A replicable methodology for testing the size and placement of Battery Energy Storage Systems connected to high-voltage transmission networks is presented in this study. The proposed approach involves the power flow analysis inside a Renewable Energy Zone, namely a high-renewable area prone to grid congestion during peak generation periods, based on time-series hourly analysis over a critical month. The model includes detailed operational descriptions such as lines ampacity, battery state of charge limits, round-trip efficiency, self-discharge behavior, and ramp rate restrictions. The methodology distinguishes itself by its simplicity, flexibility, and use of open-source tools, making it a valuable asset for supporting future transmission planning in high-renewable-energy scenarios. The model was developed in Python (version 3.12) using the open-source Pandapower library, introducing an innovative constraint management criterion, and validated against real data provided by the national Transmission System Operator. The approach was then applied to a portion of the Sicilian grid with massive wind and solar penetration. Results show that strategic allocation of batteries leads to a significant reduction in line overloads (up to 13 GWh mitigated in one month), improves the dispatch of renewable energy generated within the Renewable Energy Zone and allows a more sustainable exercise of the power system.

This paper presents a day-ahead optimal power dispatch framework for grid-connected AC/DC microgrids integrating Renewable Energy Sources (RESs) and Battery Energy Storage Systems (BESSs), aiming at power supply improvement in off-grid mode. The optimization minimizes energy imported from the main grid while maximizing the state of charge (SoC) of BESSs. Renewable power outputs were modeled for various scenarios related to external conditions using time series analysis of historical environmental data, such as wind speed, solar irradiation, and temperature. The energy management strategies were evaluated under these scenarios, including transitions to islanded mode triggered by grid faults. In grid-connected mode, a new adaptive SoC-based charging/discharging strategy is incorporated into the objective function. This strategy not only minimizes the total operation cost but also ensures that storage systems maintain sufficient energy to supply critical loads during islanded mode while reducing the frequency of switching between charging and discharging operation modes. In islanded operation, two reliability indices were introduced to measure resilience under different scenarios. In both on-grid and off-grid operation modes, a SoC balancing strategy is considered to prolong the lifespan of the BESSs. The application of the proposed model to three case studies under various energy scenarios is programmed and simulated in Python. The findings indicate that: (1) the SoC of storage systems may change depending on the season and energy scenario; (2) fast SoC balancing convergence is possible; and (3) the worst energy scenarios can sometimes lead to greater resilience, although they may also result in lower average reliability overall.

This paper investigates the impact of renewable energy source (RES) integration on the Sicilian transmission network, considering the commissioning of new Mediterranean interconnections, namely the TUN-ITA and the Tyrrhenian Link. The expansion of transmission infrastructures and the increasing penetration of RES require an assessment of the Sicilian power system's capability to accommodate high levels of power injection. This study was carried out in collaboration with the Italian transmission system operator Terna S.p.A. and the University of Palermo. It aims to evaluate the evolution of transmission line loading under future RES integration scenarios consistent with grid connection requests submitted to Terna and with national energy policy targets. The proposed methodology integrates micro-zonal assessments of wind and solar potential, estimation of capacity factors, development of RES capacity expansion scenarios, and steady-state power flow simulations. The simulations were performed using WinCreso (R) software version 7.69 for three time horizons: 2028, 2029, and 2035. The results show the most congested transmission lines and the network areas most exposed to congestion. The analysis provides operational insights for prioritizing grid reinforcement measures and proposes a replicable methodological framework for other transmission system operators facing similar RES integration challenges.

Modern power systems are characterized by massive and increasing presence of intermittent renewable energy plants. Therefore, it is necessary to improve the network through interventions that can enable safe, flexible and cost-effective network operation. For this reason, using a reliable and quick simulation tool able to assess different scenarios and compare alternatives is mandatory. The objective of this research work, carried out in collaboration with the Italian Transmission System Operator, Terna S.p.A., is to develop such a tool for simulating future developments of the power systems with installation of renewables and Battery Energy Storage Systems. The scope of the simulations was to reduce potential network congestion and system inefficiencies. The model was developed in Python programming language through the Pandapower library and was tested on a portion of the power system of Sicily, the largest island in the Mediterranean Sea. The results obtained demonstrate the potential benefits deriving from utility-scale batteries installed in high voltage grids with massive presence of renewables.

Sicily, an Italian region in the south of Italy, is a candidate for becoming an energy “hub” in the Mediterranean in the coming years. Its geographical location, between the African continent and Europe, makes it a key hub for the distribution of electricity flows. The region has great potential for the development of renewable energy sources. Inspired by the Australian “Renewable Energy Zones” model, the identification of existing Renewable Energy Zones (REZs) and the proper design of future REZs on the territory will simplify and improve the operation of the network. A very effective tool in managing REZs is Dynamic Thermal Rating (DTR) technology. This technology allows for dynamic rating of the high voltage transmission system, ensuring that the maximum allowable current is transported while preventing the annealing of the electrical conductor and complying with all necessary safety parameters. The objective of the work carried out in collaboration with Terna S.p.A. (Italian Transmission System Operator) was to evaluate the application of this technology on the Sicilian electricity network in order to reduce potential network congestion and system inefficiencies. The results obtained demonstrate the significant potential of Dynamic Thermal Rating in Sicily. These devices would allow a significant increase in the current flow of electrical lines without violating safety limits.

Hydrogen is a zero-emissions fuel that, if generated from renewable energy sources, can play a vital role in reducing carbon emissions across multiple sectors. Green hydrogen production plants are constrained by the availability of renewable sources and there is not a common sizing criterion to couple water electrolyzers with renewable technologies. This study aims at filling the research gap involving the preliminary sizing of water electrolyzers to be coupled with photovoltaic systems according to different objectives and final production targets. The problem was formulated and addressed using a MILP optimization algorithm in MATLAB and solved according to the minimum costs and minimum carbon emissions criteria. Additionally, the optimization algorithm was run on three different final demand scenarios: hydrogen production from stand-alone plant, production to meet hydrogen final demand, and production to meet hydrogen and electricity final demands. Results show that the optimal ratio is between about 1.8 and 2 in the cases with cost minimization, but it increases up to 5.75 when both costs and carbon emissions are taken into account.

The continued growth of nonprogrammable renewable energy sources, such as wind and photovoltaics, which is necessary in the energy transition process, is leading to the emergence of a number of issues for electric grid operators. Among these are reverse power flows, which consist of power going up from the distribution grid to the transmission grid at the time generation exceeds demand. In mitigating this phenomenon, power-to-gas plants can make an important contribution. In this paper, an optimization study is presented for the sizing of a power-to-hydrogen plant consisting of a PEM electrolyzer, a compressed hydrogen storage system, and a fuel cell for local hydrogen-to-power capabilities. The model was applied to the case study of an industrial medium-voltage distribution network in Malta, evaluating a scenario in which the currently installed photovoltaic capacity was doubled from the current 2 MWp to 4 MWp, according to existing expansion plans. The optimal results obtained allow for an 81.52% reduction in reverse power flows, while producing 4 tons of renewable hydrogen per year.

The increase in power generation facilities from nonprogrammable renewable sources is posing several challenges for the management of electrical systems, due to phenomena such as congestion and reverse power flows. In mitigating these phenomena, Power-to-Gas plants can make an important contribution. In this paper, a linear optimisation study is presented for the sizing of a Power-to-Hydrogen plant consisting of a PEM electrolyser, a hydrogen storage system composed of multiple compressed hydrogen tanks, and a fuel cell for the eventual reconversion of hydrogen to electricity. The plant was sized with the objective of minimising reverse power flows in a medium-voltage distribution network characterised by a high presence of photovoltaic systems, considering economic aspects such as investment costs and the revenue obtainable from the sale of hydrogen and excess energy generated by the photovoltaic systems. The study also assessed the impact that the electrolysis plant has on the power grid in terms of power losses. The results obtained showed that by installing a 737 kW electrolyser, the annual reverse power flows are reduced by 81.61%, while also reducing losses in the transformer and feeders supplying the ring network in question by 17.32% and 29.25%, respectively, on the day with the highest reverse power flows.

The wide-synchronization control is a novel wide-area control involving inverter-based resources as actuators. The concept is based on the determination of a remote frequency signal, which can be used within the control systems of the converters participating in the control. In this paper, the concept of the wide-synchronization control is investigated as solution to effectively improve the oscillatory stability of the system. The results indicate that the proposed concept is capable to provide a decisive contribution in preserving the system stability, even under severe critical conditions.

In the face of escalating global energy demands and the imperative to transition towards sustainable energy sources, the widespread diffusion of Renewable Energy Communities aims at sharing the energy, environmental and social benefits deriving from renewable energies. In this context, understanding and quantifying the uncertainties associated with renewable energy generation as well as the final demands becomes paramount. This paper delves into the main aspects of probabilistic modeling and uncertainty assessment in the context of multi-source Renewable Energy Communities, employing the Monte Carlo simulation method as a robust tool for comprehensive analysis. The results of the demonstrative case study show that the optimal size of the equipment among the several uncertain scenarios can be effectively identified using the mode of the results.

Institutions, companies, research centers and universities are paying special attention to green hydrogen, a key energy carrier for the decarbonization of various sectors because it is produced from renewable sources without producing emissions. Currently, however, the cost of producing it is high and does not make it competitive with that produced from fossil fuels. One way to cut costs could be to exploit the oxygen obtained as a by-product of water electrolysis, selling it instead of releasing it into the atmosphere as is usually done. In some studies, this idea has already been analyzed, but very often without considering the costs due to the additional components for treating the oxygen, which must be properly compressed and stored, or without directly showing how the LCOH (levelized cost of hydrogen) varies according to this choice, especially in an Italian context, limiting the study to an evaluation of the NPV. The paper analyzes plant configurations for the production of green hydrogen installed in southern Italy, in Sicily, in which a photovoltaic system powers an alkaline electrolyzer and two compressors: one for hydrogen and one for oxygen. The system is completed by the storage systems for the two gases. Levelized cost values for green hydrogen are calculated by considering the sale of oxygen either at prices found in the literature in similar studies, or at prices in the European Union for oxygen produced by air distillation, taking into account the operating and investment costs for the compressor and oxygen storage, and comparing the values obtained with the costs of green hydrogen without oxygen valorization.

This paper presents an assessment of the levelized cost of clean hydrogen produced in Sicily, a region in Southern Italy particularly rich in renewable energy and where nearly 50% of Italy’s refineries are located, making a comparison between on-site production, that is, near the end users who will use the hydrogen, and centralized production, comparing the costs obtained by employing the two types of electrolyzers already commercially available. In the study for centralized production, the scale factor method was applied on the costs of electrolyzers, and the optimal transport modes were considered based on the distance and amount of hydrogen to be transported. The results obtained indicate higher prices for hydrogen produced locally (from about 7 €/kg to 10 €/kg) and lower prices (from 2.66 €/kg to 5.80 €/kg) for hydrogen produced in centralized plants due to economies of scale and higher conversion efficiencies. How-ever, meeting the demand for clean hydrogen at minimal cost requires hydrogen distribution pipelines to transport it from centralized production sites to users, which currently do not exist in Sicily, as well as a significant amount of renewable energy ranging from 1.4 to 1.7 TWh per year to cover only 16% of refineries’ hydrogen needs.

A promising energy carrier and storage solution for integrating renewable energies into the power grid currently being investigated is hydrogen produced via electrolysis. It already serves various purposes, but it might also enable the development of hydrogen-based electricity storage systems made up of electrolyzers, hydrogen storage systems, and generators (fuel cells or engines). The adoption of hydrogen-based technologies is strictly linked to the electrification of end uses and to multicarrier energy grids. This study introduces a generic method to integrate and optimize the sizing and operation phases of hydrogen-based power systems using an energy hub optimization model, which can manage and coordinate multiple energy carriers and equipment. Furthermore, the uncertainty related to renewables and final demands was carefully assessed. A case study on an urban microgrid with high hydrogen demand for mobility demonstrates the method’s applicability, showing how the multi-objective optimization of hydrogen-based power systems can reduce total costs, primary energy demand, and carbon equivalent emissions for both power grids and mobility down to −145%. Furthermore, the adoption of the uncertainty assessment can give additional benefits, allowing a downsizing of the equipment.

This paper was conceived to investigate some central issues related to the upheaval of current energy scenarios in Sicily. New power connection lines that are about to be built in the Mediterranean area, planned with a view to a constantly increasing renewable generation, encourage the carrying out of analyses on how the Sicilian electric power system will be able to make itself ready to support large power injections, especially due to new renewables plants that will be established in the region soon. This study, carried out in close collaboration with the Italian TSO Terna S.p.A and the University of Palermo, defines what the impacts of new renewable power plants will be on the Sicilian power transmission grid under intact and non-intact grid conditions. This study consists of steady-state simulations carried out using WinCreso® software version 7.62.1-3 in two energy scenarios estimated for the years 2024 and 2027, based on real connection requests by producers to Terna, and allows one to go beyond the studies conducted so far on a 2030 basis through the precise identification of network nodes or lines in difficulty. Finally, as well as presenting an interesting case study due to Sicily’s strategic position in the Mediterranean Sea, this article proposes a methodological approach that can easily be adopted in other contexts and by other TSOs to analyze similar situations.

Hydrogen is a zero-emission fuel that, if produced from renewable sources (so-called green hydrogen), can provide a significant contribution in the decarbonization of several sectors. The main drawback that still hinders its deployment is its high cost, as well as critical operational issues related to the entire supply chain, both for safety and efficiency reasons. Incentives and certification schemes are needed to support the green hydrogen. In this paper, with the aim to identify the green hydrogen supply chain and associated costs, an energy hub with electricity and hydrogen demands has been studied comparing the centralized green hydrogen production and distribution via trucks, against the installation of an on-site green hydrogen production plant made up of renewable power generation, an electricity storage system, and an electrolyzer. The problem was modeled and solved as a MILP optimization in MATLAB environment. Furthermore, a sensitivity analysis on the cost was carried out, which showed that even if the truck transportation cost for hydrogen is set at 0 a/kg, it is still more cost-effective to install an on-site electrolyzer to produce the required hydrogen.

As part of the energy transition needed to combat climate change, photovoltaic systems are taking on an increasingly important role, with a considerable rise in the number of systems installed. This makes it necessary to find quick and reliable ways of performing inspections aimed at ensuring their proper operation, with the highest possible level of production. The amount of electricity that such plants manage to provide can, in fact, decrease due to simple shading, for the presence of deposits and debris on the modules, or, in the worst case scenario, due to a fault. The techniques used to carry out monitoring and surveying the operating status of a plant can be different. The most commonly used methods are visual inspection, I-V characteristic survey, and thermographic inspection. The latter, when carried out with the help of drones, allows inspections to be realized in a very short time and is the subject of study in this paper, in which an inspection carried out at a 999 kWp photovoltaic plant installed in Sicily and the use of the PSO algorithm to identify the optimal position of the drone are described.

The necessary acceleration of the energy transition has prompted the European Commission and the member states to reflect more carefully on the applicability of innovative solutions in the field of sustainable energy production with a special attention to the different energy carriers and in particular hydrogen. As a matter of fact, the energy transition appears not just as a single route, but rather as a path in a very complex environment of possible choices. Policy makers in the energy field have to understand what is the best choice at all stages of the transition, making investments that will not be completely withdrawn in a few years and considering the true challenges at local level. A second aspect is indeed the involvement of the territories (Regions), that becomes a central element in the energy planning and in the deployment of the Horizon Europe program for the next years. This contribution aims to provide some food for thought for the planning of sustainable energy development in Sicily and, more generally, in Southern Italy in the context of the development of the hydrogen strategy highlighted by the European Strategic Plan in the energy sector, starting from a brief analysis of the national context. In particular, an approximate evaluation of the costs of the green hydrogen produced in Sicily for industrial applications will be made, using an alkaline commercial electrolyser powered by different sizes of photovoltaic systems and considering an on/off operation at full power of the electrolyser, neglecting the compression phase.

This paper aims to implement a resilience assessment in AC/DC hybrid microgrids using a stochastic simulation approach. Self-healing measures including load shedding, control of distributed generation and flexible devices, like Energy Storage Systems (ESS) and Electrical Vehicles (EVs), are simulated to enable AC/DC hybrid microgrids to supply critical loads in islanded mode, assuming a disconnection of these microgrids from the main AC grid due to a fault. To perform this analysis, a two-stage process is proposed: first, a Monte-Carlo simulation-based stochastic approach is adopted to generate samples to simulate intermittent loads, power generation from Renewable Energy Sources (RESs), and fault occurs in the upstream grid; second, for each sample indicating islanded mode, a grid-connected daily Optimal Power Flow (OPF) is formulated in Mixed-Integer Linear Programming (MILP) form based on minimizing operation cost to withdraw the State of the Charge (SoC) of stationery and traction batteries and electrical vehicles before microgrids may go to islanded mode. Finally, resilience of islanded microgrids are evaluated through some indices. In addition, different strategies are considered for modeling the behavior of both two types of electrical vehicles V1G and V2G. Simulations results show distributed generation and flexible devices might improve resilience in islanded microgrids, optimal daily planning in grid-connected mode could affect it adversely though, due to the low energy available of flexible devices at the islanding moment.

Hydrogen has gained prominence as a versatile and sustainable energy carrier with significant potential for decarbonizing various industrial processes. This paper explores the utilization of hydrogen in an industrial context, focusing on its applications, benefits, challenges, and future prospects. Key industrial sectors, such as refining, chemicals, and steel production, are discussed, highlighting the role of hydrogen in reducing greenhouse gas emissions and enhancing energy efficiency. Additionally, the paper addresses the technical and economic challenges associated with hydrogen adoption and outlines the research and development efforts required to unlock its full industrial potential. Furthermore, the economic convenience of on-site hydrogen production is compared against the supply from an external source, proposing a formula for a quick assessment of the most profitable alternative.

The energy transition is a challenge in which all countries in the world are involved to date with the aim of achieving climate neutrality. Green hydrogen produced by electrolysis through energy from renewable sources, can play a key role in the energy transition replacing fossil fuels used in industrial processes and heavy-duty transport. The widespread diffusion and massive adoption of this new and clean fuel, as well as the creation of national, regional, and international markets, depend heavily on traceability tools that certify its origin, creating transparency and stimulating demand. In this context, new information technologies such as Blockchain, thanks to their characteristics, could solve the problems associated with the traceability of green hydrogen, thus contributing to its diffusion. This paper describes a laboratory-developed system for green hydrogen production via electrolysis and proposes a Blockchain architecture for its tracking and certification.