Solar Energy

Solar energy is one the most resourceful sources of energy for the future. One of the reasons for this is that the total energy we receive each year from the sun is around 35,000 times the total energy used by man. However, about 1/3 of this energy is either absorbed by the outer atmosphere or reflected back into space (a process called albedo)*.
Solar energy is the energy force that sustains life on the earth for all plants, animals, and people. The earth receives this radiant energy from the sun in the form of electromagnetic waves, which the sun continually emits into space. The earth is essentially a huge solar energy collector receiving large quantities of this energy which manifests itself in various forms, such as direct sunlight used through photosynthesis by plants, heated air masses causing wind, and evaporation of the oceans resulting as rain which can form rivers. It is a good option because there is an unlimited supply of this energy source, and it is available all over the world and not just in certain locations and deposits. It is nonpolluting and it could be implemented basically anywhere.

Solar energy, provided by the sun, is constantly replenished and will not produce harmful pollution unlike fossil fuels. Solar energy may be used passively, such as to heat and light buildings, or technology may be used to harness the sun's energy by collecting it and transforming it to generate electricity. Current technologies include photovoltaics, concentrating solar, solar hot water, and more.

Solar energy, experienced by us as heat and light, can be used through two routes: the thermal route uses the heat for water heating, cooking, drying, water purification, power generation, and other applications; the photovoltaic route converts the light in solar energy into electricity, which can then be used for a number of purposes such as lighting, pumping, communications, and power supply in unelectrified areas. Energy from the sun has many features, which make it an attractive and sustainable option: global distribution, pollution-free nature, and the virtually inexhaustible supply.

On the other hand, solar power is not continuous. When the sun sets, the energy source is gone until the sun rises again the next day. In order to offset this drawback a storage devise is required. Another drawback to this energy source is that the reflective panels used to absorb the sun’s energy can be blinding to passing traffic.

Advantages
In spite of its cost versus other sources of energy, solar power is attracting interest due to the following:

• Solar energy makes use of a renewable natural resource that is readily available in many parts of the world.
• The process used to generate solar energy is emission-free.
• Technological advances have reduced costs to a point that it can compete with fossil fuel alternatives in specific circumstances.
• The technology is scalable in that it can be used for domestic heating purposes or on a larger scale for commercial electricity generation, as solar water heaters are an established technology, widely available and simple to install and maintain.

Disadvantages

The biggest barriers to increasing solar power generation are the cost, the amount of land required for large-scale electricity production, and the intermittent nature of the energy source. In terms of the latter, thermal systems do not work at night or in inclement weather. Storage of hot water for domestic or commercial use is simple, needing only insulated tanks, but storage of the higher-temperature liquids needed to generate electricity on a large scale — or storage of the electricity itself — requires further technological development.