Презентация на тему Sources of power

The industrial progress of mankind is based on power: power for industrial plants, machines, heating and lighting systems, transport, communication. In fact, one can hardly find a sphere, power is not required. At present most of the power required is obtained mainly from two sources. One is from the burning of fossil fuels, i. e. coal, natural gas and oil. The second way of producing electricity is by means of generators that get power from steam, or water turbines. Electricity so produced then flows through transmission lines to houses, industrial plants, enterprises, etc. It should be noted, however, that the generation of electricity by these conventional processes is highly uneconomic. Actually, only about 40 percent of heat in the fuel is convert into electricity. Besides, the world resources of fossil fuels are not everlasting. On the other hand, the power produced by hydroelectric plants, even if increase many times, will be able to provide for only a small fraction of the power required in the near future. Therefore much effort and thought is being given to other means of generating electricity. One is energy of hot waters. Not long ago we began utilizing hot underground water for heating and hot water supply, and in some cases, for the generation of electricity. Another promising field for the production of electric power is the use of ocean tide. Our engineers are engaged in designing tidal power station of various capacities. The first station utilizing this principle began operating in the Soviet Union on the Barents Sea in 1968. The energy of the sun which is being used in various ways represents a practically unlimited source. Using atomic fuel for the production of electricity is highly promising. It is a well-known fact, that one pound of uranium contains as much energy as three million pounds of coal, so cheap power can be provided wherever it is required. However, the efficiency reached in generating power from atomic fuel is not high, namely 40 percent. No wonder, therefore, that scientists all over the world are doing their best to find more efficient ways of generating electricity directly from the fuel. They have already succeeded in developing some processes which are much more efficient, as high as 80 percent, and in creating a number of devices capable of giving a higher efficiency. Scientists are hard at work trying to solve these and many other problems. Scientists consider hydrogen, a very promising energy source. The reserves of hydrogen are practically unlimited. Per unit of weight it contains almost three times more thermal energy than benzene. Besides, hydrogen can be used as fuel in transport, industry and home. Hydrogen is easy to transport and store. It can be transported over large distances using conventional pipelines. It can be accumulated and kept for a long time either in conventional or natural reservoirs. Scientists have found many ways of producing hydrogen — basically from ordinary water. And large volumes of this fuel can be obtained from coal, whose global reserves are tremendous. There is also an idea of using nuclear power plants to generate hydrogen. Scientists hope to use the energy of the sun, wind and tides to obtain hydrogen. In several countries car engines fed by hydrogen have been tested successfully. Tests have also shown that adding five to ten per cent hydrogen to benzene increases engine efficiency by 40-45 per cent. What is still holding back the use of hydrogen as fuel, and what has to be done in order to apply it extensively in the economy? The main reason is that now it is more expensive than mineral fuels, but in the near future hydrogen can be made cheaper to obtain. This new kind of energy opens up new prospects in aviation, metallurgy and some other industries. The Japanese scientists have opened that snow is almost free energy source. Therefore in the city of Muroran in the north of Japan it is collected in special reservoirs. Scientist Masajoshi Kobijama says that snow can be burnt, as in industrial cities it on 70 % consists of methane which is absorbed from atmosphere. Snow is the natural filter. It absorbs harmful gases and dust, and in spring during thawing of snow, harmful components come back into the atmosphere. The technology, allowing to receive methane from snow, is introduced in Japan. From a ton of snow collected near a motorway, it is possible to receive about 100 litres of methane. This gas is used as fuel, and cleared snow is applied in airs condition system (кондиционирования).