Renewable Sources of Energy

Solar energy:

The main source of energy is the thermonuclear fusion reaction that continuously takes place in the sun. The sun is a huge mass of hydrogen gas and temperature in the sun is very high. The sun is considered as a big thermonuclear furnace where hydrogen atoms are continuously being fused into helium. In this process, some mass (0.7%) is lost during the reaction, which in turn liberates an enormous amount of energy. Thus, the sun, which gives us heat and light energy, derives its energy from the nuclear fusion reaction. This process is going on inside it, all the time.

Condition required in sun for nuclear fusion:

• In Sun, there is sufficient amount of hydrogen gas.
• The presence of necessary temperature in the sun for theformation of free protons.
• The presence of necessary pressure for thecombination of free protons.

Biogas:

Biogas is a mixture of methane, carbon dioxide, hydrogen and hydrogen sulphide. However, the major constituent of biogas is methane.

Biogas is produced by the anaerobic decomposition of wastes (like animal dung) or plant wastes in thepresence of water. Anaerobic bacteria decompose these waste materials in thepresence of water and convert them into methane gas and some other gas. In this way, biogas is produced in biogas plants.

Advantages of biogas:

• Biogas burns without smoke and hence does not cause air pollution.
• Biogas produces more heat while burning.
• Biogas is cheaper and can be produced easily.
• Biogas can be used to generate electricity.

Tidal energy:

The energy obtained with the help of tides of thesea is called tidal energy. Or, The energy generated from the tides of thesea is called tidal energy.

The method of generating electricity from tides of sea is given below:

Big dams are constructed at seashore near water. When tides surge up in the sea, water enters into the dam by crossing the dam and the water is trapped in the dam. When water moves back towards thesea, the water is passed through pipes, which is used to rotate turbines with the help of tides of thesea.

Geothermal energy:

Geothermal energy is obtained by following methods:

• The extremely hot rocks, present below the surface of the earth, heat the underground water and turns into steam. In such places, two holes are drilled into the earth through which metal pipes are put into them. Cold water is pumped in through one of the pipes. The cold water turns into steam due to the heat of the rocks. The steam thus formed comes out through the other pipe. The steam thus obtained is used to boil water and to produce electricity.
• In some places, the steam and extremely hot water from the hot spots comes out of the ground on its own where large cracks are present in underground rocks. The steam and hot water thus coming out are used to rotate turbines for generating electricity. It is also used for cooking food, steaming, bathing, etc.

Energy crisis:

Measures to solve energy crisis:

• Less use of non-renewable source of energy.
• Use of alternative sources of energy.
• Public awareness.