Models For Electric Power And Efficiency Of Solar Hybrid Generator System

With the background of serious pollution and energy crisis today, the solar energy, as a novel green and renewable energy, which is abundant, economic and non-pollution, attracts lots of attentions, and the application of the solar thermoelectric and photovoltaic energy technology has been the focus which people attend to. The survey, development and application foreground of solar thermoelectric and photovoltaic energy technology are given and the study of solar hybrid generator system are presented, the thermoelectric generator, the photoelectric generator and the solar hybrid generator system are also studied in this paper.The thermoelectric model and the light-thermoelectric coupling model are established and analyzed according to the theory of thermodynamics. The results show that, the output power and the efficiency increase with the increase of the contact layer's thermal conductance, they also increase with the decrease of the generator's thermal conductance, and the impact of the generator's thermal conductance is far greater than than of the contact layer. When the low temperature is fixed, the output power increases with the increase of the focus ratio, the efficiency increases first and decreases later. If the focus ratio is very large, the impact caused by the thermal radiation is greater than than of the natural convection. In addition, the emissivity and absorptivity of the thermal collector have a great impact on the output power and the efficiency, and the absorptivity's impact is greater than the emissivity's.The photoelectric model and the photoelectric-heat coupling model are established and analyzed according to the theory of semiconductor and thermodynamics. The results show that, temperature has a great impact on the photovoltaic cells' output power and efficiency. When the focus ratio is less than 50, the temperature can be reduced by using cooling plate, when the focus ratio is more than 50, other measures such as cooling water must be adopted.Finally, the model of solar hybrid generator system is established and analyzed. The results show that, with the increase of the wavelength where the sunlight is separated, the output power of the thermoelectric subsystem decreases, but the efficiency decreases after the first increasing. The output power and efficiency of the photoelectric subsystem increase, and reach the maximum at the cutoff wavelength, so does the hybrid generator system. Thus, the optimal value of wavelength where the sunlight is separated, is at the cutoff wavelength of the photovoltaic cells.In this paper, the solar hybrid generator system is analysed and optimized, the results will have an important reference to design.