Photovoltaic cells can be made with different materials and technologies. Some of these technologies, used in most commercial modules include monocrystalline silicon cells, polycrystalline and amorphous. Using this technology, each cell produces a DC voltage of about 0.5 volts and a DC current of 1-8 A, it requires a significant number of cells to produce an appreciable voltage and power. The photovoltaic cells are interconnected in series in groups ranging from 36 to 72 cells that produce open circuit voltage of about 20-40 volts this set of cells in a photovoltaic module. The photovoltaic modules are a set of interconnected photovoltaic cells in series with the following physical characteristics: They are encapsulated with silicone or other special organic materials that provide a high transmission of radiation, are hydrophobic materials, to breathe into the cell and not condensed water. Protection by the back of Tedlar or some material similar. A tempered glass cover.
An anodized aluminum frame that holds the module as a whole. The set of two or more modules called photovoltaic array (array in English) or photovoltaic panel. The photovoltaic modules that comprise an arrangement can be connected in series, parallel or mixed form for the voltage and amperage required by the system. Batteries. The battery bank of a solar lighting system is responsible for providing electricity during the hours of night operation that has the fixture. An important aspect to be determined for either battery bank is the same size, ie the amount of energy it can store, the more energy is required to store, the larger will be the bank of batteries, less energy to store the smaller the size of the bank.