Energy and Its Sources

The world is facing a serious problem of potential shortage of energy, which is extremely important to meeting all of man's physical needs—clothing, shelter, transportation, convenience, recreation, etc. The consumption of energy is expected to grow. The amount of energy consumed by a country is closely connected with its degree of technological development and industrialization, which are in turn related to the people's standard of living.

Energy can be classified according to its sources. The principal materials now used for obtaining energy are of plant and animal origin, deposited in the earth over millions of years in the form of coal, oil, and natural gas. These so-called "fossil fuels" are extremely useful raw materials because of the conveniently stored chemical energy. But when they are burned for fuel, harmful pollution may result and there is a great waste of natural resources that will never be available again.

Wood was already the main source a hundred years ago. The growth 'of coal usage in the early 1900s is associated with rapidly increasing industrial development. There followed a great expansion in the consumption of natural gas and fuel oil for heating, electrical generation and especially transportation.

The reserves of such popular sources of energy as natural gas and oil are not expected to meet the long-term demands.

Natural gas is a popular source of energy because of its convenience for use and cleanliness in burning. It is generally believed that gas will be the first fossil fuel to be in short supply, and the cost of oil extraction is high. To these sources we can add the energy obtained from water motion anal the sun.

ВАРІАНТ II

Hydroelectric power is available when a stream can be dammed to form a large reservoir, permitting falling water to turn a hydraulic turbine connected to an electric generator. It is generally agreed that this, source cannot meet the total need in power.

Solar power is often mentioned as the logical alternative. And indeed, the amount of radiant energy that reaches the earth's surface is more than what is needed. For the generation of electricity, however, there are serious problems to be solved. To collect and concentrate the energy by reflectors and converters of present efficiency is the major difficulty. There remain many technological problems in this area.

Man is consuming the remaining resources at such a rate that they may last only a few centuries. This may seem to be a long time in comparison with the life of a single generation, but in man's history it is only a short period. If the world is to solve the long-range energy problem, it must look for and make use of all available practical sources economically. Efforts to eliminate the extravagant waste of energy are needed at the same time. Several other conclusions can be made: that research and development work with a view to find new sources of energy and ways of increasing efficiency are urgently needed; that the new sources of other types of fuels must be fully developed and utilized wherever possible. And we must give a serious consideration, as a possible solution, to nuclear energy, i.e. the energy from nuclear reactions, the burning of nuclear fuel.

ВАРІАНТ III

Дата добавления: 2015-07-14