太阳能光伏发电的基本原理是利用太阳电池的光生伏打效应直接把太阳的辐射能转变为电能的一种发电方式，太阳能光伏发电的能量转换器就是太阳电池，也叫光伏电池。当太阳光照射到由P、N型两种不同导电类型的同质半导体材料构成的太阳电池上时，其中一部分光线被反射，一部分光线被吸收，还有一部分光线透过电池片。被吸收的光能激发被束缚的高能级状态下的电子，产生电子-空穴对，在PN结的内建电场作用下，电子、空穴相互运动，N区的空穴向P区运动，P区的电子向N区运动，使太阳电池的受光面有大量负电荷（电子）积累，而在电池的背光面有大量正电荷（空穴）积累。若在电池两端接上负载，负载上就有电流通过，当光线一直照射时，负载上将源源不断地有电流通过。

 

图：太阳能光伏电池发电原理

 

 

l 单片太阳电池就是一个薄片状的半导体PN结，标准光照条件下，额定输出电压为0.48~0.55V。为了获得较高的输出电压和较大的功率容量，在实际应用中往往要把多篇太阳电池连接在一起构成的电池组件，或者用更多的电池组件构成光伏方阵。太阳电池的输出功率是随机的，不同的，不同时间、不同地点、不同安装方式下，同一块太阳电池的输出功率也是不同的

The basic principle of solar photovoltaic power generation is to use the photovoltaic effect of solar cells to directly convert the solar radiation into electric energy. The energy converter of solar photovoltaic power generation is solar cells, also known as photovoltaic cells. When sunlight hits a solar cell made of a homogeneous semiconductor material of two different types of conductivity, P and N, some of it is reflected, some is absorbed, and some passes through the cell. The absorbed light energy excizes electrons in the bound state of high energy level, generating electron-hole pairs. Under the action of the built electric field of PN junction, electrons and holes move with each other, and the holes in N-zone move to P-zone, and the electrons in P-zone move to N-zone, resulting in the accumulation of a large number of negative charges (electrons) on the receiving side of the solar cell, and a large number of positive charges (holes) on the backlit side of the battery. If a load is connected to both ends of the battery, a current will flow through the load. When the light is shining, the load will continuously have a current flow through the load.

Figure: Solar photovoltaic cell power generation principle

The picture

A single solar cell is a thin sheet of semiconductor PN junction with a rated output voltage of 0.48~0.55V under standard lighting conditions. In order to obtain higher output voltage and larger power capacity, in practical applications, it is often necessary to connect multiple solar cells together to form a battery module, or use more battery modules to form a photovoltaic array. The output power of solar cells is random and different. The output power of the same solar cell is also different at different times, places and installation methods