چكيده به لاتين
Dynamic Photovoltaic Integrated Shading Devices (DPVSD) in building facades plays an significant role in solar energy absorption and electrical energy generation by adjusting the sun-tracking angle. Earlier studies on these shading devices have sought to maximize the global irradiation on these panels addressing the severe influence of mutual shading of the dynamic photovoltaic panels on reducing output power. In the present study, the optimal relation between increasing the global irradiation on solar panels and eliminating mutual shading of the solar panels was evaluated based on the rotation angle of the solar panels in order to maximize the output power. This method led to the formation of Shade-less Dynamic Photovoltaic Shading (SDPS). For this purpose, a geometric model of dynamic photovoltaic shading was first presented. Then, based on global horizontal irradiation and the partial shading effect, the generated electrical energy and efficiency of the DPVSD in the proposed model of this study, i.e. “Shade-less Sun-tracking Model” (SSM) were simulated and compared with the conventional sun-tracking model at different time intervals (a given time instant, daily, monthly and annually) by using a computer. Finally, the effect of the distance between modules on their performance was evaluated in summer solstice and autumnal equinox as two important days of the year. Simulations were conducted in Hamadan (34/°85 N, 48/°53 E), Iran, by using the climatic data of this city. The results indicated that the annual output power and the average annual efficiency of dynamic photovoltaic shading increased by 51.56% and 32.26%, respectively, in the SSM compared to the traditional vertical perpendicular sun-tracking model. However, the overall solar radiation on the solar panels was 10.24% higher in the vertical perpendicular sun-tracking model. Furthermore, unlike the high global radiation in the warm months of year, the generated power and efficiency of the SSM were higher in cold seasons. The façade cover ratio played a significant role on the performance of dynamic photovoltaic shading. The maximum energy was generated by a SSM with a Facade Cover Ratio (FCR) of one. Further, in the SSM, the output power and efficiency of each solar module increased by reducing the FCR in the summer solstice and autumnal equinox days. However, the output power of the SDPS based on SSM decreased due to faster reduction in the number and area of the modules.
