# Dynamic Thermal Rating and Development of Renewable Energy Zones in Sicily
## 7 Discussion and Conclusions  
Following the research carried out for this study, it is evident that the development prospects of the Sicilian transmission grid are both challenging and critical for the national and international electricity system. Structural interventions such as the Tyrrhenian Link, connecting Sicily, Sardinia, and Campania, and the TUN-ITA electrical channel, connecting Europe and Africa, are expected [1,4]. The integration of renewable energy sources is a fundamental aspect of the growth and development of the transmission network. In line with the Fit-for-55 development plan, the number of renewable energy plants connected to the grid is expected to increase significantly in the coming years. For this reason, the proper management of the identified Renewable Energy Zones (REZs) and the potential development of new ones will optimize energy dispatch and transmission [1,4]. This study identified six Renewable Energy Zones, some of which are already operational (A, B, C, D) while others are planned for the coming years (E, F). The application of \"Dynamic Thermal Rating\" (DTR) technology will improve the operation of the transmission system and the management of energy flows from renewable energy sources within the REZs. Current DTR technologies are effective, but they still have potential for enhancement. The results demonstrate that the potential of DTR is not uniform across the various zones of Sicily. The effectiveness of these devices increases with higher wind speeds hitting the conductor. It is, therefore, more cost-effective to install DTRs on lines in windier provinces such as Trapani, Syracuse, and Ragusa. Conversely, in less windy areas (e.g., Enna and Messina), the installation of DTRs may not be economically advantageous due to a marginal increase in the line's capacity, making the investment less worthwhile. Critical hot spots in these areas could make the use of DTR less safe. In such cases, reconductoring the line is recommended. In all the locations studied, it was possible to simulate a significant increase in current carrying capacity without reaching the annealing conditions of the conductor and while respecting the current limits imposed by network elements (such as current and voltage transformers). Furthermore, as the analyses have been carried out in the hot spots of each Renewable Energy Zone (REZ), installing a few DTR devices in these municipalities should ensure an overall increase in the allowable power flows on all lines within each REZ. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Transmission Line** & **Average Ampacity DTR Terna [A]** & **Proposed Average Ampacity [A]** \\ \hline
220 kV line & 1370 & 1371 \\
150 kV line & 785 & 886 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison of Dynamic Thermal Rating results. In particular, if each REZ is properly identified and managed, it should be possible to minimize dispatching actions within the zone. Currently, network congestion caused by a high level of renewable energy production is resolved by uniformly distributing wind production cuts evenly across Sicily. This approach reduces renewable energy production in areas not affected by congestion, resulting in untargeted interventions that do not minimize the overall production reduction. As observed, the targeted use of DTR within each REZ effectively reduces network congestion. An economic assessment was also carried out, confirming the financial viability of DTR devices. In conclusion, a comparison between the DTR simulations and the results of devices currently installed at the same sites demonstrated the validity of the analyses performed. It is important to emphasize one key point: the sensitivity analyses carried out in this study refer to a scenario of high renewable energy production (April 19, 2024). While this scenario is significant, it is not representative of all possible operating conditions.