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Solar cells
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Solar cells convert light into energy.
This is a similar technology to that which is used by the computer industry to create computer chips. Before anything else happens in the conversion process, the cell must absorb the light.
The light is the source of all energy and acts as the instigator in the whole process. Once the light has been absorbed into the cell, the electrons in the material from which the cell is made experience an increase in energy. This higher level of energy allows the electrons to be free and move around the material.
This elevated level of energy stays in effect for only a few minutes before the normal level of activity returns. A device called a pn junction is often used in these cells.
The pn junction actually is made up of two separate regions of a semi-conductor material. The material that is most commonly used is silicon. The name pn junction comes from the fact that one side of the junction is called the p-type region while the other side is called the n-type region.
It is the purpose of the pn junction to collect the carriers before they have had time to lose all of the energy that was initially gained from the effect of light hitting a solar panel. In the p-type material, the electrons are able to quickly gain energy when they are exposed to any kind of light, but if not captured, they rapidly will return to their original low-energy position.
The difference between p and n types is that if the electrons are able to move into the n-type region, they stay at a high energy level and are no longer able to lower and return to their initial state.
The process of moving these electrons from one area to the next is what is known as collection. After the light generator is collected, there are a couple of options concerning what can happen next. First of all, it can be extracted from the device and transmitted as direct current (DC). Or the energy can simply remain inside of the device. If this is the choice taken, the voltage will rise.
This rise of voltage is referred to as the photovoltaic effect. When mention is made of PV panels, the PV stands for photovoltaic. It is this combination of voltage and a current together that create an output of power from a solar cell.
The direct current can also pass through an inverter which will create an alternating current (AC) that can be used to power most household appliances.
The electrons that are part of the current leave their energy behind and then return to the n-type region back at the same low level at which the process began. After this happens, the whole process begins once again.
The use of solar cells does not depend on a person’s knowledge concerning how these cells work, however it does help to gain a basic understanding of how a solar energy system works.
