Solar panel is a device which have a response to light and able to convert sunny power into electric power. There are many kinds of materials which can produce photovoltaic effect, such as monocrystalline silicon, polycrystalline silicon, amorphous silicon and gallium arsenide, etc. Their electric-generation principles are basically the same.



The solar module uses wafer-based crystalline silicon cells or thin-film cells on the basis of cadmium telluride or silicon. The structural member of it can not only be the top layer but also the back layer. Cells must also be prevented from being damaged by mechanical force and moisture. Most of the solar modules are rigid, but the semi-flexible ones are available which based on thin-film cells.

The solar panel works through the elemental reaction between positively charged and negatively charged compounds. Silicon is the main ingredient in a solar panel while its purest form is an electromagnetically neutral element that, as a result of its four valence electrons, taking on the charge of another element will be much easier, which makes it an ideal base for the process of harnessing solar energy. Electric power is created when electrons move from a negative charge to a positive one, so a solar panel is actually made of two separate plates joined by conductive wiring. The top plate of the panel is made from silicon mixed with negatively charged phosphorus, and the bottom plate is made from silicon mixed with positively charged boron.

If being placed in the sun, an elemental reaction occurs in the solar panel between the two plates which directly leads to the production of electricity. Natural sunlight is filled with particles which is called photons. They interact with the valence electrons of the negatively charged phosphorus on the top plate. When being excited, the valence electrons bump the additional electron that makes phosphorus negative loose. The freed electron travels along the connective wiring to the electron deficient boron of the bottom plate, which create usable energy which may be used immediately to create electric power or be stored for a short period of time in a chemical battery, through the transfer of the electron. Energy will be created as long as sunlight is shining on the negative plate, and the amount of energy created will be directly proportional to the size of the solar panel. This is why devices that depend on solar panels, such as houses, enterprises or vehicles, will have several distinct panels of equal size to maximize potential energy output. Some recent solar module designs include concentrators in which light is focused by lenses or mirrors onto an array of smaller cells, which enables the use of cells with a high cost per unit area in a cost-effective way.