at hydroelectric power stations has been fully developed and is a widely developed area of ​​large-scale energy. If we consider the flow of the rivers of the entire globe in energy terms, we get a huge figure showing that every year we could use the power of a hydroelectric power station amounting to 210·10 9 kW without any production costs, and for an unlimited number of years.

However, it is considered economically feasible to use electricity with a power of only 7·10 9 kW, i.e. approximately 3.3% of possible electricity generation. This is due to the fact that damming rivers with water rising to a small height is usually not economically justified, especially when fertile lands are subject to flooding, since the harvest turns out to be much more valuable than the energy received.

There is also a factor of negative impact on the environment - salinization and alkalization of fertile lands.

In addition, a little-studied consequence of the construction of hydroelectric dams is, according to some seismologists and geologists, the so-called “induced seismicity” in the area where powerful hydraulic structures and large-volume reservoirs are located. The influence of the reservoirs themselves on local climatic conditions is dual in nature - cooling and warming effects. Therefore, the conversion of hydropower to electricity, compared to other types of renewable energy sources, results in significant environmental impacts. Therefore, the task of constructing hydroelectric power stations comes down to solving complex problems with their help: the construction of hydroelectric power stations is advisable both for generating electricity and for the development of river navigation, agriculture and fisheries, as well as near energy-intensive enterprises that could use cheap energy from hydroelectric power stations without building for these purposes of additional power lines.

Second study question:

I propose to talk about the development of the above new, alternative energy sources.

a) Solar energy . “Looking at the Sun, squint your eyes, and you will boldly see the spots on it” K. Prutkov.

All solar energy reaching the Earth's surface is about 2.2·10 21 J per year. Solar energy represents an “eternal” and potentially huge source of energy supply that does not introduce any pollution into the environment. However, there are also known disadvantages of solar energy.

First, solar radiation on the Earth's surface is a relatively low-density source of energy. Thus, at sea level, due to absorption caused by water vapor, ozone and carbon dioxide, the radiation flux weakens to approximately 1000 W/m 2. This circumstance forces us to usually collect solar energy from a fairly large area. For example, to generate energy with a capacity of 100 MW, electricity must be removed from an area of ​​1 sq. km.

Secondly, in a given location, solar radiation is not constant depending on the time of day and is subject to fluctuations due to weather conditions. Because of this, each solar energy installation must have either an energy storage device or a backup energy installation using a different energy source. These disadvantages cause high installation costs for solar energy harvesting.

A typical solar heating system consists of roof-mounted flat plate collectors. The collector is a black plate, well insulated at the bottom. The top of the plate is covered with glass or plastic, which allows light to pass through but does not allow infrared thermal radiation to pass through. In the space between the stove and the glass, pipelines with coolant (water, oil, air, etc.) are placed. Solar radiation, penetrating through glass or plastic into the collector, is absorbed by pipes and the stove and heats the coolant.

Currently, houses heated by the sun are being built in many countries - Japan, Canada, Germany, France, the USA and others. Thus, in the United States, heating and air conditioning using solar energy is produced in 35% of buildings.

To increase the temperature of the heated object, solar installations are equipped with solar radiation concentrators. A concentrator is a set of mirrors that collect (focus) solar rays. The operation of so-called solar ovens is based on this principle. The world's largest solar oven was built in France, in the Pyrenees, with a thermal capacity of 1 MW. The total area of ​​the mirrors of this furnace is about 2500 sq.m. at the focus of the furnace, a temperature of about 3800 ° C is reached, in which the most refractory substances can be melted and processed.

The main obstacle to large-scale production of electricity from solar power plants is their high estimated cost, which is due to the requirement for a large area of ​​power receivers and their roads And heat: the cost of 1 kW of installed power is currently 150-300 thousand rubles.

Semiconductor photovoltaic converters (PVCs) are used to directly convert solar radiation into electricity. And here, certain successes have been achieved in the creation of special-purpose and low-power installations. FEPs turned out to be practically irreplaceable sources of electric current in spacecraft. Semiconductor solar panels were first installed on the third Soviet artificial Earth satellite, launched on May 15, 1958. Lunokhod-1, powered by a solar battery, operated on the Moon for more than a year. Now solar panels have become a common part of spacecraft.

Thus, in small autonomous installations, where cost does not play a decisive role, it is advisable to use solar radiation now.

b) Wind energy . “Wind is the breath of nature” K. Prutkov.

Wind energy is the result of thermal processes occurring in the planet's atmosphere. The difference in the densities of heated and cold air determines the movement of air masses. Consequently, the root cause of wind energy is the energy of solar radiation, which is released in one of its forms - the energy of air currents. About 2% of solar radiation reaching the Earth is converted into wind energy.

Wind is a very large renewable energy source. Its energy can be used in almost all areas of the Earth. The preference for using wind power plants (WPPs) for economic reasons in comparison with any options based on the use of fossil fuels is beyond doubt. All wind energy potentially possible for implementation over the Earth's surface during the year is estimated at 13·10 12 kWh. For practical use, it is realistic to consider 10-20% of this energy. The difficulty, however, lies in the very large dissipation of wind energy and the variability of the wind, i.e. in low energy flux density.

Wind energy, which is very interesting, is one of the most ancient sources of energy. The age of ancient wind turbines is not precisely established. But it is believed that such engines appeared in 1700 BC. Wind energy was widely used to drive mills and water-lifting devices in ancient times in Egypt and the Middle East. In Europe, windmills appeared at the beginning of the 12th century. In Holland in the 17th century. The total power of windmills was 50-100 MW, which, given the small population, was an impressive figure: 50-100 kWh of mechanical work per person per year.

Windmills would have remained a historical curiosity if not for the energy crisis of the 70s. In recent years, both in Russia and foreign countries, there has again been increased attention to wind energy work. Currently, several designs of wind turbines have been developed. A typical air turbine consists of two or three propeller-like rotors, with a blade span of 18 m, mounted on a tall metal tower (or 25 m high concrete tower). The rotor, weighing about 8 tons, usually rotates at a speed of 5-6 times the wind speed. A generator installed on the tower converts the mechanical energy of rotor rotation into electrical current.

However, the use of wind turbines has several problems:

The engine must be stopped when the wind weakens and energy losses due to friction begin to exceed the amount of energy extracted from the wind;

The wind wheel should develop maximum power in any wind - from moderate to strong;

If the wind speed becomes too high, the air turbine requires automatic shutdown to avoid overloading the generator;

When the wind direction changes, the turbine must rotate in such a way as to use it most efficiently.

And, nevertheless, in the context of a sharp rise in the price of fuel resources abroad, wind farms are becoming more and more profitable. According to economic estimates carried out at the University of Massachusetts, even today in the United States one can expect the same cost of energy produced by nuclear power plants and wind power plants.

By 1987, experimental wind power plants with a capacity of up to 5 MW had been created in the USSR. In a number of indicators - reliability, ease of use, efficiency, efficiency and transportability - they are superior to foreign models. But in a number of regions of the Far North, the European part of Russia, the Northern Urals, Chukotka, the Magadan region, etc., these wind power plants certainly seem to be profitable. Already today, autonomous installations with a capacity of only a few, and even fractions of a kilowatt, have received widespread practical use. They are mainly intended for agricultural needs - irrigation, vertical drainage, power supply to autonomous consumers. The use of wind farms helps to preserve the environment from pollution, which is very important from an environmental point of view.

c) Ocean energy.

The world's oceans occupy 70.8% of the earth's surface and absorb about three-quarters of the solar energy falling on the earth. Ocean energy is an untapped storehouse of energy resources. Among the installations using ocean energy, tidal power plants, wave and sea current power plants are currently being considered, in which the mechanical energy of the ocean is converted into electrical energy. The presence of a temperature gradient between the upper and lower layers of the World Ocean is used in so-called hydrothermal power plants.

Tidal power plants (PS) are a new direction in electricity production. Sea tides are known to be periodic fluctuations in sea level caused by the gravitational forces mainly of the Moon and to a lesser extent of the Sun. When the Sun, Moon and Earth are on the same line, the tidal wave is at its maximum. And in cases where the angle of the Moon - Earth - Sun is 90°, the tidal wave is minimal. The average wave height on most coasts is small and reaches only about 1 meter, but in some places off the coast the height of tides can reach more than 15 meters. For example, in the Penzhina Bay of the Sea of ​​Okhotsk, the height of the tidal wave is 13 m, and on the Atlantic coast of Canada (Bay of Fundy) even 18 m.

In its simplest version, the operating principle of a PES boils down to the following: during high tide, water fills a reservoir, and during low tide it flows out of it, rotating hydraulic turbines. This is the so-called single-basin TES scheme. The two-basin TPP is somewhat more complicated: it produces energy both during high tide and during low tide.

The total power of the tides of all the seas and oceans of the Earth is estimated at 3·10 9 kW, which corresponds to the energy potential of almost all the rivers of the world. This is a big number. However, the prospect of any widespread construction of the PES, according to scientists, is very doubtful. This is explained by the high cost of constructing PES, and also by the fact that their use is limited to a few geographically favorably located areas.

And yet, TPPs were built: in 1966 in France, on the Rance River, with a capacity of 240 MW, and in 1968 in the Soviet Union, Kislogubskaya TPP on the coast of the Barents Sea near the city of Murmansk. PES have one significant advantage: the process of generating electricity at these power plants is environmentally friendly.

Renewable energy sources also include sea waves. Sea waves are generated by the wind, their energy is determined by the state of the sea surface. An average wave 3 m high carries approximately 90 kW of energy power per 1 m of wave front length. However, the practical implementation of this energy causes great difficulties. Currently, a number of technical solutions for converting wave energy into electrical energy have been patented. In Japan, wave energy is used to autonomously power floating buoys.

Work on using the energy of ocean currents to produce electricity is in a state of preparation for technical implementation. It is planned to install turbines with an impeller diameter of 170 m and a rotor length of 80 m, made of aluminum alloy, with a possible service life of at least 30 years, in areas of relatively strong currents. Flows of water from the ocean current rotate the turbine blades, and through a system of multipliers that increase the speed, they rotate an electric generator connected to the pipe. According to experts, the cost of electricity produced at such power plants is expected to be 1.8 times lower than at thermal power plants, and 2.4 times lower than at nuclear power plants.

Currently, some attention is being paid to the energy use of the temperature gradient of various layers of water in the seas and oceans, that is, to the creation of hydrothermal power plants. Experimental samples of an automatic hydrothermal power plant were demonstrated in Japan and the USA in the 80s of the 19th century. In the United States, it is planned to directly build a hydrothermal power plant with a capacity of 1 MW, which is expected to save up to 63 thousand tons of oil per day. The involvement of vast ocean energy resources in energy production will result in minimal negative impact on the environment.

d) Geothermal energy.

The problem of using the Earth's heat to produce energy is of great interest. Geothermal energy is a virtually inexhaustible source of energy. It is known that with increasing depth of the earth's layers, the temperature rises. This leads to the fact that a heat flow of considerable power continuously flows from the bowels of the Earth to its surface, according to calculations 30 times greater than the power of all power plants in the world. Currently, intensive research is being carried out on the problem of using geothermal resources (underground reserves of hot water and steam; sources associated with the heat of dry rocks) for the production of electricity.

The first successful attempt to use the heat of the Earth to produce electricity was carried out in Lorderello (Italy) in 1904, where dry steam coming out of the earth was used in a steam turbine cycle. The capacity of this geothermal power plant is now 390 MW.

Today in the world there is not yet enough experience to reliably estimate all the cost indicators of geothermal energy, but one thing is clear that the development of geothermal sources is associated with very large financial costs. In addition, the operating experience of a number of foreign geothermal power plants, including the world’s largest station “Big Geysers” (USA, 12.5 MW), has shown that a number of factors associated with their operation have a negative impact on the environment. These primarily include hydrogen sulfide contained in steam. The presence of hydrogen sulfide in the air creates an unpleasant odor and can cause corrosion of equipment and materials. Many harmful substances are dissolved in thermal waters, such as arsenic, selenium, and mercury. It is not always possible to discharge such water into natural reservoirs. When discussing environmental issues of using geothermal power plants, it is also necessary to remember that the extraction of large quantities of water and steam to the surface can affect the microclimate of the area, leading to instability of the earth's crust and earthquakes. The method of pumping waste water into unproductive wells is quite radical. But such injection increases the cost of exploitation of geothermal deposits.

And yet, work to study the problem of using geothermal energy is being carried out in many countries around the world, since its reserves are inexhaustible. In addition, unlike solar energy, which fluctuates not only daily, but also depending on the time of year and the weather, geothermal energy can be generated directly. It is assumed that with the appropriate development of geothermal power plants, the energy generated by them will cost less than energy obtained by any other means.

Third study question:

Unfortunately, the large-scale use of the considered alternative energy sources requires significant improvements, a long time and enormous financial costs, and as a result, this is a task for the foreseeable future.

Therefore, all hope for solving the global energy crisis rests on the use of nuclear and thermonuclear energy. Nuclear energy, like other types of energy, cannot be completely clean and not affect the environment. But thermonuclear reactors with deuterium-tritium fuel have significant advantages over nuclear reactors from the point of view, again, of their impact on the environment. This is due to much less volatile radioactive waste, less vulnerability to coolant leaks and other emergency situations.

But the issue of operating a thermonuclear reactor is related to the problem of controlling the thermonuclear fusion reaction. The solution to this problem is associated with large material costs, for which it is not possible to allocate public funds in any country; only a group of states can do this. And therefore hopes are pinned on a commercial thermonuclear reactor. When will it be? Academician E.P. Velikhov answers this question:

“I think that in order to carry out the planned transition to an inexhaustible source of energy already in this twentieth century, we should jointly create an experimental thermonuclear reactor. This would, of course, be a significant step forward. We would know more precisely what we can count on and what further efforts need to be made... Without international cooperation, the results would be poorer... Now we have a preliminary design of the installation. There has never been anything like this in scientific practice, and no country could have made such a preliminary design on its own. Subjectively and objectively guided synthesis is a unique area for collaboration. Research on magnetic plasma confinement has nothing to do with military purposes; it has not yet become a commercial secret. Everyone understands that controlled thermonuclear fusion is needed and cooperation is beneficial to everyone. And we must rely on it in the future. And in one of his speeches, Academician L.A. Artsimovich said that “the problem of a controlled thermonuclear reaction will certainly be solved if humanity has a real need for it.”

I think that such a time has already come. But this is a topic for another conversation.

Lesson summary:

Microtest (suggested at the end of the lesson to encourage the student to be attentive during the lesson of learning new material, to train his memory.

Students must either agree or disagree with the statements presented (put “+” or “-” before the number of each statement)).

The global energy crisis is predicted by the law of conservation of electric charge.

To generate solar energy, it must be harvested from a huge area.

One of the problems with using a wind turbine: the engine must be stopped when the wind weakens, as this is energetically unprofitable.

Geothermal energy is an environmentally friendly form of energy.

Nuclear energy will help solve the energy crisis.

Homework . Prepare projects – presentations on “Alternative energy sources”