A regular dependable source of energy is one of the most important factors in modern life. A normal day, people constantly consume energy for heating lighting cooking,transport and powering all kinds of electrical equipment. Furthermore,energy is used by industries to produce all the goods that we buy and provide all the services that we use. In this unit, we will examine difeerent sources of energy and look at the advantages and disadvantages of using theese forms of energy.
Fossil fuels are the most common source of energy used in the World. Industries make use of these fossil fuels for many processes. In power stations , fossil fuels like coal or oil are burnt. ...view middle of the document...
In nuclear power plants , however, it means electricity produced by a nuclear reactor. Nuclear power stations make use of nuclear energy to generate electricity. Nuclear energy is released mainly in two ways:
1) Nuclear fission is the process of splitting the nucleus of an atom. For example , the heavy nucleus of a radioactive uranium atom splits into two after being struck by a neutron. During a nuclear fission , the nucleus is split into several smaller fragments . These fragments are nearly equal to half the original mass. Two or three neutrons are also emitted. This allows for a chain reaction. The sum of the masses of these fragments is less thas the original mass. This ‘missing’ mass is converted into a great amount of energy. Fission can ocur when a nucleus of a heavy atom captures a neutron , or it can happen spontaneously. Many problems are associated with nuclear power plants. Besides the usual thermal pollution associated with any heat engine,there is the problem of the disposal of the radioactive fission fragments into the atmosphere and leakage of wastes pose a serious threat both to the environment and to human health.
2) Nuclear fusion is the process of combining the nuclei of particular atoms,for example,hydrogen atoms , in order to release energy. This process takes place continuously in stars such as the Sun. The combining of nuclei results in a loss of mass,which is manifested in the release of a large amount of energy. A working fusion reactor for power generation has not yet proved possible because of the difficulty in reaching and maintaining the high temperature required.
The Sun radiates a great amount of energy to the Earth. The Sun can be thought of as a renewable source of energy since it will continue to generate energy for billions of years. The solar panels installed on the roofs of buildings act as a heat transfer medium. This is an efficient heating system in warm countries.
Solar power is a clean,reliable form of renewable energy generated by converting energy from the sun’s radiation into electricity. Photovoltaic cells or solar cells are grouped and connected together in a single frame called a panel or modüle. These cells consist of special semi-conductive materials,which are the most often a piece of silicon positioned under a layer of thin glass. The current they produce can be used immediately,may be stored in rechargeable batteries or can be fed into the power grid and sold to the electic company.