SOLAR ENERGY
Importance of Solar Energy
- Sun is an abundant source of energy and it is inexhaustible. In the broadest sense, solar energy supports all life on earth and is the basis for almost every form of energy we use. The sun makes plants grow, which are burned as fuel or rot in swamps and are compressed underground for millions of years to become coal and oil. Heat from the sun causes temperature differences between areas, causing the wind to blow. Water evaporates because of the sun, water vapours are carried to high elevations, and when the water vapours condense and precipitate as rainfall. The water rushes down towards the sea through rivers, spin turbines is too made for generating electricity. It thus becomes clear that hydroelectricity is an indirect form of solar energy. However direct solar energy can be used as heat, light, and electricity through the use of solar cells.
- The sun is often regarded as the ultimate answer to our energy problems. Sun provides a continuous supply of energy that far exceeds our current energy demand. It is free of cost, available in plenty, found everywhere and has no political barrier. Actually, fossil fuels also represent sunlight stored millions of years ago. However, we are only able to trap and make use of a very small fraction of this abundant energy source. Solar energy use can be classified as: i) direct solar energy use; solar energy is captured directly as sunlight and used for heating, generating electricity and cooling ii) indirect use of solar energy derived from natural processes driven by the sun, for example wind, biomass, waves, hydroelectric power.
| 5,000 years ago, people “worshipped’ the sun. Ra, the sun-God, who was considered the first king of Egypt. In Mesopotamia, the sun-god shamash was a major deity and was equated with justice. In Greece there were two sun deities, Apollo and Helios. The influence of the sun also appears in other religions-Zoroastrianism, Mithraism, Roman religion, Hinduism, Buddhism, the Druids of England, and Aztecs of Mexico, the incase of Peru, and many Native American tribes. |
Direct Solar energy
Solar energy is abundant, everlasting and available free of cost. Direct use of solar energy can be used through various devices broadly directed into three types of systems
- a) Passive,
- b) Active
- c) Photovoltaic