• PV cell efficiency differs by the kind of semiconductor material and technology used.
• PV cells and modules make the greatest quantity of electricity when they face the sun directly.

A photovoltaic (PV) cell, or solar cell, is a nonmechanical device that changes sunlight into electricity. A handful of PV cells can turn artificial light into electricity.

PV cell efficiency differs by the kind of semiconductor material and technology used. The efficiency of commercially accessible PV modules averaged lower than 10 percent in the mid-1980s. It grew to about 15 percent by 2015. It is now nearing 20 percent for state-of-the art modules. Different kinds of experimental PV cells and ones for niche markets, for example space satellites, have an efficiency of almost 50 percent.

How photovoltaic systems operate

The PV cell is the starting point of a PV system. Individual cells can differ in size from roughly 0.5 inches to roughly 4 inches across. But one cell can only make 1 or 2 Watts, which is just enough electricity for minimal applications, such as powering calculators or watches.

PV cells are electrically bound in a weather-tight PV module or panel. PV modules differ in size and in the quantity of electricity they can make. The capacity of PV module electricity generating grows as the number of cells in the module or in the module surface area increases.

Photovoltaic cells produce a type of electricity called direct current (DC). This DC electricity can power up batteries that then charge devices that use direct current electricity. Almost all electricity is provided as alternating current (AC) in systems of electricity transmission and distribution. Devices named inverters are used to change DC electricity to AC electricity.

PV cells and modules make the greatest quantity of electricity when they face the sun directly. PV modules and arrays can utilize different tracking systems that turn the modules to always face the sun, but these are costly. The majority of PV systems have modules in a fixed position. The modules face directly south in the northern hemisphere and north in the southern hemisphere. They are put at an angle that maximizes system performance.