Photovoltaic, or PV for short, is a technology that converts light directly into electricity. Photovoltaic is also the field of study relating to this technology and there are many research institutes devoted to work on photovoltaic. Due to the growing need for solar energy, the manufacture of solar cells and solar photovoltaic array has expanded dramatically in recent years. Photovoltaic production has been doubling every two years, increasing by an average of 58 percent each year since 2002, making it the world’s fastest-growing energy technology. At the end of 2009, the total global installed capacity was more than 22 GW worldwide. Financial incentives, such as preferential feed-in tariffs for solar-generated electricity and net metering, have supported solar PV installations in many countries including Germany, Japan, and the United States.