# Dynamic Thermal Rating and Development of Renewable Energy Zones in Sicily
## 4 Methodology
### Identification of Renewable Energy Zones
\begin{table}
\begin{tabular}{c c c c c} \hline
**Overloaded** & **Simulation of a** & **Nominal** & **Current Capacity** & **Increase** \\
**Power Line** & **Contingency** & **Current [A]** & **after the Contingency [A]** & **Compared to the Nominal** \\  & & & & **Current** \\ \hline Line 1 & Contingency 1 & 740 & 1469 & +99\% \\ Line 2 & Contingency 2 & 536 & 725 & +35\% \\ Line 3 & Contingency 1 & 740 & 896 & +21\% \\ Line 4 & Contingency 2 & 480 & 750 & +56\% \\ Line 5 & Contingency 2 & 740 & 1216 & +54\% \\ Line 6 & Contingency 3 & 740 & 1138 & +54\% \\ Line 7 & Contingency 3 & 740 & 1143 & +64\% \\ Line 8 & Contingency 1 & 758 & 1217 & +61\% \\ Line 9 & Contingency 4 & 758 & 1220 & +47\% \\ Line 10 & Contingency 4 & 758 & 1116 & +41\% \\ Line 11 & Contingency 5 & 758 & 1065 & +61\% \\ Line 12 & Contingency 6 & 480 & 1219 & +35\% \\ Line 13 & Contingency 7 & 758 & 650 & +54\% \\ \hline \end{tabular}
\end{table} 
Table 1: Most overloaded power lines. Subsequently, the close correlation between overloads occurring within each REZ was highlighted. Almost always, the lines of a REZ suffer equally from the occurrence of a contingency on the transmission network. See Tables 2 and 3 as examples. This condition suggests that the effective placement of a few DTR devices in the same REZ could allow the reduction of overloads in all neighboring power lines. This is possible because if DTRs are installed on the critical spans of the most vulnerable lines, the increase in current capacity on these lines should ensure, in cascade, an increase in current capacity \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Effect of Contingency 2 on REZ A**} \\ \hline \multirow{3}{*}{**Overloaded Power Line**} & \multicolumn{3}{c}{**Current Capacity Required After the Contingency [A]**} & \multirow{3}{*}{
\begin{tabular}{c} **Increase Compared to the Nominal Current** \\ \end{tabular} } \\  & & & \\ \cline{3-3}  & & & \\ \cline{3-3}  & & & \\ \cline{3-3}  & & & \\ \hline Line 1-A & 480 & 750 & +56.25\% \\ Line 2-A & 536 & 725 & +35.26\% \\ Line 3-A & 740 & 1216 & +64.32\% \\ Line 4-A & 740 & 942 & +27.30\% \\ Line 5-A & 740 & 1458 & +97.03\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Effect of contingency 2 on REZ A. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Effect of Contingency 2 on REZ B**} \\ \hline \multirow{3}{*}{**Overloaded Power Line**} & \multicolumn{3}{c}{**Current Capacity Required After the Contingency [A]**} & \multirow{3}{*}{
\begin{tabular}{c} **Increase Compared to the Nominal Current** \\ \end{tabular} } \\  & & & \\ \cline{3-3}  & & & \\ \cline{3-3}  & & & \\ \hline Line 1-B & 740 & 1183 & +59.86\% \\ Line 2-B & 740 & 1189 & +60.68\% \\ Line 3-B & 740 & 1206 & +62.97\% \\ Line 4-B & 740 & 1216 & +64.32\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Effect of contingency 2 on REZ B.  
Figure 2: Renewable Energy Zones in Sicily, Italy [15]. on neighboring lines as well. The reason for this is that these lines certainly experience a lower overload and are in a better heat exchange condition than the critical spans of the most overloaded lines. In this step, the most overloaded lines were identified. The next step was to identify the lines that represent hot spots from the point of view of heat exchange. The lines on which the DTRs are to be installed must therefore be among the most vulnerable from both the electrical and thermal points of view.