太阳光电系统，也称为光生伏特，简称光伏（Photovoltaics；字源“photo-”光，“voltaics”伏特），是指利用光伏半导体材料的光生伏打效应而将太阳能转化为直流电能的设施。光伏设施的核心是太阳能电池板。目前，用来发电的半导体材料主要有：单晶硅、多晶硅、非晶硅及碲化镉等。由于近年来各国都在积极推动可再生能源的应用，光伏产业的发展十分迅速。

截至2010年，太阳能光伏在全世界上百个国家投入使用。虽然其发电容量仍只占人类用电总量的很小一部分，不过，从2004年开始，接入电网的光伏发电量以年均60%的速度增长。到2009年，总发电容量已经达到21GW，是当前发展速度最快的能源。据估计，没有联入电网的光伏系统，目前的容量也约有3至4GW。

Photovoltaics (PV) is the name of a method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon commonly studied in physics, photochemistry and electrochemistry. A photovoltaic system employs solar panels composed of a number of solar cells to supply usable solar power. The process is both physical and chemical in nature, as the first step involves the photoelectric effect from which a second electrochemical process takes place involving crystallized atoms being ionized in a series, generating an electric current. Power generation from solar PV has long been seen as a clean sustainable energy technology which draws upon the planet’s most plentiful and widely distributed renewable energy source – the sun. The direct conversion of sunlight to electricity occurs without any moving parts or environmental emissions during operation. It is well proven, as photovoltaic systems have now been used for fifty years in specialized applications, and grid-connected PV systems have been in use for over twenty years. They were first mass-produced in the year 2000, when German environmentalists including Eurosolar succeeded in obtaining government support for the 100,000 roofs program.