The principle of photovoltaic power generation is based on the photovoltaic effect (photoelectric effect), that is, the effect that photons (sunlight) excite electrons in semiconductor materials, causing them to jump and generate electric current. Specifically, when sunlight shines on semiconductor materials, after absorbing a certain amount of energy, it will excite electrons in the material to leave atoms and become free electrons, and form an electric current inside the material. By connecting the circuit, the free electrons can flow in the circuit, thereby generating electric current and completing the conversion from solar energy to electrical energy.