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The Principle Of Solar Panel Roof Power Generation

Sunlight shines on the semiconductor p-n junction to form new hole-electron pairs. Under the action of the p-n junction electric field, holes flow from the n-zone to the p-zone, and electrons from the p-zone to the n-zone, and a current is formed after the circuit is turned on. This is the working principle of photovoltaic effect solar cells.

Solar power generation There are two methods of solar power generation, one is the light-heat-electric conversion method, and the other is the light-electric direct conversion method.

　　 (1) The light-heat-dynamic-electric conversion method uses solar radiation to generate electricity. Generally, a solar collector converts the absorbed heat into vapor of the working fluid, and then drives a steam turbine to generate electricity. The former process is the light-heat conversion process; the latter process is the final conversion process from heat-motion to electricity, which is the same as ordinary thermal power generation. The disadvantage of solar thermal power generation is its low efficiency and high cost. It is estimated that its investment is at least 5-10 times more expensive than ordinary thermal power plants.
 

　　 (2) Light-to-electricity direct conversion method This method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device of light-to-electricity conversion is solar cells. A solar cell is a device that directly converts sunlight energy into electrical energy due to the photovoltaic effect. It is a semiconductor photodiode. When the sun shines on the photodiode, the photodiode will turn the sun’s light energy into electrical energy, producing Current. When many batteries are connected in series or in parallel, a square array of solar cells with relatively large output power can be formed. Solar cells are a promising new type of power source with three major advantages: permanence, cleanliness and flexibility. Solar cells have a long lifespan. As long as the sun exists, solar cells can be invested once and used for a long time; compared with thermal power generation, solar cells will not cause environmental pollution.