What is photovoltaic?
Photovoltaic (abbreviated PV) is the physical effect by which sunlight is converted directly into direct-current electricity inside a semiconductor. The term combines the Greek “photo” (light) with the unit “volt.” In construction it refers to solar panels and related installations that generate electricity, as opposed to thermal solar collectors, which produce heat.
How a solar cell works
A photovoltaic cell typically consists of two differently doped layers of silicon. When photons from sunlight strike the cell, electrons are released and a voltage difference appears. Connecting the cells with conductors produces usable direct current.
- Sunlight strikes the semiconductor solar cell.
- Direct current (DC) is generated.
- The inverter converts DC into alternating current (AC).
- Power is supplied to the building or fed back to the grid.
Application in construction
PV panels are most often mounted on the roof, but they can also be integrated into the building envelope. This is known as building-integrated photovoltaics (BIPV), where panels replace roof tiles, facade cladding or glazing. A roof fully covered with cells is called a solar roof. Photovoltaic systems are a key element of renewable energy and help achieve net-zero-energy buildings.
Related terms
- PV panel
- Inverter
- Solar roof
- Building-integrated photovoltaics (BIPV)
- Net-zero-energy building
- Solar thermal collector
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