A solar panel is a device that converts solar radiation directly or indirectly into electrical energy through the photoelectric effect or photochemical effect by absorbing sunlight. The main material of most solar panels is "silicon". The photons are absorbed by the silicon material; the energy of the photons is transferred to the silicon atoms, which makes the electrons transition and become free electrons that accumulate on both sides of the PN junction to form a potential difference. When the external circuit is turned on, under the action of this voltage, the There will be current flowing through the external circuit to generate a certain output power. The essence of this process is: the process of converting photon energy into electrical energy.
Solar Panel Power Calculation
The solar AC power generation system is composed of solar panels, charge controllers, inverters and batteries; the solar DC power generation system does not include the inverter. In order to enable the solar power generation system to provide sufficient power for the load, it is necessary to reasonably select each component according to the power of the electrical appliance. Take 100W output power and use it for 6 hours a day as an example to introduce the calculation method:
1. First, calculate the watt-hour consumption per day (including the loss of the inverter): if the conversion efficiency of the inverter is 90%, then when the output power is 100W, the actual output power should be 100W/90 %=111W; if it is used for 5 hours a day, the output power is 111W*5 hours=555Wh.
2. Calculate the solar panel: According to the daily effective sunshine time of 6 hours, and considering the charging efficiency and the loss during the charging process, the output power of the solar panel should be 555Wh/6h/70%=130W. Among them, 70% is the actual power used by the solar panel during the charging process.
Solar panel power generation efficiency
The photoelectric conversion efficiency of monocrystalline silicon solar energy is up to 24%, which is the highest photoelectric conversion efficiency among all types of solar cells. But monocrystalline silicon solar cells are so expensive to make that they are not yet widely and universally used in large numbers. Polycrystalline silicon solar cells are cheaper than monocrystalline silicon solar cells in terms of production cost, but the photoelectric conversion efficiency of polycrystalline silicon solar cells is much lower. In addition, the service life of polycrystalline silicon solar cells is also shorter than that of monocrystalline silicon solar cells. . Therefore, in terms of cost performance, monocrystalline silicon solar cells are slightly better.
Researchers have found that some compound semiconductor materials are suitable for solar photoelectric conversion films. For example, CdS, CdTe; III-V compound semiconductors: GaAs, AIPInP, etc.; thin film solar cells made of these semiconductors show good photoelectric conversion efficiency. Semiconductor materials with multiple gradient energy band gaps can expand the spectral range of solar energy absorption, thereby improving the photoelectric conversion efficiency. So that a large number of practical applications of thin-film solar cells show broad prospects. Among these multi-component semiconductor materials, Cu(In,Ga)Se2 is an excellent solar light absorbing material. Based on it, thin-film solar cells with significantly higher photoelectric conversion efficiency than silicon can be designed, and the photoelectric conversion rate that can be achieved is 18%.
Lifespan of solar panels
The service life of solar panels is determined by the materials of cells, tempered glass, EVA, TPT, etc. Generally, the service life of panels made by manufacturers who use better materials can reach 25 years, but with the impact of the environment, solar cells The material of the board will age over time. Under normal circumstances, the power will be attenuated by 30% after 20 years of use, and by 70% after 25 years of use.
Post time: Dec-30-2022