The sun (closest star to the Earth) has produced energy for billions of years. This energy which comes from the sun and reaches the Earth is called “ Solar Energy”. This energy is used for a number of household uses: heating of buildings, generating electrical energy etc. It is a clean, cheap and reliable way of obtain energy/electricity.
Solar Energy was first discovered in the 1830’s, when British astronomer, John Herschel, whilst on an expedition to Africa, used a solar collector box to cook food. Today, people all over the world are using the sun’s energy for a variety of things.
Solar Energy can be converted into many other forms on energy, such as heat and electricity. It can be converted into electricity instantly as it hits the Earth’s surface by using 1 of 2 methods.
1: The sun’s energy is used to heat water, thus turning it into steam. This steam is then captured and used to turn big turbines, which results in a generator which makes electrical energy.
2: Photovoltaic Method. Photovoltaic is the word used for the conversion of solar energy into electrical energy. Photovoltaic cells are used for this conversion. They are large plates, made from silicon alloys which are directed at the sun. They absorb the sun’s rays, or otherwise known as “photons” or “solar energy particles”. When the sun rays hit the solar plate, the rays are either reflected or absorbed. Therefore silicon alloys are used in the plate for they attract the sun’s rays, thereby resulting in more rays being absorbed than reflected, which results in more electricity being made for it is the rays which are absorbed by the plate that make the electrical energy.
When enough sunlight is absorbed by the plate, the electrons are moved from the materials atoms. Special treatment of the material surface during manufacturing makes the surface of the cell more accepting to free moving electrons, therefore enticing the free moving electrons to move to the surface. When the electrons move to the surface, little holes are made. When many electrons, which are negatively charged, move to the surface of the cell, a charge imbalance occurs between the front and back of the cell thus creating a voltage potential(much like the terminals of a battery-1 positive, 1 negative) . When these surfaces are connected through an external load, electricity is made. If the cells aren’t on site, they are sent to a power stations, where from there, they are conducted.
The only problems that are experienced with the absorbing of solar energy, are the uneven and un-constant ways of which the sun hits the Earth’s surface and the large area required to collect the solar energy at a useful/productive rate.
However, Solar energy is a clean, Earth friendly and useful way of creating electrical energy-something used frequently in our houses/lives.