PV Cells and Modules

The PV or solar cell converts the sunlight to electricity and is made from semiconductor material, chosen for its ability to absorb sunlight. There are several materials that can be used, including silicon (the most widely used) and compounds such as cadmium telluride and copper indium diselenide. There are also some new cell designs that use organic and polymer materials.

The device usually consists of two layers of semiconductor material into which different impurities have been introduced. At the interface between the layers, an electric field is produced. When light is absorbed in the cell, energy is provided to electrons that can then move within the cell and the electric field forces them to move in a particular direction. We can then collect the electrons and pass them through an electrical load, i.e. the cell is providing electricity.

Most of the modules available today use crystalline silicon technology, either in single crystal or multicrystalline form. There are three basic module types:

Standard opaque design using a glass front and a rigid plastic backing sheet – suitable for a wide range of purposes
Roof tile – incorporating the cells into a tile that can be used as an integral part of the roof
Glass/glass modules – these provide a semi-transparent module which is used in architectural applications for glazing areas and roofs
 
PV-NE members include both manufacturers and suppliers of PV modules. Romag produce both architectural modules (glass/glass) and roof tiles, whilst BP Solar and Winsund supply both standard and specialist modules.