Photovoltaic cells are one of the most important ways to produce energy from the sun. A photovoltaic cell or solar cell can produce electricity for watches and small electrical appliances or for hundreds of houses when used at a more massive scale. It is a non – mechanical device that is made usually from silicon and is specially manufactured to absorb as much energy from the sun as possible. But how exactly do photovoltaic cells work?
How do photovoltaic cells work?
Solar energy is made of solar particles which are called photons. These photons contain various amounts of energy according to the wavelength of solar radiation that they belong to. When photons strike through a photovoltaic cell, the photons will either be reflected, pass through the cell or be absorbed. Only the photons that are absorbed by the photovoltaic cell can produce electricity.
When a great amount of photons hits the surface of the photovoltaic panel the electrons are removed from the atoms and this creates an electrical charge. Special care during the manufacturing of the photovoltaic cells makes it easier for electrons of the material to be released and in this way it becomes easier for electricity to be produced.
When the electrons move from one part of the photovoltaic cell to the other an electrical void is created. This causes more electrons to travel towards the same direction. When many electrons travel towards the same direction they create an imbalance of charge between the two parts of the conductor. In this way a voltage potential is created that is similar to the one between the two poles of a battery. When the two surfaces get connected with an external appliance electrical power is produced.
The photovoltaic cell is the basic unit of the photovoltaic installation. Individual cells produce only one to two watts which of course is not enough for most electrical appliances. This is why photovoltaic cells are combined into modules and modules are combined together into arrays. Solar arrays are installed in many acres of land and are used to produce electricity in vast scales.
The efficiency of solar panels depends on the weather conditions. Fog and cloudy weather can greatly reduce the amount of sunlight received by a photovoltaic panel and in this way interfere with its performance. The efficiency of most photovoltaic modules ranges from 5% to 15% but researchers are trying to increase this percentage to 30%. As technology advances, increasingly efficient photovoltaic cells can be created that will absorb more solar energy even in adverse weather conditions.
Photo by flickr.com / Bernd Sleker
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