The present study aims to determine the optimized shape for the maximum electric energy production of building integrated photovoltaic system (BIPV) noise barrier through numerical analysis. The shape of BIPV noise barrier is one of the important factors in determining angle difference between direction vector of the sun and normal vector of the sound barrier surface. This study simulated numerically the flow and thermal fields for different angles in the range from $90^{circ}$ to $180^{circ}$, and from the results, the amount of isolation onto noise barrier surface was estimated along the angle between ground and top side of noise barrier. The commercial CFD code (Fluent V. 13.0) was used for calculation. It was found that the maximum amount of insolation per unit area was 19.6 MJ for $105^{circ}$ case during a day in summer and was estimated 12.4 MJ in $150^{circ}$ case during a day in winter. The results of the summer and winter cases showed the different tendency and this result would be useful in determining the appropriate shape of noise barrier which can be mounted under various circumstances.