Italian Electrical System Research Articles

Impact of PV/Wind Forecast Accuracy and National Transmission Grid Reinforcement on the Italian Electric System

The high share of PV energy requires greater system flexibility to address the increased demand/supply imbalance induced by the inherent intermittency and variability of the solar resource. In this work, we have developed a methodology to evaluate the margins for imbalance reduction and flexibility that can be achieved by advanced solar/wind forecasting and by strengthening the national transmission grid connecting the Italian market areas. To this end, for the forecasting of the day-ahead supply that should be provided by dispatchable generators, we developed three advanced load/PV/wind forecasting methodologies based on a chain or on the optimal mix of different forecasting techniques. We showed that, compared to the baseline forecast, there is a large margin for the imbalance/flexibility reduction: 60.3% for the imbalance and 47.5% for the flexibility requirement. In contrast, the TSO forecast leaves only a small margin to reduce the imbalance of the system through more accurate forecasts, while a larger reduction can be achieved by removing the grid constrains between market zones. Furthermore, we have applied the new forecasting methodologies to estimate the amount of imbalance volumes/costs/flexibility/overgenerations that could be achieved in the future according to the Italian RES generation targets, highlighting some critical issues related to high variable renewable energy share.

Multi-Objective Optimization to Identify Carbon Neutrality Scenarios for the Italian Electric System

Multi-Objective Optimization to Identify Carbon Neutrality Scenarios for the Italian Electric System

The Zonal and Seasonal CO2 Marginal Emissions Factors for the Italian Power Market

This paper estimates the seasonal and zonal \({\mathrm{CO}}_{2}\) marginal emissions factors (MEFs) from electricity production in the Italian electricity system. The inclusion of the zonal configuration of the Italian wholesale power market leads to a complete measurement of marginal emission factors which takes into account the heterogeneous distribution of RES power plants, their penetration rate and their variability within the zonal power generation mix. This article relies on a flexible econometric approach that includes the fractional cointegration methodology to incorporate the typical features of long-memory processes into the estimation of MEFs. We find high variability in annual MEFs estimated at the zonal level. Sardinia reports the highest MEF (0.7189 \({\mathrm{tCO}}_{2}\)/MWh), followed by the Center South (0.7022 \({\mathrm{tCO}}_{2}\)/MWh), the Center North (0.4236 \({\mathrm{tCO}}_{2}\)/MWh), the North (0.2018 \({\mathrm{tCO}}_{2}\)/MWh) and Sicily (0.146 \({\mathrm{tCO}}_{2}\)/MWh). The seasonal analysis also shows a large variability of MEFs in each zone across time. The heterogeneity of results leads us to recommend that policymakers consider the zonal configuration of the power market and the large seasonal variability related to carbon emissions and electricity generation when designing incentives for renewable energy sources expansion and for achieving emission reduction targets.

Assessing the Impact on Grid Infrastructure of Electrification Pathways for the Italian Residential Sector

To achieve the decarbonization objectives described in the Paris Agreement, thermal appliances’ electrification is considered an essential factor. Unfortunately, the substitution of thermal appliances with electric alternatives will inevitably increase the load on the national electric system; thus, it is crucial to perform analyses to assess these policies’ impact. This paper, using as a reference the electrification pathways studied by Besagni et al. employing the MOIRAE (bottom-up MOdel to compute the energy consumption of the Italian REsidential sector) model, calculates the energy and power increase in the residential sector in 2030 due to the substitution of different thermal appliances and discusses potential policies to take into account the effect of their implementation on the Italian electric system. Even if the current generation capacity can sustain the electrification process without problems, investments will be needed to limit the possibility of congestions on transmission lines connecting the country’s northern and southern parts.

Erratum to: On the optimal mix of Renewable Energy Sources, electrical energy storage and thermoelectric generation for the de-carbonization of the Italian electrical system

The original version of this article contained an error in the captions.

Impact on Electricity Consumption and Market Pricing of Energy and Ancillary Services during Pandemic of COVID-19 in Italy

At the moment of writing, in Italy, there is an ongoing pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Its outbreak is leading to severe global socioeconomic disruptions impacting on all economic sectors from tourism, industry and the tertiary sector, up to the operational and opening of public offices, the closure of schools and the organization of families. Measures adopted by the Italian government to deal with the COVID-19 emergency have had direct effects both on people’s daily lives and on the activity of most industrial and commercial production companies. These changes have been unequivocally reflected also on the Italian electricity system, which has shown unprecedented behavior in terms of both energy consumption and volume—and subsequently, in the observed share of renewable and conventional production technologies. The goal of this study is to show the impact on the power industry of all the restrictions and lockdown of the activities in Italy and to discuss the effects of COVID-19 outbreak on the bulk power system and the entire electricity sector. In particular, the consequences on load profiles, electricity consumption and market prices in Italy, including the environmental aspects, are examined.

The impact of e-mobility on the Italian electricity system

This paper investigates possible scenarios of electric cars introduction and their impact on the Italian electricity system. Given the foreseen increased number of cars until the year 2030, three different scenarios in terms of penetration of electric vehicles have been considered, namely 10%, 20% and 40%. A detailed bottom up energy model of the Italian car fleet has been developed. The car fleet is analyzed in terms of energy consumption, carbon emissions and externalities costs. The scenarios analysis suggests that the introduction of electric cars would always lead to primary energy savings. In particular, the increase of the penetration corresponds to a decrease of primary energy consumption, carbon emissions and externalities costs.

On the optimal mix of renewable energy sources, electrical energy storage and thermoelectric generation for the de-carbonization of the Italian electrical system

The integration of intermittent renewable energy sources (RES) requires a substantial amount of electrical energy storage and significant increase of the grid capabilities. To keep these upgrades within reasonable limits, strategies maintaining a moderate but flexible thermoelectric power have been investigated. Based on the experimental loads for Italy in 2013, the implications of increasing the contribution of scalable RES, particularly wind and photovoltaic, are investigated in detail. The optimal value of the storage depends on its round-trip efficiency (1.3 TWh for hydroelectric storage and 6 TWh for power to gas). For RES producing 100% of the annual demand, the use of the optimal storage and of about 10 GW of thermoelectric power allows a substantial de-carbonization (more than 90%) of the electricity production still maintaining a capacity factor of the thermoelectric generators above 40%. Avoiding thermoelectric generation is possible but it requires overproduction by RES, between 120 and 200% of the annual electricity demand, depending on the storage technology and the mix between wind and photovoltaic generation. The calculations have been performed for realistic values of the storage round-trip efficiency and for various combinations of photovoltaic and wind powers. The capital costs required are also estimated at current costs of present day technologies.

A new high‐resolution Meteorological Reanalysis Italian Dataset: MERIDA

During the last 15 years, weather extremes caused several disruptions to the Italian electric system. Their increasingly occurrence is mainly due to the exchanges along the meridians of air masses with very different thermal, density and moisture content properties. The Italian transmission system operator and the distribution companies have repeatedly stressed the need to have a reliable and updatable weather dataset with a history of at least 15 years to improve the resilience of the electric system. The aim of this work is to develop a new MEteorological Reanalysis Italian DAtaset (MERIDA) able to respond to the energy stakeholders, who need reliable meteorological data to implement effective adaptation strategies to operate the electric system safely. MERIDA consists of a dynamical downscaling of the new European Centre for Medium‐range Weather Forecasts (ECMWF) global reanalysis ERA5 using the Weather Research and Forecasting (WRF) model, which is configured to describe the typical weather conditions of Italy. Furthermore, the optimal interpolation (OI) technique is applied to the modelled 2 m temperature and precipitation data through the use of meteorological observations of the Regional Agencies for Environmental Protection. MERIDA is verified against COSMO REA6 of the Deutscher Wetterdienst (DWD) and ERA5 itself for the period 2010–2015, showing comparable or better results in the reconstruction of 2 m temperature and precipitation. The best results are obtained with MERIDA post‐processed by the OI. Some severe weather events that determined important electric disruptions are also analysed, showing that MERIDA is able to identify the meteorological conditions leading to significant events of wet snow, heatwaves and floods through their correct spatial and temporal location and through a quantitative assessment of each atmospheric phenomenon.

Planning & Open-Air Demonstrating Smart City Sustainable Districts

The article is focused on the “demonstration” activities carried out by the University of Genoa at Savona Campus facilities in order to implement the “Living Lab Smart City”. The idea is to transform the Savona Campus in a Living Lab of the City of the Future: smart technologies in Information and Communication Technology (ICT) and energy sectors were installed in order to show a real application of the Smart City concept to population and external stakeholders. Moreover, special attention was given to the environment, personal wellbeing, and social equalities. The sustainable energy Research Infrastructures (RIs) of Savona Campus allowed enhancement of the applied research in degree programs and the collaboration with several companies. In particular, an important partnership with the Italian electric Distribution System Operator (DSO), ENEL S.p.A., started in 2017 to test the capability of these RIs to operate disconnected from the National Grid, relying only on the supply of renewables and storage systems. The “Living Lab Smart City” is an important action to reduce the carbon footprint of the Savona Campus and to increase the awareness of students, teachers and researchers towards Sustainable Development in Higher Education Institutes.

Adoption and Diffusion of Micro-Grids in Italy. An Analysis of Regional Factors Using Agent-Based Modelling

The Italian electricity system, based on a centralized grid, presents important inefficiencies in the transmission infrastructure and is highly import-dependent. At the same time, it has a high renewable potential. These three aspects might encourage Italy to shift from the traditional centralized grid to a new decentralized electricity system by adopting Micro-Grids (MGs). This transition, however, has not yet started. This work aims to study the possible scenarios of adoption and diffusion of MGs in Italy, by analysing the influence of regional factors, the potential role of subsidies and people’s attitude. An agent-based model is formulated in order to simulate the diffusion of MGs as a function of those characteristics and to analyse which policies could facilitate the adoption of MGs in the country. The results show the high dependence of the diffusion process on regional factors (electricity demand, renewable potential and population). Moreover, the model confirms that subsidies can encourage the diffusion (mainly when they are regional-based rather than national-based) and that a higher “green” attitude by users can accelerate the diffusion of MGs in Italy.

Assessing a Potential Cyberattack on the Italian Electric System

This case study explores a hypothetic but plausible attack on the Italian electric system. Under particular scenarios of grid weakness, it could lead to a blackout costing the local economy 35 to 46 million euros in damages.

Renewable Energy Quota System in Italy and its Enlightenment for China

Renewable energy quota system (also known as renewable portfolio standard) is a new policy to promote development of renewable energy in the world. The typical pattern of the foreign quota system is studied deeply in this paper at first. Based on this, take Italian quota system policy for example, the Italian electricity system overview and key elements of the Italian quota system policies are analyzed. At last, some useful enlightenment gained from renewable portfolio standard in Italy is given to our country.

Comparative energy and exergy performance assessments of a microcogenerator unit in different electricity mix scenarios

The Directive 2004/8/EC on the promotion of cogeneration proposes a comparative indicator based on primary energy savings, neglecting some important thermodynamic aspects, such as exergy. This study aims to compare and discuss the usefulness of a set of complementary indicators for performance assessments of cogeneration systems, concerning thermodynamic principles based on first and second law (the exergy approach). As case study, a 6kW electric output micro-combined heat and power unit was experimentally tested and a model of the unit was developed in TRNSYS. Considering as reference a set of different heat and electricity scenarios, including the actual electric mixes of Portugal and Italy, the indicators case incon (PES) and Primary and Total Irreversibilities Savings (PIS and TIS), as well as energy and exergy renewability ratios were assessed and discussed. The results show that the use of MCHP has higher advantages for the Italian electric grid, than an equivalent scenario considering the Portuguese electric network as reference. As result, for a particular scenario analysed, PES and PIS have 3% and 6% for Portugal, and 10% and 18% for Italy, respectively. Furthermore, for one particular scenario evaluated, the indicators energetic and exergetic renewability ratios have 23% and 14%, respectively for the Portuguese electric grid, and 19% and 10% for the Italian electric system.

A three phase photovoltaic power system connected to the MV network: behaviour during voltage dips

The presence of Distributed Generation (DG) in t he distribution network is increasing and represents one of the most important research areas. Several reasons have forced this increase like the possibility to use renewable resources reducing the fossil fuels use with environmental and energy benefits. The paper deals with the results of a study performed by RSE, in the frame of the Research Fund for the Italian Electrical System, focused on the behaviour during voltage dips of a DG system, consisting in a Photovoltaic generator (PV) connected to the network with three phase Voltage Source Inverter (VSI).

VOLTAGE STABILITY ASSESSMENT: EXTENDED ANALYSIS ON THE ITALIAN POWER SYSTEM

The paper presents the results of extended analysis aimed to evaluatethe voltage collapse margin in the Italian electric power system,carried out through a dedicated application developed within a jointproject between TERNA [the Italian transmission system operators(TSO)], centro elettrotecnico sperimentale italiano (CESI) and MilanPolytechnic.

Recent Legal Developments in the Government of the Italian Electricity System

Recent Legal Developments in the Government of the Italian Electricity System

Birds and powerlines in Italy: an assessment

Summary Powerlines may pose severe threats to bird populations. We assessed the significance of powerlines as a source of avian mortality within the Italian electric transmission and distribution system. We reviewed data from 11 mortality censuses and compiled a list of species that were found among powerline victims in Italy, based on over 1,300 reported individual casualties. Overall, 95 species of birds were reported among powerline victims (19% of Italy’s total species). The number of recorded species was compared with the number of species in the Italian list, after grouping species based on morphology and ecology. Some groups (e.g. raptors, herons, storks and allies) were highly affected, while others (e.g. passerines and allies) appeared to be poorly represented among species involved in powerline accidents. Furthermore, we evaluated the validity of a published discriminant model for the classification of bird species as collision or electrocution victims according to body measurements. The application of the available model classified 54.7–73.5% of Italian species correctly (depending on the species included), compared with 88.6% of the original dataset. Two new discriminant models based on Italian powerline casualties classified 80.9–81.1% of species correctly. This approach can be a useful tool in assessing collision and electrocution risk for species in different geographical areas. While we recognize the need for a general preventive approach for reducing the bird–powerline conflict, our review highlights once more the importance of local situations, where powerlines may have a strong impact on avian communities.

EMERGY BASED ANALYSIS OF ITALIAN ELECTRICITY PRODUCTION SYSTEM

The continuously increasing demand for electric power together with the demand of environmental friendly technologies require a deep acknowledgement of the directions to give to electric power production in order to satisfy both necessities. The aim of this work is to evaluate the sustainability of Italian electric system by using the emergy function, a methodology developed in the early 80s by Odum, and its correlated indices. Emergy is a thermodynamic based function that calculates all the fluxes of energy requested to obtain a product going backward to the solar energy invested. We analyzed all the inputs concurring to the yield of electricity taking into account not only the final phases of the production but also all the sources and materials that had been necessary for the system to operate. We have performed a wide analysis of all the different types of production focusing on thermoelectric sector. We have obtained not only a thermodynamic analysis of electricity production but also an evaluation of the sustainability of the entire process and a scenario for a correct exploitation of resources.

The Han Powell Algorithm Applied to the Optimization of the Reactive Power Generation in a Large Scale Electric Power System

In this paper the Han-Powell algorithm is proposed as a means for optimizing the reactive power generation in a large scale system. The algorithm is based upon the iterative resolution of quadratic programming subproblems. Other approaches based upon recursive resolution of linear programs seem not to be suitable for the strongly non linear characteristics of the problem.In the adopted model, a reduced and compact problem is solved with only inequality constraints.The equality constraints (load flow equations) are utilized to eliminate a large number of variables (dependent variables). In this way the optimization model is expressed only in terms of the control variables (reactive power generations or generator terminal voltages and LTC transformer tap positions). This approach allows ns to perform the reactive power scheduling of the Italian electric production and transmission system (with about 500 nodes) with reasonable computer requirements (CPU time and central core). The main advantages of the Han-Powell method are:-it is robust and reliable-it shows a sure and fast convergence-it is easy to implement provided a good quadratic programming subroutine is available.