Working of Photovoltaic Cells
Efforts are being made to make more and more use of the renewable energy to reduce our dependency on the fossil fuels and reduce the pollution created by them. The photovoltaic cells generate electricity directly from the solar energy, an important type of renewable energy source, without needing any intermediary device. The photovoltaic cells comprises of two layers of oppositely charge silicon slices joined together by wire. When the sunrays fall on silicon the electrons starts moving through the wire in natural manner thus generating the electricity. The amount of electricity generated by two silicon layers in the photovoltaic cells is very small and it can be used only for the small devices like calculator, watches, small light bulbs etc.
To increase the amount of electricity generated by the photovoltaic cells, a number of silicon layers are joined together by wires to form what are called photovoltaic arrays. The photovoltaic arrays are used for powering lights and appliances at homes and offices. They are also used to supply electricity to the street lights, pumps, billboards. The solar photovoltaic arrays are an excellent source of supplying electricity to the remote places, places located away from the main power grids, far off villages, various site operations including construction and exploration, and much more.
How and Where the Electricity is Stored in Photovoltaic Cells
The photovoltaic cells can make the electricity throughout the day when sun is visible and in almost all the seasons including the cloudy skies. Of course the electricity will not be formed during the night times. The electricity generated by the photovoltaic cells is first stored in the rechargeable lead batteries. These batteries should be of high quality so that they can be discharged and recharged continuously on daily basis without getting damaged soon. The batteries used with the solar photovoltaic cells are different from the disposable batteries that have lower life and capacity.
The present day photovoltaic cells also have an electronic charge controller connected to the battery. It efficiently transfers the energy from photovoltaic cells to the battery and also prevents overcharging of the battery and any electrical damage to the solar panels.
Another device which is required with the photovoltaic cells is the inverter. The voltage produced by the batteries is low and they produce direct current (DC current). At home we need alternating current supply with the voltage of 110. The inverter converts small voltage and direct current supply from the batteries to alternating current of 100V, which is ready to be used for all the purposes.
Apart from the other applications, one important area where the photovoltaic cells are being experimented is the cars. In cars the electricity generated from the photovoltaic cells is used to run the motor, which is connected to the wheels of the car. As the motor rotates the vehicle also runs. In the coming years we are sure to see on roads the cars running on solar energy, an important form of renewable energy available abundantly and freely.
Photovoltaic cell (Source: Wikipedia)
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