Study on the effects of tilted angle for power generation of PV modules based on Pareto chart

Studying the tilted angle is useful for photovoltaic (PV) module to obtain the maximum amount of solar radiation and high power output. According to the one year observational data of four PV modules with different tilted angle in Beijing, Pareto diagram is utilized to analyze the effects of tilted angle on power generation in this paper. The inclined radiation can be calculated with the horizontal radiation through sky anisotropic model. By creating the Pareto diagram and curve graph between different tilted angle, the daily changes, monthly changes, seasonal changes and yearly changes of power generation can be analyzed, the best tilted angle is recommended in a certain time period. The result showed that, the actual optimal tilted angle is approximately consistent with the theoretical optimal tilted angle. The power output of PV module with 14.5 degrees tilted angle are better than others in spring and summer; the power generation of PV module with 65 degrees tilted angle are better than others in autumn and winter. Decreasing tilted angle in spring and summer and increasing it in autumn and winter can improve the power generating efficiency. The annual analysis showed that 14.5 degrees is the optimal tilted angle if the fixed PV array is only admitted.