Basic Principles of Photovoltaic Power Generation

Photovoltaic power generation uses the photovoltaic effect of a solar cell (a semiconductor device similar to a crystal diode) to directly convert the sun's radiant energy into electrical energy.

The basic characteristics of solar cells are similar to those of diodes, which can be explained by a simple PN junction. When photons with energy are injected into the semiconductor, the light interacts with the materials that make up the semiconductor to generate electrons and holes (positively charged charges due to the loss of electrons). If there is a PN junction in the semiconductor, the electrons diffuse to the N-type semiconductor. The holes diffuse to the P-type semiconductor and gather in the two electrode parts respectively. If both ends of the solar cell are connected to a load, the load will have current flowing through it.
A single solar cell is a thin semiconductor PN junction. Under standard light conditions, the rated output voltage is about 0.5V. In order to obtain a higher output voltage and a larger output power, multiple solar cells need to be connected in series and parallel used in conjunction with each other.

The output power of solar cells presents random characteristics with different light intensities, and the output power of the same solar cell is also different at different times, different locations, and different installation methods.

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