A typical PV system uses panels of solar cells, made from semi-conducting materials that react with sunlight to produce electricity. This electricity is then transferred into the property to power appliances and provides lighting, or if surplus to requirements, is sold to the local electricity network.

The Solar Cell
Solar cells are the power units of every PV system.
A PV cell consists of two thin layers of semi-conducting materials, usually silicon , that have been treated with chemical substances. These chemicals react to sunlight when it shines on the cell, creating an electric field across the layers and producing electricity. The greater the intensity of sunlight, the greater the flow of electricity. This process is called the 'photovoltaic effect' and is explained in greater detail below.

1.  The cell is covered with a thin layer of anti-reflective coating (ARC) to minimize light reflection.

2.  The top semi-conducting layer, or 'n' type layer, is doped with tiny amounts of phosphorus so that almost every thousandth silicon atom is replaced by a phosphorus atom. This creates free moving negative charges called 'electrons'.

3.  The base semi-conducting layer, or 'p' type layer, is doped with miniscule amounts of boron sothat almost every millionth silicon atom is replaced by a boron atom. This creates free moving positive charges called 'holes'.

4.  When the 'n' and 'p' type layers are placed close together, as they are in a solar cell, the positively charged 'holes' and the negatively charged 'electrons' are attracted to each other. As they move into their respective neighboring layers they cross a boundary layer called the 'p-n junction'. This movement of negatively and positively charged particles generates a strong electrical field across the p-n junction. When sunlight strikes this field it causes the electron particles and the hole particles to separate, which in turn creates a voltage of around 0.5V.

5.  The voltage pushes the flow of electrons or 'DC current' to contacts at the front and back of the cell where it is conducted away along the wiring circuitry that connects the cells together.