Types of Solar Panels

Solar panels are classified into three classes: mono-crystalline (single crystal), poly-crystalline (multiple crystals), or amorphous silicon. Mono-crystalline is indicative of the continuous and unbroken sample of silicon in which the cell is manufactured from. This method uses very pure silicon grown in a complex growth process, and then sliced into wafers that compose the individual cells. This was the first method used to manufacture solar cells, and are still highly regarded for their efficiency ratios.

Poly-crystalline panels are composed of many crystallites of varying size and orientation. These multi-crystalline panels are generally less expensive and slightly less efficient than mono-crystalline modules, yet lately the difference in efficiency is very small. Like their mono-crystalline counterpart, the cells are also cut into wafers that make up the individual cells of a solar panel.

Amorphous solar panels use the non-crystalline, allotropic form of silicon, in which a thin layer of this silicon substrate is applied to the back of a plate of glass. These panels are much cheaper and less energy efficient, yet they are more versatile in how they can be used. For example, amorphous solar panels can be manufactured into long sheets of roofing material. Thin Film solar panels also fall into the amorphous category. This type of cells can be mounted on a flexible backing, making them more suited for mobile applications.

Each of the solar panel types is estimated to last at least twenty-five years. Instead of stopping production completely, electricity production will decline a little, gradually, over decades. The longevity of a solar panel refers to the number of years before the unit starts producing only 80 percent of its original power rating. The industry standard for warranties is 20 to 25 years, although it is not uncommon for panels to produce adequate power for over 30 years.