Experimental Study Of The Cooling Problem In Concentration Photovoltaic System

With the increasingly severe problems of energy crisis and environmental pollution, countries around the world pay high attention to development and utility of clean energy. Solar energy is the most widely distributed renewable energy sources. Under the support and guidance of national policy, photovoltaic industry develops rapidly. At present, power generating cost is the main factor of impeding development of photovoltaic. Concentrating photovoltaic technology is capable of concentrating sunlight into a small area of solar cell rendering the solar cell with high performance work under solar irradiation with high energy flux density. Compared with the expensive solar cell material, using low-cost concentration system can cut down the cost of power generation system starkly. Thus, this technology has bright development prospect. However, heat dissipation problem of solar cell with high concentrated ratio is a vital factor that makes an impact on solar cell’s efficiency and reliability of power generation system.Focusing on high heat production problem of solar cell, this thesis designs and set up a minitype concentrating photovoltaic system with thermoelectric power generation in back board in order to recycle the waste heat of solar cell and then deduces the mathematical expression of the system output power. The experiment and research are conducted outdoor finding that combined power generating system is able to satisfy the needs of heat dissipation of solar cell. Compared with natural cooling control groups, output voltage of solar cell in combined generation system which daily averagely increases by 0.16V amounting to averagely increase by 5.67% remains stable. With radiation intensity increased, both the short-circuit current of solar cell in combined power generating system and output power of module in thermoelectric power generating show an approximately liner increase. The maximum output power appears in decline range of radiation intensity curve. And the increase ratio under the high radiation intensity is smaller than that in low radiation intensity. The generation capacity of thermoelectric power generation accounts for low proportion in combined power generating system, In term of the quality of the energy, optimizing the effect of heat dissipation of solar cell should be prioritized in order to augmenting the generating efficiency of the whole system.By setting up a high magnification concentrating photovoltaic generating system and changing the type of cooling of three junction GaAs as well as testing the output characteristics of solar cell, we find that compared with using natural cooling, the short-circuit of solar cell slightly declines when using hydrocooling and the open-circuit voltage is increased and keeps a stable voltage output. The variation tendency of the open-circuit testing curve of solar cell using natural convection cooling heat dissipation has the negative correlation with variation tendency of radiation curve. With time variation, composed of their curvilinear figure shows narrow in middle and width in both sides. In addition, after using natural cooling heat dissipation, the fluctuation of open-circuit of solar cell becomes greater. By using high efficient cooling method, the threshold power of solar cell maybe decline, in contrast, the maximum output power will be increase. Compared with the natural convection cooling, using fin or hydrocooling has the better cooling performance. For those clients who require stable output voltage of solar cell, using hydrocooling can satisfy their heat dissipation need.