The energy yield of PV system with different material, declination angle and land covering ratio are presented. Comparisons are made between two Chinese cities, Beijing and Nanjing. Shading effects are also investigated for the PV systems energy yield calculation. It shows that by neglecting the losses due to weather and the temperature effects, for the location with higher latitude (such as Beijing) the PV system installed with double junction solar cells (micromorph silicon) is predicted to have lower Performance Ratio than that with mono-crystalline silicon and multi-crystalline silicon. An optimum row spacing of a PV system should be considered for limited occupation area. The criteria above are important for large scale PV system design and its efficiency maximization. The simulation is useful to predict the power fluctuation delivered by PV system due to the spectral, seasonal variation and geometry difference.