The photovoltaic effect occurs when sunlight energizes electrons in a semiconductor material and causes them to flow through a circuit, creating electric current. The basic building block of the solar electric system is the photovoltaic (PV) cell. Traditionally the PV cell has been manufactured from pure single crystal or semicrystalline silicon. The silicon is processed to enhance the ability of the electrons to break free and flow. Strips of conductive metal alloys, such as copper, are deposited on the cell to act as a circuit. As the electrons are excited by the sun, the resulting current is collected by the circuit and transmitted through wires to a power conditioner or a battery.
PV cells are soldered together in series and parallel, encapsulated in thermoplastic and laminated between layers of glass and a backing material to form weather sealed “modules.” The edges are sealed into frames of aluminum or plastic. These frames add structural stiffness and a means to fasten them to mounting hardware. PV panels are typically fastened onto roofs of structures or on the top of poles or ground mount racks in the yard.