# Dynamic Thermal Rating and Development of Renewable Energy Zones in Sicily
## 1 Introduction
If we also consider the production of electricity from traditional sources, about 60% of the total energy is produced in eastern Sicily, and this is due to the greater presence of industrial poles in the eastern provinces compared to the western ones [2]. Energy demand also differs significantly between the western and eastern regions of the island. In the western region, the residential and service are the main energy consumers, while in the east, the industrial sector is the main energy consumer. This difference is mainly due to the higher level of industrialization in the Catania area and the larger population in Palermo [1]. So, the most energy-intensive provinces are Catania, Syracuse, and Palermo [3]. These considerations show that Sicily's electricity load is unevenly distributed, reflecting the imbalance in energy production; this is, therefore, the main peculiarity of the current Sicilian transmission network. In the light of the above, there are several challenges that will have to be met in the coming years [4; 5]:  
* Increasing congestion of the network due to uneven distribution of RES installations in relation to consumption;
* The progressive reduction of voltage regulation sources, which leads to significant variations in the voltage waveform after a disturbance in the network, thus reducing the degree of robustness of the network;
* The progressive reduction in regulation energy is driven by the replacement of traditional rotating mass generators with inverter-based systems. The increase in 'inverter-based' generation results in a reduced inertial response of the electrical system, thereby reducing frequency stability during abrupt load changes. In the past, this response was provided by synchronous generators and their mechanically coupled turbines using stored kinetic energy; moreover, the electronics of inverters provide a short-circuit current much lower than that of large thermoelectric power plants, which affects the correct intervention of protections and automatisms, both in terms of timeliness and selectivity;
* The management of extreme weather events, which are responsible for interruptions and reductions in the electricity transmission service. In order to solve these critical problems in the grid, numerous interventions have already been launched and approved in the Development Plan [1; 6]. For example, the Tyrrhenian Link will improve electricity connections between Sicily, Sardinia, and the rest of the peninsula. The TUN-ITA link will create a very important electricity connection between Africa and Europe. These interventions will not only solve the current critical problems of the electricity system but will also be essential to prepare the region for the development scenarios expected in the coming years. This development path is in line with the Fit-For-55 (FF55) scenario, a single policy scenario to 2030, which aims to achieve the European targets of a 55% reduction in emissions thanks to a push towards electrification and a significant increase in renewable energy sources [7]. The significant development of the energy infrastructure and electricity transmission infrastructure will allow the integration of the planned new RES plants. From 2018 to 2022, the requests for the connection of RES plants to the grid in Sicily have increased exponentially, and the expected future scenarios indicate a further increase in requests for the connection of RES plants [4]. In the case of Sicily, a study carried out by the University of Palermo, in collaboration with Terna S.p.A. (Rome, Italy), indicates that by 2030, the power lines and transformers currently installed will be overloaded by more than 70% of their capacity on average, given the rapid increase in new connection requests. The upgrading of the network to 400 kV must also be accompanied by targeted local interventions that would have a major impact on relieving congestion [5].