Sun is the source of all energy on earth. Capturing the solar energy was done by humans in the past as well. Initially it was for drying and heating by direct contact. Now the most important need of the human race is the electric energy and we have devised methods to harness the energy of sun for that also.
The technologies used to capture solar energy are characterized into either passive solar or active solar. Active solar technologies involve usage of photovoltaic cells, solar thermal panels, solar cookers, etc. Passive usage of sun’s energy involves construction of buildings so as to receive maximum amount of light rays and designing areas which naturally circulate air.
The solar energy which falls on the earth for one hour is about the same that we humans use in one year. The earth receives about 174 petawatts of incoming radiation at the upper atmosphere. The solar energy is available at different intensities at different geographical locations; therefore, for best use of the solar energy there are certain factors to take into consideration.
Solar energy is a potential alternative for fossil fuels. It is a renewable source of energy and will be available as long as the sun lasts. It is estimated that the sun will be shining for another 4.5 million years more. Even then effective capitalization on this free source is hindered by the lack of proper advancement of the technical knowhow. At present the solar energy is captured using solar cells, also called photovoltaic cell which is only 15% efficient.
Advantages of Using Solar energy
- It is the cheapest energy source available. After the initial investments are recovered, it is basically a free source of energy. The use of solar energy does not require any fuel. The savings from the investment is immediate. The reduction in health cost due to use of solar energy is high.
- It is a renewable source of energy which does not harm our environment in any way because the pollution induced by solar energy is nil. There is no release of nitrogen oxide, carbon di oxide, sulphur dioxide, or mercury into the atmosphere. It contributes for reduction of harmful greenhouse gas emission. Since it is mostly generated where it is needed, the cost involved in transportation and recovery is nil.
- Most of the solar energy systems work independently. There are no strings attached to it. There are no monthly bills or tax. Government subsidies are available for its establishment and maintenance. It reduces our dependency on centralized sources of energy, so that in the event of a disaster there will be sustained provision of energy for us.
- The maintenance costs associated a solar energy system is very minimal. Once established it will last for about 10 years without further maintenance.
There are also certain disadvantages in choosing a solar power plant. The main fact which outstretch is the initial cost of installing. Considering its numerous advantages this is the best available alternative to the present deteriorating fossil fuel.