## 6 Results and Discussion
### Comparison between Turaif and Wejh  
A mutual comparison was also performed to observe the commonalities and differences between the results for the two sites. As mentioned earlier, both sites have topographic and geographic differences, with the main ones being differences in terms of the height above sea level, and longitude and latitude. Figures 3-6 shows the plots for the 15 turbines for various attributes. Some interesting facts are observed from these figures. In Figure 3, the annual energy production for each turbine for the two sites is shown. It can be seen from this figure that the energy production of the turbines relative to each other is the same for both sites; the only difference is that the energy production for Turaif is shifted upwards. For example, Windtec FC 3000-130 shows the maximum production for Turaif among all turbines, while Acciona AW 70/1500 Class I shows the worst production. Other turbines show production in different ranges. The same observation can ve made for Wejh; Windtec FC 3000-130 is the best performer and Acciona AW 70/1500 Class I is the worst, with other turbines showing the same pattern as that of Turaif, but with lower production levels. Similar trends were observed with regard to percentage of zero power output and percentage of rated power output in Figures 4 and 5 respectively, where the relative trends between turbines have the same patterns for the two sites, but shifted by a certain scale. The results make sense since Turaif is at much higher altitude than Wejh, which results in more energy absorption by turbines by the former. However, the relative performances of different turbines are the same for both sites, which indicates that a turbine would exhibit the same level of relative performance when compared with the same turbine but at a different location. This further indicates that if the relative performances of turbines can be studied and analyzed for any given site, the same relative performances and behaviors may be predicted for any other site. These observations are further strengthened by the plots given in Figure 6 which show the relative closeness to an ideal solution for each turbine. Again, the trends pertaining to different turbines are generally similar for the two sites, except the up-shift trends for Turaif. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Turbine** & **HH** & **WS** & **ZP** & **RP** & **AEP** & \({\mathbf{d_{j}}}^{+}\) & \({\mathbf{d_{j}}}^{-}\) & \({\mathbf{R_{i}}}\) \\ \hline Acciona & 140 & 5.76 & 17.41 & 0.13 & 2,467,511 & 0.057 & 0.109 & 0.656 \\ Alstom & 140 & 5.76 & 0.10 & 0.04 & 5,265,803 & 0.057 & 0.123 & 0.681 \\ DeWind & 140 & 5.76 & 29.77 & 0.36 & 3,523,561 & 0.057 & 0.102 & 0.640 \\ Dongfang & 130 & 5.70 & 12.45 & 5.43 & 6,164,460 & 0.051 & 0.067 & 0.566 \\ Doosan & 140 & 5.76 & 12.20 & 0.60 & 4,468,187 & 0.057 & 0.099 & 0.632 \\ EnerconE2 & 140 & 5.76 & 2.22 & 0.74 & 3,858,955 & 0.057 & 0.098 & 0.630 \\ EnerconE4 & 140 & 5.76 & 7.88 & 0.02 & 3,848,353 & 0.057 & 0.145 & 0.717 * \\ Games & 140 & 5.76 & 7.51 & 0.13 & 4,805,785 & 0.057 & 0.106 & 0.649 \\ Hanjin & 140 & 5.76 & 12.23 & 0.61 & 4,427,608 & 0.057 & 0.098 & 0.632 \\ Leitwind & 140 & 5.76 & 7.86 & 0.35 & 2,602,009 & 0.057 & 0.101 & 0.637 \\ Nordex & 140 & 5.76 & 11.58 & 1.74 & 8,185,010 & 0.057 & 0.088 & 0.606 \\ Sinovel & 140 & 5.76 & 12.19 & 1.54 & 6,492,396 & 0.057 & 0.089 & 0.609 \\ Vestas110 & 140 & 5.76 & 12.2 & 1.69 & 5,703,519 & 0.057 & 0.088 & 0.606 \\ Vestas112 & 140 & 5.76 & 17.22 & 0.36 & 6,315,349 & 0.057 & 0.098 & 0.630 \\ Windtec & 130 & 5.70 & 14.95 & 3.52 & 7,959,208 & 0.052 & 0.072 & 0.581 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Best tradeoff for each turbine for Wejh. The best turbine among all is marked with an asterisk. Figure 4: Comparison of ZPO for different turbines for Turaif and Wejh. Figure 3: Comparison of annual energy production (AEP) for different turbines for Turaif and Wejh. Figure 5: Comparison of RPO for different turbines for Turaif and Wejh.