The concept of using sun as a source of energy is as old as man himself. Man’s relation to solar energy gradually became more systematic and planned as he entered the industrial age from his ages old agricultural heritage. Solar energy began to be used as the driving force for a variety of tasks and culminated in solar power generation in our age. Solar power generation, as we know it now, refers to the generation of electric power by direct conversion of solar energy-a process known as photovoltaics.
Early Use Of Solar Energy
While the use of solar energy for drying wet objects of human households and heating dates to antiquity, the idea of more systematic use of solar energy emerged at around mid 19th century. British astronomer John Herschel, in the 1830s, cooked food in a solar collector box, during a trip to Africa. The exact channel for generating electricity was introduced by Henri Becquerel’s discovery of the photovoltaic effect. It produces electricity directly from the sun through a photovoltaic (PVs) cell or solar cell, as it came to be known in general.
Solar Power Generation Through A Photovoltaic Cell
A photovoltaic cell is basically a non-mechanical device made from alloys of silicon. When sunlight falls on the photovoltaic cell, part of the solar energy is absorbed by the material of the cell. This energy excites the cell’s material to release free electrons that migrate to the cell’s surface. An imbalance of positive and negative charges results between the cell’s front and back surfaces. Connecting these two surfaces through an external load results in a flow of electricity from the surface of higher potential to the lower one. A number of these solar cells are connected electrically to form a module (a weather-tight package). Connecting the modules constitutes the PV system, also called an array. The output of the PV generating plant depends on the size of the array i.e. the number of modules connected.
Performance Of PV Generating Plant
The performance of the PV generating plant directly depends on the amount of sunlight received on its surface. Climatic conditions (fog, clouds etc.) thus affect the performance. Currently, most PV generating plants are 10 % efficient in conversion of solar energy to electricity.
Advantages Of Solar Power Generation
The greatest advantage of solar power generation is perhaps its minimal environmental impact. It requires no water for cooling of the system, thus creating no large heat imbalance. Also, no by-products are produced that are detrimental to the environment. Another advantage of solar power generation is that bulky mechanical generators are not needed. The process of electricity generation is quick and the arrays are available in a variety of sizes according to the specific use.