Concentrating solar cells are defined as the basic photovoltaic devices used under concentrating conditions. Concentrating solar cells are known for their advantages of high conversion efficiency and low cost. They are called the third generation solar cells and the forefront of exploration and research.
Concentrating technology is an effective measure to reduce the total utilization cost of solar cells. It makes a large area of sunlight converge in a small range through the concentrator, and places the solar cell on the spot or light band to increase the light intensity, overcome the defect of low solar radiation energy flow density, and obtain more electric energy output.
Characteristics of concentrated pv cell solar panel:
Generally speaking, solar cells can be divided into ordinary flat-panel photovoltaic solar cells and concentrating solar cells. The biggest difference between concentrating solar cells and ordinary flat panel photovoltaic solar cells is the different irradiance incident on the solar cells. The incident irradiance on ordinary flat panel photovoltaic solar cells is usually one sun (1x = 1000 W / m2), while the incident irradiance on concentrating solar cells is x sun (x > 1), so the current generated by concentrating solar cells per unit area is larger than that of ordinary flat panel photovoltaic solar cells.
In addition, the cost of concentrating solar cells only accounts for a small part of the total cost of concentrating photovoltaic system, so solar cells with advanced technology, higher efficiency and higher price can be used to improve the performance of the whole system. With the increase of solar incident energy flow density, the concentrating solar cell shows different electrical and thermal characteristics from the ordinary flat panel photovoltaic solar cell. In addition to RS, the parasitic resistance of the solar cell also includes the parallel resistance RSH, but the parasitic resistance of the solar cell caused by RSH under high power concentrating conditions η Losses are usually negligible. Another very important feature of concentrating solar cell is its thermal characteristics. With the increase of temperature, the ISC of the solar cell will rise slightly, while the VOC will decrease, resulting in battery failure η Reduction of. however η The decreasing range of will decrease with the increase of the condensing ratio, that is, the solar cell working under the condensing condition will decrease under the influence of temperature. With the increase of incident light intensity per unit area, the heat generated by the concentrating solar cell also increases in proportion, which increases the working temperature of the cell and reduces the efficiency of the cell. In order to ensure that the concentrating photovoltaic system can work under high efficiency, the system needs an effective heat dissipation device to cool the battery. In general, even without cooling device, the working temperature of flat panel photovoltaic is only about 20 ℃ higher than the ambient temperature.