Conventional PV: Primarily designed for power generation, installed as an add-on to buildings (rooftops, ground-mounted systems) without altering the original structure. It is a "retrofit" energy system. Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. These technologies are pivotal in reducing fossil fuel dependency, leading to cleaner energy alternatives. Definition emphasizes solar energy's. A photovoltaic system, also called a PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. A single PV device is known as a cell. An individual PV cell is usually small, typically producing about 1 or 2 watts of power.