Improving Efficiency of PV Module

A solar cell is the building block of a solar panel. A photovoltaic module is formed by connecting many solar cells in series and parallel. Considering onlya single solar cell; it can be modelled by utilizing a current source, a diode and two resistors. This model is known as a single diode model of solar cell. The equivalent electric circuit diagram of PV cell consists of a photocurrent source, adiode, aparallelresistoralsocalledshuntresistor (Rsh) expressingaleakage currentandaseriesresistor (Rs) describing internal resistance to the current flow ThePVcellselectricalcharacteristicunder solarirradiance (S) is given in terms of PV cell output current (I) and PV cell voltage (V). PVcellsaremadeof semiconductormaterials, suchassilicon. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forminganelectrical circuit, theelectronscanbecapturedin the formof an electric current - that is, electricity. This electricity can then be used to power a load. The power produced by a single PV cell is not enough for general use. So by connecting many single PV cell in series (for high voltage requirement) and in parallel (for high current requirement) can get us the desired power. Generally a series connection is chosen this set of arrangement is known as a module. Generally commercial modules consist of 36 or 72 cells. The p-n junctions of mono-crystalline silicon cells may have adequate reverse current characteristics and these are not necessary. Reverse currentswaste power and can also lead to overheating of shaded cells. Solar cells becomelessefficientat highertemperaturesandinstallerstryto provide good ventilation behind solar panels.