|A 3 kW photovoltaic panel array| Photovoltaics (PV) is a method
of generating electrical power by converting solar radiation
into direct current electricity using semiconductors that
exhibit the photovoltaic effect. Photovoltaic power generation
employs solar panels comprising a number of cells containing a
photovoltaic material. Materials presently used for
photovoltaics include monocrystalline silicon, polycrystalline
silicon, amorphous silicon, cadmium telluride, and copper indium
selenide/sulfide. Due to the growing demand for renewable energy
sources, the manufacturing of solar cells and photovoltaic
arrays has advanced considerably in recent years. As of 2010,
solar photovoltaics generates electricity in more than 100
countries and, while yet comprising a tiny fraction of the 4.8
TW total global power-generating capacity from all sources, is
the fastest growing power-generation technology in the world.
Between 2004 and 2009, grid-connected PV capacity increased at
an annual average rate of 60 percent,