Solar power generation methods There are two solar power generation methods: one is the light-heat-electricity conversion method and the other is the direct light-electricity conversion method.
(1) The light-heat-dynamic-electricity conversion method generates electricity using thermal energy generated by solar radiation. Generally, a solar collector converts the absorbed thermal energy into steam as the working fluid and then. trains him. Steam turbines produce electricity. The first process is a process of converting light into heat; the second process is a conversion of moving heat into electricity and the final conversion process, which is the same as ordinary thermal power generation. The disadvantages of solar thermal power generation are as follows. that the yield is very low and the cost is very high. It is estimated that its ininvestment is at least 5 to 10 times more expensive than ordinary thermal power plants.
(2) Direct light-to-electricity conversion method This method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device for converting light into electricity is the solar cell. A solar cell is a device that directly converts solar energy into electrical energy through the photovoltaic effect. When the sun shines on the photodiode, the photodiode converts light energy from the sun into electrical energy, producing current. When many batteries are connected in series or parallel, a solar cell array with relatively large output power can be formed. Solar cells are a promising new energy source with three major advantages: Solar cells have a long lifespan and can bebe invested once and used for a long time as long as the sun exists in relation to the production of thermal energy. the cells do not cause environmental pollution.
Principle, photovoltaic effect: assuming that light shines on the solar cell and light is admitted at the interface layer, photons with sufficient energy can remove electrons from the bonds covalents in P-type silicon and N-type silicon. excited, resulting in the generation of electron-hole pairs. The electrons and holes adjacent to the interface layer will be separated from each other by the result of the space charge electric field before recombination. The electrons move towards the positively charged N region and the holes move towards the negatively charged P region. Through the charge separation of the interface layer, an outward testable voltage will be generated between the regulatorion P and the N region. At this point, electrodes can be added to both sides of the silicon wafer and connected to a voltmeter. For crystalline silicon solar cells, the typical value of open circuit voltage is 0.5 to 0.6 V. The more electron-hole pairs generated by light illuminating the interface layer, the lower the current is high. The more light energy the interface layer absorbs, the larger the surface area of the interface layer, i.e. the battery, and the greater the current formed in the solar cell.