Photovoltaic Cell

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What is a photovoltaic cell (PV Cell)? What are the Characteristics of

PV Cell?

Answer:

Photovoltaic Cell

The Photovoltaic cells (PV cells) are also made of semiconducting material such as silicon. Basically, when the photon (light) strikes the cell, a certain amount of light is absorbed within the semiconducting material and produces electricity. This means that it transferred the energy of the absorbed light to the semiconductor. The energy knocks electrons loose, allowing them to flow freely. The name photovoltaic (PV) implies photo meaning ‘light’ and voltaic meaning ‘electricity’.

So, a photovoltaic cell is a semiconductor diode that converts the visible light into direct current. Some photovoltaic cells can also convert infrared (IR) or ultraviolet (UV) radiation into DC electricity. Photovoltaic cells are an integral part of solar-electric energy systems, which are becoming increasingly important as alternative sources of utility power.

The photovoltaic cell characteristics depend on three basic variables; the intensity of solar radiation, temperature, and area of the cell. The intensity of solar radiation has no significant effect on the open-circuit voltage; vice versa, the intensity of the short-circuit current varies in proportion to the varying intensity of the irradiation, increasing as this increases.

PV Cell Characteristics

• Regardless of size, a typical PV cell produces about 0.5-0.6 DC volt under an open-circuit, with no load condition.
• The current and power output of a PV cell depends upon the size (surface area) and efficiency and intensity of the light source striking the surface of the cell.
• For example, under peak sunlight conditions, a typical commercial PV cell with a surface area 0f 25 inch² and V = 0.5-0.6 V_DC will produce about 2 watts of peak power.
• If the sunlight intensity were 40% of the peak, this PV cell would produce about 0.8 watts.