Photovoltaics (PV), also called solar cells, are electronic devices that convert sunlight directly into electricity. The modern solar cell is likely an image most people would recognize – they are in the panels installed on houses and in calculators. They were invented in 1954 at Bell Telephone Laboratories in the United States. Today, PV is one of the fastest-growing renewable energy technologies and is ready to play a major role in the future global electricity generation mix.