# M-Shape PV Arrangement for Improving Solar Power Generation Efficiency
## 7 Results  
Figures 10 and 11 show the simulation results of the S-shape and M-shape panel setting, respectively. The optimal tilt and azimuth angle for each region was obtained. The azimuth angle should be 0, but the actual data are affected by weather and geographical location, which also affects the simulation results. It can be observed from Figure 10 that the amount of solar radiation received on both sides of the east and the west is symmetrical about the azimuth 0 direction. To show the result accurately, Table 9 has shown the result of NEDO [22] and this paper's simulation result based on the optimal tilt angle in several areas provided by NEDO. Tables 10 and 11 display the optimal tilt azimuth angle of two types of PV array, respectively. The results of the M-shape show that the optimal tilt angle is close to 0. This means that when we make two pieces of PV panels as a group, the optimal tilt angle will let the PV array almost be at surface level. It is easy for the PV array to accumulate dust rain and snow in an actual situation, and it can also be easily destroyed in harsh environments. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Number of panels** & 40 & 50 & 60 & 70 & 80 & 90 & 100 \\
**Overloaded rate** & 100\% & 125\% & 150\% & 175\% & 200\% & 225\% & 250\% \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Overloaded rate of panels. \begin{table}
\begin{tabular}{c c} \hline \hline
**Electricity price** & 21 [Yen/kWh] \\
**Panel Price** & 70,000 [Yen/piece] \\
**PCS** & 210,000 [Yen] \\
**Land Price** & 5000 [Yen/m\({}^{2}\)] \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Reference price. Figure 9: Flowchart for determining the optimum tilt angle and azimuth. Figure 11: 3D solar radiation simulation result of six locations for the M-shape. Figure 10: 3D solar radiation simulation result of six locations for the S-shape. Based on different optimal tilt angles and calculation methods, there are variations in results, especially in the case of Kagoshima. However, NEDO's calculation approach considered a large area, and the optimal tilt angle is based on approximation; hence, the results obtained in this study are reliable. Hong Kong's optimal tilt angle was determined to be the same as that of Bangkok. This is because they are both closer to the equator, and hence, the optimal tilt angle will be close to the local latitude. Table 12 shows the four directions of the M-shape, which are north-south (0,180\({}^{\circ}\)), northeast-southwest (45\({}^{\circ}\),\(-\)135\({}^{\circ}\)), southeast-northwest (135\({}^{\circ}\),\(-\)45\({}^{\circ}\)) and east-west (90\({}^{\circ}\),\(-\)90\({}^{\circ}\)) respectively. The overload rate is set at 200% and 250%. Additionally, the optimal azimuth angle of each direction is also calculated in this step. The tilt angle of Darkhan and Shenyang is 25\({}^{\circ}\), Jeju and Naha is 20\({}^{\circ}\), Hongkong and Bankok is 15\({}^{\circ}\). The results for west-east and optimal-azimuth are almost the same when compared. Figure 12 shows the two types of daily power generation characteristics throughout one year, which are under the number of the same panels (80) and in six different latitude regions. It can be seen that at mid-latitudes (Darkhan, Shenyang, Jeju), the overall graphic shape is similar to the situation described in Figure 1. It is well explained here that the M-shape can effectively reduce the overload rate when the solar radiation is strong at solar noon and increases power generation in the morning and at nightfall. This indicates that the M-shape can increase the amount of power generation while controlling the overload rate. At lower latitudes (Naha, Hongkong, Bangkok), the graphic features of the M-shape and S-shape will be closer. It can be seen that the M-shape does not have an impact on the traditionally designed power generation but shows a good advantage in terms of area savings.