Salar photo voltaic (SPV) system enables the conversion of solar energy directly to electrical energy.Energy conversion devices used to convert sunlight to electrical energy are called solar cells.Thus, the basic building block of a photo voltaic system is the solar cell.
A solar cell is basically a semiconductor diode capable of developing a voltage of 0.5 to 1.0 V.A solar cell can be made from various semiconductor materials which are processed with special additives.This makes them photosensitive.When photons(particles of energy in sunlight)strike the surface of the solar cell, electron hole pairs are generated and current starts flowing. conductive layers are provided at the top and bottom of the solar cell to collect current.
Solar cells are connected together in series and parallel suitably to provide desired voltage and power output.This group of solar cells is put in a special protective enclosure called a module.Several modules grouped together form a panel.When a number of panels are interconnected to supply higher voltage and power output,the arrangement is known as an array.
The performance and quality of a photovoltaic devices is represented by its efficiency,which is the ratio of electrical energy produced to the solar energy incident on its surface.
Most commercial solar cells today are made of silicon.Efficiencies of about 24% have been realised with crystalline silicon solar cells in the laboratory.Efficiencies of commerically produced solar cells range between 13-15%.Higher efficiencies have been achieved using concentrated sunlight.Several alternative materials and techniques have been investigated to reduce the costs of PV devices.Amorphous silicon technology has achieved some success.Here ,thin layers of silicon are deposited on glass or stainless steel substrates.These layers do not possess a crystalline structure and, therefore,they are called amorphous films.other thin film materials being used are copper indium diselenide(CuInse2) and camium telluride (CdTe).The main advantages of thin film technology are the small quantity of materials needed and the lower energy consumption.
A solar cell is basically a semiconductor diode capable of developing a voltage of 0.5 to 1.0 V.A solar cell can be made from various semiconductor materials which are processed with special additives.This makes them photosensitive.When photons(particles of energy in sunlight)strike the surface of the solar cell, electron hole pairs are generated and current starts flowing. conductive layers are provided at the top and bottom of the solar cell to collect current.
Solar cells are connected together in series and parallel suitably to provide desired voltage and power output.This group of solar cells is put in a special protective enclosure called a module.Several modules grouped together form a panel.When a number of panels are interconnected to supply higher voltage and power output,the arrangement is known as an array.
The performance and quality of a photovoltaic devices is represented by its efficiency,which is the ratio of electrical energy produced to the solar energy incident on its surface.
Most commercial solar cells today are made of silicon.Efficiencies of about 24% have been realised with crystalline silicon solar cells in the laboratory.Efficiencies of commerically produced solar cells range between 13-15%.Higher efficiencies have been achieved using concentrated sunlight.Several alternative materials and techniques have been investigated to reduce the costs of PV devices.Amorphous silicon technology has achieved some success.Here ,thin layers of silicon are deposited on glass or stainless steel substrates.These layers do not possess a crystalline structure and, therefore,they are called amorphous films.other thin film materials being used are copper indium diselenide(CuInse2) and camium telluride (CdTe).The main advantages of thin film technology are the small quantity of materials needed and the lower energy consumption.
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