PVs

PVs most often refers to photovoltaic systems and technologies that convert sunlight into electricity. Photovoltaics use semiconductor devices known as PV cells, typically made of silicon, to generate electric current when exposed to light.

A PV cell relies on the photovoltaic effect: photons create electron-hole pairs that are driven by an internal electric field at a PN junction, producing direct current that can be used or converted. The cells are assembled into modules and then arrays to provide usable power for homes, buildings, or the grid.

History shows the concept dates to the 19th century, with practical silicon solar cells developed in the 1950s and commercial deployment expanding in the 1970s, aided by space programs and growing demand for renewable energy. Since then, PV technology has evolved rapidly, improving efficiency and reducing cost.

Typical PV technologies include crystalline silicon (monocrystalline and polycrystalline) and thin films such as amorphous silicon, cadmium telluride (CdTe), and copper indium gallium selenide (CIGS). Module efficiency, manufacturing quality, temperature, shading, and orientation influence performance and energy output.

PV installations range from utility-scale farms to rooftop systems and building-integrated photovoltaics (BIPV); floating and agrivoltaic configurations are also used. Balance-of-system components include inverters to convert DC to AC, mounting structures, wiring, combiner boxes, monitoring equipment, and sometimes energy storage.

Performance is described by efficiency, capacity factor, and the performance ratio; economics are often summarized by levelized cost of energy (LCOE) and metrics such as payback period. Environmental considerations cover lifecycle emissions, land and water use, material recycling, and end-of-life disposal.

Global PV capacity has grown rapidly, with major contributions from China, the United States, the European Union, and other regions, reflecting its role in decarbonization and flexible distributed energy resources.