The solar energy absorbed by the Earth is ultimately converted into chemical energy stored in plants, energy radiated into space, etc.
The energy of the earth has not increased.
The sun brings energy to the earth every day in the form of radiation, causing an increase in the temperature of the radiated surface. But at night, heat will also be emitted into space in the form of radiation. The energy received during the day is equal to the energy radiated at night, so the earth will maintain a constant surface temperature.
Of course, strictly speaking, a very small part of the radiation is stored by plants on the surface in the form of photosynthesis. But this will not increase the energy of the earth, because after the plants die, the decomposition of organic matter and the consumption of the plants by animals will release the energy stored in the plants, and eventually dissipate it into the earth. universe underform of heat.
The energy conversion of solar cells converts what energy into what energy?
The law of conservation of energy is well known to us. According to the law, we know that energy can be converted into different forms and converted into each other. For example, a wind turbine can use the rotation of the wind to drive a propeller to convert wind energy into mechanical energy and finally into electrical energy. Solar panels installed in every home in rural areas now use the photovoltaic effect to convert light energy into electrical energy and store it. Electrical energy can also be converted into light energy using electric lamps.
There are two main forms of solar energy applications: photovoltaic and photothermal. Light energy can be converted into electrical energy, thermal energy and chemical energy. IsEssentially, light is absorbed by the medium via various channels, thus inducing the excited state of the medium. There are many forms of excited states in media, most of which are obtained by absorbing photons.
When “solar energy” comes into contact with molecules forming an excited state, the electrons in the molecular orbitals will be pushed into empty orbits. Because the molecular structure has changed, the molecule becomes a more powerful oxidizing and reducing agent than before. When this molecule is in an excited state and encounters a stronger oxidant or reducing agent, electron transfer occurs and the original shape of the molecule is completely changed. The product is an ionic free radical and the opposite charge of the foreign reactant. It is the process by which solar energy is converted into electrical energy.
The process of converting light energy into chemical energy: electronss cause the atomic nucleus to move, making it impossible for electrons to return to their original position, leading to changes in the state and composition of matter. This conversion process is different from the conversion process to electrical energy in that the electrons do not flow from the anode to the cathode, but remain directly in the "receiver".
Convert light energy into heat energy: The collision between photons transfers the kinetic energy they carry to the affected particle, increasing its energy, thereby reducing its own energy, then continues to strike d other particles. energy. Simply put, you throw a ball and give it some kinetic energy. When it hits other balls, the other balls move and the kinetic energy of the thrown ball is reduced.
Light energy is converted into electrical energy.
Solar cells are also called“Solar chips” or “photovoltaic cells”., is an optoelectronic semiconductor sheet that uses sunlight to directly produce electricity. As long as it is illuminated by light that meets certain lighting conditions, it can instantly produce voltage and generate current if there is a loop. In physics, it is called solar photovoltaic (photovoltaic, abbreviated PV), or photovoltaic for short.
Solar cells are devices that directly convert light energy into electrical energy by the photoelectric effect or photochemical effect. Crystalline silicon solar cells that work with the photoelectric effect are the most widespread, while thin-film cells that work with the photochemical effect are still in their infancy.
Detailed information:
1. Operating principle
The lightThe sun shines on the p-n junction of the semiconductor to form new hole-electron pairs. Under the action of the integrated electric field of the p-n junction, the photo-generated holes move towards the p region and the photo-generated electrons. circulate towards region n. Once the circuit is activated, a current is generated. This is how photovoltaic solar cells work.
2. Basic Characteristics
(1) Polarity of Solar Cells
Silicon solar cells are generally made of P+/N type or N+/P type structure. the structure, P+ and N+, represents the conductivity type of the semiconductor material of the lighting layer on the front of the solar cell; N and P, represent the conductivity type of the semiconductor material of the rear substrate of the solar cell; The electrical properties of solar cells are related to the properties of the semiconductor materials used to make them.cells.
(2) Solar cell performance parameters
Solar cell performance parameters include open circuit voltage, short circuit current, maximum output power, fill factor, conversion efficiency, etc. These parameters are a measure of the performance of solar cells.
(3) Voltage-ampere characteristics of solar cells
P-N junction solar cells include a shallow P-N junction formed on the surface, a band-shaped front ohmic contact and finger-shaped, and a Backside ohmic contact covering the entire rear surface and an anti-reflective layer on the front side.
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