How is Solar Power Generated
Solar panels have been replacing traditional sources of energy at a rapid rate. For nearly ten years, solar power generation has been the flag bearer for alternative sources of energy. They are used in domestic solar modules, solar public lights and in spaceships and satellites. There are numerous methods of solar power generation. The most widespread technique involves the use of photovoltaic solar panels. Other power generation methods include solar thermal power and concentrated solar power. Let us take a brief look at the various ways by which solar power can be generated.
Photovoltaic solar panels
Light consists of particles known as photons. Each photon carries a particular amount of energy. When light strikes on a photosensitive, rather photovoltaic plate then this energy is transferred to the electrons of the atoms. The electrons are knocked out of the atom's orbit or influence thus generating a flow of current. Each photovoltaic panel consists of numerous small photovoltaic cells which convert the energy of photons into electricity. A photovoltaic cell is made from two layers of silicon, which is a semiconductor. In order for a photovoltaic cell to work there needs to be an electric field. To create this field, photovoltaic cell manufacturers use doped silicon layers. Each layer corresponding to the positive and negative poles. Phosphorus is added to the top layer giving silicon an extra electron. This becomes the negative pole. The lower layer is doped with boron which results in a lesser number of electrons, making it the positive end. When the photon strikes such a dual layer silicon cell, the electron that is knocked out travels due to the presence of this field. The electric field forces the electron to travel beyond the silicon junction. There are conducting, metallic plates present at the sides of each solar cell that that transfers the electrons into the wire to generate regular electricity.
Solar thermal power and concentrated solar power
Thermal solar power basically involves generating enormous heat through concentrated sunlight. All solar thermal units have two main components. The first is the mirror that directs the sunlight. The second is the receiver which collects the sunlight. Heat-transfer fluids like water are channeled through the receiver to convert it into steam. The steam can then be used to run turbines which can generate electricity. Most solar thermal power units have an inbuilt tracking system that directs the mirrors to continuously focus sunlight throughout the course of the day.
There are many kinds of thermal or concentrated solar power units. There are linear systems, parabolic trough systems, linear Fresnel collectors and many more. Parabolic collectors have a parabola-shaped mirror and a receiver rod located at the focus of the parabola. Fresnel collectors also contain parabolic, trough-shaped mirrors, but they focus the sunlight above the mirror. The reflectors are fitted with a Fresnel lens that focuses sunlight with a large aperture and short focal length. Other technologies like a solar engine and solar power towers are used for large-scale solar power generation.