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Energy problem. Energy problem and ways to solve it. Prospects for alternative energy

Energy problem. Energy problem and ways to solve it. Prospects for alternative energy

19.07.2019

Energy problems of humanity

In order to present the energy needs of humanity and compare them with the energy of processes occurring in the Earth's geospheres, we present these energy values in Table. 21.1.

Examination of the table shows that humanity has powerful energy sources in reserve. However, their use is probably a matter of the distant future. The table also shows that the energy of technogenic processes has already become comparable with the energy of large geophysical processes.

The materials in this chapter are based mainly on the works of.

Natural resources are widely used for energy. Fossil fuels, radioactive elements, and potential energy of water are the main types of energy resources. Their use causes significant harm to the environment.

Energy is the basis of human well-being. There is a continuous increase in energy consumption around the world. For example, in the 50-70s. XX century Average per capita energy consumption has almost doubled. Over 200 years, global energy consumption has increased almost 30 times and amounted to 13 Gt cu. t. (ton of equivalent fuel (ce) is equal to 29.3 GJ). The standard of living of the population of all countries is determined by the availability of energy, although the availability of energy can vary greatly, for example, due to climatic conditions. Per capita energy consumption is the most important indicator characterizing not only the level of well-being of the country’s residents, but also its stage of economic development. In the richest countries, per capita there are 10-14 tons of fuel equivalent per year. (USA, Canada, Norway), in the poorest - 0.3-0.4 t.e. t. (Mali, Chad, Bangladesh). Absolute figures for per capita fuel consumption do not provide an idea of how fuel is consumed. In countries located in severe climatic conditions, with significant

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3. Hydrosphere pollution: thermal pollution of water bodies,
emissions of pollutants, changes in operating conditions
ground and surface waters.

4. Pollution of the lithosphere during energy transportation
bodies and waste disposal, during energy production.

5. Pollution with radioactive and toxic waste
environment.

6. Changes in the hydrological regime of hydroelectric rivers
stations and, as a consequence, pollution in the area
watercourse

7. Creation of electromagnetic fields around electrical lines
transmission

8. Species diversity changes in areas of distribution
objects of the fuel and energy complex. "

9. Initiation of geological processes.

The fuel and energy complex supplies huge quantities of carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, soot, heavy metals, petroleum products, phenols, chlorides, sulfates, etc. to the environment.

How to ensure that a constant increase in energy consumption is not accompanied by an increase negative consequences energy, given that in the near future humanity will feel the limitations of fossil fuels? The following can be indicated as ways to solve the problem.

1. Energy saving. The degree of influence of progress on energy saving can be demonstrated by the example of steam engines. As you know, the efficiency of steam engines 100 years ago was 3-5%, and now it reaches 40%. The development of the world economy after the energy crisis of the 70s also showed that humanity has significant reserves along this path. Between 1975 and 1985, the energy intensity of the US gross national product decreased by 71%, France by 70%, and Japan by 78%. However, overall energy consumption continued to rise. The use of resource-saving and energy-saving technologies has ensured a significant reduction in the consumption of fuel and materials in developed countries.

Ch. 21. Environmental problems of energy

2. Development of environmentally cleaner types of energy production.

The problem can probably be solved by the development of alternative types of energy, such as solar and geothermal energy, wind energy, the use of ocean energy and other types of energy. /According to accepted terminology, all types of energy based on solar energy are called renewable energy sources. In Europe, 6% of total energy consumption is produced using biomass and hydropower.

The main technologies using renewable energy sources are given in table. 21.2.

The list given in the table is quite broad; its consideration shows that in the future, renewable types of energy production may displace methods of energy production based on fossil fuels. In most countries of the world, the reserves of renewable types of energy far exceed the reserves of non-renewable types of energy. For example, in the United States, estimates of total renewable energy reserves are about 600,000 billion barrels of oil equivalent, and estimates of total non-renewable energy reserves are about 45,000 billion barrels of oil equivalent. More realistic estimates, taking into account the limitations imposed on the use of geothermal and wind energy, reduce this superiority of renewable energy reserves, but the prospectivity of the reserves remains.

So far, renewable sources provide no more than 20% of global energy consumption. The main contribution to this 20% comes from the use of biomass and hydropower. As technology improves, the contribution of solar and wind energy increases. When determining the prospects for the development of a particular type of energy, the question arises of assessing environmental risk. Environmental risk refers to the likelihood of adverse consequences of environmental pollution for humans and biota. Environmental risk includes economic, environmental, biological, social, toxicological aspects.

The bulk of electricity is currently produced at thermal power plants (TPPs). In 1989, in the USSR, 65% was produced at thermal power plants, 24% at hydroelectric power stations, and 11% at nuclear power plants. In 1997 in Russia, the share of different sources in electricity production was as follows: natural gas - 41.7%;

___________ Ch. 21 Environmental problems of energy__________ 489

tens of times. Ultimately, the species structure of the reservoir's ecosystem changes - the development of blue-green algae, changes in the abundance and species composition of plankton and fish. For example, in the polar Lake Imandra, which is used to cool water from the Kola Nuclear Power Plant, cold-loving char disappeared, but heat-loving rainbow trout appeared. There are many cases where fish of heat-loving species acclimatize well in cooler reservoirs in the middle zone. For example, in the cooling pond of the Berezovskaya TPP, such heat-loving species as bighead carp and buffalo were acclimatized, and in the cooling pond of the Shakhtinskaya TPP, the African fish tilapia was acclimatized. Sometimes herbivorous heat-loving species “help” fight the overgrowth of water bodies.

Evaporative cooling towers, widely used in thermal and nuclear power plants, have proven to be powerful sources of infrasonic noise with frequencies less than 10 Hz. The infrasonic noise emitted by the cooling tower is weakly attenuated and propagates along the acoustic channel formed by the thermal torch of the cooling tower over considerable distances. This is another negative impact of thermal power plants and nuclear power plants on the environment. Residents exposed to infrasound radiation may experience changes in blood pressure and heart rate.

Thermal power plants are characterized by high radiation and toxic environmental pollution. This is due to the fact that ordinary coal and its ash contain microimpurities of uranium and a number of toxic elements (cadmium, cobalt, arsenic, etc.) in higher concentrations than the earth’s crust. During the operation of thermal power plants, radionuclides and toxic elements enter the atmosphere, soil, and water bodies. As a consequence, radiation contamination and contamination with toxic elements around coal-fired thermal power plants are on average 10-100 times higher than background contamination.

Significant areas around thermal power plants are exposed to acid rain and ash containing toxic impurities. In areas where thermal power plants are located, chronic suppression of vegetation is observed. As a consequence, there is a reduction in agricultural products and the accumulation of toxic elements in plants.

In the Russian Federation, thermal power plants account for 90-95% of the total emissions into the atmosphere from energy facilities of solid and liquid pollution, sulfur dioxide, and nitrogen oxide. Terrestrial and aquatic ecosystems are polluted mainly by thermal power plants.

Ch. 21. Environmental problems of energy

During the construction of large thermal power plants or their complexes, environmental pollution is even more significant. In this case, new effects may arise, for example, caused by the excess of the rate of oxygen combustion over the rate of its formation due to photosynthesis of terrestrial plants in a given territory or caused by an increase in the concentration of carbon dioxide in the ground layer.

Of the fossil fuel sources, coal is the most promising - this is due to the fact that its reserves are huge compared to oil and gas reserves. The world's largest coal reserves are concentrated in Russia, China and the USA. Currently, the main amount of energy is generated at thermal power plants through the use of petroleum products. Thus, the structure of fossil fuel reserves does not correspond to the structure of its modern use for energy production. In the future, the transition to a new structure of fossil fuel consumption will cause significant environmental problems, material costs and major changes in the entire industry. A number of developed countries in the world have already begun structural restructuring of the energy sector. For example, the concept for the development of electricity production in the United States is characterized by an increase in the contribution of coal while a reduction in the contribution of gas and oil.

The main advantages of hydroelectric power plants are the low cost of generated electricity, quick payback (the cost is about 4 times lower, and the payback is 3-4 times faster than at thermal power plants), high maneuverability, which is very important during periods of peak loads, and the ability to accumulate energy. Even with the full potential of all the Earth's rivers, it is possible to provide no more than a quarter of humanity's current energy needs. In Russia, less than 20% of hydropower potential is currently used. However, more full use hydropower potential of the Russian Federation is associated with significant economic costs, since rivers that are promising for use are located in hard-to-reach regions. In developed countries, the efficiency of using hydro resources is 2-3 times higher than in Russia, so Russia has certain reserves here.

The construction of hydroelectric power stations on lowland rivers leads to many environmental problems. Reservoirs, necessary to ensure the uniform operation of hydroelectric power plants, cause climate changes in adjacent territories at distances of up to hundreds of kilometers, and are natural reservoirs of pollution, including radioactive ones. If you implement some

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Projects for the liquidation of reservoirs, then an equally complex task will arise of recycling the pollution that has accumulated in reservoirs over a long period of time. Blue-green algae develop in reservoirs, eutrophication processes accelerate, which leads to a deterioration in water quality and disrupts the functioning of ecosystems. During the construction of reservoirs, natural spawning grounds are disturbed, fertile lands are flooded, and the groundwater level changes. More promising is the construction of hydroelectric power stations on mountain rivers. This is due to the higher hydropower potential of mountain rivers compared to lowland rivers. When constructing reservoirs in mountainous areas, large areas of fertile land are not removed from land use. Hydroelectric power plants of small and medium power are not widely used, since the specific capital investments in them are much higher than in thermal power plants and large hydroelectric power plants and nuclear power plants. However, recently, due to difficulties encountered with the delivery of fuel to the Far North and other hard-to-reach regions, there has been renewed interest in the construction of small and medium-sized hydroelectric power plants. Within the framework of the federal target program “Fuel and Energy”, subprogram “Energy supply to the regions of the Far North and equivalent territories, as well as places of residence of small peoples of the North, Siberia and the Far East through the use of non-traditional renewable energy sources and local fuels”, the construction of hydroelectric power stations has begun power from tens of W to tens of MW. Dozens of low-power hydroelectric power plants have been built in the last five years in Sakhalin, Kamchatka, the Far North, Altai, and in several areas of the Urals.

In a number of developed countries, the share of electricity generated at nuclear power plants (NPPs) is high. Thus, in France, the share of energy generated at nuclear power plants reaches 77% of the country’s energy supply, in Germany - 34%. Nuclear power plants do not produce carbon dioxide, and the volume of other air and land pollution is also small compared to thermal power plants. During normal operation of nuclear power plants, radioactive contamination in the plant areas is small compared to the natural background and does not have a noticeable effect on radiation doses to the population and biota. The amount of radioactive substances generated during the operation of a nuclear power plant is relatively small. The radiological impact of waste may appear after a long time and in a limited area. This is

Ch. 21. Environmental problems of energy

An important advantage of nuclear power plants over thermal power plants, the toxic effects of waste appear immediately and over large areas. For a long time, nuclear power plants were presented as the most environmentally friendly clean look power plants and as a promising replacement for thermal power plants that affect global warming. However, the process of safe operation of nuclear power plants has not yet been resolved, and the problem of disposal of radioactive waste, for example, long-lived C 14 (half-life is 5,760 years, and therefore it can accumulate in the biosphere), has not been resolved. Carbon is the basis of all organic compounds and is part of protein molecules and DNA. Entering the molecules of organic compounds, C 14 is an internal irradiator.

On the other hand, replacing the bulk of thermal power plants with nuclear power plants to eliminate their contribution to atmospheric pollution on a planetary scale is not feasible due to the enormous economic costs.

During the existence of nuclear energy, three major radiation accidents occurred: in 1957 in the UK (Windscale), in 1979 in the USA (Three Mile Island), and in 1986 at the Chernobyl nuclear power plant. In terms of the area of contamination and the amount of activity released, the Chernobyl accident is the most severe. As a result of the accident, the territory of not only the USSR, but also other European countries was exposed to radioactive contamination, and significant economic damage was caused to the affected regions. The Chernobyl disaster led to a radical change in the population's attitude towards nuclear power plants, primarily in the regions where the stations are located or where they might be built. In a number of countries, the problem of social continuity of nuclear energy has arisen. Psychological stress associated with living in contaminated areas and relocating the affected population will persist for a long time. Therefore, the prospects for the development of nuclear energy in the coming years are unclear.

The limited capabilities of nuclear energy and hydropower, the limited reserves of fossil fuels (and in the future - depletion) necessary for the operation of thermal power plants, and their powerful thermal impact on the atmosphere force us to take a closer look at non-traditional sources of energy.

Some countries have already achieved significant success in the use of non-traditional methods of energy production. For example, India ranks 3rd in the world in terms of total

Ch. 21. Environmental problems of energy 493

Power of wind power plants. The construction of small hydroelectric power stations is widespread in the Himalayan regions. whose total capacity has already exceeded 160 MW. In rural communities of India, biogas plants and solar cookers are being built, the use of which significantly reduces the flow of combustion products into the atmosphere. Wind turbines at three passes in California (Altamont, Tehachapi, San Gorgonio) have a total capacity of 1,500 MW. Wind power plants in Denmark provide more than 5% of all energy generated in the country, and the cost of electricity obtained from wind power plants is already lower than the cost of energy obtained from nuclear power plants and thermal power plants.

Russia is implementing a comprehensive program for the development of non-traditional energy sources. The program was developed for 1991-2005; it provided for bringing the share of non-traditional energy sources to 0.8% of domestic energy consumption by 2000. The state scientific and technical program “Environmentally Clean Energy” determines the direction and pace of development of photoelectric converters. Specific issues of the development of non-traditional types of energy are being resolved within the framework of the federal target program “Fuel and Energy”, the sub-program “Energy supply for the regions of the Far North and equivalent territories, as well as places of residence of indigenous peoples of the North, Siberia and the Far East through the use of non-traditional renewable energy sources and local fuels." In Russia, about 45% of homes are heated by stoves. Currently, in the Russian Federation, about 70% of the territory with a population of 10 million people belongs to the zone of decentralized energy supply. Electricity generation in such regions is carried out mainly by low-power gasoline and diesel generators. The sharp increase in the cost of imported organic fuel makes remote areas of the Far North and Far East of the Russian Federation promising for the development of non-traditional energy sources.

Solar energy

The power of solar radiation absorbed by the atmosphere and the earth's surface is 10 5 TW (10 17 W). This value seems huge compared to the current global energy consumption of 10 TW. There are also great other energy flows near the Earth's surface. So heat transfer by the atmosphere

Chapter 21. Environmental problems of energy 495

The converter is a large-area semiconductor diode. The efficiency of light absorption depends on the material and thickness of the element. For example, amorphous silicon absorbs 50 times more efficiently than crystalline silicon. The performance of semiconductor converters is highly dependent on the purity of the material. Silicon purity must be 99.99%; achieving this requires complex technology and significant costs. The efficiency of the transducer also depends on the spectral sensitivity of the material. Elements based on crystalline silicon are sensitive in the ultraviolet, visible and near-infrared regions of the solar spectrum. Theoretically, the efficiency of a crystalline silicon converter reaches 28%.

As already mentioned, the low density of solar radiation is one of the obstacles to its widespread use. To eliminate this drawback, various types of radiation concentrators are used in the design of photoelectric converters. To compensate for the periodicity of solar energy, it is advisable to include photovoltaic systems in hybrid stations. At such stations, during periods of bad weather conditions, energy production can be carried out using traditional systems. The main advantages of photovoltaic installations are as follows. They have no moving parts, their design is very simple, and their production is technologically advanced. Solar batteries are assembled from the same type of modules. An important advantage of photoelectric converters is the steady trend towards reducing their cost. In the early 90s. There were about 20 large solar power plants in the world with a capacity of up to 7 MW using photovoltaic conversion of solar energy.

The disadvantages of photoelectric converters include the destruction of semiconductor material over time, the dependence of the efficiency of the system on its dust content, and the need to develop complex methods for cleaning batteries from contamination. All this limits the service life of photoelectric converters.

Hybrid stations consisting of photovoltaic converters and diesel generators are already widely used to supply electricity in areas where there are no electrical distribution networks. For example, this type of system provides electricity to the residents of Cocos Island, located in the Torres Strait.

Ch. 21. Environmental problems of energy 497

Thermal accumulator that provides softening
depending on daily variability and weather conditions
Viy;

Heat exchangers forming heating and cooling
telny sources of the heat engine.

Solar radiation capture systems, depending on the design, provide different degrees of concentration. A low degree of concentration (up to 100) is obtained by using, for example, parabolic reflectors, the axis of which is perpendicular to the plane of motion of the Sun. An average degree of concentration (up to 1000) can be achieved by using focusing heliostats controlled by two degrees of freedom. An example of such a heliostat is a mirror in the shape of a paraboloid of rotation, the axis of which is oriented towards the Sun. High degree concentration (more than 1000) is carried out by an optical system consisting of flat heliostats and a paraboloid reflector. The accumulation system helps mitigate the effects of weather variability and diurnal variability. Accumulation can be short-term to prevent fluctuations in heat load due to cloudiness, daily - to generate electricity at night, and seasonal - to provide energy to consumers during unfavorable seasons. Energy accumulation is usually carried out through heat accumulation. Low-temperature accumulation systems (up to 100°C), in particular water ones, are widely used for heating buildings and hot water supply. Low-temperature systems also use phase transitions and reversible reactions of hydration and solvation of salts and acids. For medium-temperature accumulation (from 100 to 550 °C) hydrates of alkaline earth metal oxides are used. High-temperature accumulation (temperatures above 550 °C) is carried out using reversible exo-endothermic reactions.

The type of thermodynamic cycle and working fluid is determined by the operating temperature range of the heat engine.

Currently, the ideas of thermodynamic transformation are implemented in two types of schemes: tower-type heliostats and stations with a distributed energy receiver.

In a tower-type solar station, the energy from each heliostat is transmitted optically. The heliostats are controlled by a computer. Up to 80% of the cost of the station is the cost of heliostats. Energy collection and transmission system

Chapter 21 Environmental problems of energy 499

Solar stations in low-Earth orbit. The designers propose to place high-power solar batteries in geosynchronous orbit. Placing a station in a geosynchronous orbit ensures that the station is located above a certain point on Earth. Energy is transmitted to the earth's surface in the form of high-frequency electromagnetic radiation. The density of solar radiation in geosynchronous orbit turns out to be higher than on Earth. An appropriate choice of the position of the orbital plane ensures an almost year-round supply of solar energy to the station’s batteries. There are no problems with cleaning the station’s panels and disturbing land use and thermal pollution.

Bioconversion of solar energy

Biomass has been used as an energy source since ancient times. During the process of photosynthesis, solar energy is stored as chemical energy in the green mass of plants. The energy stored in biomass can be used in the form of food by humans or animals or to produce energy in everyday life and production. Currently, up to 15% of the world's energy is produced from biomass From one ton of sawdust modern technologies make it possible to obtain 700 kg of liquid fuel, and Russia has 20% of the planet’s forest resources.

The most ancient, and still widely used, method of obtaining energy from biomass is to burn it. In rural areas, up to 85% of energy is obtained this way. As a fuel, biomass has several advantages over fossil fuels. When burning biomass, 10-20 times less sulfur is released and 3-5 times less ash than when burning coal. The amount of carbon dioxide released during the combustion of biomass is equal to the amount of carbon dioxide expended in the process of photosynthesis. This ensures a zero balance of carbon monoxide emissions.

Biomass energy can be obtained from specialty crops. For example, in the subtropical zone of Russia it is proposed to grow dwarf breeds of the fast-growing papaya species. From one hectare in 6 months on experimental plots more than 5 tons of biomass by dry weight are obtained, which can be used to produce biogas. Biomass can also be used to obtain biologically active food and feed additives. Promising species include fast-growing trees and plants rich in carbohydrates, which are used to produce ethyl alcohol.

Chapter 21 Environmental problems of energy

Sugar cane is most widely used for the production of ethyl alcohol. In Brazil, pure ethanol and ethanol-gasoline blends are widely used fuels. Such biofuel is easy to store and transport, it has a high calorific value and burns more completely in the engine. When burning such fuel, the atmosphere is polluted much less than when burning conventional fuel. Brazil, which began using ethanol as a vehicle fuel in the 70s, has the best production technology in the world. Promising bioconversion methods include a method for producing motor fuel (methyl ester) from rapeseed. Motor fuel based on rapeseed, having characteristics close to diesel fuel, produces virtually no emissions of harmful substances. The Czech Republic produces about 1 million tons of biodiesel fuel per year. In the USA, a method for producing alcohol from corn has been developed; in Italy, work is underway to develop a method for the cost-effective production of alcohol from sorghum. About 200 buses in Stockholm already run on alcohol.

A widespread method of obtaining energy from biomass is to produce biogas through anaerobic digestion. This gas contains about 70% methane. Biomethanogenesis was discovered back in 1776 by Volta, who discovered methane in swamp gas. Biogas allows the use of gas turbines, which are the most modern means of thermal power engineering. Organic waste from agriculture and industry is used to produce biogas. This direction is one of the promising and promising ways to solve the problem of energy supply in rural areas. For example, from 300 tons of dry matter of manure converted into biogas, the energy yield is about 30 tons of oil equivalent. More promising is the thermochemical conversion of biomass, in which synthetic gas is obtained by burning biomass at a temperature of 800-15,000 °C. Gas turbine power plants with gasification units have an efficiency of 40-45%.

In India and China, several tens of millions of biogas production plants are operated in rural areas.

Biomass for subsequent biogas production can be grown in an aquatic environment by cultivating algae and microalgae.

Chapter 21 Environmental problems of energy 503

Relatively low density, strong time variability and high cost of wave energy plants.

Currently, a significant amount of instrumental measurements of wind waves in the World Ocean has been accumulated. Based on these data, wave climatology identifies areas with the most intense and persistent waves. Wave energy losses due to surf for the globe are estimated at 2 ■ 10 9 kW. The total length of the coastline is 200,000 km, i.e. on average 10 kW per meter of coastline. However, there are coastal areas in which the average wave power is significantly higher. They are constantly exposed to ocean waves, 50-200 m long and more than 2-5 m high. The formation of these waves is not necessarily related to the action of local winds. Waves originating in one part of the ocean are capable of traveling vast distances of hundreds and thousands of miles, since they are weakly attenuated in the deep ocean. According to some estimates, the average annual wave power per meter of the west coast of Great Britain reaches 80 kW, and the total wave power of the coast is 120 GW, which is approximately 5 times higher modern needs electricity in the country. In many areas of the shelf zone of the USA and Japan, the wave energy density is about 40 kW/m.

Most wave energy converters use a two-stage conversion scheme; at the first stage, energy is transferred from the wave to the absorber body and the problem of concentrating the wave energy is solved. At the second stage, the absorbed energy is converted into a form convenient for consumption. There are three main types of wave energy harvesting projects. The first uses a method of increasing the concentration of wave energy and converting it into potential energy water. In the second, a body with several degrees of freedom is located at the surface of the water. Wave forces acting on a body transfer part of the wave energy to it. The main disadvantage of such a project is the vulnerability of the body under the influence of waves. In the third type of project, the system that absorbs wave energy is located underwater. The transfer of wave energy to the receiving device occurs under the influence of wave pressure or speed. A more general classification of wave converters is their division into active and passive. Active types of wave energy converters include converters that have

Ch. 21 Environmental problems of energy

The name of its inventor. In England, where a number of improvements to the installation have been proposed, it is called an oscillating water column. Devices of this type are already widely used to supply power to autonomous buoy stations.

The force with which waves act on structures in the coastal zone reaches several tons per square meter. This force action can also be used to convert wave energy. Let's imagine a buoy with a trapezoidal base, anchored in the coastal zone. The wide side of the trapezoid faces the ocean - this allows you to concentrate wave energy. This side of the buoy is open to the waves. Inside, the buoy is divided into sections that end in cylinders with pistons. The waves, acting on the pistons, set the air in motion, which in turn moves the air turbine. With a base size of 350 m and a buoy height of 20 m, the power will be about 100 MW.

Wave energy converters, which have a significant number of moving parts, are sensitive to seawater and irregular power loads. Therefore, preference is given to systems with a minimum number of moving parts.

The parallelism of wave crests in the coastal zone, due to the phenomenon of refraction, is used in the next type of wave energy converter. The positive buoyancy cylinder is completely submerged in the water. The axis of the cylinder is parallel to the crest of the incident wave. At a given depth, the cylinder is held using four neutrally buoyant cables. A spring load is attached to the ends of the cables. This fastening system allows the cylinder to move in horizontal and vertical planes. If the crest of the incident wave is parallel to the axis of the cylinder, then the cylinder will perform a motion similar to that of the water particles in the wave. The arrangement of additional cylinders with other parameters makes it possible to expand the range of wavelengths in which wave energy is effectively absorbed. Fully buried cylinders increase the operational reliability of the system compared to schemes in which moving parts are located on the surface of the water.

Induction-capacitive wave energy converters have recently been considered as promising types of wave energy converters. In converters of this type, one plate of the capacitor is a wave

Chapter 21 Environmental problems of energy

The energy problem is the problem of reliably providing humanity with fuel and energy. On a global scale, this problem manifested itself in the 70s of the 20th century, when the energy crisis broke out, marking the end of the era of cheap oil. The global problem of providing fuel and energy remains important today.

The causes of the energy problem are presented in Fig. 3

In the world from the beginning to the 80s of the twentieth century, more mineral fuels were used than in the entire previous history of mankind. Including only from 1960 to 1980, 40% of the coal, almost 75% of the oil and about 80% of the natural gas produced since the beginning of the century were extracted from the bowels of the Earth.

The amount of extraction of fuel and energy resources has led to a deterioration of the environmental situation. And the growth in demand for these resources has increased competition between countries exporting fuel resources for Better conditions sales and between importing countries for access to energy resources.

Large-scale geological exploration work has intensified under the influence of the energy crisis, leading to the discovery and development of new energy deposits. The availability of the most important types of mineral fuels has directly increased. According to calculations, the extraction of proven coal reserves should be sufficient for 325 years, oil for 37 years, and natural gas for 62 years.

Solving the energy problem involves a further increase in energy production and an increase in energy consumption. World energy consumption in absolute terms from 1996 to 2003 increased from 12 billion to 15.2 billion tons of fuel equivalent. However, a number of countries are facing reaching the limit own production energy resources (China) or with the prospect of reducing this production (Great Britain). This development encourages the search for ways to use energy resources more rationally.

The main ways to solve the global energy problem are presented in Fig. 4.

Many countries with emerging markets (Russia, Ukraine, China, India) continue to develop energy-intensive industries, as well as use outdated technologies. In these countries, we should expect an increase in energy consumption due to increased standard of living and changes in the lifestyle of the population, as well as a lack of funds to reduce the energy intensity of the economy. Therefore, it is in countries with emerging markets that the consumption of energy resources is growing, while in developed countries consumption remains at a relatively stable level.

In the modern period and even in long years In the future, the solution to the global energy problem will depend on the degree of reduction in the energy intensity of the economy, that is, on energy consumption per unit of GDP produced.

Thus, the global energy problem in its previous understanding as a threat of an absolute shortage of resources in the world does not exist. Nevertheless, the problem of providing energy resources remains in a modified form.

Raw material problem

The raw materials problem is a problem that has become urgent due to the technological progress of mankind and the use of more fuel and raw materials for its life.

The emergence of a global resource and raw materials problem is explained, to a large extent, by the very rapid and explosive growth in the consumption of mineral fuels and raw materials, and, accordingly, the scale of their extraction from the bowels of the earth.

Only during the period from the beginning to the 80s of the twentieth century, more fuel and raw materials were produced and consumed in the world than in the entire previous history of mankind. From 1960 to 1980, 40% of coal, 50% of copper and zinc, 55% of iron ore, 60% of diamonds, 65% of nickel, potassium salts and phosphorites, almost 75% of oil and about 80% of natural gas and bauxite were extracted from the bowels of the Earth. , mined since the beginning of the century.

The main ways to solve the raw material problem are presented in Fig. 5.

Humanity is becoming ever larger every year. This is due to the growth of the planet’s population and the intensive development of technology, which leads to an ever-increasing level of energy consumption. Despite the use of nuclear, alternative and hydropower, people continue to extract the lion's share of fuel from the bowels of the Earth. Oil, natural gas and coal are non-renewable natural resources energy resources, by now their reserves have decreased to a critical level.

Beginning of the End

The globalization of humanity's energy problem began in the 70s of the last century, when the era of cheap oil ended. The shortage and sharp rise in price of this type of fuel provoked a serious crisis in the global economy. And although its cost has decreased over time, its volumes are steadily declining, so humanity’s energy and raw materials problem is becoming more acute.

For example, only in the period from the 60s to the 80s of the twentieth century, the global volume of coal production amounted to 40%, oil - 75%, natural gas - 80% of the total volume of these resources used since the beginning of the century.

Despite the fact that fuel shortages began in the 70s and it was discovered that the energy problem is a global problem for humanity, forecasts did not provide for an increase in its consumption. It was planned that the volume of mineral extraction would increase 3 times by 2000. Subsequently, of course, these plans were reduced, but as a result of extremely wasteful exploitation of resources, which lasted for decades, today there are practically no such plans left.

Main geographical aspects of humanity's energy problem

One of the reasons for the growing shortage of fuel is the increasingly difficult conditions for its extraction and, as a consequence, the rise in cost of this process. If just a few decades ago natural resources lay on the surface, today we have to constantly increase the depth of mines, gas and oil wells. The mining and geological conditions for the occurrence of energy resources in the old industrial areas of North America, Western Europe, Russia and Ukraine have deteriorated especially noticeably.

Taking into account the geographical aspects of humanity’s energy and raw materials problems, it must be said that their solution lies in expanding the resource boundaries. It is necessary to develop new areas with easier mining and geological conditions. In this way, the cost of fuel production can be reduced. It should be taken into account that the total capital intensity of energy resource extraction in new locations is usually much higher.

Economic and geopolitical aspects of energy and raw materials problems of humanity

The depletion of natural fuel reserves has caused fierce competition in the economic, political and geopolitical spheres. Giant fuel corporations are engaged in the division of fuel and energy resources and the redistribution of spheres of influence in this industry, which entails constant fluctuations in prices on the world market for gas, coal and oil. The instability of the situation is seriously aggravating the energy problem of humanity.

Global Energy Security

This concept came into use at the beginning of the 21st century. The principles of such a security strategy provide for a reliable, long-term and environmentally acceptable energy supply, the prices of which will be justified and acceptable to both countries exporting and importing fuel.

The implementation of this strategy is possible only if the causes of mankind’s energy problem are eliminated and practical measures aimed at further providing the world economy with both traditional types of fuel and energy from alternative sources. Moreover, the development of alternative energy should be given Special attention.

Energy saving policy

In times of cheap fuel, many countries around the world have developed very resource-intensive economies. First of all, this phenomenon was observed in countries rich in mineral resources. The list was topped by the Soviet Union, the USA, Canada, China and Australia. At the same time, in the USSR the volume of fuel consumption was several times greater than in America.

This state of affairs required the urgent introduction of energy saving policies in public utilities, industrial, transport and other sectors of the economy. Taking into account all aspects of humanity’s energy and raw materials problems, technologies began to be developed and implemented aimed at reducing the specific energy intensity of the GDP of these countries, and the entire economic structure of the world economy began to be rebuilt.

Successes and failures

The most noticeable successes in the field of energy saving have been achieved in economically developed Western countries. Over the first 15 years, they managed to reduce the energy intensity of their GDP by 1/3, which resulted in a reduction in their share of global energy consumption from 60 to 48 percent. Today, this trend continues, and GDP growth in the West is outpacing the growing volumes of fuel consumption.

The situation is much worse in Central-Eastern Europe, China and the CIS countries. The energy intensity of their economy is declining very slowly. But the leaders of the economic anti-rating are developing countries. For example, in most African and Asian countries, losses of associated fuels (natural gas and oil) range from 80 to 100 percent.

Realities and prospects

The energy problem of humanity and ways to solve it are of concern to the whole world today. To improve the existing situation, various technical and technological innovations are being introduced. In order to save energy, industrial and utility equipment is being improved, more economical cars are being produced, etc.

The priority macroeconomic measures include a gradual change in the very structure of gas, coal and oil consumption with the prospect of increasing the share of non-traditional and renewable energy resources.

To successfully solve humanity's energy problem, it is necessary to pay special attention to the development and implementation of fundamentally new technologies available in modern

Nuclear power

One of the most promising areas in the field of energy supply is New generation nuclear reactors have already been put into operation in some developed countries. Nuclear scientists are now again actively discussing the topic of reactors powered by fast neurons, which, as was once expected, would become a new and much more efficient wave of nuclear energy. However, their development was stopped, but now this issue has again become relevant.

Using MHD generators

The direct conversion of heat energy into electricity without steam boilers and turbines makes it possible to carry out the development of this promising direction began in the early 70s of the last century. In 1971, the first pilot industrial MHD with a capacity of 25,000 kW was launched in Moscow.

The main advantages of magnetohydrodynamic generators are:

high efficiency;
environmental friendliness (no harmful emissions into the atmosphere);
instant launch.

Cryogenic turbogenerator

The operating principle of a cryogenic generator is that the rotor is cooled, resulting in the effect of superconductivity. The indisputable advantages of this unit include high efficiency, low weight and dimensions.

A pilot industrial prototype of a cryogenic turbogenerator was created back in the Soviet era, and now similar developments are underway in Japan, the USA and other developed countries.

Hydrogen

The use of hydrogen as a fuel has enormous prospects. According to many experts, this technology will help solve the most important global problems of humanity - the energy and raw materials problem. First of all, hydrogen fuel will become an alternative to natural energy resources in mechanical engineering. The first one was created by the Japanese company Mazda back in the early 90s; a new engine was developed for it. The experiment turned out to be quite successful, which confirms the promise of this direction.

Electrochemical generators

These are fuel cells that also run on hydrogen. The fuel is passed through polymer membranes with a special substance - a catalyst. As a result of a chemical reaction with oxygen, hydrogen itself is converted into water, releasing chemical energy upon combustion, which is converted into electrical energy.

Engines with fuel cells are characterized by the highest efficiency (over 70%), which is twice as much as that of conventional power plants. Plus, they are easy to use, silent during operation and undemanding to repair.

Until recently, fuel cells had a narrow scope of application, for example in space research. But now work on the introduction of electrochemical generators is actively underway in most economically developed countries, among which Japan ranks first. The total power of these units in the world is measured in millions of kW. For example, power plants using such elements are already operating in New York and Tokyo, and the German automaker Daimler-Benz was the first to create a working prototype of a car with an engine operating on this principle.

Controlled thermonuclear fusion

Research in the field of thermonuclear energy has been ongoing for several decades. Atomic energy is based on the reaction of nuclear fission, and thermonuclear energy is based on the reverse process - the nuclei of hydrogen isotopes (deuterium, tritium) merge. In the process of nuclear combustion of 1 kg of deuterium, the amount of energy released is 10 million times greater than that obtained from coal. The result is truly impressive! That is why thermonuclear energy is considered one of the most promising areas in solving the problems of global energy shortage.

Forecasts

Today, there are different scenarios for the development of the global energy situation in the future. According to some of them, by 2060 global energy consumption in oil equivalent will increase to 20 billion tons. At the same time, in terms of consumption volumes, currently developing countries will overtake developed ones.

By the middle of the 21st century, the volume of fossil energy resources should significantly decrease, but the share of renewable energy sources, in particular wind, solar, geothermal and tidal energy sources, will increase.

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ABSTRACT

on the topic: “Global energy problem”

The global energy problem is the problem of providing humanity with fuel and energy now and in the foreseeable future. The main reason for the global energy problem should be considered the rapid increase in the consumption of mineral fuels in the 20th century. On the supply side, it is caused by the discovery and exploitation of huge oil and gas fields in Western Siberia, Alaska, and on the North Sea shelf, and on the demand side, by an increase in the vehicle fleet and an increase in the production of polymer materials. The main environmental problems are the problem of rapid depletion of non-renewable fossil fuels with an increasing rate of consumption - the problem of supply of oil, coal, natural gas, the growth of electricity consumption, many times exceeding its production. It is believed that at the current level of mining, proven coal reserves should last for 325 years. natural gas - for 62 years, and oil - for 37 years. Today, the total consumption of thermal energy in the world is a colossal amount - more than 1013 W per year (equivalent to 36 billion tons of standard fuel).

As for the prospects for nuclear energy, all known industrial reserves of uranium will be exhausted in the first decade of the 21st century. Taking into account the costs of fuel extraction, neutralization, recycling and disposal of waste, conservation of spent reactors (and their resource is no more than 30 years), costs for social and environmental needs, the cost of nuclear power plant energy will many times exceed any economically acceptable level. According to experts, the costs alone for the removal, disposal and neutralization of nuclear waste accumulated at Russian enterprises will amount to about $400 billion, and to ensure the required level of technological safety - $25 billion. As the number of reactors increases, the likelihood of their accidents increases. Thus, nuclear energy has no long-term prospects.

The main ways to solve the global energy problem:

An extensive way to solve the energy problem involves a further increase in energy production and absolute growth energy consumption. This path remains relevant for the modern world economy. World energy consumption in absolute terms from 1996 to 2003 increased from 12 billion to 15.2 billion tons of fuel equivalent. At the same time, a number of countries are faced with reaching the limit of their own energy production (China) or with the prospect of reducing this production (Great Britain). This development of events encourages the search for ways to more rationally use energy resources and transition to non-traditional, alternative energy sources (AES). They are environmentally friendly, renewable, and are based on the energy of the Sun and Earth. Solar energy is based on the direct use of solar radiation to produce energy in some form. Solar energy uses an inexhaustible source of energy and is environmentally friendly, that is, it does not produce harmful waste. Advantages: Public availability and inexhaustibility of the source and complete safety for the environment. Disadvantages: Dependence on weather and time of day, As a consequence, the need for energy accumulation,

High cost of construction, The need to periodically clean the reflective surface from dust, Heating of the atmosphere above the power plant.

In 2010, 2.7% of Spain's electricity came from solar energy, and 2% of Germany's electricity came from photovoltaics. In December 2011, the construction of the last, fifth, 20-megawatt stage of the solar park in Perovo was completed in Ukraine, as a result of which its total installed capacity increased to 100 MW. It is followed by the Canadian power plant Sarnia (97 MW), the Italian Montalto di Castro (84.2 MW) and the German Finsterwalde (80.7 MW). Rounding out the world's top five largest photovoltaic parks is another project in Ukraine - the 80-megawatt Okhotnikov power plant in the Saki region of Crimea. Russia's first solar power plant with a capacity of 100 kW was launched in September 2010 in the Belgorod region. Energy generated from solar radiation will hypothetically be able to provide 20-25% of humanity's electricity needs by 2050 and reduce carbon dioxide emissions. According to experts from the International Energy Agency (IEA), solar energy in 40 years, with the appropriate level of dissemination of advanced technologies, will generate about 9 thousand terawatt-hours - or 20-25% of all necessary electricity, and this will reduce carbon dioxide emissions by 6 billion tons annually.

Wind energy. Wind turbines are a fairly promising way to obtain energy from an environmentally friendly source. Especially in conditions of rising prices for oil, gas and coal. Wind energy is competitive in regions with moderate to high wind speeds. Considering the fact that the process of producing wind energy does not require anything other than wind turbines. There are no costs for the purchase and delivery of raw materials or for reducing environmental pollution. Unlike modern power plants, a wind power plant can operate uninterruptedly even if one of the wind turbines breaks down - because the rest of the installations will continue to work. A wind farm can operate at full capacity only 10% of the time, despite the fact that they are built in areas where it is generally windy. However, wind turbines produce electrical energy most of the time they operate (65-80%), although the amount of energy produced may vary. One typical two-megawatt installation produces electricity for 600-800 homes. And with the use of new technologies, this figure may increase.

Thermal energy of the earth. Some countries of the world (not all) are rich in hot springs and famous geysers-fountains of hot water, bursting out of the ground with chronometer precision. For example, Iceland. Residents of this small northern country operate the underground boiler house very intensively. The capital, Reykjavik, where half the country's population lives, is heated only by underground sources. There are even power plants using hot underground springs. Iceland is fully self-sufficient in tomatoes, apples and even bananas! Numerous Icelandic greenhouses receive their energy from the heat of the earth - there are practically no other local energy sources in Iceland. fuel energy problem bioenergy

Biomass energy. The term "biomass" refers to organic matter that has retained energy from the sun through the process of photosynthesis. In its original form it exists in the form of plants. Further along the food chain it can be transmitted to herbivores, and if they are eaten, then to carnivores. When biomass (wood, dried vegetation) is burned, stored energy and carbon dioxide are released. Today, this industry ranks second after hydropower on the list of alternative sources due to its cheapness and availability. It accounts for 15% of the world's energy supply and up to 35% in developing countries. Used mainly for cooking and heating. The positive side is that less pure carbon dioxide will be emitted, leading to the greenhouse effect. But on the other hand, deforestation will increase. And today this is one of the global problems. Deserts are gaining more and more space. The once fertile land, left without vegetation cover, will be subject to erosion and lose organic matter.

Thus, the global energy problem in its previous understanding as a threat of an absolute shortage of resources in the world does not exist. However, the problem of providing energy resources remains in a modified form.

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Energy: forecast from the perspective of sustainable development of humanity

According to what laws will the world's energy sector develop in the future, based on the UN Concept of Sustainable Development of Humanity? The results of research by Irkutsk scientists and their comparison with the works of other authors made it possible to establish a number of general patterns and features.

The concept of sustainable development of humanity, formulated at the 1992 UN Conference in Rio de Janeiro, undoubtedly affects energy. The Conference shows that humanity cannot continue to develop in the traditional way, which is characterized by irrational use of natural resources and progressive negative impacts on the environment. If developing countries follow the same path in which developed countries achieved their prosperity, then a global environmental catastrophe will be inevitable.

The concept of sustainable development is based on the objective necessity (as well as the right and inevitability) of the socio-economic development of third world countries. Developed countries could, apparently, “come to terms” (at least for some time) with the achieved level of well-being and consumption of the planet’s resources. However, we are talking not just about preserving the environment and the conditions of human existence, but also about simultaneously increasing the socio-economic level of developing countries (the “South”) and bringing it closer to the level of developed countries (the “North”).

The requirements for sustainable energy will, of course, be broader than for clean energy. The requirements of inexhaustibility of used energy resources and environmental cleanliness, embedded in the concept of an environmentally friendly energy system, satisfy two the most important principles sustainable development - respecting the interests of future generations and preserving the environment. Analyzing the remaining principles and features of the concept of sustainable development, we can conclude that in this case at least two additional requirements should be presented to the energy sector:

Ensuring energy consumption (including energy services to the population) is not lower than a certain social minimum;

The development of national energy (as well as the economy) must be mutually coordinated with its development at the regional and global levels.

The first follows from the principles of priority social factors and ensuring social justice: in order to realize the right of people to a healthy and fruitful life, reduce the gap in the standard of living of the peoples of the world, eradicate poverty and misery, it is necessary to ensure a certain living wage, including meeting the minimum necessary energy needs of the population and the economy.

The second requirement is related to the global nature of the impending environmental disaster and the need for coordinated actions by the entire world community to eliminate this threat. Even countries that have sufficient energy resources of their own, such as Russia, cannot plan their energy development in isolation due to the need to take into account global and regional environmental and economic constraints.

In 1998--2000 ISEM SB RAS conducted research into the prospects for the development of energy in the world and its regions in the 21st century, in which, along with the usually set goals of determining long-term trends in energy development, rational directions of scientific and technical progress, etc. An attempt was made to test the resulting energy development options “for sustainability”, i.e. for compliance with the conditions and requirements of sustainable development. Moreover, in contrast to development options that were previously developed on the principle of “what will happen if...”, the authors tried to offer as plausible a forecast as possible for the development of the energy sector of the world and its regions in the 21st century. Despite all its conventionality, it gives a more realistic idea of the future of energy, its possible impact on the environment, the necessary economic costs, etc.

The general scheme of these studies is largely traditional: the use of mathematical models for which information is prepared on energy needs, resources, technologies, and limitations. To take into account the uncertainty of information, primarily regarding energy needs and limitations, a set of scenarios for future conditions of energy development is generated. The results of model calculations are then analyzed with appropriate conclusions and recommendations.

The main research tool was the Global Energy Model GEM-10R. This model is optimization, linear, static, multi-regional. As a rule, the world was divided into 10 regions: North America, Europe, the countries of the former USSR, Latin America, China, etc. The model optimizes the energy structure of all regions simultaneously, taking into account the export-import of fuel and energy at 25-year intervals - 2025, 2050, 2075 and 2100 The entire technological chain is optimized, starting with the extraction (or production) of primary energy resources, ending with technologies for the production of four types of final energy (electrical, thermal, mechanical and chemical). The model presents several hundred technologies for the production, processing, transport and consumption of primary energy resources and secondary energy carriers. Environmental regional and global restrictions are provided (on emissions of CO 2, SO 2 and particulate matter), restrictions on the development of technologies, calculation of costs for the development and operation of regional energy, determination of dual assessments, etc. Primary energy resources (including renewable ones) in regions are set divided into 4-9 cost categories.

Analysis of the results showed that the obtained options for the development of the world and regional energy sector are still difficult to implement and do not fully meet the requirements and conditions for sustainable development of the world in socio-economic aspects. In particular, the level of energy consumption under consideration seemed, on the one hand, difficult to achieve, and on the other hand, not ensuring the desired approximation of developing countries to developed countries in terms of per capita energy consumption and economic development (specific GDP). In this regard, a new forecast of energy consumption (reduced) was carried out, assuming a higher rate of reduction in the energy intensity of GDP and the provision of economic assistance from developed countries to developing countries.

The high level of energy consumption is determined based on specific GDP, largely consistent with World Bank forecasts. At the same time, at the end of the 21st century, developing countries will only achieve the current level of GDP of developed countries, i.e. the lag will be about 100 years. In the low energy consumption option, the amount of assistance from developed countries to developing countries is based on the indicators discussed in Rio de Janeiro: about 0.7% of the GDP of developed countries, or 100-125 billion dollars. in year. At the same time, the GDP growth of developed countries decreases somewhat, while that of developing countries increases. On average, the world's per capita GDP in this scenario increases, which indicates the feasibility of providing such assistance from the point of view of all humanity.

Per capita energy consumption in the low version in industrialized countries will stabilize, in developing countries it will increase by the end of the century by about 2.5 times, and on average around the world - by 1.5 times compared to 1990. Absolute world consumption of final energy (from taking into account population growth) will increase by the end of the century, according to a high forecast, by approximately 3.5 times, and according to a low forecast, by 2.5 times.

The use of certain types of primary energy resources is characterized by the following features. Oil in all scenarios is consumed approximately the same - in 2050 the peak of its production is reached, and by 2100 cheap resources (of the first five cost categories) are completely or almost completely exhausted. This steady trend is explained by the high efficiency of oil for the production of mechanical and chemical energy, as well as heat and peak electricity. At the end of the century, oil is replaced by synthetic fuel (primarily from coal).

Natural gas production increases continuously throughout the century, peaking at the end of the century. The two most expensive categories (unconventional methane and methane hydrates) turned out to be uncompetitive. Gas is used to produce all types of final energy, but most importantly for heat production.

Coal and nuclear power are subject to the greatest changes depending on the restrictions imposed. Being approximately equally economical, they replace each other, especially in “extreme” scenarios. They are mostly used in power plants. Much of the coal in the second half of the century is processed into synthetic motor fuel, and nuclear energy is used on a large scale to produce hydrogen in scenarios with stringent CO 2 emissions restrictions.

The use of renewable energy varies significantly across different scenarios. Only traditional hydropower and biomass, as well as low-cost wind resources, are used sustainably. The remaining types of renewable energy sources are the most expensive resources, they close the energy balance and are developed as needed.

It is interesting to analyze global energy costs in different scenarios. They are least likely, naturally, in two latest scenarios with reduced power consumption and moderate restrictions. By the end of the century, they will increase approximately 4 times compared to 1990. The highest costs were incurred in the scenario with increased energy consumption and strict restrictions. At the end of the century, they are 10 times higher than the costs in 1990 and 2.5 times higher than the costs in the latest scenarios.

It should be noted that the introduction of a moratorium on nuclear energy in the absence of restrictions on CO 2 emissions increases costs by only 2%, which is explained by the approximately equal economic efficiency of nuclear power plants and coal-fired power plants. However, if, during a moratorium on nuclear energy, strict restrictions on CO 2 emissions are introduced, then energy costs will almost double.

Consequently, the “prices” of a nuclear moratorium and restrictions on CO 2 emissions are very high. The analysis showed that the cost of reducing CO 2 emissions could amount to 1-2% of global GDP, i.e. they turn out to be comparable to the expected damage from climate change on the planet (with warming of several degrees). This gives grounds to talk about the admissibility (or even the need) of easing restrictions on CO 2 emissions. In fact, it is necessary to minimize the amount of costs for reducing CO 2 emissions and damage from climate change (which, of course, represents an extremely difficult task).

It is very important that the additional costs of reducing CO 2 emissions should be borne mainly by developing countries. Meanwhile, these countries, on the one hand, are not to blame for the situation created by the greenhouse effect, and on the other hand, they simply do not have such funds. Obtaining these funds from developed countries will undoubtedly cause great difficulties and this is one of the most serious problems in achieving sustainable development.

In the 21st century, we are soberly aware of the realities of the third millennium. Unfortunately, the reserves of oil, gas, and coal are by no means endless. It took nature millions of years to create these reserves; they will be used up in hundreds. Today, the world has begun to seriously think about how to prevent the predatory plunder of earthly wealth. After all, only under this condition can fuel reserves last for centuries. Unfortunately, many oil-producing countries live for today. They mercilessly consume the oil reserves given to them by nature. What will happen then, and this will happen sooner or later, when the oil and gas fields are exhausted? The likelihood of a rapid depletion of global fuel reserves, as well as the deterioration of the environmental situation in the world (oil refining and fairly frequent accidents during its transportation pose a real threat to the environment) have forced us to think about other types of fuel that can replace oil and gas.

Now in the world, more and more scientific engineers are searching for new, unconventional sources that could take on at least part of the worries of supplying humanity with energy. Non-traditional renewable energy sources include solar, wind, geothermal, biomass and ocean energy.

Energy of sun

Recently, interest in the problem of using solar energy has increased sharply, and although this source is also a renewable source, the attention paid to it around the world forces us to consider its possibilities separately. The potential of energy based on the use of direct solar radiation is extremely large. Note that using only 0.0125% of this amount of solar energy could meet all of today's world energy needs, and using 0.5% could completely cover future needs. Unfortunately, it is unlikely that these enormous potential resources will ever be realized on a large scale. One of the most serious obstacles to such implementation is the low intensity of solar radiation.

Even under the best atmospheric conditions (southern latitudes, clear skies), the solar radiation flux density is no more than 250 W/m2. Therefore, in order for solar radiation collectors to “collect” in a year the energy necessary to satisfy all the needs of humanity, they need to be placed on an area of 130,000 km 2! The need to use huge size collectors also entails significant material costs. The simplest solar radiation collector is a blackened metal sheet, inside of which there are pipes with a liquid circulating in it. Heated by solar energy absorbed by the collector, the liquid is supplied for direct use. According to calculations, the manufacture of solar radiation collectors with an area of 1 km 2 requires approximately 10 4 tons of aluminum. The proven world reserves of this metal today are estimated at 1.17 * 10 9 tons.

It is clear that there are various factors limiting the power of solar energy. Let's assume that in the future it will become possible to use not only aluminum, but also other materials for the manufacture of collectors. Will the situation change in this case? We will proceed from the fact that in a separate phase of energy development (after 2100), all global energy needs will be met by solar energy. Within the framework of this model, it can be estimated that in this case it will be necessary to “collect” solar energy over an area from 1*10 6 to 3*10 6 km 2. At the same time, the total area of arable land in the world today is 13 * 10 6 km 2. 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, their enrichment, obtaining materials, manufacturing heliostats, collectors, other equipment, and their transportation. Calculations show that to produce 1 MW of electrical energy per year using solar energy, it will take from 10,000 to 40,000 man-hours.

In traditional energy production using fossil fuels, this figure is 200-500 man-hours. Electrical energy generated by solar rays is still much more expensive than that obtained traditional ways. Scientists hope that the experiments they will conduct at pilot installations and stations will help solve not only technical, but also economic problems.

The first attempts to use solar energy on a commercial basis date back to the 80s of the last century. The greatest successes in this area have been achieved by Loose Industries (USA). In December 1989, it put into operation a solar-gas station with a capacity of 80 MW. Here, in California, in 1994, another 480 MW of electrical power was introduced, and the cost of 1 kW/h of energy was 7-8 cents. This is lower than at traditional stations. At night and in winter, energy is provided mainly by gas, and in summer and during the daytime - by the sun. A power plant in California has demonstrated that gas and solar, as the main energy sources of the near future, can effectively complement each other. Therefore, it is not accidental that the partner of solar energy should be different kinds liquid or gaseous fuel. The most likely “candidate” is hydrogen.

Its production using solar energy, for example, by electrolysis of water, can be quite cheap, and the gas itself, which has a high calorific value, can be easily transported and stored for a long time. Hence the conclusion: the most economical possibility of using solar energy, which is visible today, is to direct it to obtain secondary types of energy in sunny regions of the globe. The resulting liquid or gaseous fuel can be pumped through pipelines or transported by tanker to other areas. Fast development solar energy became possible thanks to a reduction in the cost of photovoltaic converters per 1 W of installed power from $1000 in 1970 to $3-5 in 1997 and an increase in their efficiency from 5 to 18%. Reducing the cost of a solar watt to 50 cents will allow solar power plants to compete with other autonomous energy sources, such as diesel power plants.

Wind energy

The energy of moving air masses is enormous. Wind energy reserves are more than a hundred times greater than the hydroelectric energy reserves of all the rivers on the planet. The winds blowing across the vast expanses of our country could easily satisfy all its electricity needs! Climatic conditions allow the development of wind energy over a vast territory from our western borders to the banks of the Yenisei. The northern regions of the country along the coast of the Arctic Ocean are rich in wind energy, where it is especially needed by the courageous people living in these rich lands. Why is such an abundant, accessible and environmentally friendly source of energy so little used? Today, wind powered engines supply just one thousandth of the world's energy needs. The technology of the 20th century opened up completely new opportunities for wind energy, the task of which became different - generating electricity. At the beginning of the century N.E. Zhukovsky developed the theory of a wind engine, on the basis of which high-performance installations could be created that could receive energy from the weakest breeze. Many designs of wind turbines have appeared that are incomparably more advanced than the old windmills. New projects use the achievements of many branches of knowledge. Nowadays, aircraft specialists who know how to select the most appropriate blade profile and study it in a wind tunnel are involved in the creation of wind wheel designs - the heart of any wind power plant. Through the efforts of scientists and engineers, a wide variety of designs of modern wind turbines have been created.

The first bladed machine to use wind power was a sail. In addition to one source of energy, a sail and a wind engine share the same principle. Research by Yu. S. Kryuchkov showed that a sail can be represented in the form of a wind engine with an infinite wheel diameter. The sail is the most advanced bladed machine, with the highest efficiency, which directly uses wind energy for propulsion.

Wind energy, using wind wheels and wind carousels, is now being revived, primarily in ground-based installations. Commercial installations have already been built and are operating in the United States. Projects are half financed from the state budget. The second half is invested by future consumers of clean energy.

The first developments of the theory of a wind engine date back to 1918. V. Zalewski became interested in wind turbines and aviation at the same time. He began to create a complete theory of the windmill and derived several theoretical principles that a wind turbine must meet.

At the beginning of the twentieth century, interest in propellers and wind wheels was not isolated from the general trends of the time - to use the wind wherever possible. Initially, wind turbines were most widespread in agriculture. The propeller was used to drive ship mechanisms. On the world famous “Fram” he rotated the dynamo. On sailboats, windmills drove pumps and anchor mechanisms.

In Russia, by the beginning of the last century, about 2,500 thousand wind turbines with a total capacity of one million kilowatts were spinning. After 1917, the mills were left without owners and gradually collapsed. True, attempts have been made to use wind energy on a scientific and government basis. In 1931, near Yalta, the largest wind power plant at that time with a capacity of 100 kW was built, and later a design for a 5000 kW unit was developed. But it was not possible to implement it, since the Wind Energy Institute, which dealt with this problem, was closed.

In the USA, by 1940, a wind turbine with a capacity of 1250 kW was built. Towards the end of the war, one of its blades was damaged. They didn’t even bother to repair it - economists calculated that it would be more profitable to use a conventional diesel power plant. Further research on this installation was stopped.

The failed attempts to use wind energy in large-scale energy production in the forties of the 20th century were not accidental. Oil remained relatively cheap, specific capital investments at large thermal power plants dropped sharply, and the development of hydropower, as it seemed then, would guarantee both low prices and satisfactory environmental cleanliness.

A significant disadvantage of wind energy is its variability over time, but this can be compensated for by the location of wind turbines. If, under conditions of complete autonomy, several dozen large wind turbines are combined, then their average power will be constant. If other energy sources are available, a wind generator can complement existing ones. And finally, mechanical energy can be directly obtained from a wind turbine.

Thermal energy of the earth

People have long known about the spontaneous manifestations of gigantic energy hidden in the depths of the globe. The power of the eruption is many times greater than the power of the largest power plants created by human hands. True, there is no need to talk about the direct use of the energy of volcanic eruptions - people do not yet have the ability to curb this rebellious element, and, fortunately, these eruptions are quite rare events. But these are manifestations of energy hidden in the bowels of the earth, when only a tiny fraction of this inexhaustible energy finds release through the fire-breathing vents of volcanoes. The small European country of Iceland is completely self-sufficient in tomatoes, apples and even bananas! Numerous Icelandic greenhouses receive their energy from the heat of the earth - there are practically no other local energy sources in Iceland. But this country is very rich in hot springs and famous geysers-fountains of hot water, bursting out of the ground with chronometer precision. And although Icelanders do not have priority in using the heat from underground sources, the inhabitants of this small northern country operate the underground boiler house very intensively.

Reykjavik, home to half the country's population, is heated only by underground sources. But people draw energy from the depths of the earth not only for heating. Power plants using hot underground springs have been operating for a long time. The first such power plant, still very low-power, was built in 1904 in the small Italian town of Larderello. Gradually, the power of the power plant grew, more and more new units were put into operation, new sources of hot water were used, and today the power of the station has already reached an impressive value - 360 thousand kilowatts. In New Zealand, there is such a power plant in the Wairakei area, its capacity is 160 thousand kilowatts. 120 kilometers from San Francisco in the United States, a geothermal station with a capacity of 500 thousand kilowatts produces electricity.

Inland water energy

First of all, people learned to use the energy of rivers. But during the golden age of electricity, the water wheel was reborn in the form of the water turbine. Electric generators that produced energy needed to be rotated, and water could do this quite successfully. Modern hydropower can be considered to have been born in 1891. 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 provide considerable assistance to hydropower engineers.

However, in order to spin powerful hydraulic turbines, it is necessary to accumulate a huge supply of water behind the dam. 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. In 1926, the Volkhov hydroelectric power station came into operation, and the following year the construction of the famous Dnieper hydroelectric station began. The energy policy of our country has led to the development of a system of powerful hydroelectric stations. No state can boast of such energy giants as the Volga, Krasnoyarsk and Bratsk, Sayano-Shushenskaya hydroelectric power stations. The power plant on the Rance River, consisting of 24 reversible turbine generators and having an output power of 240 megawatts, is one of the most powerful hydroelectric power plants in France. Hydroelectric power plants are the most cost-effective source of energy. But they have disadvantages - when transporting electricity through power lines, losses of up to 30% occur and environmentally hazardous electromagnetic radiation is created. So far, only a small part of the earth's hydroelectric potential serves people. Every year, huge streams of water generated by rain and melting snow flow into the seas unused. If it were possible to delay them with the help of dams, humanity would receive an additional colossal amount of energy.

Biomass energy

In the United States, in the mid-70s, a group of ocean research specialists, marine engineers and divers created the world's first ocean energy farm at a depth of 12 meters under the sun-drenched surface of the Pacific Ocean near the city of San Clemente. The farm grew giant California kelp. According to project director Dr. Howard A. Wilcox of the Center for Marine and Ocean Systems Research in San Diego, California, "up to 50% of the energy from these algae could be converted into fuel - the natural gas methane. Ocean farms of the future growing brown algae "on an area of approximately 100,000 acres (40,000 hectares), will be able to provide enough energy to completely meet the needs of an American city with a population of 50,000 people."

In addition to algae, biomass can also include waste products of domestic animals. Thus, on January 16, 1998, the newspaper “St. Petersburg Vedomosti” published an article entitled “Electricity... from chicken droppings,” which stated that a subsidiary of the international Norwegian shipbuilding concern Kvaerner, located in the Finnish city of Tampere, was seeking support EU for the construction of a power plant in British Northampton, operating... on chicken droppings. The project is part of the EU Thermie program, which provides for the development of new, non-traditional energy sources and methods of saving energy resources. The EU Commission distributed ECU 140 million to 134 projects on 13 January.

The power plant designed by the Finnish company will burn 120 thousand tons of chicken manure per year in furnaces, generating 75 million kilowatt-hours of energy.

Conclusion

We can identify a number of general trends and features in the development of world energy in the beginning of the century.

1. In the 21st century. A significant increase in global energy consumption is inevitable, primarily in developing countries. In industrialized countries, energy consumption may stabilize around current levels or even decline by the end of the century. According to a low forecast made by the authors, global final energy consumption could amount to 350 million TJ/year in 2050, and 450 million TJ/year in 2100 (with current consumption of about 200 million TJ/year).

2. Humanity is sufficiently provided with energy resources for the 21st century, but rising energy prices are inevitable. Annual costs for global energy will increase 2.5-3 times by the middle of the century and 4-6 times by the end of it compared to 1990. The average cost of a unit of final energy will increase in these periods by 20-30 and 40-fold, respectively. 80% (fuel and energy price increases could be even greater).

3. The introduction of global restrictions on CO 2 emissions (the most important greenhouse gas) will greatly affect the energy structure of the regions and the world as a whole. Attempts to maintain global emissions at the current level should be considered unrealistic due to a difficult contradiction: additional costs for limiting CO 2 emissions (about 2 trillion dollars/year in the middle of the century and more than 5 trillion dollars/year at the end of the century) will have to be borne by predominantly developing countries, which, meanwhile, are “not to blame” for the problem that has arisen and do not have the necessary funds; developed countries are unlikely to be willing or able to pay such costs. It can be considered realistic from the point of view of ensuring satisfactory energy structures in the regions of the world (and the costs of its development) to limit global CO 2 emissions to 12-14 Gt C/year in the second half of the century, i.e. to a level approximately twice as high as it was in 1990. At the same time, the problem of distributing quotas and additional costs for limiting emissions between countries and regions remains.

4. The development of nuclear energy represents the most effective remedy reduction of CO 2 emissions. In scenarios where strict or moderate restrictions on CO 2 emissions were introduced and there were no restrictions on nuclear energy, the optimal scale of its development turned out to be extremely large. Another indicator of its effectiveness was the “price” of the nuclear moratorium, which, with strict restrictions on CO 2 emissions, results in an 80 percent increase in global energy costs (more than $8 trillion/year at the end of the 21st century). In this regard, scenarios with “moderate” restrictions on the development of nuclear energy were considered to search for realistically possible alternatives.

5. An indispensable condition for the transition to sustainable development is assistance (financial, technical) to the most backward countries from developed countries. To obtain real results, such assistance must be provided in the very next decades, on the one hand, to accelerate the process of bringing the living standards of developing countries closer to the level of developed countries, and on the other, so that such assistance can still make up a significant share in the rapidly increasing total GDP of developing countries.