DEMONSTRATION MODULE FOR SOLAR ENERGY KIT

DEMONSTRATION MODULE FOR SOLAR ENERGY KIT

A solar cell is also known as photovoltaic cell which produces electric current when the surface is exposed to sunlight. In solar cells, the amount of electrical energy generated by the cells depends on the intensity of em radiation that reaches the surface of the cell. Solar cell converts Electromagnetic radiation to DC current. Basic Operating Principle of A Photovoltaic / Solar Cell

The principle operation of a solar cell is similar to conduction in a semiconductor like silicon. As seen in the picture, the dark surface is the part that is exposed to sunlight. When Electromagnetic radiation strikes the surface of the cell, it excites the electrons and as such cause them to jump from one energy level (orbit) to the other leaving holes behind.

These holes serve as the positive charge carriers while the electrons serve as negative charge carriers. Do not get confused, the electrons or holes do not constitute to give the electrical charges. They only carry the charges. By so doing EM radiation is converted to electrical energy. Solar cells are made basically from semiconductors like silicon and selenium being the most widely used.

The terminal voltage of the cell is directly proportional to the intensity of the incident light. The voltage may be as high as 0.6V depending on the external load. Usually a large number of cells are arranged in an array in order to obtained higher voltages and currents.

A solar cell operates with fair efficiency, has unlimited life, can be easily mass-produced and has a high power capacity per weight. It is because of these qualities that it has becomes an important source of power for earth satellites. 

Advantages and disadvantages of Solar Cell

1. It doesn’t produce noise and its driving power is free in nature.

2. It doesn’t require fuel to power it up and require little maintenance.

3. The surface of the cell has to be large in order to produce reasonable amount of electrical energy.

4. When the sun goes into hiding in the clouds amount of energy generated will be cut down.

5. They cannot be employed as energy source because of fluctuations in the amount of energy generated.

Applications & Uses of Solar Cells

Solar cells have numerous applications despite its disadvantages which are as follows:

1. Group of series – parallel connected solar cells can be used as a battery charger.

2. They are extensively used as source of power for satellites.

3. Multiple-unit silicon photovoltaic devices can be used for sensing light in applications like reading punched cards in data processing industry.

4. Gold – doped germanium cells with controlled spectral response characteristic can be used as infrared detectors.